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8806235 | Synergistic interaction of photodynamic treatment with the sensitizer aluminum phthalocyanine and hyperthermia on loss of clonogenicity of CHO cells. | When CHO cells were exposed to hyperthermia and subsequently to photodynamic treatment, the combined effects were additive but in the reverse sequence the interaction was synergistic. The synergistic interaction comprised two quite different components: (1) photodynamically induced sensitization of cellular proteins an... |
8798633 | Native peptide inhibition. Specific inhibition of type II phospholipases A2 by synthetic peptides derived from the primary sequence. | The binding of low molecular weight type II phospholipase A2 (EC) to membrane surfaces and hydrolysis of phospholipid are thought to involve the formation of a hydrophobic channel into which a single substrate molecule diffuses before cleavage. The floor and right side of the channel are provided by hydrophobic residue... |
8798565 | A 35-kDa protein is the basic unit of the core from the 2 x 10(4)-kDa aggregation factor responsible for species-specific cell adhesion in the marine sponge Microciona prolifera. | Dissociated sponge cells quickly reaggregate in a species-specific manner, differentiate, and reconstruct tissue, providing a very handy system to investigate the molecular basis of more complex intercellular recognition processes. Species-specific cell adhesion in the marine sponge Microciona prolifera is mediated by ... |
8795627 | Laser ablation of Drosophila embryonic motoneurons causes ectopic innervation of target muscle fibers. | We have tested the effects of neuromuscular denervation in Drosophila by laser-ablating the RP motoneurons in intact embryos before synaptogenesis. We examined the consequences of this ablation on local synaptic connectivity in both 1st and 3rd instar larvae. We find that the partial or complete loss of native innervat... |
8795569 | The influence of iron chelators on the accumulation of protoporphyrin IX in 5-aminolaevulinic acid-treated cells. | Human adenocarcinoma cells of the line WiDr and Chinese hamster lung fibroblasts of the line V79 were treated with 5-aminolaevulinic acid (5-ALA) and exposed to light. The effects of the iron chelators ethylenediaminetetraacetic acid (EDTA) and desferrioxamine (DEF) were assessed. Both cell lines were treated with vari... |
8794919 | Mechanism of enantioseparation of salsolinols, endogenous neurotoxins in human brain, with ion-pair chromatography using beta-cyclodextrin as a mobile phase additive. | A novel method for direct separation of the enantiomers of salsolinol and N-methylsalsolinol was devised. The enantiomers were completely separated with ion-pair chromatography on a reversed-phase column with beta-cyclodextrin as a chiral mobile phase additive and sodium 1-heptanesulfonate as a counterion. The mechanis... |
8794889 | Hydrophilic side chains in the third and seventh transmembrane helical domains of human A2A adenosine receptors are required for ligand recognition. | Hydrophilic residues of the G protein-coupled human A2A adenosine receptor that are potentially involved in the binding of the ribose moiety of adenosine were targeted for mutagenesis. Residues in a T88QSS91 sequence in the third transmembrane helical domain (TM3) were individually replaced with alanine and other amino... |
8790355 | An RNA topoisomerase. | A synthetic strand of RNA has been designed so that it can adopt two different topological states (a circle and a trefoil knot) when ligated into a cyclic molecule. The RNA knot and circle have been characterized by their behavior in gel electrophoresis and sedimentation experiments. This system allows one to assay for... |
8790354 | A sequential dimerization mechanism for erythropoietin receptor activation. | We have probed the interaction of human erythropoietin (EPO) with its receptor (EPO-R) by analyzing a panel of 17 EPO mutants in a variety of in vitro assays. Mutant proteins were expressed in 293s cells and quantified by using an N-terminal epitope tag in conjunction with a surface plasmon resonance assay. Receptor bi... |
8787681 | Cross-linking of the dermo-epidermal junction of skin regenerating from keratinocyte autografts. Anchoring fibrils are a target for tissue transglutaminase. | Since transglutaminases create covalent gamma-glutamyl-epsilon-lysine cross-links between extracellular matrix proteins they are prime candidates for stabilizing tissue during wound healing. Therefore, we studied the temporo-spatial expression of transglutaminase activity in skin regenerating from cultured epithelial a... |
8784181 | Residues in the seventh membrane-spanning segment of the dopamine D2 receptor accessible in the binding-site crevice. | The binding site of the dopamine D2 receptor, like that of other homologous G-protein-coupled receptors, is contained within a water-accessible crevice formed among its seven membrane-spanning segments. Using the substituted-cysteine accessibility method, we previously mapped the residues that form the surface of the b... |
8703191 | Formation of the light-harvesting complex I (B870) of anoxygenic phototrophic purple bacteria. | The light-harvesting (LH) complex I (B870) of anoxygenic photosynthetic purple bacteria is the oligomeric form of its subunit B820 consisting of the low-molecular-weight polypeptides alpha, beta, bacteriochlorophyll (BChl), and carotenoids in the stoichiometric ratio [alpha1 beta1 (BChl2) Crt1-2]n. LHI surrounds the ph... |
