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10668805 | Mitochondrial minicircles in the free-living bodonid Bodo saltans contain two gRNA gene cassettes and are not found in large networks. | In trypanosomatids, the majority of the guide (g) RNAs that provide the information for U-insertion/deletion RNA editing are encoded by minicircles that are catenated into large networks. In contrast, in the distantly related cryptobiid Trypanoplasma borreli, gRNA genes appear to reside in large 180-kb noncatenated DNA... |
10668800 | Expanded CUG repeat RNAs form hairpins that activate the double-stranded RNA-dependent protein kinase PKR. | Myotonic dystrophy is caused by an expanded CTG repeat in the 3' untranslated region of the DM protein kinase (DMPK) gene. The expanded repeat triggers the nuclear retention of mutant DMPK transcripts, but the resulting underexpression of DMPK probably does not fully account for the severe phenotype. One proposed disea... |
10668794 | On the wobble GoU and related pairs. | The wobble GoU pairs have been implicated in several biological processes where RNA molecules play a key role. We review the geometrical and conformational properties of wobble GoU pairs on the basis of available crystal structures of RNAs at high resolution. The similarities with the wobble A+oC pairs and UoU pairs ar... |
10664533 | Drug/cyclodextrin/hydroxy acid multicomponent systems. Properties and pharmaceutical applications. | The objective of this mini-review is to summarize the findings concerning the properties and the pharmaceutical applications of multicomponent complexes made of a sparingly water-soluble amino-type drug, a cyclodextrin, and a hydroxy carboxylic acid. Simultaneous complexation and salt formation with these acids signifi... |
10663531 | Effects of inorganic salts on the structural heterogeneity of serum albumin solutions. | The formation of protein clusters or a protein-rich phase in undersaturated solutions of biopolymers is considered theoretically on the basis of phase diagrams of a water-protein-salt system. Concentrated (50-200 mg/ml of protein) water-salt solutions of human serum albumin molecules modified by a maleimide spin-label ... |
10662495 | Design of affinity tags for one-step protein purification from immobilized zinc columns. | Affinity tags are often used to accomplish recombinant protein purification using immobilized metal affinity chromatography. Success of the tag depends on the chelated metal used and the elution profile of the host cell proteins. Zn(II)-iminodiacetic acid (Zn(II)-IDA) may prove to be superior to either immobilized copp... |
10667855 | Selectively 2H-labeled Glu/Asp: application to pKa measurements in Abeta amyloid peptides. | Human Abeta peptides have been linked to Alzheimer's disease, and it is hypothesized that formation of amyloid as well as neurotoxicity are important events in the etiology of the disease. Previous studies have shown that the soluble precursor to Alzheimer's amyloid undergoes a pH-dependent folding transition as the se... |
10667600 | A peptide mimic of E-selectin ligand inhibits sialyl Lewis X-dependent lung colonization of tumor cells. | Selectins bind to carbohydrate ligands in a calcium-dependent manner and play critical roles in host defense and possibly in tumor metastasis. To isolate peptides that mimic E-selectin ligands, we screened a phage peptide library using E-selectin as a target molecule. This attempt unexpectedly failed, probably because ... |
10656808 | Protein-protein interaction revealed by NMR T(2) relaxation experiments: the lipoyl domain and E1 component of the pyruvate dehydrogenase multienzyme complex of Bacillus stearothermophilus. | T(2) relaxation experiments in combination with chemical shift and site-directed mutagenesis data were used to identify sites involved in weak but specific protein-protein interactions in the pyruvate dehydrogenase multienzyme complex of Bacillus stearothermophilus. The pyruvate decarboxylase component, a heterotetrame... |
10660215 | Surface properties of unsaturated non-oxidized and oxidized free fatty acids spread as monomolecular films at an argon/water interface. | The interfacial properties of monomolecular films of stearic acid (SA) oleic acid (OA), linoleic acid (LA), ricinoleic acid (RA), 13(S)-hydroperoxyoctadeca-9Z,11E-dienoic acid (13-HPODE) and 13(S)-hydroxyoctadeca-9Z,11E-dienoic acid (13-HODE) were studied by recording the changes occurring in response to monomolecular ... |
10658329 | Membrane characterization of anion-selective CHEMFETs by impedance spectroscopy. | Impedance spectroscopy can be used to determine the influence of several membrane parameters on the membrane resistance of anion selective CHEMFETs. The concentration of the ammonium sites in the membrane, the anion-receptor complex stoichiometry, and the polarity of the membrane matrix are of particular importance. In... |
10658324 | A family of single-isomer, sulfated gamma-cyclodextrin chiral resolving agents for capillary electrophoresis. 1. Octakis(2,3-diacetyl-6-sulfato)-gamma-cyclodextrin. | The first member of the single-isomer, sulfated gamma-cyclodextrin family, the sodium salt of octakis(2,3-diacetyl-6-sulfato)-gamma-cyclodextrin (ODAS-gamma CD) has been synthesized, analytically characterized, and used to separate, by capillary electrophoresis, a variety of neutral, acidic, basic, and amphoteric enant... |
10655639 | Selectivity in capillary electrochromatography using native and single isomer anionic cyclodextrin reagents. | Separations of naphthalene compounds that differ in position of substitution and type of substituent were accomplished using cyclodextrin distribution capillary electrochromatography. Separation systems composed of running buffers containing mixtures of native neutral and single isomer anionic cyclodextrins (CDs) were ... |
