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9463910 | Enantioselectivity in chiral capillary electrophoresis with polysaccharides. | This review surveys enantiomer separation by capillary electrophoresis (CE) using polysaccharides as chiral selectors. Many ionic or electrically neutral polysaccharides, such as heparin, chondroitin sulfate, dextrin, etc., have been employed successfully for the CE separation of enantiomers. The operational conditions... |
9463908 | Controlling enantioselectivity in chiral capillary electrophoresis with inclusion-complexation. | The separation of chiral compounds is of key importance in different fields of application, e.g., pharmaceutical, industrial, forensic, biological, clinical etc. Capillary electrophoresis (CE) is a powerful analytical method applied in chiral analysis and inclusion-complexation is one of the most frequently used mechan... |
9463904 | Selectivity in capillary electrophoresis in the presence of micelles, chiral selectors and non-aqueous media. | In addition to high efficiency, short analysis times and small sample volumes, a further attractive feature of capillary electrophoretic techniques is the possibility to achieve, high selectivities. Usually, selectivity control also allows improvement in the resolution. A simple way to enhance the selectivity of capill... |
9462219 | The potential role of procalcitonin and interleukin 8 in the prediction of infected necrosis in acute pancreatitis. | <h4>Background</h4>Infection of pancreatic necrosis has a major impact on clinical course, management, and outcome in acute pancreatitis. Currently, guided fine needle aspiration is the only means for an early and accurate diagnosis of infected necrosis. Procalcitonin (PCT), a 116 amino acid propeptide of calcitonin, a... |
9460061 | Changes in the ageing brain in health and disease. | The brains of individuals, who are cognitively normal, show age-related changes that include an overall reduction in brain volume and weight, which are associated with gyral atrophy and widening of the sulci of the cerebral cortex, and enlargement of the brain ventricles. These changes are partly the result of nerve ce... |
9455085 | [Epidural anesthesia reduces mortality rate in the patients after emergency abdominal surgery]. | Stress response and increased sympathetic stimulation constrict gastrointestinal blood vessels. In patients after abdominal surgery, anastomotic leakage and bacterial translocation may occur as a result of gastrointestinal hypoperfusion. These patients are at risk for severe SIRS and MOF, especially after emergency sur... |
9455921 | Elucidation of the mechanism enhancing the avidity of lectin with oligosaccharides on the solid phase surface. | The mechanism underlying molecular recognition of lectins was elucidated by a novel solid phase binding assay system based on surface plasmon resonance. When the apparent affinities of interactions between chitooligosaccharides and wheat germ agglutinin were compared between lectin-immobilized and oligosaccharide-immob... |
9453062 | Effects of topical alpha-substituted anandamides on intraocular pressure in normotensive rabbits. | <h4>Purpose</h4>Anandamides have been observed to lower intraocular pressure in the rabbit eye, preceded by a period of hypertension. Amidases are thought to catabolize these compounds into their component parts, including arachidonic acid. Direct application of arachidonic acid has been observed to cause a marked rise... |
9453362 | Axon sprouting in the spinal cord: growth promoting and growth inhibitory mechanisms. | After lesions in the central nervous system (CNS), the affected nerve fibers usually cannot regenerate and reconnect to their original target cells. One important reason for this failure to regenerate is the presence of neurite growth inhibitory molecules in the myelin sheath of central nerve fibers. Despite the absenc... |
9451957 | Two tandemly repeated telomere-associated sequences in Nicotiana plumbaginifolia. | Two tandemly repeated telomere-associated sequences, NP3R and NP4R, have been isolated from Nicotiana plumbaginifolia. The length of a repeating unit for NP3R and NP4R is 165 and 180 nucleotides respectively. The abundance of NP3R, NP4R and telomeric repeats is, respectively, 8.4 x 10(4), 6 x 10(3) and 1.5 x 10(6) copi... |
9451956 | Cytological characterization of four meiotic mutants of Arabidopsis isolated from T-DNA-transformed lines. | A secondary screen of the Feldmann collection of T-DNA transformed Arabidopsis lines identified several meiotic mutants. We used a spreading technique combined with DAPI staining in a detailed cytogenetic analysis of meiotic chromosome behaviour in four of these mutants, all of which are putatively T-DNA tagged and the... |
9451955 | FISH mapping of seven cDNA sequences in the pig. | Fluorescence in situ hybridization (FISH) technique was applied to localize seven clones derived from a porcine (SSC) intestinal directionally cloned cDNA library. The size of the clones ranged from 1.1 to 1.3 kb. Three of the clones corresponded to histidyl-tRNA synthetase (HARS), immunoglobulin alpha (IGA) and lysozy... |
9451954 | Six bovine cosmid-derived microsatellites mapping different syntenic groups are fluorescence in situ hybridization mapped to six river buffalo chromosomes. | Six bovine cosmid-derived microsatellites (IDVGA53, BTA3/U6; IDVGA61, U13; IDVGA41, BTA12/U27; IDVGA32, BTA15/U19; IDVGA59, BTA26/U26 and IDVGA71, U8), previously assigned to cattle chromosomes, were FISH-mapped to river buffalo chromosomes (BBU) 6q15, 8q34, 13q15, 16q25, 23q22 and 24q13 respectively. Sequential FISH/R... |
