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11872717 | TrwD, the hexameric traffic ATPase encoded by plasmid R388, induces membrane destabilization and hemifusion of lipid vesicles. | TrwD, a hexameric ATP hydrolase encoded by plasmid R388, is a member of the PulE/VirB11 protein superfamily of traffic ATPases. It is essential for plasmid conjugation, particularly for expression of the conjugative W pilus. In the present study, we analyzed the effects that TrwD produced on unilamellar vesicles consis... |
11872712 | Osmoregulation of dimer resolution at the plasmid pJHCMW1 mwr locus by Escherichia coli XerCD recombination. | Xer-mediated dimer resolution at the mwr site of plasmid pJHCMW1 is osmoregulated in Escherichia coli. Whereas under low-salt conditions, the site-specific recombination reaction is efficient, under high-salt conditions, it proceeds inefficiently. Regulation of dimer resolution is independent of H-NS and is mediated by... |
11872491 | Intraspecies genomic groups in Enterococcus faecium and their correlation with origin and pathogenicity. | Seventy-eight Enterococcus faecium strains from various sources were characterized by random amplified polymorphic DNA (RAPD)-PCR, amplified fragment length polymorphism (AFLP), and pulsed-field gel electrophoresis (PFGE) analysis of SmaI restriction patterns. Two main genomic groups (I and II) were obtained in both RA... |
11872489 | Surface modifications created by using engineered hydrophobins. | Hydrophobins are small (ca. 100 amino acids) secreted fungal proteins that are characterized by the presence of eight conserved cysteine residues and by a typical hydropathy pattern. Class I hydrophobins self-assemble at hydrophilic-hydrophobic interfaces into highly insoluble amphipathic membranes, thereby changing th... |
11869831 | The effect of lofepramine and other related agents on the motility of Tetrahymena pyriformis. | Tricyclic antidepressants (TCAs) were introduced almost 50 years ago. Whilst there is no doubt that TCAs are effective in treating depression, they are also more cardiotoxic when taken in overdose than other antidepressant groups. Lofepramine is a more recently introduced modified TCA, which in animals and man has low ... |
11869113 | Toward novel polyacetals by transacetalation techniques: dendrimeric diacetals. | [structure: see text] A new approach to polyacetal systems using sequential transacetalation and protection-deprotection techniques was developed for the preparation of macromolecular polyacetals and applied to secure new dendrimers with 2,4,8,10-tetraoxaspiro[5,5]undecane dendrons from pentaerythritol and polyaldehyde... |
11869111 | A chiral 28-membered macrocycle with symmetry and structure similar to that of trans-cyclooctene. | [reaction: see text] A bridged N,N-di(aryl)-1,2,4,5-benzenediimide was synthesized in which restricted rotation led to two diasteriomeric conformations at room temperature. The more stable syn-macrocycle is achiral, whereas the strained anti-macrocycle possesses planar chirality similar to that of trans-cyclooctene. Th... |
11869100 | Dendrimer with rotaxane-like mechanical branching. | [reaction: see text] A dendrimer wherein the branching points are mechanical in nature has been synthesized. It contains two identical covalently linked bis-dendrons and a core unit fused to two rings that encircle the two bis-dendrons. A "threading-followed-by-stoppering" approach is used in the template-directed synt... |
11869942 | Predicting factors for admission to an intensive care unit and clinical outcome in pediatric patients receiving hematopoietic stem cell transplantation. | <h4>Background and objectives</h4>In children, hematopoietic stem cell transplantation (HSCT) implies life-threatening complications and some patients need admission to a pediatric intensive care unit (PICU). Few studies have been reported analyzing this issue in a pediatric population and most focused on risk factors ... |
11866621 | Noncovalent binding of sensitizers for lanthanide(III) luminescence in an EDTA-bis(beta-cyclodextrin) ligand. | EDTA-linked beta-cyclodextrin dimer 3 was synthesized from EDTA bis(anhydride) 1 and mono(propylamino)-appended beta-cyclodextrin 2. p-tert-butylbenzoate 5, bound by the beta-cyclodextrin cavities of 3 with an association constant of 10(4) M(-1) in water, acts as a sensitizer for the Eu(III) and Tb(III) complexes of 3.... |
11866614 | Multichannel digital transmission in an optical network of communicating molecules. | In present telecommunication networks, information transfer relies on the interplay of optical and electrical signals. Data are communicated optically but processed electronically. Methods to maintain the propagating signals solely at the optical level must be developed to overcome the transmission capacities and speed... |
11866606 | Interaction of biotin with Mg-O bonds: bifunctional binding and recognition of biotin and related ligands by the Mg(15-crown-5)2+ unit. | The interaction between biotin and the macrocyclic magnesium complex Mg(15-crown-5)(Otf)2 (15-crown-5 is 1,4,7,10,13-pentaoxacyclopentadecane, Otf(-) is trifluoromethanesulfonate anion) in solution was studied as a model for metal-biotin interactions that may be important in its speciation and function. Shifts in the s... |
11867545 | The hepatitis C viral NS3 protein is a processive DNA helicase with cofactor enhanced RNA unwinding. | The RNA helicase/protease NS3 plays a central role in the RNA replication of hepatitis C virus (HCV), a cytoplasmic RNA virus that represents a major worldwide health problem. NS3 is, therefore, an important drug target in the effort to combat HCV. Most work has focused on the protease, rather than the helicase, activi... |