10649887 | Use of styrene radical cations as probes for the complexation dynamics of charged guests with alpha- and beta-cyclodextrins. | The complexation dynamics of radical cations with cyclodextrins (CD) was studied using photophysical techniques. Radical cations of 4-vinylanisole and trans-anethole were formed within alpha- and beta-CD cavities by two-photon photolysis of the respective styrene precursors. Exit of the radical cations from alpha-CD co... |
10644983 | Non-activated p53 co-localizes with sites of transcription within both the nucleoplasm and the nucleolus. | The p53 tumour suppressor functions as a sensor of genotoxic stress and, once activated, induces cell growth arrest or apoptosis. The precise intranuclear localization of latent p53 protein in non-stressed cells is unknown. Such information is essential in order to understand how relatively few molecules of p53 can det... |
10644758 | The visual G protein of fly photoreceptors interacts with the PDZ domain assembled INAD signaling complex via direct binding of activated Galpha(q) to phospholipase cbeta. | Visual transduction in the compound eye of flies is a well-established model system for the study of G protein-coupled transduction pathways. Pivotal components of this signaling pathway, including the principal light-activated Ca(2+) channel transient receptor potential, an eye-specific protein kinase C, and the norpA... |
10644692 | Conformational distributions and proximity relationships in the rigor complex of actin and myosin subfragment-1. | Cyclic conformational changes in the myosin head are considered essential for muscle contraction. We hereby show that the extension of the fluorescence resonance energy transfer method described originally by Taylor et al. (Taylor, D. L., Reidler, J., Spudich, J. A., and Stryer, L. (1981) J. Cell Biol. 89, 362-367) all... |
10642593 | Defective HDL particle uptake in ob/ob hepatocytes causes decreased recycling, degradation, and selective lipid uptake. | Levels of plasma HDL are determined in part by catabolism in the liver. However, it is unclear how the hepatic catabolism of holo-HDL is regulated or mediated. Recently, we found that ob/ob mice have defective liver catabolism of HDL apoproteins in vivo that can be reversed by low-dose leptin treatment. Here we examine... |
10643798 | A polymorphism in the tau gene associated with risk for Alzheimer's disease. | Searching for tau genetic variations which could be associated with risk for Alzheimer's disease (AD), we have performed a mutational analysis of a region containing the whole exon 11 of the tau gene, which encodes a microtubule binding region critical for tau self-assembly, and we have found a biallelic polymorphism a... |
10637359 | Targeting multi-stranded DNA structures. | The design of agents targeted toward a structure-specific molecular recognition of DNA triplexes or tetraplexes ( quadruplexes ) is discussed, where such structures are relevant to antigene-based chemotherapies and the in situ cellular inhibition of telomerase function, respectively. Using principles that stem from the... |
10639150 | Enzymatic reduction of disulfide bonds in lysosomes: characterization of a gamma-interferon-inducible lysosomal thiol reductase (GILT). | Proteins internalized into the endocytic pathway are usually degraded. Efficient proteolysis requires denaturation, induced by acidic conditions within lysosomes, and reduction of inter- and intrachain disulfide bonds. Cytosolic reduction is mediated enzymatically by thioredoxin, but the mechanism of lysosomal reductio... |
10639126 | In vivo selection of functional ribosomes with variations in the rRNA-binding site of Escherichia coli ribosomal protein S8: evolutionary implications. | The highly conserved nature of rRNA sequences throughout evolution allows these molecules to be used to build philogenic trees of different species. It is unknown whether the stability of specific interactions and structural features of rRNA reflects an optimal adaptation to a functional task or an evolutionary trap. I... |
10637278 | A balance between positive and negative signals in cytotoxic lymphocytes regulates the polarization of lipid rafts during the development of cell-mediated killing. | Plasma membrane microdomains containing sphingolipids and cholesterol (lipid rafts) are enriched in signaling molecules. The cross-linking of certain types of cell surface receptors initiates the redistribution of these lipid rafts, resulting in the formation of signaling complexes. However, little is known about the r... |
10637267 | A single amino acid determines the immunostimulatory activity of interleukin 10. | Cellular interleukin 10s (cIL-10s) of human and murine origin have extensive sequence and structural homology to the Epstein-Barr virus BCRF-I gene product, known as viral IL-10 (vIL-10). Although these cytokines share many immunosuppressive properties, vIL-10 lacks several of the immunostimulatory activities of cIL-10... |
10637221 | New structural motifs on the chymotrypsin fold and their potential roles in complement factor B. | Factor B and C2 are two central enzymes for complement activation. They are multidomain serine proteases and require cofactor binding for full expression of proteolytic activities. We present a 2.1 A crystal structure of the serine protease domain of factor B. It shows a number of structural motifs novel to the chymotr... |