9451953 | Part of the RBM gene cluster is located distally to the DAZ gene cluster in human Yq11.23. | Normal human Y and inverted Y chromosomes were chosen for physical fluorescence in situ hybridization (FISH) mapping of RBM and DAZ probes for the relative positioning of the RBM and DAZ gene clusters in interval 6 of the human Y chromosome. The inversion breakpoint in Yq11.23 turned out to be distal to the DAZ gene cl... |
9451952 | Mapping chromosomal homology between humans and the black-handed spider monkey by fluorescence in situ hybridization. | We hybridized human chromosome-specific DNA probes to metaphases of the New World monkey Ateles geoffroyi to map the chromosomal homology between these two species. In the haploid Ateles geoffroyi karyotype the total number of signals was 51 for the 22 human autosomal probes used. Compared with Old World monkeys, the n... |
9451951 | Longitudinal differentiation of chromosomes of Asellus aquaticus (Crust. Isop.) by in situ nick translation using restriction enzymes and DNase I. | Asellus aquaticus is an isopod crustacean whose chromosomes cannot be differentiated by G- or R-banding techniques. In this work, we have obtained a longitudinal differentiation of these chromosomes by in situ nick translation using restriction enzymes (HaeIII, DraI and BamHI) and DNase I digestions. The four nucleases... |
9451950 | A radiation hybrid framework map of bovine chromosome 13. | In this paper we present a 5000-rad radiation hybrid framework map of bovine chromosome 13 (BTA13) containing 13 loci, including five conserved genes and eight polymorphic microsatellites. All framework markers are ordered with odds greater than 1000:1. Furthermore, we present a comprehensive map of BTA13 integrating 1... |
9441929 | Practical image restoration of thick biological specimens using multiple focus levels in transmission electron microscopy. | Three-dimensional electron tomographic studies of thick specimens such as cellular organelles or supramolecular structures require accurate interpretations of transmission electron micrograph intensities. In addition to microscope lens aberrations, thick specimen imaging is complicated by additional distortions resulti... |
9447719 | Synthesis and photophysical properties of a new cationic water-soluble Zn phthalocyanine. | The synthesis of tetrakis (1,1-dimethyl-2-trimethylammonium)ethylphthalocyaninato Zn(II) tetraiodide 2--a new cationic phthalocyanine--is reported as well as its photophysical properties in water, relevant for the use of this dye as photodynamic sensitizer. The hydrophobicity of the macrocycle leads to strong aggregati... |
9447246 | The influence of diet on the mucin carbohydrates in the chick intestinal tract. | The presence of nutrients in the intestinal lumen is a major factor influencing bacterial colonization in poultry. This study was conducted to investigate the effects of poultry feed on viscosity of intestinal contents and on mucin carbohydrates by comparing jejunal supernatants and the histochemical composition of gob... |
9447245 | Favourable interaction between heavy and light chains arrests the undesirable oligomerization of heavy chains in the refolding of denatured and reduced immunoglobulin G. | Recently we developed a slow dialysis method that effectively refolds denatured and reduced immunoglobulin G (IgG) [Maeda, Ueda and Imoto (1996) Prot. Engng 9: 95-100]. This method allows both individual and simultaneous refolding of denatured and reduced H and L chains. Analysis by SDS-polyacrylamide gel electrophores... |
9447239 | The molecular basis of amyloidosis. | Amyloidoses are diseases, including some currently prominent such as Alzheimer's disease, bovine spongiform encephalophaty (BSE) and Type II diabetes, in which soluble proteins are deposited in a specific, highly stable, fibrillar form. The amyloid fibrils are made up of protofilaments whose molecular structure is comp... |
9447237 | Non-native architectures in protein design and mimicry. | Protein design aims to mimic some of the structural and functional properties of native proteins. The complexity of the folding mechanism, i.e. the pathway by which a linear polypeptide chain finds its unique 3D-structure, represents one of the most intriguing hurdles in this rapidly growing field. In order to bypass t... |
9448090 | Capillary electrophoresis stereoselective determination of R-(+)- and S-(-)-pentobarbital from serum using hydroxypropyl-gamma-cyclodextrin, solid-phase extraction and ultraviolet detection. | Pentobarbital is a sedative hypnotic which is used in the treatment of people suffering from anxiety related conditions and to manage elevated intracranial pressures and cerebral ischemia due to neurosurgical procedures. This paper develops and validates a rapid and sensitive method for the determination of S-(-)- and ... |
9448087 | Resolution and quantitation of pentazocine enantiomers in human serum by reversed-phase high-performance liquid chromatography using sulfated beta-cyclodextrin as chiral mobile phase additive and solid-phase extraction. | A sensitive and stereospecific HPLC method was developed for the analysis of (-)- and (+)-pentazocine in human serum. The assay involves the use of a phenyl solid-phase extraction column for serum sample clean-up prior to HPLC analysis. Chromatographic resolution of the pentazocine enantiomers was performed on a octade... |