8752327 | Identification of sigma S-regulated genes in Salmonella typhimurium: complementary regulatory interactions between sigma S and cyclic AMP receptor protein. | sigma S (RpoS)-regulated lacZ transcriptional fusions in Salmonella typhimurium were identified from a MudJ transposon library by placing the rpoS gene under the control of the araBAD promoter and detecting lacZ expression in the presence or absence of arabinose supplementation. Western blot (immunoblot) analysis of ba... |
8752322 | Interaction between FtsZ and inhibitors of cell division. | The interaction between inhibitors of cell division and FtsZ were assessed by using the yeast two-hybrid system. An interaction was observed between FtsZ and SulA, a component of the SOS response, and the interacting regions were mapped to their conserved domains. This interaction was reduced by mutations in sulA and b... |
8751933 | Role of lipopolysaccharide in colonization of the mouse intestine by Salmonella typhimurium studied by in situ hybridization. | An avirulent, streptomycin-resistant Salmonella typhimurium strain, SL5319, and its lipopolysaccharide (LPS)-deficient mutant strain, SL5325, differ in their ability to colonize the large intestines of streptomycin-treated mice. When fed to mice independently, the strains colonize equally well, but when fed together, t... |
8751902 | Variation in repeat number within the alpha C protein of group B streptococci alters antigenicity and protective epitopes. | Variable expression of repeating units of the protective alpha C proteins among clinical isolates of group B streptococci (GBS) may have implications for vaccine development. In this study, alpha C protein genes containing various numbers of repeats (1,2,9, and 16) were cloned in a T7 overexpression vector in Escherich... |
8751886 | Interactions between Campylobacter jejuni and lipids. | We previously showed that motility plays several key roles in Campylobacter jejuni pathogenesis, including increasing the efficiency of C. jejuni attachment to host epithelial cells. To further characterize C. jejuni attachment, we first examined the role of carbohydrates. Experiments with Chinese hamster ovary (CHO) c... |
8751987 | Molecular recognition in vitamin D-binding protein. | Vitamin D-binding protein (DBP) or group-specific component (Gc) is a relatively abundant serum protein with multiple functions, the majority of which are initiated by the highly specific recognition and binding of a ligand by this protein. During the past decade and a half, several structure-functional studies have be... |
8752125 | Polymerization of tau into filaments in the presence of heparin: the minimal sequence required for tau-tau interaction. | Paired helical filaments isolated from the brains of patients with Alzheimer's disease are composed of a major protein component, the microtubule-associated protein termed tau, together with other nonprotein components, including heparan, a glycosaminoglycan, the more extensively sulfated form of which is heparin. As s... |
8751852 | Succinyl CoA: 3-oxoacid CoA transferase (SCOT): human cDNA cloning, human chromosomal mapping to 5p13, and mutation detection in a SCOT-deficient patient. | Succinyl CoA: 3-oxoacid CoA transferase (SCOT; E.C.2.8.3.5) mediates the rate-determining step of ketolysis in extrahepatic tissues, the esterification of acetoacetate to CoA for use in energy production. Hereditary SCOT deficiency in humans causes episodes of severe ketoacidosis. We obtained human-heart SCOT cDNA clon... |
8756676 | Protein-protein and protein-DNA interaction regions within the DNA end-binding protein Ku70-Ku86. | DNA ends are generated during double-strand-break repair and recombination. A p70-p86 heterodimer, Ku, accounts for the DNA end binding activity in eukaryotic cell extracts. When one or both subunits of Ku are missing, mammalian cells are deficient in double-strand-break repair and in specialized recombination, such as... |
8756632 | The nuclear factor YY1 suppresses the human gamma interferon promoter through two mechanisms: inhibition of AP1 binding and activation of a silencer element. | Our group has previously reported that the nuclear factor Yin-Yang 1 (YY1), a ubiquitous DNA-binding protein, is able to interact with a silencer element (BE) in the gamma interferon (IFN-gamma) promoter region. In this study, we demonstrated that YY1 can directly inhibit the activity of the IFN-gamma promoter by inter... |
8709267 | Identification of domains in the simian immunodeficiency virus matrix protein essential for assembly and envelope glycoprotein incorporation. | The matrix domain (MA) of the simian immunodeficiency virus (SIV) is encoded by the amino-terminal region of the Gag polyprotein precursor and is the component of the viral capsid that lines the inner surface of the virus envelope. To define domains of the SIV MA protein that are involved in virus morphogenesis, deleti... |
8709238 | Increased envelope spike density and stability are not required for the neutralization resistance of primary human immunodeficiency viruses. | Previous observations that the gp120 envelope glycoprotein contents of some primary, clade B human immunodeficiency virus type 1 (HIV-1) isolates were higher than those of laboratory-passaged HIV-1 isolates suggested the hypothesis that increased envelope glycoprotein spike density or stability contributes to the relat... |