10639081 | Noncovalent adducts of poly(ethylene glycols) with proteins. | A new method of preparation of noncovalent complexes between poly(ethylene glycol) (PEG) and proteins (alpha-chymotrypsin (ChT), lysozyme, bovine serum albumine) under high pressure has been developed. The involvement of polymer in the complexes was proved using (3)H-labeled PEG. The composition of the complexes (the n... |
10639036 | Development of a tumor-targeting MR contrast agent using the high-affinity folate receptor: work in progress. | <h4>Rationale and objectives</h4>Macromolecular contrast agents enhance tumors by means of active or passive targeting. Active targeting requires surface receptors. Many tumors of epithelial origin express the high-affinity folate receptor (hFR), including ovarian tumors. The objective of this research was to enhance t... |
10638666 | Stored red blood cells selectively activate human neutrophils to release IL-8 and secretory PLA2. | Packed red blood cell (PRBC) transfusion has been invoked previously with immunosuppression and increased infections, but it has now been demonstrated that stored PRBCs (>14 days) can prime PMNs and provoke multiple organ failure. Recently, the role of PMNs in the genesis of MOF has been extended to their release of in... |
10633129 | The molecular genetics of Marfan syndrome and related microfibrillopathies. | Mutations in the gene for fibrillin-1 (FBN1) have been shown to cause Marfan syndrome, an autosomal dominant disorder of connective tissue characterised by pleiotropic manifestations involving primarily the ocular, skeletal, and cardiovascular systems. Fibrillin-1 is a major component of the 10-12 nm microfibrils, whic... |
10633077 | Altered synthesis of laminin 1 and absence of basement membrane component deposition in (beta)1 integrin-deficient embryoid bodies. | Basement membranes are the earliest extracellular matrices produced during embryogenesis. They result from synthesis and assembly into a defined supramolecular architecture of several components, including laminins, collagen IV, nidogen, and proteoglycans. In vitro studies have allowed us to propose an assembly model b... |
10636237 | The utilization of a unified pharmacophore query in the discovery of new antagonists of the adenosine receptor family. | Pharmacophore queries from previously known potent selective A3 antagonists were generated by Chem-X. These queries were used to search a pharmacophore database of diverse compounds (CNS-Set). In vitro assays of 186 'hits' yielded over 30 active compounds, for four adenosine receptor subtypes. This search strategy may ... |
10632721 | Efficient purification and kinetic characterization of a bimodular derivative of the erythromycin polyketide synthase. | Modular polyketide synthases (PKSs), such as the 6-deoxyerythronolide B synthase (DEBS), are giant multienzymes that biosynthesize a number of clinically important natural products. The modular nature of PKSs suggests the possibility of a combinatorial approach to the synthesis of novel bioactive polyketides, but the e... |
10632705 | Assembly of the Rieske iron-sulphur protein into the cytochrome bf complex in thylakoid membranes of isolated pea chloroplasts. | The assembly of the Rieske iron-sulphur protein into the cytochrome bf complex was examined following import of 35S-labeled precursor protein by isolated pea chloroplasts. Rieske protein assembled into the cytochrome bf complex was resolved from unassembled Rieske protein and from other membrane complexes by nondenatur... |
10634489 | High-speed chiral separations on microchip electrophoresis devices. | High-speed electrophoretic chiral separations have been successfully performed in a microfabricated device by employing cyclodextrin-modified micellar electrokinetic chromatography (CD-MEKC). Utilizing short separation channels and relatively high field strengths in combination with small volume-defined injection plugs... |
10629217 | Correlative light-electron microscopy reveals the tubular-saccular ultrastructure of carriers operating between Golgi apparatus and plasma membrane. | Transport intermediates (TIs) have a central role in intracellular traffic, and much effort has been directed towards defining their molecular organization. Unfortunately, major uncertainties remain regarding their true structure in living cells. To address this question, we have developed an approach based on the comb... |
10629196 | Role and mechanism of action of C. PvuII, a regulatory protein conserved among restriction-modification systems. | The PvuII restriction-modification system is a type II system, which means that its restriction endonuclease and modification methyltransferase are independently active proteins. The PvuII system is carried on a plasmid, and its movement into a new host cell is expected to be followed initially by expression of the met... |
10629174 | Differential processing of propeptide inhibitors of Rap phosphatases in Bacillus subtilis. | In the phosphorelay signal transduction system for sporulation initiation in Bacillus subtilis, the opposing activities of histidine kinases and aspartyl phosphate phosphatases determine the cell's decision whether to continue with vegetative growth or to initiate the differentiation process. Regulated dephosphorylatio... |
10627611 | Increased spontaneous unit activity and appearance of spontaneous negative potentials in the goldfish tectum during refinement of the optic projection. | Spontaneous (not retinally driven) postsynaptic activity was examined during activity-dependent refinement of optic fibers in the goldfish tectum. Unit recordings in vivo and in vitro demonstrated that spontaneous tectal activity increased to 150% of normal during refinement at 1-2 months after optic nerve crush and su... |