9435910 | Synthesis, structure, dopamine transporter affinity, and dopamine uptake inhibition of 6-alkyl-3-benzyl-2-[(methoxycarbonyl)methyl]tropane derivatives. | A series of 6-alkyl-3 beta-benzyl-2-[(methoxycarbonyl)methyl]tropane analogues were synthesized and evaluated as cocaine binding site ligands at the dopamine transporter (DAT). The in vitro affinity (Ki) for the DAT of the 6-alkyl-3 beta-benzyl-2-[(methoxycarbonyl) methyl]tropane analogues was determined by inhibition ... |
9435576 | Calcium-stimulated Cl- secretion in Calu-3 human airway cells requires CFTR. | Human airway serous cells secrete antibiotic-rich fluid, but, in cystic fibrosis (CF), Cl(-)-dependent fluid secretion is impaired by defects in CF transmembrane conductance regulator (CFTR) Cl- channels. Typically, CF disrupts adenosine 3',5'-cyclic monophosphate (cAMP)-mediated Cl- secretion but spares Ca(2+)-mediate... |
9435489 | Contribution of the NH2 terminus of Kv2.1 to channel activation. | Opening and closing of voltage-operated channels requires the interaction of diverse structural elements. One approach to the identification of channel domains that participate in gating is to locate the sites of action of modifiers. Covalent reaction of Kv2.1 channels with the neutral, sulfhydryl-specific methylmethan... |
9427655 | Beyond guanine quartets: cation-induced formation of homogenous and chimeric DNA tetraplexes incorporating iso-guanine and guanine. | <h4>Background</h4>iso-Guanine (iso-G) is the purine component of an isomeric Watson-Crick base pair that may have existed prebiotically. By comparing the abiotic molecular recognition properties of iso-G and its complement, iso-cytosine (iso-C), with those of genomic nucleotide bases, it may be possible to explain the... |
9428681 | Structure, catalysis and supramolecular assembly of adenylate kinase from maize. | The crystal structure of adenylate kinase from maize ligated with an inhibitor has been determined by molecular replacement and refined to 3.5-A resolution. The enzyme keeps the ATP/ADP/AMP equilibrium in the cell. In the C4 plant maize, it has the special task to recycle the AMP produced in large amounts in primary CO... |
9425307 | Loss of cytokeratin expression and formation of actin stress fibers in dedifferentiated MDCK-C7 cell lines. | MDCK-C7 cells dedifferentiated either by transient alkaline stress (C7F cells) or by transfection with a constitutively active mutant of the mitogen-activated protein kinase kinase MEK1 (C7caMEK1 cells) were analyzed by western blot and immunofluorescence microscopy to compare the expression of different cytokeratins, ... |
9425266 | The A3 adenosine receptor mediates cell spreading, reorganization of actin cytoskeleton, and distribution of Bcl-XL: studies in human astroglioma cells. | The pathophysiological role of the adenosine A3 receptor in the central nervous system is largely unknown. We have investigated the effects of the selective A3 receptor agonist 2-chloro-N6-(3-iodobenzyl)-adenosine, Cl-IB-MECA, in cells of the astroglial lineage (human astrocytoma ADF cells). A marked reorganization of ... |
9422818 | The interaction of general anaesthetics with recombinant GABAA and glycine receptors expressed in Xenopus laevis oocytes: a comparative study. | 1. The effects of five structurally dissimilar general anaesthetics were examined in voltage-clamp recordings of agonist-evoked currents mediated by recombinant gamma-aminobutyric acid (GABA)A receptors composed of human alpha 1 beta 1 and gamma 2L subunits expressed in Xenopus laevis oocytes. A quantitative comparison... |
9421897 | Cytochemical studies of cell viability and gene expression in Bacillus subtilis macrofibres. | The viability of cells and the expression of a reporter gene in Bacillus subtilis macrofibres have been examined using cytochemical approaches. Previous studies have shown that macrofibres grow at an exponential rate in fluid environments and undergo complex dynamic motions as they elongate but the behaviour of individ... |
9420044 | Concentrations in plasma and safety of 7 days of intravenous itraconazole followed by 2 weeks of oral itraconazole solution in patients in intensive care units. | Pharmacokinetics and safety of a hydroxy-beta-propyl solution of itraconazole were assessed in 16 patients in an intensive care unit. On the first 2 days, four 1-h infusions of 200 mg were given at 0, 8, 24, and 32 h. From day 3 to 7, inclusive, a single 1-h infusion of 200 mg of itraconazole was given daily. The intra... |
9416604 | Cross-strand side-chain interactions versus turn conformation in beta-hairpins. | A series of designed peptides has been analyzed by 1H-NMR spectroscopy in order to investigate the influence of cross-strand side-chain interactions in beta-hairpin formation. The peptides differ in the N-terminal residues of a previously designed linear decapeptide that folds in aqueous solution into two interconverti... |
9416598 | Knowledge-based model of a glucosyltransferase from the oral bacterial group of mutans streptococci. | Mutans streptococci glucosyltransferases catalyze glucosyl transfer from sucrose to a glucan chain. We previously identified an aspartyl residue that participates in stabilizing the glucosyl transition state. The sequence surrounding the aspartate was found to have substantial sequence similarity with members of alpha-... |
9414240 | Investigation of the image contrast of tapping-mode atomic force microscopy using protein-modified cantilever tips. | In this work we have designed a simple system to investigate empirically the image contrast of tapping-mode atomic force microscopy (TMAFM). We modified the cantilever tips with protein molecules (bovine serum albumin or goat anti-biotin antibody) and used these protein-modified cantilevers to scan poly-L-lysine films ... |