11867536 | The roX genes encode redundant male-specific lethal transcripts required for targeting of the MSL complex. | The roX1 and roX2 genes of Drosophila produce male-specific non-coding RNAs that co-localize with the Male-Specific Lethal (MSL) protein complex. This complex mediates up-regulation of the male X chromosome by increasing histone H4 acetylation, thus contributing to the equalization of X-linked gene expression between t... |
11867522 | The Tim9p-Tim10p complex binds to the transmembrane domains of the ADP/ATP carrier. | The soluble Tim9p-Tim10p (Tim, translocase of inner membrane) complex of the mitochondrial intermembrane space mediates the import of the carrier proteins and is a component of the TIM22 import system. The mechanism by which the Tim9p-Tim10p complex assembles and binds the carriers is not well understood, but previous ... |
11867520 | The Ppz protein phosphatases are key regulators of K+ and pH homeostasis: implications for salt tolerance, cell wall integrity and cell cycle progression. | The yeast Ppz protein phosphatases and the Hal3p inhibitory subunit are important determinants of salt tolerance, cell wall integrity and cell cycle progression. We present several lines of evidence showing that these disparate phenotypes are connected by the fact that Ppz regulates K+ transport. First, salt tolerance,... |
11867473 | Spectroscopic studies on the interaction of a water soluble porphyrin and two drug carrier proteins. | The interaction of meso-tetrakis(p-sulfonatophenyl)porphyrin (TSPP) sodium salt to human serum albumin and beta-lactoglobulin was studied by steady-state and dynamic fluorescence at different pH of aqueous solutions. The formation of TSPP J-aggregates and a noncovalent TSPP-protein complex was monitored by fluorescence... |
11867469 | Entrapment and condensation of DNA in neutral reverse micelles. | DNA condensation and compaction is induced by a variety of condensing agents such as polycations. The present study analyzed the structure of plasmid DNA (DNA) in the small inner space of reverse micelles formed from nonionic surfactants (isotropic phase). Spectroscopic studies indicated that DNA was dissolved in an or... |
11867457 | Rapid transbilayer movement of spin-labeled steroids in human erythrocytes and in liposomes. | The transbilayer movement and distribution of spin-labeled analogs of the steroids androstane (SLA) and cholestane (SLC) were investigated in the human erythrocyte and in liposomes. Membranes were labeled with SLA or SLC, and the analogs in the outer leaflet were selectively reduced at 4C using 6-O-phenylascorbic acid.... |
11867447 | Polyanions decelerate the kinetics of positively charged gramicidin channels as shown by sensitized photoinactivation. | The effects of different anionic polymers on the kinetic properties of ionic channels formed by neutral gramicidin A (gA) and its positively charged analogs gramicidin-tris(2-aminoethyl)amine (gram-TAEA) and gramicidin-ethylenediamine (gram-EDA) in a bilayer lipid membrane were studied using a method of sensitized phot... |
11865065 | Heparan sulfate proteoglycans are ligands for receptor protein tyrosine phosphatase sigma. | RPTPsigma is a cell adhesion molecule-like receptor protein tyrosine phosphatase involved in nervous system development. Its avian orthologue, known as cPTPsigma or CRYPalpha, promotes intraretinal axon growth and controls the morphology of growth cones. The molecular mechanisms underlying the functions of cPTPsigma ar... |
11863433 | Hydrophobicity maps of the N-peptide coiled coil of HIV-1 gp41. | Blocking HIV-1 viral entry into the host cell offers a promising new strategy for interfering with the HIV-1 life cycle. A major target of inhibitor design is to prevent binding of fusogenic gp41 C-peptides to the trimeric coiled coil of fusion-active N-peptides. Here, we map the hydrophobic character of the binding su... |
11861910 | Protein and drug interactions in the minor groove of DNA. | Interactions between proteins, drugs, water and B-DNA minor groove have been analyzed in crystal structures of 60 protein-DNA and 14 drug-DNA complexes. It was found that only purine N3, pyrimidine O2, guanine N2 and deoxyribose O4' are involved in the interactions, and that contacts to N3 and O2 are most frequent and ... |
11861904 | Methylation-dependent silencing at the H19 imprinting control region by MeCP2. | Methylation of CpG dinucleotides is correlated with transcriptional repression of genes, including imprinted genes. In the case of the imprinted H19 gene, a 2 kb imprinting control region (ICR) is subject to differential methylation, as it is methylated only on the silenced paternal allele. This region has previously b... |
11861868 | Expression and self-assembly of norwalk virus capsid protein from venezuelan equine encephalitis virus replicons. | The Norwalk virus (NV) capsid protein was expressed using Venezuelan equine encephalitis virus replicon particles (VRP-NV1). VRP-NV1 infection resulted in large numbers of recombinant NV-like particles that were primarily cell associated and were indistinguishable from NV particles produced from baculoviruses. Mutation... |