10627576 | Positive modulation of AMPA receptors increases neurotrophin expression by hippocampal and cortical neurons. | This study investigated whether positive modulators of AMPA-type glutamate receptors influence neurotrophin expression by forebrain neurons. Treatments with the ampakine CX614 markedly and reversibly increased brain-derived neurotrophic factor (BDNF) mRNA and protein levels in cultured rat entorhinal/hippocampal slices... |
10629018 | Serum itraconazole concentrations and clinical responses in Candida-associated denture stomatitis patients treated with itraconazole solution and itraconazole capsules. | The aim of this study was to compare the concentrations of itraconazole in serum and saliva after treatment with itraconazole cyclodextrin solution or itraconazole capsules in Candida-associated denture stomatitis patients without evidence of immunodeficiency. Forty patients were randomly assigned to receive either itr... |
10627489 | Exotoxins of Staphylococcus aureus. | This article reviews the literature regarding the structure and function of two types of exotoxins expressed by Staphylococcus aureus, pyrogenic toxin superantigens (PTSAgs) and hemolysins. The molecular basis of PTSAg toxicity is presented in the context of two diseases known to be caused by these exotoxins: toxic sho... |
10625612 | Self-assembly of laminin induced by acidic pH. | The supramolecular architecture of the basement membrane is provided by two enmeshed networks of collagen IV and laminin. The laminin network is maintained exclusively by interactions among individual laminin molecules and does not depend on the presence of other extracellular matrix components. Laminin polymers can be... |
10625601 | Multimeric self-assembly equilibria involving the histone-like protein H-NS. A thermodynamic study. | The thermodynamic parameters affecting protein-protein multimeric self-assembly equilibria of the histone-like protein H-NS were quantified by "large zone" gel-permeation chromatography. The abundance of the different association states (monomer, dimer, and tetramer) were found to be strictly dependent on the monomeric... |
10625497 | Expression of scavenger receptor BI in COS-7 cells alters cholesterol content and distribution. | Previous studies have shown that scavenger receptor BI (SR-BI) stimulates the bidirectional flux of free cholesterol (FC) between HDL and SR-BI-expressing cells. A major component of the enhanced FC flux appears to occur independently of HDL binding to SR-BI and may be due to changes in membrane lipid domains resulting... |
10623753 | Second-site changes affect viability of amphotropic/ecotropic chimeric enveloped murine leukemia viruses. | Chimeras were previously generated between the ecotropic (Moloney-MuLV) and amphotropic (4070A) SU and TM proteins of murine leukemia virus (MuLV). After passage in D17 cells, three chimeras with junctions in the C terminus of SU (AE5, AE6, and AE7), showed improved kinetics of viral spreading, suggesting that they had... |
10623734 | Nuclear import of moloney murine leukemia virus DNA mediated by adenovirus preterminal protein is not sufficient for efficient retroviral transduction in nondividing cells. | Moloney murine leukemia virus (MoMLV)-derived vectors require cell division for efficient transduction, which may be related to an inability of the viral DNA-protein complex to cross the nuclear membrane. In contrast, adenoviruses (Ad) can efficiently infect nondividing cells. This property may be due to the presence o... |
10623724 | A recombinant human immunodeficiency virus type 1 envelope glycoprotein complex stabilized by an intermolecular disulfide bond between the gp120 and gp41 subunits is an antigenic mimic of the trimeric virion-associated structure. | The few antibodies that can potently neutralize human immunodeficiency virus type 1 (HIV-1) recognize the limited number of envelope glycoprotein epitopes exposed on infectious virions. These native envelope glycoprotein complexes comprise three gp120 subunits noncovalently and weakly associated with three gp41 moietie... |
10625428 | The structural basis for molecular recognition by the vitamin B 12 RNA aptamer. | Previous solution structures of ligand-binding RNA aptamers have shown that molecular recognition is achieved by the folding of an initially unstructured RNA around its cognate ligand, coupling the processes of RNA folding and binding. The 3 A crystal structure of the cyanocobalamin (vitamin B12) aptamer reported here ... |
10623527 | Structural determinants of post-translational modification and catalytic specificity for the lipoyl domains of the pyruvate dehydrogenase multienzyme complex of Escherichia coli. | The lipoyl domains of the dihydrolipoyl acyltransferase (E2p, E2o) components of the pyruvate and 2-oxoglutarate dehydrogenase multienzyme complexes are specifically recognised by their cognate 2-oxo acid decarboxylase (E1p, E1o). A prominent surface loop links the first and second beta-strands in all lipoyl domains, c... |
10623931 | Mass spectrometric study of randomly methylated beta-cyclodextrins using ionspray, atmospheric pressure chemical ionization and matrix-assisted laser desorption/ionization. | Mixtures of methylated beta-cyclodextrins were characterized using three different methods of mass spectrometry: ionspray, atmospheric pressure chemical ionization (APCI) and matrix-assisted laser desorption/ionization (MALDI). Each of these methods allows a fast and simple determination of the degree of substitution, ... |
