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1711227 | Crystal structure of [Leu1]zervamicin, a membrane ion-channel peptide: implications for gating mechanisms. | Structures in four different crystal forms of [Leu1]zervamicin (zervamicin Z-L, Ac-Leu-Ile-Gln-Iva-Ile5-Thr-Aib-Leu-Aib-Hyp10-Gln-Aib-Hyp-Aib-P ro15-Phol, where Iva is isovaline, Aib is alpha-amino isobutyric acid, Hyp is 4-hydroxyproline, and Phol is phenylalaninol), a membrane channel-forming polypeptide from Emerice... |
2052576 | In vivo channeling of substrates in an enzyme aggregate for beta-carotene biosynthesis. | The existence and the mode of operation of certain enzyme aggregates may be established from the concentrations of intermediates measured in the presence of specific inhibitors. beta-Carotene, the most abundant carotenoid pigment in the fungus Phycomyces blakesleeanus, arises from ring formation at both ends of lycopen... |
1711206 | Self-assembled B19 parvovirus capsids, produced in a baculovirus system, are antigenically and immunogenically similar to native virions. | B19 parvovirus is pathogenic in humans, causing fifth disease, transient aplastic crisis, some cases of hydrops fetalis, and acquired pure red cell aplasia. Efforts to develop serologic assays and vaccine development have been hampered by the virus's extreme tropism for human bone marrow and the absence of a convenient... |
2048855 | Survival after massive transfusions exceeding four blood volumes in patients with blunt injuries. | The authors' experience with 29 patients with blunt injuries who sustained massive transfusions exceeding four blood volumes in the initial posttraumatic 12 hours was reviewed. The overall mortality was 62 per cent. Only one patient survived when the amount of transfusions exceeded 50 units. The most common bleeding si... |
2046766 | Large differences in the helix propensities of alanine and glycine. | The standard view of alpha helix formation in water, based on helix propensities determined by the host-guest method, is that differences in helix propensity among the amino acids are small, except for proline, and that the average value of the helix propagation parameter s is near 1. A contradictory view of alpha heli... |
2046022 | Tin(Sn+4)-diiododeuteroporphyrin; an in vitro and in vivo inhibitor of heme oxygenase with substantially reduced photoactive properties. | Iodination of Sn-deuteroporphyrin (Ki = 0.185 microM) at positions C2 and C4 of the porphyrin ring results in an enhanced ability of the resulting derivative, Sn-diiododeuteroporphyrin, to inhibit (Ki = 0.069 microM) heme oxygenase activity in vitro. The potency of Sn-diiododeuteroporphyrin inhibition of bilirubin prod... |
1904442 | Protein U, a late-developmental spore coat protein of Myxococcus xanthus, is a secretory protein. | Protein U is a spore coat protein produced at the late stage of development of Myxococcus xanthus. This protein was isolated from developmental cells, and its amino-terminal sequence was determined. On the basis of this sequence, the gene for protein U (pru) was cloned and its DNA sequence was determined, revealing an ... |
1904437 | The metR binding site in the Salmonella typhimurium metH gene: DNA sequence constraints on activation. | Transcription of the metH gene in Salmonella typhimurium and Escherichia coli is positively regulated by the metR gene product, a DNA binding protein. The interaction between the MetR activator protein and the S. typhimurium metH control region was investigated. In vitro gel mobility shift assays and DNase I protection... |
1904432 | Behavior of peripheral rods and their role in the life cycle of Myxococcus xanthus. | Myxococcus xanthus is a gram-negative bacterium with a complex life cycle including a developmental phase in which cells aggregate and sporulate in response to starvation. In previous papers, we have described a heretofore unsuspected layer of complexity in the development of M. xanthus: vegetatively growing cells diff... |
1904431 | Analysis of Myxococcus xanthus cell types by two-dimensional polyacrylamide gel electrophoresis. | Myxococcus xanthus is a gram-negative, soil-dwelling bacterium that undergoes development in response to depletion of nutrients. Whereas most cells aggregate into multicellular mounds in which they differentiate into spores, 10 to 20% of the developing cells remain outside fruiting bodies as peripheral rods. We used tw... |