24271608 | Supramolecular architecture of cyanobacterial thylakoid membranes: How is the phycobilisome connected with the photosystems? | Cyanobacteria, as the most simple organisms to perform oxygenic photosynthesis differ from higher plants especially with respect to the thylakoid membrane structure and the antenna system used to capture light energy. Cyanobacterial antenna systems, the phycobilisomes (PBS), have been shown to be associated with Photos... |
20865136 | Naphthalene, Phenanthrene, and Pyrene as DNA Base Analogues: Synthesis, Structure, and Fluorescence in DNA. | We describe the synthesis, structures, and DNA incorporation of deoxyribonucleosides carrying polycyclic aromatic hydrocarbons as the DNA "base" analogue. The new polycyclic compounds are 1-naphthyl, 2-naphthyl, 9-phenanthrenyl, and 1-pyrenyl deoxynucleosides. The compounds are synthesized using a recently developed C-... |
18966608 | Variable-angle synchronous fluorescence spectrometry and rank annihilation methods for mixture resolution. | The potential of variable angle synchronous spectroscopy (VASS) for fluorescent mixtures resolution was assessed and compared with the rank annihilation method (RAM). For this purpose, a set of excitation-emission matrices from three standard cyclodextrin fluorescence-enhanced solutions of the pesticides aminocarb, car... |
11666700 | "Swollen" Macrocycles: Palladium(II)-Directed Template Syntheses of Pendant-Arm 14-, 16-, and 18-Membered Macrocycles. | The bis(diamine)palladium(II) cations (diamine = ethane-1,2-diamine, propane-1,3-diamine, or butane-1,4-diamine) all undergo condensation reactions with formaldehyde and nitroethane to produce macromonocycles where each pair of cis-disposed primary amines has been converted to a -NH-CH(2)-C(CH(3))(NO(2))-CH(2)-NH- stra... |
11666680 | Monomeric and Trimeric Manganese(III) Complexes of 2-Hydroxy-5,10,15,20-tetraphenylporphyrin. Synthesis and Characterization. | The hydrolysis of the monomeric five-coordinate (2-BzO-TPP)Mn(III)Cl complex has been investigated.(1) Evidence for the formation of the cyclic trimeric complex [(2-O-TPP)Mn(III)](3) is presented. The (1)H NMR spectroscopic evidence indicates that the trimeric manganese(III) complex has a head-to-tail cyclic trimeric s... |
15048376 | Cyclodextrin- and sugar-derivatives as stationary phases for the gas chromatography of semivolatiles. | Cyclodextrins as cyclic hexa-(alpha) to octa-(gamma) saccharides are widely and successfully used after esterification or etherification as stationary phases in gas chromatography for the separation of chiral compounds. Their basic potential as thermostable stationary phases as such or after derivatisation offers a uni... |
9196995 | [Management of patients with severe pneumonia in mechanical ventilation: usefulness of bronchoalveolar lavage]. | <h4>Unlabelled</h4>Bacterial pneumonia is a frequent complication in patients requiring mechanical ventilation (9-21%) and carries a significant mortality. The optimal management of these patients remains controversial. Some investigators have advocated invasive diagnostic testing using bronchoscopic techniques.<h4>Aim... |
8807900 | Molecular basis for the binding of SH3 ligands with non-peptide elements identified by combinatorial synthesis. | <h4>Background</h4>Protein-structure-based combinatorial chemistry has recently been used to discover several ligands containing non-peptide binding elements to the Src SH3 domain. The encoded library used has the form Cap-M1-M2-M3-PLPPLP, in which the Cap and Mi's are composed of a diverse set of organic monomers. The... |
8807898 | A Zn(II)-binding site engineered into retinol-binding protein exhibits metal-ion specificity and allows highly efficient affinity purification with a newly designed metal ligand. | <h4>Background</h4>The Zn(II)-binding site from the active center of human carbonic anhydrase II, formed by three His side chains, can be grafted onto the recombinant serum retinol-binding protein (RBP). The artificial binding site in the resulting variant RBP/H3(A) has high affinity for Zn(II) and stabilizes the prote... |
8906413 | Dynamics of beta-cyclodextrin hydrate: solid state 2H NMR studies. | The 2H NMR spectra and spin-lattice relaxation times of powder samples of C-deuterated beta-cyclodextrin (CD) hydrate (beta-CD-2,3,6,6-d28.11H2O) 1 and O-deuterated beta-CD hydrate (beta-CDd21.11H2 O-d22) 2 were measured in the temperature range from 160 to 295 K at 46 MHz. Information about the degree and time scales ... |
8887726 | Time-dependent densification behaviour of cyclodextrins. | Understanding of volume reduction mechanisms is a valuable aid in the development of robust cyclodextrin tablet formulations. The particle and powder properties of alpha-, beta-, gamma- and hydroxypropyl (HP)-beta-cyclodextrins and their behaviour under compression were examined. The cyclodextrins studied showed big di... |
8884226 | Site-directed mutagenesis of the human adenosine A2A receptor. Critical involvement of Glu13 in agonist recognition. | A glutamic acid residue in the first transmembrane domain of the human adenosine A2A receptor was mutated to glutamine. Radioligand binding studies on COS-7 cell membranes expressing either the wild-type or the mutant receptor revealed that the affinity of the prototypic agonist CGS21680 (2-[4-[(2-carboxyethyl)phenyl]e... |
8877566 | Sodium and potassium ion-promoted formation of supramolecular aggregates of 2'-deoxyguanylyl-(3'-5')-2'-deoxyguanosine. | Guanine mono-, oligo-, and polynucleotides, including the guanine-rich telomeric sequences found at the ends of chromosomes, have been shown to form self-associated species which contain cyclic tetramers of hydrogen-bonded guanines (G-tetrads). In this study the effect of the tetramethylammonium (TMA+), Na+, and K+ ion... |