10623927 | Electrospray ionisation Fourier-transform ion cyclotron resonance mass spectrometry of dynamic combinatorial libraries. | The use of electrospray ionisation Fourier-transform ion cyclotron resonance tandem mass spectrometry (ESI-FTICR-MS/MS) for the analysis of dynamic combinatorial libraries (DCLs) of pseudo-peptide macrocyclic hydrazone oligomers is presented. The design of library building blocks results in mixtures of compounds with g... |
10623611 | Molecular recognition templates of peptides: driving force for molecular evolution of peptide transporters. | Small peptides derived from protein hydrolysis occur ubiquitously. To utilize these structurally diverse compounds, organisms possess generic peptide transporters for di- (Dpp), tri- (Tpp), and oligopeptides (Opp). Using conformational analysis, we describe the predominant conformers of di-, tri-, and oligopeptides in ... |
10626980 | The effect of muscle transplantation after unilateral partial facial paralysis on craniofacial growth and development: relationship between muscle and nerve histomorphometric findings. | Muscle transplantation has become an indispensable tool to restore the smile in patients with long-standing or congenital facial paralysis. However, little is known of the effect of this surgical intervention on craniofacial growth and development or of the adaptation of the transplant to its recipient site under circu... |
10620605 | The CC chemokine thymus-derived chemotactic agent 4 (TCA-4, secondary lymphoid tissue chemokine, 6Ckine, exodus-2) triggers lymphocyte function-associated antigen 1-mediated arrest of rolling T lymphocytes in peripheral lymph node high endothelial venules. | T cell homing to peripheral lymph nodes (PLNs) is defined by a multistep sequence of interactions between lymphocytes and endothelial cells in high endothelial venules (HEVs). After initial tethering and rolling via L-selectin, firm adhesion of T cells requires rapid upregulation of lymphocyte function-associated antig... |
10620502 | Proteins isolated from lucerne roots by affinity chromatography with sugars analogous to Nod factor moieties. | Nod factors are important elicitors in legume-bacterium symbiosis. Any candidate plant receptor(s) for these lipo-oligosaccharides can be expected to show some lectin-like properties. A novel protein (P60), a native tetramer with 60 kDa monomers, has been isolated from a membrane fraction of Medicago sativa (lucerne, a... |
10620329 | Kinetics and inhibition of cyclomaltodextrinase from alkalophilic Bacillus sp. I-5. | The cyclomaltodextrinase from alkalophilic Bacillus sp. I-5 (CDase I-5) was expressed in Escherichia coli and the purified enzyme was used for characterization of the enzyme action. The hydrolysis products were monitored by both HPLC and high-performance ion chromatography analysis that enable the kinetic analysis of t... |
10618290 | Homocysteine and laminin are not prognostic markers in patients with septic inflammatory response syndrome. | The aim of this study was to measure plasma homocysteine and laminin concentrations in patients with nonbacteremic systemic inflammatory response syndrome (SIRS) and to compare them with those of a healthy control group. Concerning laminin, significant increased concentrations could be observed in the SIRS group compar... |
10618362 | Specific molecular recognition of mixed nucleic acid sequences: an aromatic dication that binds in the DNA minor groove as a dimer. | Phenylamidine cationic groups linked by a furan ring (furamidine) and related compounds bind as monomers to AT sequences of DNA. An unsymmetric derivative (DB293) with one of the phenyl rings of furamidine replaced with a benzimidazole has been found by quantitative footprinting analyses to bind to GC-containing sites ... |
10619853 | MSL1 plays a central role in assembly of the MSL complex, essential for dosage compensation in Drosophila. | In male Drosophila, histone H4 acetylated at Lys16 is enriched on the X chromosome, and most X-linked genes are transcribed at a higher rate than in females (thus achieving dosage compensation). Five proteins, collectively called the MSLs, are required for dosage compensation and male viability. Here we show that one o... |
10619851 | Replicase activity of purified recombinant protein P2 of double-stranded RNA bacteriophage phi6. | In nature, synthesis of both minus- and plus-sense RNA strands of all the known double-stranded RNA viruses occurs in the interior of a large protein assembly referred to as the polymerase complex. In addition to other proteins, the complex contains a putative polymerase possessing characteristic sequence motifs. Howev... |
10620313 | Confocal raman microspectroscopy and imaging study of theraphthal in living cancer cells. | Binary systems combining a transition metal complex and ascorbate have been proposed recently for catalytic therapy of malignant tumors. The killing effect on tumor cells is achieved by production of free radicals in the course of accelerated oxidation of ascorbate by dioxygen in the presence of transition metal comple... |
10620312 | Specific adhesion of vesicles monitored by scanning force microscopy and quartz crystal microbalance. | The specific adhesion of unilamellar vesicles with an average diameter of 100 nm on functionalized surfaces mediated by molecular recognition was investigated in detail. Two complementary techniques, scanning force microscopy (SFM) and quartz crystal microbalance (QCM) were used to study adhesion of liposomes consistin... |