11861867 | Inhibition of human immunodeficiency virus type 1 activity in vitro by a new self-stabilized oligonucleotide with guanosine-thymidine quadruplex motifs. | An oligonucleotide with a dimeric hairpin guanosine quadruplex (basket type structure) (dG3T4G3-s), containing phosphorothioate groups, was able to inhibit human immunodeficiency virus type 1 (HIV-1)-induced syncytium formation and virus production (as measured by p24 core antigen expression) in peripheral blood mononu... |
11861851 | Purification and characterization of oligomeric envelope glycoprotein from a primary R5 subtype B human immunodeficiency virus. | Human immunodeficiency virus (HIV) continues to be a major public health problem throughout the world, with high levels of mortality and morbidity associated with AIDS. Considerable efforts to develop an effective vaccine for HIV have been directed towards the generation of cellular, humoral, and mucosal immune respons... |
11861832 | Repression of African swine fever virus polyprotein pp220-encoding gene leads to the assembly of icosahedral core-less particles. | African swine fever virus (ASFV) polyprotein pp220, encoded by the CP2475L gene, is an N-myristoylated precursor polypeptide that, after proteolytic processing, gives rise to the major structural proteins p150, p37, p34, and p14. These proteins localize at the core shell, a matrix-like virus domain placed between the D... |
11861300 | Failure of red blood cell maturation in mice with defects in the high-density lipoprotein receptor SR-BI. | Mammalian erythrocytes undergo a unique maturation process in which they discard their nuclei and organelles and assume a flexible biconcave shape. We found that altered plasma lipoprotein metabolism can profoundly influence these events. Abnormal erythrocyte morphology was observed in hypercholesterolemic mice lacking... |
11859110 | Lipid raft heterogeneity in human peripheral blood T lymphoblasts: a mechanism for regulating the initiation of TCR signal transduction. | Lateral mobility and spatial organization of proteins within the plasma membrane are likely to mediate the initial events coordinating T cell activation. Lipid rafts, distinct cholesterol/sphingolipid-rich membrane microdomains, provide a mechanism for this regulation by concentrating or excluding signaling proteins. W... |
11854434 | Agonist-induced translocation of the kinin B(1) receptor to caveolae-related rafts. | The kallikrein-kinin system, activated during inflammatory conditions and the regulation of specific cardiovascular and renal functions, includes two G protein-coupled receptors for bradykinin (BK)-related peptides. The B(1) receptor (B(1)R) subtype is not believed to undergo agonist-induced phosphorylation and endocyt... |
11854258 | Role of cholesterol and the ganglioside GM(1) in entry and short-term survival of Brucella suis in murine macrophages. | Brucella species are gram-negative, facultative intracellular bacteria that infect humans and animals. These organisms can survive and replicate within a membrane-bound compartment inside professional and nonprofessional phagocytic cells. Inhibition of phagosome-lysosome fusion has been proposed as a mechanism for intr... |
11854248 | Lack of fusion of azurophil granules with phagosomes during phagocytosis of Mycobacterium smegmatis by human neutrophils is not actively controlled by the bacterium. | Biogenesis of phagolysosomes is a very rapid event in neutrophils which takes place with nascent unclosed phagosomes, leading to the release of lysosomal enzymes such as beta-glucuronidase in the extracellular medium. We have previously shown that, under nonopsonic conditions, both pathogenic and nonpathogenic mycobact... |
11854209 | Mutational analysis of ganglioside GM(1)-binding ability, pentamer formation, and epitopes of cholera toxin B (CTB) subunits and CTB/heat-labile enterotoxin B subunit chimeras. | Variants of cholera toxin B subunit (CTB) were made by bisulfite- and oligonucleotide-directed mutagenesis of the ctxB gene. Variants were screened by a radial passive immune hemolysis assay (RPIHA) for loss of binding to sheep erythrocytes (SRBC). Variant CTBs were characterized for the formation of immunoreactive pen... |
11854187 | Intracellular induction of Listeria monocytogenes actA expression. | Following entry into the host cytosol, the bacterial pathogen Listeria monocytogenes dramatically increases the expression of several key virulence factors. The expression of actA, whose protein product is required for L. monocytogenes actin-based intracellular motility, is increased by more than 200-fold in cytosolic ... |
11853552 | Interaction of syncollin with GP-2, the major membrane protein of pancreatic zymogen granules, and association with lipid microdomains. | Syncollin, a novel pancreatic zymogen granule protein, is present on the luminal side of the granule membrane. To address the function of syncollin, we searched for putative binding partners. Cross-linking experiments with purified syncollin, and granule content and membrane proteins revealed a direct interaction betwe... |
11853551 | Measurement of ferrochelatase activity using a novel assay suggests that plastids are the major site of haem biosynthesis in both photosynthetic and non-photosynthetic cells of pea (Pisum sativum L.). | Ferrochelatase is the terminal enzyme of haem biosynthesis, catalysing the insertion of ferrous iron into the macrocycle of protoporphyrin IX, the last common intermediate of haem and chlorophyll synthesis. Its activity has been reported in both plastids and mitochondria of higher plants, but the relative amounts of th... |