8875778 | Noxiustoxin 2, a novel K+ channel blocking peptide from the venom of the scorpion Centruroides noxius Hoffmann. | A novel peptide called Noxiustoxin 2 (NTX2) was purified from the venom of the scorpion Centruroides noxius and characterized chemically and functionally. It is composed of 38 amino acid residues linked by three disulfide bridges and its primary structure is 61% identical to that of Noxiustoxin (NTX). It is not toxic t... |
8875771 | Fab fragments of the monoclonal antibody BCF2 are capable of neutralizing the whole soluble venom from the scorpion Centruroides noxius Hoffmann. | BCF2 is a murine hybridoma cell line that produces a neutralizing antibody against toxin 2 (Cn2) from the scorpion Centruroides noxius Hoffmann of Mexico. In this communication we report the preparation and use of the BCF2 antibody and its antigen binding fragments (Fab) in experiments aiming at obtaining protection of... |
8875147 | Reactivity parameters in structure-activity relationship-based risk assessment of chemicals. | New approaches to the risk assessment process are needed that might be more definitive and satisfying to the scientific community, interest groups, and the public at large. This commentary examines an alternative approach that is based on understanding the relationships of chemical structure and reactivity properties t... |
8874818 | Absorption, distribution and excretion of beta-cyclodextrin and glucosyl-beta-cyclodextrin in rats. | The absorption, distribution and excretion of intravenously and orally administered beta-cyclodextrin (beta-CD) and glucosyl (G)-beta-CD in rats were studied using HPLC with pulsed amperometric detection. Within 10 h after intravenous administration, unchanged beta-CD and G-beta-CD recovered in urine were about 90% of ... |
8874816 | Pharmacodynamics and pharmacokinetics of recombinant human granulocyte colony-stimulating factor (rhG-CSF) after administration of a rectal dosage vehicle. | The pharmacodynamic activities (leukopoietic effect) and pharmacokinetics of recombinant human granulocyte colony-stimulating factor (rhG-CSF) administered rectally in various doses as hollow-type suppositories were investigated in rabbits. Three kinds of rhG-CSF hollow-type suppositories were employed: suppository I c... |
8872530 | A convenient method for determining cyclic peptide conformation from 1D 1H-NMR information. | A rapid and convenient method for determining the backbone conformation of cyclic peptides results from the combination of 1D 1H NMR information and molecular modeling. phi Angle torsional constraints calculated from 3JHN.H alpha coupling constants are used to determine the position of multiple-welled potential energy ... |
8871828 | Chromosomal localization of a highly repeated EcoRI DNA fragment in Megoura viciae (Homoptera, Aphididae) by nick translation and fluorescence in situ hybridization. | To investigate the genome of the aphid Megoura viciae at molecular level, we have studied total DNA by agarose gel electrophoresis after cleavage with different restriction endonucleases. EcoRI digestion produced a highly repeated DNA fragment, about 600 pb long. The contribution of this EcoRI element to the total geno... |
8871827 | Redistribution of ribosomal DNA after blocking of transcription induced by actinomycin D. | We report on the effect of different doses and times of incubation of the cytostatic drug actinomycin D (AMD) on nucleolar morphology, rRNA gene transcription and rDNA gene localization using in situ hybridization and the immunocytochemical detection of the human upstream binding factor (UBF) at the electron microscopi... |
8871826 | Autosomal location of a new subtype of 1.688 satellite DNA of Drosophila melanogaster. | During the screening of a Drosophila melanogaster YAC library with DNA from the minichromosome Dp(1;f)1187 we isolated a clone, yw20D5, which contains a new subtype of 1.688 satellite DNA. Although the sequences of several monomers subcloned from the YAC show a considerable variation in length, the derived consensus se... |
8871825 | Genomic instability in MycER-activated Rat1A-MycER cells. | The deregulated expression of c-Myc protein is associated with the non-random locus-specific amplification of the dihydrofolate reductase (DHFR) gene. This study was performed to determine whether additional chromosomal aberrations occur when c-Myc protein levels are up-regulated for prolonged periods. To this end, we ... |
8871824 | The Ty1-copia group retrotransposons of Allium cepa are distributed throughout the chromosomes but are enriched in the terminal heterochromatin. | The genomic organization and diversity of the Ty1-copia group retrotransposons has been investigated in a monocotyledonous plant, Allium cepa. We used the polymerase chain reaction (PCR) to generate sequences corresponding to a conserved domain of the reverse transcriptase gene of Ty1-copia retrotransposons in this pla... |
8871823 | Meiotic behavior of the X1X2Y1Y2 quadrivalent of the primate Alouatta caraya. | A multiple sex chromosome system was found in three unrelated individuals of the primate Alouatta caraya. This mechanism is originated by a translocation between the Y chromosome and one of the autosomes (A7). Mitotic karyotypes show two small, acrocentric chromosomes (AY and YA), which are the translocation products. ... |