1904430 | Development in Myxococcus xanthus involves differentiation into two cell types, peripheral rods and spores. | Myxococcus xanthus, a gram-negative bacterium, has a complex life cycle. In response to starvation, most cells in a population participate in the formation of multicellular aggregates (i.e., fruiting bodies) in which cells differentiate into spores. However, some cells do not enter aggregates. In this and the two accom... |
2043644 | Thermodynamics and mechanism of alpha helix initiation in alanine and valine peptides. | We used molecular dynamics simulations to study the folding/unfolding of one of turn of an alpha helix in Ac-(Ala)3-NHMe and Ac-(Val)3-NHMe. Using specialized sampling techniques, we computed free energy surfaces as functions of a conformational coordinate that corresponds to alpha helices at small values and to extend... |
1710235 | Fibrinogen acts as a bridging molecule in the adherence of Staphylococcus aureus to cultured human endothelial cells. | The propensity of Staphylococcus aureus to cause acute endovascular infections during transient bacteremia is poorly understood. To examine the events leading to the attachment of staphylococci to endothelium, adherence assays were developed to study the role of blood factors in the mediation of staphylococcal adherenc... |
1903836 | In vivo stimulation of a chimeric promoter by binding sites for nuclear factor I. | Nuclear factor I (NFI) is composed of a family of site-specific DNA-binding proteins which recognize a DNA-binding site with the consensus sequence TGGC/A(N)5GCCAA. Binding sites for NFI have previously been shown to stimulate mRNA synthesis in vitro when present upstream of the TATA box of the adenovirus major late pr... |
2037362 | Correlation between molecular size of the surface array protein and morphology and antigenicity of the Campylobacter fetus S layer. | The correlation between the molecular size of the surface layer protein (S protein) and both structure and antigenicity of the Campylobacter fetus surface layer (S layer) was investigated in several clinical strains and their spontaneous variants which produce S proteins of molecular weights (MW) different from those o... |
2037357 | Local skin response in mice induced by a single intradermal injection of bacterial lipopolysaccharide and lipid A. | Dermal inflammation and hemorrhagic necrosis induced by bacterial lipopolysaccharide (LPS) and lipid A were studied in mice. In ddY mice, a single intradermal injection of Salmonella typhimurium S-form LPS and lipid A into the abdominal dermis elicited an edematous change due to an increase in local vascular permeabili... |
2035536 | A single base mutation in type I procollagen (COL1A1) that converts glycine alpha 1-541 to aspartate in a lethal variant of osteogenesis imperfecta: detection of the mutation with a carbodiimide reaction of DNA heteroduplexes and direct sequencing of products of the PCR. | Skin fibroblasts from a proband with a lethal variant of osteogenesis imperfecta synthesized both apparently normal type I procollagen and a type I procollagen that had slow electrophoretic mobility because of posttranslational overmodifications. The thermal unfolding of the collagen molecules as assayed by protease di... |
1851878 | Herpes simplex virus origin-binding protein (UL9) loops and distorts the viral replication origin. | To investigate the role of the herpes simplex virus origin-binding protein (UL9) in the initiation of DNA replication, we have examined the effect of UL9 binding on the structure of the viral origin of replication. UL9 loops and alters the DNA helix of the origin regardless of the phasing of the binding sites. DNase I ... |
1851877 | Human parainfluenza virus type 3 transcription in vitro: role of cellular actin in mRNA synthesis. | Purified ribonucleoprotein complexes of human parainfluenza virus type 3 (HPIV-3) virions required, in addition to the viral proteins, soluble cytoplasmic proteins from uninfected cells for the synthesis of mRNAs in vitro. In contrast to Sendai virus transcription, in vitro RNA synthesis from HPIV-3 ribonucleoprotein c... |
2033658 | Chicken ovalbumin upstream promoter transcription factor binds to a negative regulatory region in the human immunodeficiency virus type 1 long terminal repeat. | The human immunodeficiency virus type 1 (HIV-1) long terminal repeat (LTR) contains a negative regulatory element (NRE) which downregulates the rate of LTR-directed transcription and HIV-1 replication. Within the NRE is a GGTCA palindrome, which binds a possible member of the steroid/thyroid hormone receptor superfamil... |