10620305 | A thermodynamic molecular switch in biological systems: ribonuclease S' fragment complementation reactions. | It is well known that essentially all biological systems function over a very narrow temperature range. Most typical macromolecular interactions show DeltaH degrees (T) positive (unfavorable) and a positive DeltaS degrees (T) (favorable) at low temperature, because of a positive (DeltaCp degrees /T). Because DeltaG deg... |
10620304 | Fast events in protein folding: structural volume changes accompanying the early events in the N-->I transition of apomyoglobin induced by ultrafast pH jump. | Ultrafast, laser-induced pH jump with time-resolved photoacoustic detection has been used to investigate the early protonation steps leading to the formation of the compact acid intermediate (I) of apomyoglobin (ApoMb). When ApoMb is in its native state (N) at pH 7.0, rapid acidification induced by a laser pulse leads ... |
10620302 | Probing protein-sugar interactions. | We have investigated the partial specific volumes (2) (ml/g), hydration, and cosolvent interactions of rabbit muscle aldolase by equilibrium sedimentation in the analytical ultracentrifuge and by direct density increment (partial differential/partial differentialc(2))(mu) measurements over a range of sugar concentratio... |
10620273 | Exploring models of the influenza A M2 channel: MD simulations in a phospholipid bilayer. | The M2 protein of influenza A virus forms homotetrameric helix bundles, which function as proton-selective channels. The native form of the protein is 97 residues long, although peptides representing the transmembrane section display ion channel activity, which (like the native channel) is blocked by the antiviral drug... |
10617880 | Nerve repair by means of vein filled with muscle grafts. II. Morphological analysis of regeneration. | The morphological features of regeneration in long-distance (3 cm) muscle-vein-combined grafts were experimentally investigated in the rat sciatic nerve by means of light and electron microscopy. In the early phases of regeneration (14 days after surgery), many regenerating nerve fibers were detected along the muscle-v... |
10617661 | Maturation and specificity of Plasmodium falciparum subtilisin-like protease-1, a malaria merozoite subtilisin-like serine protease. | Plasmodium falciparum subtilisin-like protease-1 (PfSUB-1) is a protein belonging to the subtilisin-like superfamily of serine proteases (subtilases). PfSUB-1 undergoes extensive posttranslational proteolytic processing. The primary translation product is converted in the parasite endoplasmic reticulum to p54. This is ... |
10613863 | The VirR response regulator from Clostridium perfringens binds independently to two imperfect direct repeats located upstream of the pfoA promoter. | Regulation of toxin production in the gram-positive anaerobe Clostridium perfringens occurs at the level of transcription and involves a two-component signal transduction system. The sensor histidine kinase is encoded by the virS gene, while its cognate response regulator is encoded by the virR gene. We have constructe... |
10610807 | Escherichia coli one- and two-hybrid systems for the analysis and identification of protein-protein interactions. | Genetic methods based on fusion proteins allow the power of a genetic approach to be applied to the self-assembly of proteins or protein fragments, regardless of whether or not the normal function of the fused assembly domains is either known or amenable to selection or screening. The widespread adoption of variations ... |
10610821 | DNA bending and twisting properties of integration host factor determined by DNA cyclization. | The binding of many proteins to DNA is profoundly affected by DNA bending, twisting, and supercoiling. When protein binding alters DNA conformation, interaction between inherent and induced DNA conformation can affect protein binding affinity and specificity. Integration host factor (IHF), a sequence-specific, DNA-bind... |
10613705 | Transposon associated markers for the parasitic nematode Haemonchus contortus. | We have previously characterized a Tcl-like transposable element Hctcl, from the parasitic nematode Haemonchus contortus. Here we describe the genetic variation of Hctcl insertion sites in H. contortus populations differing in geographical origin, resistance to chemotherapeutics and level of inbreeding. Clear differenc... |
10606785 | Safety assessment of selected cyclodextrins - effect on ciliary activity using a human cell suspension culture model exhibiting in vitro ciliogenesis. | The objective of this study was to assess the cilio-inhibitory effect of a series of cyclodextrins using a human cell suspension culture system exhibiting in vitro ciliogenesis. Enzymatically released human nasal epithelial cells were cultured as sequential monolayer-suspension culture showing in vitro ciliogenesis. Ci... |
10606655 | Bacillus subtilis LrpC is a sequence-independent DNA-binding and DNA-bending protein which bridges DNA. | Genetic evidence suggests that the Bacillus subtilis lrpC gene product participates in cell growth and sporulation. The purified LrpC protein, which has a predicted molecular mass of 16.4 kDa, is a tetramer in solution. LrpC binds with higher affinity ( K (app) approximately 80 nM) to intrinsically curved DNA than to n... |
10606647 | RNA aptamers for the MS2 bacteriophage coat protein and the wild-type RNA operator have similar solution behaviour. | We have probed the effects of altering buffer conditions on the behaviour of two aptamer RNAs for the bacterio-phage MS2 coat protein using site-specific substitution of 2'-deoxy-2-aminopurine nucleotides at key adenosine positions. These have been compared to the wild-type operator stem-loop oligonucleotide, which is ... |