11853535 | Increasing the redox potential of isoform 1 of yeast cytochrome c through the modification of select haem interactions. | The oxidation-reduction potential of eukaryotic cytochromes c varies very little from species to species. We have introduced point mutations into isoform 1 of yeast cytochrome c (iso-1-cytochrome c) to selectively engineer a protein with a higher redox potential. Of the ten different mutant proteins generated for the p... |
11853533 | The transfer of transthyretin and receptor-binding properties from the plasma retinol-binding protein to the epididymal retinoic acid-binding protein. | Members of the lipocalin superfamily share a common structural fold, but differ from each other with respect to the molecules with which they interact. They all contain eight beta-strands (A-H) that fold to form a well-defined beta-barrel, which harbours a binding pocket for hydrophobic ligands. These strands are conne... |
11852235 | Analysis of self-assembly and apatite binding properties of amelogenin proteins lacking the hydrophilic C-terminal. | Amelogenins, the major protein component of the mineralizing enamel extracellular matrix, are critical for normal enamel formation as documented in the linkage studies of a group of inherited disorders, with defective enamel formation, called Amelogenesis imperfecta. Recent cases of Amelogenesis imperfecta include muta... |
11849913 | Cyclodextrin complexation: influence on the solubility, stability, and cytotoxicity of camptothecin, an antineoplastic agent. | The solubility of camptothecin (CPT), a highly potent antineoplastic agent, as a function of different concentrations of cyclodextrins (alpha-cyclodextrin, alpha-CD; beta-cyclodextrin, beta-CD; and gamma-cyclodextrin, gamma-CD; hydroxypropyl-beta-cyclodextrin, HP-beta-CD; and randomly substituted dimethyl-beta-cyclodex... |
11850289 | Efficacy of ravuconazole in treatment of systemic murine histoplasmosis. | Ravuconazole (RCZ) was evaluated for efficacy in comparison to fluconazole (FCZ) and itraconazole (ITZ) in murine models of disseminated histoplasmosis. All regimens tested prolonged survival (P < 0.05 to 0.0001). At equivalent doses of 50 mg/kg of body weight, RCZ and ITZ were equally effective and RCZ was more effect... |
11850260 | Mutations in ponA, the gene encoding penicillin-binding protein 1, and a novel locus, penC, are required for high-level chromosomally mediated penicillin resistance in Neisseria gonorrhoeae. | Chromosomally mediated penicillin resistance in Neisseria gonorrhoeae occurs in part through alterations in penicillin-binding proteins (PBPs) and a decrease in outer membrane permeability. However, the genetic and molecular mechanisms of transformation of a penicillin-susceptible strain of N. gonorrhoeae to high-level... |
11850252 | Interference between D30N and L90M in selection and development of protease inhibitor-resistant human immunodeficiency virus type 1. | We studied the evolutionary relationships between the two protease inhibitor (PI) resistance mutations, D30N and L90M, of human immunodeficiency virus type 1 (HIV-1). The former is highly specific for nelfinavir resistance, while the latter is associated with resistance to several PIs, including nelfinavir. Among patie... |
11850238 | Sublethal concentrations of pleurocidin-derived antimicrobial peptides inhibit macromolecular synthesis in Escherichia coli. | Cationic bactericidal peptides are components of natural host defenses against infections. While the mode of antibacterial action of cationic peptides remains controversial, several targets, including the cytoplasmic membrane and macromolecular synthesis, have been identified for peptides acting at high concentrations.... |
11847280 | Electrostatics in protein-protein docking. | A novel geometric-electrostatic docking algorithm is presented, which tests and quantifies the electrostatic complementarity of the molecular surfaces together with the shape complementarity. We represent each molecule to be docked as a grid of complex numbers, storing information regarding the shape of the molecule in... |
11846378 | Methodologies for monitoring nanoparticle formation by self-assembly of DNA with poly(l-lysine). | DNA self-assembly with polycations produces nanoparticles suitable for gene delivery, although there is no standard methodology to measure particle formation and stability. Here we have compared three commonly used assays, namely, light scattering, inhibition of ethidium bromide fluorescence, and modified electrophoret... |
11844768 | Gamma integrase complementation at the level of DNA binding and complex formation. | Site-specific recombinases of the gamma Int family carry out two single-strand exchanges by binding as head-to-head dimers on inverted core-type DNA sites. Each protomer may cleave its own site as a monomer in cis (as for Cre recombinase), or it may recruit the tyrosine from its partner in trans to form a composite act... |
11844757 | YopD and LcrH regulate expression of Yersinia enterocolitica YopQ by a posttranscriptional mechanism and bind to yopQ RNA. | Pathogenic yersiniae secrete 14 Yop proteins via the type III pathway. Synthesis of YopQ occurs when the type III machinery is activated by a low-calcium signal, but not when the calcium concentration is above 100 microM. To characterize the mechanism that regulates the expression of yopQ, mutants that permit synthesis... |