1827828 | The binding affinity of human IgG for its high affinity Fc receptor is determined by multiple amino acids in the CH2 domain and is modulated by the hinge region. | A family of chimeric immunoglobulins (Igs) bearing the murine variable region directed against the hapten dansyl linked to human IgG1, -2, -3, and -4 has been characterized with respect to binding to the human high affinity Fc gamma receptor, Fc gamma RI. Chimeric IgG1 and -3 have the highest affinity association (Ka =... |
2032232 | New platinum, titanium, and ruthenium complexes with different patterns of DNA damage in rat ovarian tumor cells. | DNA protein cross-links (DPC), DNA interstrand cross-links (ISCL), and DNA single strand breaks following treatment of experimental ovarian tumor cells (O-342) with five new metal complexes (three platinum, one titanium, one ruthenium compounds) were investigated at 6, 24, and 48 h after drug exposure and compared with... |
1851089 | Identification of two functional regions in Fis: the N-terminus is required to promote Hin-mediated DNA inversion but not lambda excision. | The Fis protein of E. coli binds to a recombinational enhancer sequence that is required to stimulate Hin-mediated DNA inversion. Fis is also required for efficient lambda prophase excision in vivo. The properties of mutant Fis proteins were examined in vivo and in vitro with respect to their stimulatory effects on the... |
1902784 | The bx region enhancer, a distant cis-control element of the Drosophila Ubx gene and its regulation by hunchback and other segmentation genes. | The Drosophila homeotic gene Ultrabithorax (Ubx) is regulated by complex mechanisms that specify the spatial domain, the timing and the activity of the gene in individual tissues and in individual cells. In early embryonic development, Ubx expression is controlled by segmentation genes turned on earlier in the developm... |
11607191 | Clusters of clusters: self-organization and self-similarity in the intermediate stages of cluster growth of Au-Ag supraclusters. | A systematic structural investigation of a new series of high-nuclearity Au-Ag clusters containing 25, 37, 38, and 46 metal atoms led to the description of these clusters as "clusters of clusters" based on vertex-sharing icosahedra as building blocks. Based on the observed structures, a growth sequence is proposed here... |
1804281 | A comparative study of the supramolecular structure of frog sartorius and dorsal semitendinosus muscle. | This report describes a comparative X-ray diffraction study of the supramolecular structure of frog sartorius and semitendinosus muscles. For sarcomere lengths of 2.7 microns and below the X-ray diffraction diagrams of each muscle type are very similar; the only differences being that the diffraction diagram for semite... |
1723964 | Biological microemulsions: Part III--The formation characteristics and transport properties of saffola-aerosol OT-hexylamine-water system. | The results of formation, phase behaviour and physical properties of biological microemulsions prepared from saffola/AOT/hexylamine/water in presence of different additives, viz. cholesterol, crown ether, urea and brine, are presented. It has been found that the additives and temperature have striking effects; mono-, b... |
1834826 | Effect of hydrotropic substances on the complexation of sparingly soluble drugs with cyclodextrin derivatives and the influence of cyclodextrin complexation on the pharmacokinetics of the drugs. | The influence of hydrotropic compounds on complex formation by 2-hydroxypropyl-beta-cyclodextrin (2-HP-beta-CD) was investigated with methyltestosterone (MeT). Various representatives of the lyotropic series were used for this purpose. Additive hydrotropic effects were observed for nicotinamide and urea, which disrupt ... |
1834229 | [Hexosaminidase A-hexosaminidase B complex from human kidneys]. | Isolation and purification on human kidney hexosaminidases A and B (EC 3.2.1.30) were carried out. The regulation of the supramolecular organization and catalytic activity of the hexosaminidases in the AOT reversed micellar system modelling the enzyme microenvironment in the lysosomes, were investigated. It was found t... |
1931784 | Etiology and pathogenesis of marked elevation of serum transaminase in patients with acute gallstone disease. | From 1980 through 1988, biliary surgery was performed in 197 patients with acute gallstone disease and concomitant elevation of serum glutamic oxalacetic transaminase (SGOT) or serum glutamic pyruvic transaminase (SGPT) of over 300 Karmen units. In 137 patients, anatomic inspection and liver biopsy were performed durin... |