10603397 | Differential binding of clonal variants of Plasmodium falciparum to allelic forms of intracellular adhesion molecule 1 determined by flow adhesion assay. | Adhesion of Plasmodium falciparum-infected erythrocytes to the endothelial ligand intercellular adhesion molecule 1 (ICAM-1) has been implicated in the pathogenesis of cerebral malaria. Recently, a high-frequency coding polymorphism in the N-terminal domain of ICAM-1 (ICAM-1(Kilifi)) that is associated with susceptibil... |
10602264 | Dysprosium(III)-diethylenetriaminepentaacetate complexes of aminocyclodextrins as chiral NMR shift reagents. | A metal chelating ligand is bonded to alpha-, beta-, and gamma-cyclodextrin by the reaction of diethylenetraminepentaacetic dianhydride with the corresponding 6-mono- and 2-mono(amine)cyclodextrin. Adding Dy(III) to the cyclodextrin derivatives causes shifts in the (1)H-NMR spectra of substrates such as propranolol, tr... |
10600633 | The proteasome activator 11 S REG (PA28) and class I antigen presentation. | There are two immune responses in vertebrates: humoral immunity is mediated by circulating antibodies, whereas cytotoxic T lymphocytes (CTL) confer cellular immunity. CTL lyse infected cells upon recognition of cell-surface MHC Class I molecules complexed with foreign peptides. The displayed peptides are produced in th... |
10594387 | Influence of surfactants (present in the dissolution media) on the release behaviour of tolbutamide from its inclusion complex with beta-cyclodextrin. | The possible competitive displacement of a drug from its cyclodextrin-based inclusion complex by a third substance was investigated by studying the dissolution behaviour of tolbutamide-beta-cyclodextrin inclusion complex in demineralised water and in aqueous solution of different surfactants. Physical mixtures and knea... |
10592262 | Aminoacyl-tRNA synthetases database Y2K. | The aminoacyl-tRNA synthetases (AARS) are a diverse group of enzymes that ensure the fidelity of transfer of genetic information from DNA into protein. They catalyse the attachment of amino acids to transfer RNAs and thereby establish the rules of the genetic code by virtue of matching the nucleotide triplet of the ant... |
10594034 | Biological characteristics of the leukemia-associated transcriptional factor AML1 disclosed by hematopoietic rescue of AML1-deficient embryonic stem cells by using a knock-in strategy. | AML1 is one of the most frequently mutated genes associated with human acute leukemia and encodes the DNA-binding subunit of the heterodimering transcriptional factor complex, core-binding factor (CBF) (or polyoma enhancer binding protein 2 [PEBP2]). A null mutation in either AML1 or its dimerizing partner, CBFbeta, re... |
10594033 | The drosophila MSL complex acetylates histone H4 at lysine 16, a chromatin modification linked to dosage compensation. | In Drosophila, dosage compensation-the equalization of most X-linked gene products in males and females-is achieved by a twofold enhancement of the level of transcription of the X chromosome in males relative to each X chromosome in females. A complex consisting of at least five gene products preferentially binds the X... |
10590118 | Measles virus structural components are enriched into lipid raft microdomains: a potential cellular location for virus assembly. | The process of measles virus (MV) assembly and subsequent budding is thought to occur in localized regions of the plasma membrane, to favor specific incorporation of viral components, and to facilitate the exclusion of host proteins. We demonstrate that during the course of virus replication, a significant proportion o... |
10590089 | Adenovirus type 37 uses sialic acid as a cellular receptor. | Two cellular receptors for adenovirus, coxsackievirus-adenovirus receptor (CAR) and major histocompatibility complex class I (MHC-I) alpha2, have recently been identified. In the absence of CAR, MHC-I alpha2 has been suggested to serve as a cellular attachment protein for subgenus C adenoviruses, while members from all... |
10590084 | Hepatitis B virus core gene mutations which block nucleocapsid envelopment. | Recently we generated a panel of hepatitis B virus core gene mutants carrying single insertions or deletions which allowed efficient expression of the core protein in bacteria and self-assembly of capsids. Eleven of these mutations were introduced into a eukaryotic core gene expression vector and characterized by trans... |
11773049 | Intestinal dipeptidyl peptidase IV is efficiently sorted to the apical membrane through the concerted action of N- and O-glycans as well as association with lipid microdomains. | The apical sorting of human intestinal dipeptidyl peptidase IV (DPPIV) occurs through complex N-linked and O-linked carbohydrates. Inhibition of O-linked glycosylation by benzyl-N-acetyl-alpha-d-galactosaminide affects significantly the sorting behavior of DPPIV in intestinal Caco-2 and HT-29 cells. However, random del... |
11801042 | Novel mechanism for molecular self-assembly on metal substrates: unidirectional rows of pentacene on Cu(110) produced by a substrate-mediated repulsion. | The formation of one-dimensional, unidirectional nanoscopic molecular structures by self-assembly on metal substrates with a long range ordering up to several hundred nanometers has been achieved by a novel mechanism, an oscillatory modulation of the adsorption energy due to charge-density waves related to a surface st... |
11756675 | Biosensors from conjugated polyelectrolyte complexes. | A charge neutral complex (CNC) was formed in aqueous solution by combining an orange light emitting anionic conjugated polyelectrolyte and a saturated cationic polyelectrolyte at a 1:1 ratio (per repeat unit). Photoluminescence (PL) from the CNC can be quenched by both the negatively charged dinitrophenol (DNP) derivat... |