11844752 | Shigella Spa32 is an essential secretory protein for functional type III secretion machinery and uniformity of its needle length. | The Shigella type III secretion machinery is responsible for delivering to host cells the set of effectors required for invasion. The type III secretion complex comprises a needle composed of MxiH and MxiI and a basal body made up of MxiD, MxiG, and MxiJ. In S. flexneri, the needle length has a narrow range, with a mea... |
11839805 | Functional analysis of yeast snoRNA and snRNA 3'-end formation mediated by uncoupling of cleavage and polyadenylation. | Many nuclear and nucleolar small RNAs are accumulated as nonpolyadenylated species and require 3'-end processing for maturation. Here, we show that several genes coding for box C/D and H/ACA snoRNAs and for the U5 and U2 snRNAs contain sequences in their 3' portions which direct cleavage of primary transcripts without ... |
11836427 | Complete inhibition of tobamovirus multiplication by simultaneous mutations in two homologous host genes. | The TOM1 gene of Arabidopsis thaliana encodes a putative multipass transmembrane protein which is necessary for the efficient multiplication of tobamoviruses. We have previously shown that mutations severely destructive to the TOM1 gene reduce tobamovirus multiplication to low levels but do not impair it completely. In... |
11836416 | The maturation process of pVP2 requires assembly of infectious bursal disease virus capsids. | Infectious bursal disease virus (IBDV) is a nonenveloped avian virus with a two-segment double-stranded RNA genome. Its T=13 icosahedral capsid is most probably assembled with 780 subunits of VP2 and 600 copies of VP3 and has a diameter of about 60 nm. VP1, the RNA-dependent RNA polymerase, resides inside the viral par... |
11836413 | An endoplasmic reticulum protein, p180, is highly expressed in human cytomegalovirus-permissive cells and interacts with the tegument protein encoded by UL48. | We have used a virus overlay assay to detect cellular proteins associated with human cytomegalovirus (HCMV) particles. The radiolabeled HCMV particles specifically bound to two host proteins with molecular sizes of 150 and 180 kDa. By a micro-amino-acid sequencing technique, the 180-kDa protein was identified as a huma... |
11836392 | Complement-mediated enhancement of antibody function for neutralization of pseudotype virus containing hepatitis C virus E2 chimeric glycoprotein. | We previously reported a number of features of hepatitis C virus (HCV) chimeric glycoproteins related to pseudotype virus entry into mammalian cells. In this study, pseudotype virus was neutralized by HCV E2 glycoprotein-specific antibodies and infected human sera. Neutralization (50% reduction of pseudotype virus plaq... |
11837977 | The effect of oral absorption enhancers on the in vivo performance of insulin-loaded poly(ethylcyanoacrylate) nanospheres in diabetic rats. | Poly(ethylcyanoacrylate) (PECA) nanospheres have been employed as biodegradable polymeric carriers for oral (po) delivery of insulin. The main goal of this investigation was to screen various absorption enhancers, which were used to protect insulin-loaded PECA, by following their in vivo performance after oral administ... |
11807759 | A comparison of lipase-catalysed ester and lactone synthesis in low-water systems: analysis of optimum water activity. | We investigated the effects of the lyophilisation medium (enzyme plus buffer salt and additives) and of water activity (a(w)) on the catalytic properties of lipase from Chromobacterium viscosum (lipase CV) in organic solvents; catalysis of ester and lactone synthesis were compared and, despite the similarities of the r... |
11877393 | Altered amelogenin self-assembly based on mutations observed in human X-linked amelogenesis imperfecta (AIH1). | A hallmark of biological systems is a reliance on protein assemblies to perform complex functions. We have focused attention on mammalian enamel formation because it relies on a self-assembling protein complex to direct mineral habit. The principle protein of enamel is amelogenin, a 180-amino acid hydrophobic protein t... |
11867768 | Phosphatidylinositol 4,5-bisphosphate stimulates vesicle formation from liposomes by brain cytosol. | As a step toward the elucidation of mechanisms in vesicle budding, a cell-free assay that measures cytosol-induced vesicle generation from liposomes was established. This assay then was used to explore the role of phosphoinositides in vesicle formation. Liposomes incubated with brain cytosol in the presence of ATP and ... |
11864980 | The high specificities of Phaseolus vulgaris erythro- and leukoagglutinating lectins for bisecting GlcNAc or beta 1-6-linked branch structures, respectively, are attributable to loop B. | Despite very similar tertiary structures based upon a common framework, legume lectins exhibit an amazing variety of sugar binding specificities. While most of these lectins recognize rather discrete sugar linkages, Phaseolus vulgaris erythroagglutinating and leukoagglutinating lectins (E(4)- and L(4)-PHA) are unique i... |
11859071 | Uncoupling of the cholera toxin-G(M1) ganglioside receptor complex from endocytosis, retrograde Golgi trafficking, and downstream signal transduction by depletion of membrane cholesterol. | To induce toxicity, cholera toxin (CT) must first bind ganglioside G(M1) at the plasma membrane, enter the cell by endocytosis, and then traffic retrograde into the endoplasmic reticulum. We recently proposed that G(M1) provides the sorting motif necessary for retrograde trafficking into the biosynthetic/secretory path... |