1656851 | Binding affinities of structurally related human rhinovirus capsid-binding compounds are related to their activities against human rhinovirus type 14. | The binding affinities (Kds) and the rates of association and dissociation of members of a chemical class of antiviral compounds at their active sites in human rhinovirus type 14 (HRV-14) were determined. On the basis of analysis by LIGAND, a nonlinear curve-fitting program, of saturation binding experiments with HRV-1... |
1681057 | Enhancement of 4-biphenylacetic acid bioavailability in rats by its beta-cyclodextrin complex after oral administration. | 4-Biphenylacetic acid, a potent non-steroidal anti-inflammatory agent forms a solid inclusion complex with beta-cyclodextrin in a 1:1 molar ratio, which exhibits better solubility and dissolution characteristics than the uncomplexed drug. Following oral administration of the complex to rats, quicker and higher drug pla... |
1916219 | Effects of some potassium channel blockers on the ionic currents in myelinated nerve. | The effects of some potassium channel blockers on the ionic currents and on the so-called K(+)-depolarization in intact myelinated nerve fibres were studied. 4-AP, and in particular, Flaxedil, proved to be selective K(+)-current blockers. However, TEA, a crown ether (DCH18C6), a longchained triethylammonium compound (C... |
1832870 | Dipotassium and sodium/potassium crystalline picrate complexes with the crown ether 6,7,9,10,12,13,20,21,23,24,26,27-dodecahydrodibenzo[b,n]-[1,4, 7,10,13,16,19,22]octaoxacyclotetracosin (dibenzo-24-crown-8). | The crystal structures of the dipotassium and the mixed sodium/potassium picrate complexes with the crown ether dibenzo-24-crown-8 (DB24C8) were solved and found to be nearly identical. (I): NaK-pic2(DB24C8), [NaK(C6H2N3O7)2(C24H32O8)]. Mr = 966.8, triclinic, P1, a = 8.164 (2), b = 9.960 (2), c = 13.368 (3) A, alpha = ... |
1893770 | Characterization of the major cyanogen bromide fragment of alpha-A crystallin. | Alpha crystallin from the bovine lens has been digested with cyanogen bromide, and the major fragment (CB-1) has been purified using reverse phase HPLC. Characterization of this fragment by Edman degradation and antisera to synthetic peptides indicates that it originates from alpha-A crystallin, but lacks the N-termina... |
1891457 | Molecular recognition at the active site of subtilisin BPN': crystallographic studies using genetically engineered proteinaceous inhibitor SSI (Streptomyces subtilisin inhibitor). | Unlike trypsin-like serine proteases having only one conspicuous binding pocket in the active site, subtilisin BPN' has two such pockets, the S1 and S4 pockets, which accommodate the P1 and P4 residues of ligands (after Schechter and Berger notation) respectively. Using computer graphics, the geometrical nature of the ... |
1678537 | Design and synthesis of new enzymes based on the lactate dehydrogenase framework. | Analysis of the mechanism and structure of lactate dehydrogenases is summarized in a map of the catalytic pathway. Chemical probes, single tryptophan residues inserted at specific sites and a crystal structure reveal slow movements of the protein framework that discriminate between closely related small substrates. Onl... |
1866372 | Absorption enhancing effect of cyclodextrins on intranasally administered insulin in rats. | The absorption enhancing effect of alpha-, beta-, and gamma-cyclodextrin (CD), dimethyl-beta-cyclodextrin (DM beta CD), and hydroxypropyl-beta-cyclodextrin (HP beta CD) on intranasally administered insulin was investigated in rats. Coadministration of 5% (w/v) DM beta CD to the insulin solution resulted in a high bioav... |
1830615 | Distribution of collagens type V and VI in the normal human alveolar mucosa: an immunoelectronmicroscopic study using ultrathin frozen sections. | The ultrastructural localization of collagens type V and VI in normal human gingival mucosa was investigated by immunoelectron microscopy. Twenty biopsies were fixed in dimethylsuberimidate and shock-frozen in slush nitrogen. Collagen type V was mainly located to meshworks of uniform nonstriated microfibrils of 12 to 2... |
2049377 | Interaction of beta-cyclodextrin with the granular starch binding domain of glucoamylase. | The granular starch binding domain of glucoamylase 1 (EC 3.2.1.3 1,4-alpha-D-glucan glucohydrolase) binds two molecules of beta-cyclodextrin, with a dissociation constant (Kd) for the second ligand of 1.68 microM. The catalytic domain showed no interaction with beta-cyclodextrin. Beta-cyclodextrin competitively inhibit... |