8871822 | Evidence for a sequence-directed conformation periodicity in the genomic highly repetitive DNA detectable with single-strand-specific chemical probe potassium permanganate. | A single-strand-specific chemical probe, potassium permanganate (KMnO4), was used to study the sequence-dependent conformation periodicity of tandem multicopy repetitive DNA sequences HRS60 and GRS (Nicotiana Species) at the level of single base pair and dinucleotide step. Local DNA structures, sensitive to KMnO4, reve... |
8871821 | Cytogenetic and molecular analysis of the satellite DNA of the genus Ctenomys (Rodentia Octodontidae) from Uruguay. | The genus of subterranean rodents Ctenomys presents the widest range of variability in diploid number among mammals (from 2n = 10 to 2n = 70). In Uruguay, this variability is observed in karyotypes with 2n = 44, 50 or 58 and two geographically isolated populations with 70 chromosomes but different karyotypic structure.... |
8869884 | Alterations in cell cholesterol content modulate Ca(2+)-induced tight junction assembly by MDCK cells. | Transepithelial electrical resistance (TER), a measure of tight junction (TJ) barrier function, develops more rapidly and reaches higher values after preincubation of MDCK cells for 24 h with 2 microM Lovastatin (lova), an inhibitor of 3-hydroxy-3-methylglutaryl-CoA reductase. While this effect was attributed to a 30% ... |
8865339 | Quantifying biological specificity: the statistical mechanics of molecular recognition. | The Random Energy Model of statistical physics is applied to the problem of the specificity of recognition between two biological (macro)molecules forming a non-covalent complex. In this model, the native mode of association is separated by an energy gap from a large body of non-native modes. Whereas the native mode is... |
8863266 | Prediction of binding constants of alpha-cyclodextrin complexes. | Proceeding from a phenomenological theory of pairwise interactions (solvent-solvent, solvent-solute, and solute-solute), the binding constant K11 (in M-1) for 1:1 complex formation by alpha-cyclodextrin at a substrate binding site, at 25 degrees C in water, is given by log K11 = -1.74 - [Z] + 0.032(-delta A), where [Z]... |
8861956 | A novel class of small amphipathic peptides affect aerial hyphal growth and surface hydrophobicity in Ustilago maydis. | Ustilago maydis, a fungal pathogen of corn, can alternate between yeast-like and filamentous growth. This dimorphic switch is governed by the mating-type loci. We have identified an abundant class of small SDS-insoluble cell wall proteins, designated repellents, specifically present in the filamentous form. Genetic ana... |
8856661 | Phytol metabolites are circulating dietary factors that activate the nuclear receptor RXR. | RXR is a nuclear receptor that plays a central role in cell signaling by pairing with a host of other receptors. Previously, 9-cis-retinoic acid (9cRA) was defined as a potent RXR activator. Here we describe a unique RXR effector identified from organic extracts of bovine serum by following RXR-dependent transcriptiona... |
8844856 | Hydrophobic regions on protein surfaces. Derivation of the solvation energy from their area distribution in crystallographic protein structures. | For the first time, a direct approach for the derivation of an atomic solvation parameter from macromolecular structural data alone is presented. The specific free energy of solvation for hydrophobic surface regions of proteins is delineated from the area distribution of hydrophobic surface patches. The resulting value... |
8844847 | Contribution of the tyrosines to the structure and function of the human U1A N-terminal RNA binding domain. | RNA binding domains (RBDs) are members of a large family of proteins that share minimal sequence conservation but adopt an alpha beta sandwich global fold. Defining the contributions of specific amino acids to RBD structure and RNA binding is critical to understanding the functions of these proteins. In these experimen... |
8844203 | Activation of the complement system by synthetic DNA complexes: a potential barrier for intravenous gene delivery. | We have examined the complement-activating properties of synthetic cationic molecules and their complexes with DNA. Commonly used gene delivery vehicles include complexes of DNA with polylysine of various chain lengths, transferrin-polylysine, a fifth-generation poly(amidoamine) (PAMAM) dendrimer, poly(ethyleneimine), ... |
8844170 | Cloning and characterization of a novel human clathrin heavy chain gene (CLTCL). | An exon representing a novel clathrin heavy chain gene (CLTCL) was isolated during gene identification studies and transcription mapping of human chromosome 22. Isolation and sequencing of cDNA clones corresponding to this exon revealed extensive similarity of the predicted amino acid sequence of this gene product to t... |
8843280 | Mechanism of differential activities of ofloxacin enantiomers. | Ofloxacin, a potent quinolone antibacterial agent, has a tricyclic ring structure with a methyl group attached to the asymmetric carbon at the C-3 position on the oxazine ring. The S isomer (DR-3355) of ofloxacin has antibacterial activity up to 2 orders of magnitude greater than that of the R isomer (DR-3354). This di... |
8842418 | Differential effects of angiostatic steroids and dexamethasone on angiogenesis and cytokine levels in rat sponge implants. | 1. Subcutaneous implantation of sterile polyether sponges elicited a reproducible neovascular response in rats, as determined by blood flow measurement with a 133Xe clearance technique and confirmed histologically. This model was used to monitor the levels of two cytokines during angiogenesis and to compare the activit... |