11856727 | Slac2-a/melanophilin, the missing link between Rab27 and myosin Va: implications of a tripartite protein complex for melanosome transport. | Myosin Va is a member of the unconventional class V myosin family, and a mutation in the myosin Va gene causes pigment granule transport defects in human Griscelli syndrome and dilute mice. How myosin Va recognizes its cargo (i.e. melanosomes), however, has remained undetermined over the past decade. In this study, we ... |
11882902 | Structure of the HP1 chromodomain bound to histone H3 methylated at lysine 9. | Specific modifications to histones are essential epigenetic markers---heritable changes in gene expression that do not affect the DNA sequence. Methylation of lysine 9 in histone H3 is recognized by heterochromatin protein 1 (HP1), which directs the binding of other proteins to control chromatin structure and gene expr... |
11870293 | catena-Poly[[di-mu-chloro-bis[(triphenylphosphine)silver(I)]]-mu-2-aminopyrimidine-kappa 2N1:N3]. | In the title supramolecular complex, [Ag(2)Cl(2)(C(4)H(5)N(3))(C(18)H(15)P)(2)](n), a one-dimensional chain is formed by dimeric [Ag(2)Cl(2)(PPh(3))(2)] units bridged by 2-aminopyrimidine moieties. The Ag atoms are four-coordinate, with an AgCl(2)NP core. A crystallographic inversion centre is located in the centre of ... |
12185575 | The use of neutral cyclodextrins as additives in capillary electrophoresis for the separation and identification of propoxyphene enantiomers. | A simple, efficient, and rapid method is described for separation of the enantiomers of propoxyphene by capillary electrophoresis with neutral cyclodextrins as chiral separators. This method has several advantages over the crystallization method employed by some forensic laboratories, including unambiguous results, eas... |
11897020 | Using orthologous and paralogous proteins to identify specificity determining residues. | <h4>Background</h4>Concepts of orthology and paralogy are become increasingly important as whole-genome comparison allows their identification in complete genomes. Functional specificity of proteins is assumed to be conserved among orthologs and is different among paralogs. We used this assumption to identify residues ... |
11847228 | Self-assembly of human MxA GTPase into highly ordered dynamin-like oligomers. | Human MxA protein is a member of the interferon-induced Mx protein family and an important component of the innate host defense against RNA viruses. The Mx family belongs to a superfamily of large GTPases that also includes the dynamins and the interferon-regulated guanylate-binding proteins. A common feature of these ... |
11870286 | Aquachloro(1,10-phenanthroline-kappa 2N,N')(p-toluenesulfonato-kappa O)copper(II). | In the title compound, [CuCl(C(7)H(7)O(3)S)(C(12)H(8)N(2))(H(2)O)], the central Cu atom is coordinated by a water molecule, a chloride ion, an O-monodentate p-toluenesulfonate anion and an N,N'-bidentate 1,10-phenanthroline ligand. The copper environment is best described as a slightly distorted square pyramid, with bo... |
11842218 | Biological water at the protein surface: dynamical solvation probed directly with femtosecond resolution. | Biological water at the interface of proteins is critical to their equilibrium structures and enzyme function and to phenomena such as molecular recognition and protein-protein interactions. To actually probe the dynamics of water structure at the surface, we must examine the protein itself, without disrupting the nati... |
11842183 | A liposome-based therapeutic vaccine against beta -amyloid plaques on the pancreas of transgenic NORBA mice. | Immune tolerance to beta-amyloid (Abeta) was broken in NORBA transgenic mice presenting Abeta plaques on their pancreases. Vaccination of Black C57, BALB/c, and NORBA mice with the synthetic Abeta(1-16) sequence modified by covalently attaching two palmitoyl residues at each end of the peptide, subsequently reconstitut... |
11839762 | Synthesis and biological evaluation in vitro of a selective, high potency peptide agonist of human melanin-concentrating hormone action at human melanin-concentrating hormone receptor 1. | Human melanin-concentrating hormone (hMCH) is a nonselective natural ligand for the human melanin-concentrating hormone receptors: hMCH-1R and hMCH-2R. Similarly, the smaller peptide encompassing the disulfide ring and Arg(6) of hMCH, Ac-Arg(6)-cyclo(S-S)(Cys(7)-Met(8)-Leu(9)-Gly(10)-Arg(11)-Val(12)-Tyr(13)-Arg(14)-Pro... |
11839753 | Cholesterol-modulating agents selectively inhibit calcium influx induced by chemoattractants in human neutrophils. | The effects of cholesterol-perturbing agents on the mobilization of calcium induced upon the stimulation of human neutrophils by chemotactic factors were tested. Methyl-beta-cyclodextrin and filipin did not alter the initial peak of calcium mobilization but shortened the duration of the calcium spike that followed the ... |
11839768 | Tpr is localized within the nuclear basket of the pore complex and has a role in nuclear protein export. | Tpr is a coiled-coil protein found near the nucleoplasmic side of the pore complex. Since neither the precise localization of Tpr nor its functions are well defined, we generated antibodies to three regions of Tpr to clarify these issues. Using light and EM immunolocalization, we determined that mammalian Tpr is concen... |