9414236 | Effects of molecular crowding on the interaction between DNA and the Escherichia coli regulatory protein TyrR. | Fluorescence quenching has been used to measure quantitatively the effects of sucrose and triethylene glycol on the interaction between the Escherichia coli regulatory protein TyrR and a 30-basepair oligonucleotide containing the strong TyrR box of the TyrR operon. It was observed that the apparent binding constant inc... |
9414231 | Statistical mechanics of simple models of protein folding and design. | It is now believed that the primary equilibrium aspects of simple models of protein folding are understood theoretically. However, current theories often resort to rather heavy mathematics to overcome some technical difficulties inherent in the problem or start from a phenomenological model. To this end, we take a new ... |
9414220 | Characterization of biomimetic surfaces formed from cell membranes. | A method for fabricating biomimetic surfaces from intact cell membranes is described. A monolayer of alkanethiol on gold is covered by a second layer derived from the components of erythrocyte membranes either by self-assembly or by Langmuir-Blodgett methods. The resulting asymmetric hybrid layer was characterized by e... |
9414201 | Ice-binding mechanism of winter flounder antifreeze proteins. | We have studied the winter flounder antifreeze protein (AFP) and two of its mutants using molecular dynamics simulation techniques. The simulations were performed under four conditions: in the gas phase, solvated by water, adsorbed on the ice (2021) crystal plane in the gas phase and in aqueous solution. This study pro... |
9413989 | Molecular basis for the binding promiscuity of an anti-p24 (HIV-1) monoclonal antibody. | Multiple binding capabilities utilized by specific protein-to-protein interactions in molecular recognition events are being documented increasingly but remain poorly understood at the molecular level. We identified five unrelated peptides that compete with each other for binding to the paratope region of the monoclona... |
9409151 | Cell biology and molecular basis of denitrification. | Denitrification is a distinct means of energy conservation, making use of N oxides as terminal electron acceptors for cellular bioenergetics under anaerobic, microaerophilic, and occasionally aerobic conditions. The process is an essential branch of the global N cycle, reversing dinitrogen fixation, and is associated w... |
9409150 | Metabolism of sulfur amino acids in Saccharomyces cerevisiae. | Sulfur amino acid biosynthesis in Saccharomyces cerevisiae involves a large number of enzymes required for the de novo biosynthesis of methionine and cysteine and the recycling of organic sulfur metabolites. This review summarizes the details of these processes and analyzes the molecular data which have been acquired i... |
9409148 | Rolling-circle replication of bacterial plasmids. | Many bacterial plasmids replicate by a rolling-circle (RC) mechanism. Their replication properties have many similarities to as well as significant differences from those of single-stranded DNA (ssDNA) coliphages, which also replicate by an RC mechanism. Studies on a large number of RC plasmids have revealed that they ... |
9409844 | The TRANSFORMER genes of the fern Ceratopteris simultaneously promote meristem and archegonia development and repress antheridia development in the developing gametophyte. | The sex of the haploid gametophyte of the fern Ceratopteris is determined by the presence or absence of the pheromone antheridiogen, which, when present, promotes male development and represses female development of the gametophyte. Several genes involved in sex determination in Ceratopteris have been identified by mut... |
9409833 | Drosophila male-specific lethal-2 protein: structure/function analysis and dependence on MSL-1 for chromosome association. | MSL-2 is required for the male-specific assembly of a dosage compensation regulatory complex on the X chromosome of Drosophila melanogaster. We found that MSL-2 binds in a reproducible, partial pattern to the male X chromosome in the absence of MLE or MSL-3, or when ectopically expressed at a low level in females. More... |
9409826 | Allele-specific suppression by formation of new protein-protein interactions in yeast. | Yeast fimbrin is encoded by the SAC6 gene, mutations of which suppress temperature-sensitive mutations in the actin gene (ACT1). To examine the mechanism of suppression, we have conducted a biochemical analysis of the interaction between various combinations of wild-type and mutant actin and Sac6 proteins. Previously, ... |
9405633 | Otogelin: a glycoprotein specific to the acellular membranes of the inner ear. | Efforts to identify the specific components of the mammalian inner ear have been hampered by the small number of neuroepithelial cells and the variety of supporting cells. To circumvent these difficulties, we used a PCR-based subtractive method on cDNA from 2-day-old mouse cochlea. A cDNA encoding a predicted 2910-amin... |
9405626 | Virus-sized self-assembling lamellar complexes between plasmid DNA and cationic micelles promote gene transfer. | Gene therapy is based on the vectorization of genes to target cells and their subsequent expression. Cationic amphiphile-mediated delivery of plasmid DNA is the nonviral gene transfer method most often used. We examined the supramolecular structure of lipopolyamine/plasmid DNA complexes under various condensing conditi... |