8842243 | Atomic force microscopy of insulin single crystals: direct visualization of molecules and crystal growth. | Atomic force microscopy performed on single crystals of three different polymorphs of bovine insulin revealed molecularly smooth (001) layers separated by steps whose heights reflect the dimensions of a single insulin hexamer. Whereas contact mode imaging caused etching that prevented molecular-scale resolution, tappin... |
8842237 | Excitation energy transfer in chlorosomes of green bacteria: theoretical and experimental studies. | A theory of excitation energy transfer within the chlorosomal antennae of green bacteria has been developed for an exciton model of aggregation of bacteriochlorophyll (BChl) c (d or e). This model of six exciton-coupled BChl chains with low packing density, approximating that in vivo, and interchain distances of approx... |
8842222 | Fourier-transform infrared spectroscopic studies on avidin secondary structure and complexation with biotin and biotin-lipid assemblies. | Fourier-transform infrared studies have been carried out to investigate the secondary structure and thermal stability of hen egg white avidin and its complexes with biotin and with a biotinylated lipid derivative, N-biotinyl dimyristoyl phosphatidylethanolamine (DMBPE) in aqueous dispersion. Analysis of the amide I str... |
8842194 | Molecular dynamics simulations of valinomycin and its potassium complex in homogeneous solvents. | Molecular dynamics simulations of kalinomycin (VM) and its potassium complex in water and in a Lennard Jones solvent are reported. In agreement with experimental evidence the structure of K(+)-VM in nonpolar solution is similar to the solid state structure whereas the structure of uncomplexed VM is not. In water uncomp... |
8841914 | Morphological subclasses of lateral olivocochlear terminals? Ultrastructural analysis of inner spiral bundle in cat and guinea pig. | The lateral olivocochlear efferent pathway terminates in vesicle-filled swellings in the inner spiral bundles under inner hair cells (IHCs) and has been suggested to include at least two chemically distinct subclasses (see, e.g., Vetter et al. [1991] Synapse 7:21-43). In the present study, the ultrastructure and periph... |
8831261 | [Creation of new supramolecular science with macrocyclic polyamines]. | Exploitation of saturated macrocyclic polyamines has led to a discovery of numerous novel functions and new molecules such as (1) unique proton sponge properties; (2) uptake of biological polyanions; (3) peptide-like metal uptake properties; (4) stabilization of unusual oxidation states of metal ions (e.g. CuIII, NiIII... |
8818899 | Differentiation of Mycobacterium genavense and Mycobacterium simiae by automated mycolic acid analysis with high-performance liquid chromatography. | Mycobacterium genavense, a fastidious opportunist in patients with AIDS, cannot be identified by conventional biochemical methods. Computerized mycolic acid analysis by high-performance liquid chromatography offers an alternative that distinguishes the mycolic acid profile of M. genavense from those of all other organi... |
8975376 | [Results of peripheral arterial vascular injury in polytraumatized patients]. | The therapeutic concept of limb salvage or immediate amputation is controversial in patients with multiple trauma. Sixty-three multiple trauma patients (injury severity score ISS > 18 patients) with blunt arterial injuries were investigated. Twenty-seven had injuries of the upper limb and 36 patients of the lower limb.... |
8799309 | Proton transfer reactivity of large multiply charged ions. | Charge-charge interactions dramatically influence the dissociation and proton transfer reactivity of large multiply protonated ions. In combination with tandem mass spectrometry, proton transfer reactions have been used to determine the charge state of an ion and to increase the effective mass resolution of electrospra... |
8799187 | Direct modulation of calmodulin targets by the neuronal calcium sensor NCS-1. | Ca2+ and its ubiquitous intracellular receptor calmodulin (CaM) are required in the nervous system, among a host of cellular responses, for the modulation of several important enzymes and ion channels involved in synaptic efficacy and neuronal plasticity. Here, we report that CaM can be replaced by the neuronal calcium... |
8799164 | Menstrual breakdown of human endometrium can be mimicked in vitro and is selectively and reversibly blocked by inhibitors of matrix metalloproteinases. | The mechanisms underlying the menstrual lysis leading to shedding of the human endometrium and its accompanying bleeding are still largely unknown. In particular, whether breakdown of the endometrial fibrillar extra-cellular matrix that precedes bleeding depends on aspartic-, cysteine-, serine-, or metalloproteinases r... |
8799133 | Unraveling principles of lead discovery: from unfrustrated energy landscapes to novel molecular anchors. | The search for novel leads is a critical step in the drug discovery process. Computational approaches to identify new lead molecules have focused on discovering complete ligands by evaluating the binding affinity of a large number of candidates, a task of considerable complexity. A new computational method is introduce... |
8794156 | The design and engineering of nucleic acid nanoscale assemblies. | It is possible to design DNA molecules that can form unusual structures and topologies. Stable DNA-branched junctions have been used to construct polyhedral catenated molecules with the connectivities of a cube and of a truncated octahedron. The truncated octahedron has been constructed following a solid-support-based ... |