11839767 | Serum response factor is crucial for actin cytoskeletal organization and focal adhesion assembly in embryonic stem cells. | The activity of serum response factor (SRF), an essential transcription factor in mouse gastrulation, is regulated by changes in actin dynamics. Using Srf(-/-) embryonic stem (ES) cells, we demonstrate that SRF deficiency causes impairments in ES cell spreading, adhesion, and migration. These defects correlate with def... |
12806022 | Chiral pesticides in soil and water and exchange with the atmosphere. | The enantiomers of chiral pesticides are often metabolised at different rates in soil and water, leading to nonracemic residues. This paper reviews enantioselective metabolism of organochlorine pesticides (OCPs) in soil and water, and the use of enantiomers to follow transport and fate processes. Residues of chiral OCP... |
11836242 | Heliothis virescens and Manduca sexta lipid rafts are involved in Cry1A toxin binding to the midgut epithelium and subsequent pore formation. | Lipid rafts are characterized by their insolubility in nonionic detergents such as Triton X-100 at 4 degrees C. They have been studied in mammals, where they play critical roles in protein sorting and signal transduction. To understand the potential role of lipid rafts in lepidopteran insects, we isolated and analyzed ... |
11834780 | Protein nanoarrays generated by dip-pen nanolithography. | Dip-pen nanolithography was used to construct arrays of proteins with 100- to 350-nanometer features. These nanoarrays exhibit almost no detectable nonspecific binding of proteins to their passivated portions even in complex mixtures of proteins, and therefore provide the opportunity to study a variety of surface-media... |
16290400 | Interaction between a novel gemini surfactant and cyclodextrin: NMR and surface tension studies. | The interaction between cyclodextrins, hydroxypropyl-beta-cyclodextrin (HPbetaCD), and hydroxypropyl-gamma-cyclodextrin (HPgammaCD) and a novel type of nonionic surfactant synthesized from a fatty acid has been investigated. The so-called nonionic heterogemini surfactant (NIHG750) contains two hydrophobic groups and tw... |
12908318 | Molecular recognition by wall-assembling-type nanocavity in aqueous media. | Steroid cyclophanes, each having a macrocyclic ring attached to four bile acid moieties via chiral lysine connectors, were synthesized, and the binding of the 2-naphthylphenylketone (guest) to the steroid cyclophanes in water was investigated. The circular dichroism spectra of the steroid cyclophane with cholic acid an... |
12908317 | Atomic force microscopic observation of the molecular orientation in ultrathin films of alkanoic acid-derivatized porphyrins on a mica surface. | The observation of the molecular orientation of alkanoic acid-derivatized porphyrins in ultrathin films deposited on mica was carried out by atomic force microscopy. It was observed that the tetraacid derivative 5, 10, 15, 20-tetra(N-10-carboxydecyl-pyridinium-4-yl) porphyrin was arranged as a monolayer with the porphy... |
12908315 | Layer-by-layer nanostructured hybrid films of polyaniline and vanadium oxide. | Supramolecular structures of polyaniline (PANI) and vanadium oxide (V2O5) have been assembled via the electrostatic layer-by-layer (ELBL) technique. Strong ionic interactions and H-bonding impart unique features to the ELBL films, which are distinct from cast films obtained with the same materials. The interactions wer... |
12908313 | Organic-inorganic nanostructured colloids. | The synthesis and applications of organic-inorganic nanostructured colloids and colloidal-based materials are reviewed here. Emphasis is placed on the strategies and synthetic methods developed to organize organic-inorganic architectures. The article begins with a description and a general hierarchical classification o... |
12604043 | Optimization of cationic lipid mediated gene transfer: structure-function, physico-chemical, and cellular studies. | The rationale design aimed at the enhancement of cationic lipid mediated gene transfer is discussed. These improvements are based on the straight evaluation of the structure-activity relationship and on the introduction of new structures. Much attention have been given to the supramolecular structures of the lipid/DNA ... |
12604035 | Heat shock protein micro-encapsulation as a double tool for the improvement of new generation vaccines. | The modern vaccinology encompasses the recombinant DNA technology, protein and carbohydrate chemistry to obtain safe molecularly defined vaccines. Nevertheless most of the vaccines are poorly immunogenic because a large number of antigens are membrane proteins and consequently they are not present in their active confo... |
12599411 | [Study on the inclusion compound of qucertin with hydroxypropyl-beta-cyclodextrin]. | The inclusion compound of qucertin-HP-beta-CD was manufactured by aqueous solution-stirring method. The inclusion compound of qucertin-HP-beta-CD was confirmed by IR spectroscopy and differential theramal analysis (DTA). The results indicated that the inclusion compound of qucertion-HP-beta-CD was formed. The content a... |
12503614 | Analysis of ligand-receptor interactions in cells by atomic force microscopy. | Atomic force microscopy (AFM) increasingly has been used to analyse "receptor" function, either by using purified proteins ("molecular recognition microscopy") or, more recently, in situ in living cells. The latter approach has been enabled by the use of a modified commercial AFM, linked to a confocal microscope, which... |