9405598 | Design of potent and selective human cathepsin K inhibitors that span the active site. | Potent and selective active-site-spanning inhibitors have been designed for cathepsin K, a cysteine protease unique to osteoclasts. They act by mechanisms that involve tight binding intermediates, potentially on a hydrolytic pathway. X-ray crystallographic, MS, NMR spectroscopic, and kinetic studies of the mechanisms o... |
9405597 | Peroxynitrite rapidly permeates phospholipid membranes. | Peroxynitrite (ONOO-) is a potent oxidant implicated in a number of pathophysiological processes. The activity of ONOO- is related to its accessibility to biological targets before its spontaneous decomposition (t1/2 approximately 1 s at pH 7.4, 37 degrees C). Using model phospholipid vesicular systems and manganese po... |
9405596 | Solid and liquid phase 59Co NMR studies of cobalamins and their derivatives. | We describe the application of 59Co NMR to the study of naturally occurring cobalamins. Targets of these investigations included vitamin B12, the B12 coenzyme, methylcobalamin, and dicyanocobyrinic acid heptamethylester. These measurements were carried out on solutions and powders of different origins, and repeated at ... |
9405381 | Solution structure of the Mu end DNA-binding ibeta subdomain of phage Mu transposase: modular DNA recognition by two tethered domains. | The phage Mu transposase (MuA) binds to the ends of the Mu genome during the assembly of higher order nucleoprotein complexes. We investigate the structure and function of the MuA end-binding domain (Ibetagamma). The three-dimensional solution structure of the Ibeta subdomain (residues 77-174) has been determined using... |
9406528 | A persubstituted cationic beta-cyclodextrin for chiral separations. | The applications of a novel polycationic derivative of beta-cyclodextrin (beta-CD), heptakis(6-hydroxyethylamino-6-deoxy-beta-cyclodextrin) (beta-CD-EA), as a chiral host--guest additive for the enantioseparation of various classes of chiral anionic analytes are presented. The cationic beta-CD described in this paper i... |
9406417 | Recombinant thermostable cycloinulo-oligosaccharide fructanotransferase produced by Saccharomyces cerevisiae. | A truncated fragment of the cycloinulo-oligosaccharide fructanotransferase (CFTase) gene of Bacillus circulans MCI-2554 was fused to the prepro secretion sequence of the alpha-factor and expressed in Saccharomyces cerevisiae under the control of the 5' upstream region of the isocitrate lyase gene of Candida tropicalis ... |
9406406 | Construction of a Helicobacter pylori-Escherichia coli shuttle vector for gene transfer in Helicobacter pylori. | In this study, a Helicobacter pylori-Escherichia coli shuttle vector was constructed for transferring DNA into H. pylori. The smallest cryptic plasmid (1.2 kb), pHP489, among those harbored by 77 H. pylori isolates was selected as a base replicon for constructing vectors. HindIII-digested pHP489 was ligated with a kana... |
9406015 | Targeting dendrimer-chelates to tumors and tumor cells expressing the high-affinity folate receptor. | <h4>Rationale and objectives</h4>The authors developed a new method for delivering contrast agents to tumors and tumor cells. Gadolinium complexes of folate-conjugated dendrimer-chelates increased the longitudinal relaxation rate of tumor cells expressing the high-affinity folate receptor, hFR. The coupling of folate t... |
9398189 | Resonance Raman characterization of reaction centers in which bacteriochlorophyll replaces the photoactive bacteriopheophytin. | Qy-excitation resonance Raman (RR) spectra are reported for two mutant reactions centers (RCs) from Rhodobacter sphaeroides in which the photoactive bacteriopheophytin (BPhL) is replaced by a bacteriochlorophyll (BChl) molecule, designated by beta L. One mutation, (M)L214H, yields the pigment change via introduction of... |
9402575 | Familial intracranial aneurysms: an autopsy study. | <h4>Objective</h4>Familial intracranial aneurysms are more common than has been appreciated, but systematic autopsy studies of affected individuals have not been reported. We reviewed the autopsy findings of a group of patients with familial aneurysms to elucidate the nature of the putative underlying arteriopathy.<h4>... |
9403722 | Lymphocyte recruitment and the kinetics of adhesion receptor expression during the pulmonary immune response to particulate antigen. | The selectins and beta2 integrins participate in the recruitment of neutrophils in acute pulmonary inflammation. However, the cell adhesion receptors that mediate lymphocyte trafficking into the lung have not been defined. This study examined the relationship between cell adhesion molecules on the pulmonary vasculature... |
9399943 | The calcimimetic compound NPS R-568 suppresses parathyroid cell proliferation in rats with renal insufficiency. Control of parathyroid cell growth via a calcium receptor. | Parathyroid (PT) cell hyperplasia is a common consequence of chronic renal insufficiency (CRI). NPS R-568 is a phenylalkylamine compound that acts as an agonist (calcimimetic) at the cell surface calcium receptor (CaR). To test the hypothesis that the CaR plays a role in PT hyperplasia in CRI, we tested the effect of N... |