8794467 | Improvement of some pharmaceutical properties of drugs by cyclodextrin complexation. Part 6: Ampicillin. | The potentiality of interaction of ampicillin with beta-cyclodextrin (beta-CD) was investigated by spectrophotometric and vapour pressure osmometric methods. The results revealed formation of a two-to-one inclusion complex of the drug in beta-CD. Complexation of the drug with beta-CD was found to increase both the solu... |
8848053 | [Fatty acid synthases--strategic functions of multienzymes]. | Several decades of biochemical research have led to our present detailed knowledge on cellular metabolism, is wealth of individual reactions, enzymes, and pathways, and their organization, interplay, and regulation. Although most metabolic reactions are simultaneous and occur in the same cell, they may also act indepen... |
8784449 | Cyclic HIV protease inhibitors: synthesis, conformational analysis, P2/P2' structure-activity relationship, and molecular recognition of cyclic ureas. | High-resolution X-ray structures of the complexes of HIV-1 protease (HIV-1PR) with peptidomimetic inhibitors reveal the presence of a structural water molecule which is hydrogen bonded to both the mobile flaps of the enzyme and the two carbonyls flanking the transition-state mimic of the inhibitors. Using the structure... |
8780784 | Solution structure of the lipoyl domain of the 2-oxoglutarate dehydrogenase complex from Azotobacter vinelandii. | The three-dimensional solution structure of the lipoyl domain of the 2-oxoglutarate dehydrogenase complex from Azotobacter vinelandii has been determined from nuclear magnetic resonance data by using distance geometry and dynamical simulated annealing refinement. The structure determination is based on a total of 580 e... |
8772183 | Distinct effects of heat shock and ATP depletion on distribution and isoform patterns of human Hsp27 in endothelial cells. | To study the cytoprotective capacity of Hsp27 under various cellular stresses, we compared the effects of heating and energy deprivation on its distribution and isoform composition. Cultured endothelial cells from human aorta or umbilical vein were subjected to heat shock (45 degrees C) and ATP-depleting metabolic stre... |
8771787 | Characterization of LRP, a leucine-rich repeat (LRR) protein from tomato plants that is processed during pathogenesis. | This paper describes the isolation and characterization of LRP, a new gene from tomato plants. The deduced amino acid sequence showed that the encoded protein is enriched in leucine, and contains interesting structural motifs. LRP contains four tandem repeats of a canonical 24 amino acid leucine-rich repeat (LRR) seque... |
8771392 | The development of articular cartilage: I. The spatial and temporal patterns of collagen types. | Articular cartilage is both morphologically and biochemically heterogeneous. Its susceptibility to degenerative diseases such as arthritis and its limited repair capacity have made cartilage the focus of intense study; surprisingly, little is known of its development. Using a panel of specific antibodies, we have docum... |
8761444 | The lipocalin protein family: structure and function. | The lipocalin protein family is a large group of small extracellular proteins. The family demonstrates great diversity at the sequence level; however, most lipocalins share three characteristic conserved sequence motifs, the kernel lipocalins, while a group of more divergent family members, the outlier lipocalins, shar... |
8761364 | Radioimmunotherapy of colorectal carcinoma xenografts in nude mice with yttrium-90 A33 IgG and Tri-Fab (TFM). | The monoclonal antibody A33 recognises a tumour-associated antigen on human colorectal carcinoma, and has undergone preliminary evaluation in the clinic where selective localisation to hepatic metastases has been demonstrated [Welt et al. (1994) J. Clin. Oncol. 12, 1561-1571]. A33 and an A33 tri-fab fragment (TFM) were... |
8760890 | Covalent attachment of synthetic DNA to self-assembled monolayer films. | The covalent attachment of thiol-modified DNA oligomers; to self-assembled monolayer silane films on fused silica and oxidized silicon substrates is described. A heterobifunctional crosslinking molecule bearing both thiol- and amino-reactive moieties was used to tether a DNA oligomer (modified at its terminus with a th... |
8764053 | Identification of domains in canine parvovirus VP2 essential for the assembly of virus-like particles. | Canine parvovirus capsids are composed of 60 copies of VP2 and 6 to 10 copies of VPl. To locate essential sites of interaction between VP2 monomers, we have analyzed the effects of a number of VP2 deletion mutants representing the amino terminus and the four major loops of the surface, using as an assay the formation o... |
8764025 | Cyclosporine A-resistant human immunodeficiency virus type 1 mutants demonstrate that Gag encodes the functional target of cyclophilin A. | The cellular peptidyl-prolyl isomerase cyclophilin A is incorporated into human immunodeficiency virus type 1 virions via contacts with the proline-rich domain of the Gag polyprotein. Cyclosporine A and nonimmunosuppressive analogs bind with high affinity to cyclophilin A, compete with Gag for binding to cyclophilin A,... |