12120383 | Dendritic chiral auxiliaries on silica: a new heterogeneous catalyst for enantioselective addition of diethylzinc to benzaldehyde. | This article reports the first work on the use of silica supported dendritic chiral auxiliaries for the enantioselective addition of diethylzinc to benzaldehyde: the control of dendrimer propagation on the silica surface is of prime importance to obtain enhanced conversion, selectivity, and enantioselectivity. |
12120372 | Discriminating between lanthanide ions: self-assembly of heterodimetallic triple-stranded helicates. | A bis-terdentate segmental ligand has been designed which self-assembles with lanthanide ions of different size to yield heterodimetallic triple-stranded helicates. |
12120363 | Solid-phase template-directed synthesis of a [2]rotaxane using a solid-phase stopper. | The first synthesis of a rotaxane by solid phase chemistry has been achieved, using the resin bead as a 'Mega' stopper during the synthesis. One of the advantages of this methodology over traditional solution routes include the ability to use mass action to drive the chemistry, without complicating the purification pro... |
12120072 | Evidence that gold(III) porphyrins are not electrochemically inert: facile generation of gold(II) 5,10,15,20-tetrakis(3,5-di-tert-butylphenyl)porphyrin. | Gold(III) porphyrin 1 is shown to undergo reduction at the central metal ion to give the first known gold(II) porphyrin overturning the long held assumption that reduction of such complexes only occurs at the macrocycle. |
12120063 | Calixarenes as ligands for transition-metal catalysts: a bis(calix[4]arene-11,23-dicarboxylato) dirhodium complex. | A novel dirhodium tetracarboxylate complex is described in which two calix[4]arene macrocycles, bridged at the upper rim by a Rh-Rh unit, serve as ligands and whose solid-state structure shows an unusual coordination of a toluene molecule in the axial position at each rhodium atom. |
12120058 | [30]heptaphyrin(1.1.1.1.1.0.0): an aromatic expanded porphyrin with a 'figure eight' like structure. | The synthesis, characterization, and X-ray structure of a heptapyrrolic macrocycle, [30]heptaphyrin(1.1.1.1.1.0.0) is reported; despite showing aromatic features, it exhibits a 'figure eight'-like structure in the solid state. |
12120057 | Para-acyl calix[4]arenes: amphiphilic self-assembly from the molecular to the mesoscopic level. | Studies of the properties of a series of amphiphilic calixarenes show that they can form stable monolayers, Langmuir-Blodgett layers and solid lipid nanoparticles, the mesostructures were investigated by atomic force microscopy and the crystal structure of one compound shows a partially interdigitated tilted bilayer st... |
12120056 | Hexakis(2-pyridyl)- and hexakis(3-pyridyl)[3]radialene: novel, water-soluble [3]radialenes with potential utility for supramolecular chemistry. | The titled [3]radialenes are the first, water-soluble hexaaryl[3]radialenes with considerably high electron affinity, their alkali metal reduction giving rise to anion-radicals and dianions stepwise as fairly stable species in degassed tetrahydrofuran. |
12120051 | Unusual cyclo-tetra and hexa peptidation of bis-boc-cystine with cystine-di-OMe: one step preparation of the novel 32- and 48-membered cyclotetracystine and cyclohexacystine. | The unprecedented formation of 32- and 48-membered macrocycles that inscribe 4 and 6 cystine units, in the peptidation of bis-Boc-cystine with cystine di-OMe is reported. |
12120047 | Helix versus zig-zag: control of supramolecular topology via carboxylic acid conformations in ortho-substituted phenyl amines. | ortho-Substituted phenyl amines form supramolecular helices or zig-zag structures, depending on the conformation of the carboxylic acid substituents--which can be controlled by an intramolecular hydrogen-bonding interaction. |
12053962 | Efficacy of beta-cyclodextrin against experimental cryptosporidiosis in neonatal lambs. | The efficacy of beta-cyclodextrin against experimental Cryptosporidium parvum infection was evaluated in neonatal lambs. The animals were treated by oral administration of the drug at 1 g/kg of body weight during 3 consecutive days. Preventive treatment was started within 1 day of birth, and therapeutic treatment was i... |
11999771 | Study of the enantioselective elimination of four toxaphene congeners in rat after intravenous administration by high resolution gas chromatography negative ion mass spectrometry. | This study was performed to investigate the possible enantioselective metabolism of the four chlorinated bornanes: #26, #32, #50 and #62 (according to the Parlar nomenclature) by rats. Rats were exposed to a mixture of these toxaphenes by a single intravenous injection. Enantiomer ratios (ER) as well as the enantiomer ... |
11955003 | Phosphates, DNA, and the search for nonterrean life: a second generation model for genetic molecules. | Phosphate groups are found and used widely in biological chemistry. We have asked whether phosphate groups are likely to be important to the functioning of genetic molecules, including DNA and RNA. From observations made on synthetic analogs of DNA and RNA where the phosphates are replaced by nonanionic linking groups,... |
11939542 | A new macrocyclic polystyrene-based sensor for chromium (III) ions. | A new tetradentate dihydrogen perchlorate macrocyclic ligand (2,4,9,11-tetraphenyl-1,5,8,12-tetraazacyclotetradeca-1,4,8,11-tetraene dihydrogen perchlorate) was prepared and characterised. The macrocycle behaves as a selective chelating ion-exchanger for some metal ions. The polystyrene-based membrane electrode is foun... |
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