9398675 | Ubiquitously expressed dynamin-II has a higher intrinsic GTPase activity and a greater propensity for self-assembly than neuronal dynamin-I. | To begin to understand mechanistic differences in endocytosis in neurons and nonneuronal cells, we have compared the biochemical properties of the ubiquitously expressed dynamin-II isoform with those of neuron-specific dynamin-I. Like dynamin-I, dynamin-II is specifically localized to and highly concentrated in coated ... |
9398662 | RanGTP targets p97 to RanBP2, a filamentous protein localized at the cytoplasmic periphery of the nuclear pore complex. | RanBP2, a protein containing FG repeat motifs and four binding sites for the guanosine triphosphatase Ran, is localized at the cytoplasmic periphery of the nuclear pore complex (NPC) and is believed to play a critical role in nuclear protein import. We purified RanBP2 from rat liver nuclear envelopes and examined its s... |
9398318 | Identification of acetylcholine receptor channel-lining residues in the M1 segment of the beta-subunit. | The substituted cysteine accessibility method (SCAM) was applied to the first membrane-spanning segment (M1) of the mouse-muscle acetylcholine (ACh) receptor beta subunit. One at a time, each residue from betaR219 to betaP247, except betaC233, was mutated to Cys, and the mutant beta subunits were expressed together wit... |
9396828 | Antibody-ribosome-mRNA (ARM) complexes as efficient selection particles for in vitro display and evolution of antibody combining sites. | We describe a rapid, eukaryotic, in vitro method for selection and evolution of antibody combining sites using antibody-ribosome-mRNA (ARM) complexes as selection particles. ARMs carrying single-chain (VH/K) binding fragments specific for progesterone were selected using antigen-coupled magnetic beads; selection simult... |
9396819 | Minor groove DNA alkylation directed by major groove triplex forming oligodeoxyribonucleotides. | We describe sequence-specific alkylation in the minor groove of double-stranded DNA by a hybridization-triggered reactive group conjugated to a triplex forming oligodeoxyribonucleotide (TFO) that binds in the major groove. The 24 nt TFOs (G/A motif) were designed to form triplexes with a homopurine tract within a 65 bp... |
9396789 | Template directed incorporation of nucleotide mixtures using azole-nucleobase analogs. | DNA that encodes elements for degenerate replication events by use of artificial nucleobases offers a versatile approach to manipulating sequences for applications in biotechnology. We have designed a family of artificial nucleobases that are capable of assuming multiple hydrogen bonding orientations through internal b... |
9396751 | Activation of a retroviral membrane fusion protein: soluble receptor-induced liposome binding of the ALSV envelope glycoprotein. | It is not known how membrane fusion proteins that function at neutral pH, for example the human immunodeficiency virus envelope (Env) glycoprotein and intracellular fusion machines, are activated for target bilayer binding. We have addressed this question using a soluble oligomeric form of an avian retroviral Env glyco... |
9396729 | Dependence of the anti-chaperone activity of protein disulphide isomerase on its chaperone activity. | Protein disulphide isomerase (PDI) shows chaperone and anti-chaperone activities in assisting refolding of denatured and reduced lysozyme in redox Hepes buffer, but only chaperone activity in phosphate buffer and redox Hepes buffer containing 0.1 M NaCl. In non-redox Hepes buffer its anti-chaperone activity is very wea... |
9395489 | Self-assembly of laminin isoforms. | The alpha, beta, and gamma subunits of basement membrane laminins can combine into different heterotrimeric molecules with either three full short arms (e.g. laminins-1-4), or molecules containing one (laminins-6-9) or more (laminin-5) short arm truncations. Laminin-1 (alpha1beta1gamma1), self-assembles through a calci... |
9395477 | Positional preferences of ionizable residues in Gly-X-Y triplets of the collagen triple-helix. | Collagens contain a high amount of charged residues involved in triple-helix stability, fibril formation, and ligand binding. The contribution of charged residues to stability was analyzed utilizing a host-guest peptide system with a single Gly-X-Y triplet embedded within Ac(Gly-Pro-Hyp)3-Gly-X-Y-(Gly-Pro-Hyp)4-Gly-Gly... |
9395473 | Site-directed disulfide mapping of helices M4 and M6 in the Ca2+ binding domain of SERCA1a, the Ca2+ ATPase of fast twitch skeletal muscle sarcoplasmic reticulum. | In an attempt to define the spatial relationships among SERCA1a transmembrane helices M4, M5, M6, and M8, involved in Ca2+ binding, all six cysteine residues were removed from predicted transmembrane sequences by substitution with Ser or Ala. The cysteine-depleted protein retained 44% of wild type Ca2+ transport activi... |
9394471 | Four-stranded DNA formed by isoguanine quartets: complex stoichiometry, thermal stability and resistance against exonucleases. | Single stranded DNA-fragments containing short runs of isoguanine such as d(T4iG4T4) (5) or d(iG4T4) (6) form quartet structures by self-assembly of the isoguanine residues. The stoichiometry of the complexes is deduced from mixed aggregates formed between d(T4iG4T4) and d(iG4T4). The iGd-tetrads are more stable with r... |
9391132 | Mutations in dihydropteroate synthase are responsible for sulfone and sulfonamide resistance in Plasmodium falciparum. | Plasmodium falciparum causes the most severe form of malaria in humans. An important class of drugs in malaria treatment is the sulfone/sulfonamide group, of which sulfadoxine is the most commonly used. The target of sulfadoxine is the enzyme dihydropteroate synthase (DHPS), and sequencing of the DHPS gene has identifi... |