8702948 | Intracellular trafficking of cholesterol monitored with a cyclodextrin. | The sterol binding agent 2-hydroxypropyl-beta-cyclodextrin is shown to be a convenient and useful experimental tool to probe intracellular pathways of cholesterol transport. Biochemical and cytochemical studies reveal that cyclodextrin specifically removes plasma membrane cholesterol. Depletion of plasma membrane sphin... |
8702938 | Two distinct modes of strand unlinking during theta-type DNA replication. | DNA gyrase and topoisomerase IV (Topo IV) are type II bacterial DNA topoisomerases that show a high degree of similarity to each other yet appear to have different functions during DNA replication. We show here that the torsional stress generated during theta-type DNA replication in vitro can take the form of either po... |
8702717 | Amino acid residues critical for the interaction between bacteriophage T7 DNA polymerase and Escherichia coli thioredoxin. | Upon infection of Escherichia coli, bacteriophage T7 annexes a host protein, thioredoxin, to serve as a processivity factor for its DNA polymerase, T7 gene 5 protein. In a previous communication (Himawan, J., and Richardson, C. C. (1992) Proc. Natl. Acad. Sci. U. S. A. 89, 9774-9778), we reported that an E. coli strain... |
8769426 | A novel calmodulin-binding protein, belonging to the WD-repeat family, is localized in dendrites of a subset of CNS neurons. | A rat brain synaptosomal protein of 110,000 M(r) present in a fraction highly enriched in adenylyl cyclase activity was microsequenced (Castets, F., G. Baillat, S. Mirzoeva, K. Mabrouk, J. Garin, J. d'Alayer, and A. Monneron. 1994. Biochemistry. 33:5063-5069). Peptide sequences were used to clone a cDNA encoding a nove... |
8764994 | Conserved secondary structure in the actinorhodin polyketide synthase acyl carrier protein from Streptomyces coelicolor A3(2) and the fatty acid synthase acyl carrier protein from Escherichia coli. | The acyl carrier protein (ACP) of Streptomyces coelicolor A3(2) functions as a molecular chaperone during the biosynthesis of the polyketide actinorhodin (act). Here we compare structural features of the polyketide synthase (PKS) ACP, determined by two-dimensional 1H-NMR, with the Escherichia coli fatty acid synthase (... |
8764993 | Cyclodextrins as templates for the presentation of protease inhibitors. | Mono(6-succinylamido-6-deoxy)-beta-cyclodextrin was synthesized by classical carbohydrate chemistry and used as a template mono-functionalized with the linear, fully flexible 4C-spacer carboxylate for covalent linkage of the calpain inhibitor leucyl-leucyl-norleucinal. Spectroscopic analyses of the conjugate do not sup... |
8765123 | Wheat germ agglutinin-reactive chains of giant hemoglobin from the polychaete Perinereis aibuhitensis. | Wheat germ agglutinin-reactive chains of multisubunit extracellular hemoglobin from the polychaete Perinereis aibuhitensis were identified to clarify the carbohydrate gluing which is the carbohydrate-dependent supramolecular architecture of the hemoglobin (Ebina S. et al. (1995) Proc. Natl. Acad. Sci. USA 92, 7367-7371... |
8765512 | Paracyclophanes: a novel class of water-soluble inhibitors of HIV proteinase. | A versatile synthesis of functionalized para- and metacyclophanes (macrocycles with one or more aromatic rings incorporated; ansa-compounds) has been developed. Cyclophanes constitute a novel building block for potent human immunodeficiency virus (HIV) protease inhibitors. The synthesis of the macrocyclic ring system w... |
8756705 | Sequence and environmental effects on the self-assembly of DNA oligomers possessing GxT2Gy segments. | It is well-known that DNA oligomers possessing contiguous guanine bases can assume non-Watson-Crick type structures through the formation of four-stranded species. The architecture of these four-stranded structures is highly dependent upon the sequence of the DNA and the conditions (e.g., buffer, pH, ionic strength, ca... |
8756681 | A host-guest set of triple-helical peptides: stability of Gly-X-Y triplets containing common nonpolar residues. | Host-guest peptide sets have been useful in evaluating the propensity of different amino acids to adopt an alpha-helical or beta-sheet form, and this concept is applied here to the triple-helical conformation. A set of host-guest peptides of the form acetyl-(Gly-Pro-Hyp)3-Gly-X-Y-(Gly-Pro-Hyp)4-Gly-GlyCONH2 was designe... |
8759342 | Human corneal fibrillogenesis. Collagen V structural analysis and fibrillar assembly by stromal fibroblasts in culture. | <h4>Purpose</h4>The stroma of the developing cornea is a highly organized extracellular matrix formed essentially by uniform, small-diameter collagen fibrils with constant interfibrillar spacing. Unlike the fibrillogenesis of chicken cornea, the assembly and maturation of human corneal fibrils have been poorly investig... |
8757870 | Influence of lipoteichoic acid structure on recognition by the macrophage scavenger receptor. | Lipoteichoic acids (LTAs) belong to the immunostimulatory class of molecules of gram-positive bacteria (GPB). Previous investigations showed that the macrophage scavenger receptor (SR), a glycosylated trimeric transmembrane protein, binds directly to many GPB, possibly via LTA. SR binding to other ligands is dependent ... |
8757845 | Influence of agr on fibrinogen binding in Staphylococcus aureus Newman. | The ability of Staphylococcus aureus to bind fibrinogen is believed to be important in promoting bacterial adherence to both intravascular catheters and host tissues during infection. We investigated the influence of the global regulator agr on the fibrinogen binding capacity and its relationship to the expression of c... |
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