11756664 | Functional self-association of von Willebrand factor during platelet adhesion under flow. | We have used recombinant wild-type human von Willebrand factor (VWF) and deletion mutants lacking the A1 and A3 domains, as well as specific function-blocking monoclonal antibodies, to demonstrate a functionally relevant self-association at the interface of soluble and surface-bound VWF. Platelets perfused at the wall ... |
11756473 | Small cargo proteins and large aggregates can traverse the Golgi by a common mechanism without leaving the lumen of cisternae. | Procollagen (PC)-I aggregates transit through the Golgi complex without leaving the lumen of Golgi cisternae. Based on this evidence, we have proposed that PC-I is transported across the Golgi stacks by the cisternal maturation process. However, most secretory cargoes are small, freely diffusing proteins, thus raising ... |
11756470 | Cytoplasmic dynein/dynactin drives kinetochore protein transport to the spindle poles and has a role in mitotic spindle checkpoint inactivation. | We discovered that many proteins located in the kinetochore outer domain, but not the inner core, are depleted from kinetochores and accumulate at spindle poles when ATP production is suppressed in PtK1 cells, and that microtubule depolymerization inhibits this process. These proteins include the microtubule motors CEN... |
11781492 | A comparison of the supramolecular structures of 1-(6-amino-1,3-benzodioxol-5-yl)-3-(3,4,5-trimethoxyphenyl)prop-2-en-1-one and 1-(6-amino-1,3-benzodioxol-5-yl)-3-[4-(N,N-dimethylamino)phenyl]prop-2-en-1-one. | 1-(6-amino-1,3-benzodioxol-5-yl)-3-(3,4,5-trimethoxyphenyl)prop-2-en-1-one, C19H19NO6, (I), contains an intramolecular N-H...O hydrogen bond and a weak C-H...O hydrogen bond, which forms a C10 chain motif running parallel to the c axis. The 6-amino-1,3-benzodioxol-5-yl moieties are involved in pi-pi stacking. 1-(6-amin... |
11781491 | Supramolecular structures of 5-[3-(4-methylphenyl)- and 5-[3-(4-chlorophenyl)-2-propenylidene]-2,2-dimethyl-1,3-dioxane-4,6-dione. | 2,2-dimethyl-5-[3-(4-methylphenyl)-2-propenylidene]-1,3-dioxane-4,6-dione, C16H16O4, crystallizes in the triclinic space group P-1, with two molecules in the asymmetric unit. These molecules and a centrosymmetrically related pair, linked together by weak C-H...O hydrogen bonds, form a tetramer. 5-[3-(4-Chlorophenyl)-2-... |
11781487 | 2,4-dihydroxy-1,3-bis(methoxycarbonylmethoxy)calix[4]arene and 1,3-bis(ethoxycarbonylmethoxy)-2,4-dihydroxycalix[4]arene chloroform solvate. | The two title calix[4]arene compounds, C34H32O8, (I), and C36H36O8*CH3Cl, (II), respectively, which differ only in the size of the alkyl function on the pendant ester group, are compared. Compound (I) forms a novel supramolecular array, whilst (II) fails to do so due to accommodating a chloroform guest molecule in the ... |
11752793 | Crystallization and preliminary crystallographic study of an invertebrate C-type lectin, CEL-I, from the marine invertebrate Cucumaria echinata. | CEL-I is a GalNAc-specific carbohydrate-binding protein (lectin) isolated from the sea cucumber Cucumaria echinata. This protein belongs to the widely distributed C-type lectin family of animal lectins, which require Ca(2+) for their carbohydrate-binding ability and play important roles in various molecular-recognition... |
11751579 | Dynamic association of human insulin receptor with lipid rafts in cells lacking caveolae. | Cholesterol-sphingolipid rich plasma membrane domains, known as rafts, have emerged as important regulators of signal transduction. The adipocyte insulin receptor (IR) is localized to and signals via caveolae that are formed by polymerization of caveolins. Caveolin binds to IR and stimulates signalling. We report that,... |
11936103 | Molecular recognition by indoleacetic acid-imprinted polymers--effects of 2-hydroxyethyl methacrylate content. | Molecularly imprinted polymers for indole-acetic acid were prepared by co-polymerizing N,N-dimethylaminoethyl methacrylate, 2-hydroxyethyl methacrylate (HEMA), and ethylene glycol dimethacrylate. The dependence of the affinity and selectivity of the imprinted polymers on HEMA content was evaluated chromatographically. ... |
11752404 | Efficient bacterial transcription of DNA nanocircle vectors with optimized single-stranded promoters. | We describe experiments aimed at establishing whether circular single-stranded DNAs can form promoters for bacterial transcription from small folded motifs. In vitro selection experiments were carried out on circular 103-nt DNA libraries encoding 40-nt randomized sequences as well as self-processing hammerhead ribozyme... |
11743588 | Tetraspan microdomains distinct from lipid rafts enrich select peptide-MHC class II complexes. | Complexes of peptide and major histocompatibility complex (MHC) class II are expressed on the surface of antigen-presenting cells but their molecular organization is unknown. Here we show that subsets of MHC class II molecules localize to membrane microdomains together with tetraspan proteins, the peptide editor HLA-DM... |
11781480 | A novel binucleating macrocyclic ligand with two alcohol pendants. | A novel binucleating 24-membered macrocyclic ligand, 6,20-bis(2-hydroxyethyl)-3,6,9,17,20,23-hexazatricyclo[23.3.1.1(11,15)]triaconta-1(29),11(30),12,14,25,27-hexaene (L), was synthesized and crystallized as the tetrahydrobromide salt, i.e. 6,20-bis(2-hydroxyethyl)-6,20-diaza-3,9,17,23-hexaazoniatricyclo[23.3.1.1(11,15... |
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