9391131 | Chaperone-supervised conversion of prion protein to its protease-resistant form. | Transmissible spongiform encephalopathies (TSEs) are lethal, infectious disorders of the mammalian nervous system. A TSE hallmark is the conversion of the cellular protein PrPC to disease-associated PrPSc (named for scrapie, the first known TSE). PrPC is protease-sensitive, monomeric, detergent soluble, and primarily a... |
9391086 | Syntenin, a PDZ protein that binds syndecan cytoplasmic domains. | The syndecans are transmembrane proteoglycans that place structurally heterogeneous heparan sulfate chains at the cell surface and a highly conserved polypeptide in the cytoplasm. Their versatile heparan sulfate moieties support various processes of molecular recognition, signaling, and trafficking. Here we report the ... |
9391066 | A terbenzimidazole that preferentially binds and conformationally alters structurally distinct DNA duplex domains: a potential mechanism for topoisomerase I poisoning. | The terbenzimidazoles are a class of synthetic ligands that poison the human topoisomerase I (TOP1) enzyme and promote cancer cell death. It has been proposed that drugs of this class act as TOP1 poisons by binding to the minor groove of the DNA substrate of TOP1 and altering its structure in a manner that results in e... |
9391018 | Development of membrane properties in taste cells of fungiform papillae: functional evidence for early presence of amiloride-sensitive sodium channels. | Behavioral and physiological studies have demonstrated a reduced sensitivity to several taste stimuli early in development. It has been suggested that this reduced sensitivity results from a late maturation of underlying transduction mechanisms. Little is known, however, about maturation of membrane properties of taste... |
9393845 | Quantification of conserved antigens in Helicobacter pylori during different culture conditions. | In this study, we raised monoclonal antibodies (MAbs) against three conserved Helicobacter pylori antigens, i.e., the N-acetylneuraminyllactose-binding fibrillar hemagglutinin, HpaA; the flagellin subunits, FlaA and FlaB; and a species-specific 26-kDa protein. The MAbs were used for the development of sensitive inhibit... |
9393833 | A nonamer peptide derived from Listeria monocytogenes metalloprotease is presented to cytolytic T lymphocytes. | Listeria monocytogenes is an intracellular bacterium that secretes proteins into the cytosol of infected macrophages. Major histocompatibility complex (MHC) class I molecules bind peptides that are generated by the degradation of bacterial proteins and present them to cytolytic T lymphocytes (CTL). In this study we hav... |
9393832 | Expression of thin aggregative fimbriae promotes interaction of Salmonella typhimurium SR-11 with mouse small intestinal epithelial cells. | The factors that mediate binding of Salmonella typhimurium to small intestinal epithelial cells have not been fully characterized. In this paper we demonstrate that elimination of production of thin aggregative fiber by a transposon insertion within the gene encoding the subunit protein of the fiber reduced binding of ... |
9393820 | Identification of a Fusobacterium nucleatum PK1594 galactose-binding adhesin which mediates coaggregation with periopathogenic bacteria and hemagglutination. | Attachment of Fusobacterium nucleatum to various oral surfaces is mediated by several adhesins anchored on its outer surface. Monoclonal antibodies (MAbs) were prepared and used to identify the putative galactose-binding adhesin of F. nucleatum PK1594. Four unique MAbs, 8G7, 26B9, 28G11, and 29D4, were isolated on the ... |
9393706 | Fis, an accessorial factor for transcriptional activation of the mar (multiple antibiotic resistance) promoter of Escherichia coli in the presence of the activator MarA, SoxS, or Rob. | Transcription of the multiple antibiotic resistance marRAB operon increases when one of the sequence-related activators, MarA, SoxS, or Rob, binds to the "marbox" centered at -61.5 relative to the transcriptional start site. Previous deletion analyses showed that an adjacent upstream "accessory region" was needed to au... |
9393700 | A study of iterative type II polyketide synthases, using bacterial genes cloned from soil DNA: a means to access and use genes from uncultured microorganisms. | To examine as randomly as possible the role of the beta-ketoacyl and acyl carrier protein (ACP) components of bacterial type II polyketide synthases (PKSs), homologs of the chain-length-factor (CLF) genes were cloned from the environmental community of microorganisms. With PCR primers derived from conserved regions of ... |
9388197 | Modification of histidine 5 in sarcoplasmic reticulum Ca2+-ATPase by diethyl pyrocarbonate causes strong inhibition of formation of the phosphoenzyme intermediate from inorganic phosphate. | Sarcoplasmic reticulum vesicles were modified with diethyl pyrocarbonate (DEPC), a histidine-modifying reagent. Phosphoenzyme formation from Pi in the Ca2+-ATPase (reversal of hydrolysis of the phosphoenzyme intermediate) was almost completely inhibited by this modification. Tight binding of F- and Mg2+ and high affini... |
9384588 | Using altered specificity Oct-1 and Oct-2 mutants to analyze the regulation of immunoglobulin gene transcription. | Oct-1 and Oct-2 represent the prototypical example of related transcription factors with identical DNA recognition properties. They bind functionally critical octamer elements found in diverse regulatory sequences. It has not been possible to determine directly if these factors are functionally redundant or selective w... |
9383710 | Actin isoform utilization during differentiation and remodeling of BC3H1 myogenic cells. | Mouse BC3H1 myogenic cells and a bi-functional chemical cross linking reagent were utilized to investigate the polymerization of newly-synthesized vascular smooth muscle (alpha-actin) and non-muscle (beta- and gamma-actin) actin monomers into native F-actin filament structures during myogenesis. Two actin dimer species... |
9371731 | Molecular cloning, characterization and localization of PfPK4, an eIF-2alpha kinase-related enzyme from the malarial parasite Plasmodium falciparum. | PfPK4, a protein kinase gene from the human malarial parasite Plasmodium falciparum, has been cloned utilizing oligonucleotide probing. The gene encodes a protein of a predicted length of 1123 amino acids, and within this amino acid sequence all the conserved regions characteristic of protein kinases can be identified.... |
9371726 | Formation and properties of dimeric recombinant horseradish peroxidase in a system of reversed micelles. | Wild-type recombinant horseradish peroxidase purified and refolded from Escherichia coli inclusion bodies has been studied in the system of bis(2-ethylhexyl)sulphosuccinate sodium salt (Aerosol OT)-reversed micelles in octane. In contrast with native horseradish peroxidase the wild-type recombinant enzyme forms dimeric... |
9371718 | A novel type of thermostable alpha-D-glucosidase from Thermoanaerobacter thermohydrosulfuricus exhibiting maltodextrinohydrolase activity. | An alpha-glucosidase with the ability to attack polymeric substrates was purified to homogeneity from culture supernatants of Thermoanaerobacter thermohydrosulfuricus DSM 567. The enzyme is apparently a glycoprotein with a molecular mass of 160 kDa. Maximal activity is observed between pH5 and 7 at 75 degrees C. The al... |
9371612 | The murine coronavirus mouse hepatitis virus strain A59 from persistently infected murine cells exhibits an extended host range. | In murine 17 Cl 1 cells persistently infected with murine coronavirus mouse hepatitis virus strain A59 (MHV-A59), expression of the virus receptor glycoprotein MHVR was markedly reduced (S. G. Sawicki, J. H. Lu, and K. V. Holmes, J. Virol. 69:5535-5543, 1995). Virus isolated from passage 600 of the persistently infecte... |
9371611 | Genetic dissection of interaction between poliovirus 3D polymerase and viral protein 3AB. | Poliovirus RNA-dependent RNA polymerase 3D and viral protein 3AB are both thought to be required for the initiation of RNA synthesis. These two proteins physically associate with each other and with viral RNA replication complexes found on virus-induced membranes in infected cells. An understanding of the interface bet... |
9371602 | Direct interaction of hepatitis C virus core protein with the cellular lymphotoxin-beta receptor modulates the signal pathway of the lymphotoxin-beta receptor. | Previous studies suggest that the core protein of hepatitis C virus (HCV) has a pleiotropic function in the replication cycle of the virus. To understand the role of this protein in HCV pathogenesis, we used a yeast two-hybrid protein interaction cloning system to search for cellular proteins physically interacting wit... |
9371596 | Differential regulation of the pre-C and pregenomic promoters of human hepatitis B virus by members of the nuclear receptor superfamily. | Synthesis of the pre-C and pregenomic RNAs of human hepatitis B virus (HBV) is directed by two overlapping yet separate promoters (X. Yu and J. E. Mertz, J. Virol. 70:8719-8726, 1996). Previously, we reported the identification of a binding site for the nuclear receptor hepatocyte nuclear factor 4 (HNF4) spanning the T... |
9359872 | Genetic analysis of beta1 integrin function: confirmed, new and revised roles for a crucial family of cell adhesion molecules. | Integrins are heterodimeric cell adhesion proteins connecting the extracellular matrix to the cytoskeleton and transmitting signals in both directions. These integrins are suggested to be involved in many different biological processes such as growth, differentiation, migration, and cell death. Of more than 20 known in... |
9667891 | Synthetic methods of glycopeptide assembly, and biological analysis of glycopeptide products. | The technology of glycopeptide synthesis has recently developed into a fully mature science capable of creating diverse glycopeptides of biological interest, even in combinatorial displays. This has allowed biochemists to investigate substrate specificity in the biosynthetic processing and immunology of various protein... |
9667884 | Photoprocesses. | The development of supramolecular chemistry has allowed the construction of structurally organized and functionally integrated chemical systems capable of elaborating the energy and information input of photons to perform complex functions. Model systems capable of mimicking the two fundamental steps of photosynthesis,... |
9667885 | Bilayer membranes and transporter models. | Significant advances in the understanding of the mechanisms of artificial transporters appeared in the past year which provide insights into natural transporters and suggest directions for regulation of transport. Parallel developments in the control of bilayer formation and molecular recognition by synthetic lipids ha... |
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