2040285 | Fluorescence study of the conformational properties of myoglobin structure. 3. pH-dependent changes in porphyrin and tryptophan fluorescence of the complex of sperm whale apomyoglobin with protoporphyrin IX; the role of the porphyrin macrocycle and iron in formation of native myoglobin structure. | The porphyrin and tryptophan fluorescence of sperm whale apomyoglobin complexed with protoporphyrin IX has been studied in the pH range 2-13. It has been shown that the fluorescence and absorption spectra of protoporphyrin incorporated into the heme crevice remain constant in the pH range 5.5-10.8 but change significan... |
2039692 | Generation of bispecific monoclonal antibodies for two phase radioimmunotherapy. | A two phase radioimmunotherapy based on bispecific MAbs in which one arm recognises a tumour antigen and the other a radiolabelled chelate, may prove more effective in the treatment of carcinomas than currently available immunotherapies. To establish this system we first showed that penetration into human carcinoma xen... |
1645528 | Interactions between inositol tris- and tetrakis-phosphates. Effects on intracellular Ca2+ mobilization in SH-SY5Y cells. | The potential Ca2(+)-releasing activity of the inositol tetrakisphosphates Ins(1,3,4,6)P4 and DL-Ins(1,4,5,6)P4 and the inositol pentakisphosphate Ins(1,3,4,5,6)P5 and their effect on Ins(1,4,5)P3- and DL-Ins (1,3,4,5)P4-mediated Ca2+ release were examined in permeabilized SH-SY5Y human neuroblastoma cells. Neither DL-... |
1645524 | Insulin activates GTP binding to a 40 kDa protein in fat cells. | The first steps in insulin action are binding of insulin to its receptor and activation of the insulin receptor kinase. As there is indirect evidence that further signal transduction might involve a guanine-nucleotide-binding protein (G-protein), we studied whether insulin modulates GTP binding to plasma membrane prote... |
2039439 | Chemical cleavage of plasmid DNA by glutathione in the presence of Cu(II) ions. The Cu(II)-thiol system for DNA strand scission. | In the presence of Cu(II) ions, supercoiled DNA is cleaved in neutral solution by low concentrations of thiols. Supercoiled plasmid DNA is cleaved first to open circular DNA, which in turn produces linear DNA and eventually fragments. Cleavage is strongly temperature-dependent and is maximal at 0.10-0.25 M-NaCl concent... |
1903659 | Soybean lipoxygenase catalysed oxygenation of unsaturated fatty acid encapsulated in cyclodextrin. | The linoleic or arachidonic acid entrapped in cyclodextrin (alpha, beta or gamma) serves as an excellent substrate for soybean lipoxygenase-1 catalysis. At pH 9.0 the Km values for the beta-cyclodextrin encapsulated arachidonic acid, referred herein as encapsulated substrate, and the Tween-20 dispersed substrate were 7... |
1709734 | Effects of metal ions, including Mg2+ and lanthanides, on the cleavage of ribonucleotides and RNA model compounds. | The cyclization/cleavage of 3',5'-uridyluridine to form 2',3'-cyclic uridylic acid is very effectively catalyzed by Eu3+, and the cyclization/cleavage of the 1-p-nitrophenyl phosphate ester of propane-1,2-diol also shows strong metal ion catalysis by Eu3+, Tb3+, and Yb3+. It also shows moderate catalysis by Mg2+, but n... |
2030509 | Gut bacterial translocation via the portal vein: a clinical perspective with major torso trauma. | Animal studies implicate gut bacterial translocation via the portal vein as a major factor in the pathogenesis of postinjury multiple organ failure (MOF). We therefore inserted portal vein catheters for sequential blood sampling in the operating room, at 6, 12, 24, and 48 hours, and 5 days postoperatively in 20 injured... |
1851337 | The role of platelet activating factor and its antagonists in shock, sepsis and multiple organ failure. | PAF has been implicated as a mediator of shock, sepsis and MOF. The results of experimental data demonstrate that PAF induces changes characteristic of endotoxemia and sepsis, including systemic hypotension and diffuse microvascular leakage. These effects are prevented by PAF antagonists. PAF induces many of the charac... |
2027053 | Specific monosynaptic sensory-motor connections form in the absence of patterned neural activity and motoneuronal cell death. | The importance of neural activity and motoneuronal cell death in the formation of specific synaptic connections between muscle afferents and motoneurons was studied in chick embryos. Patterned neural activity was blocked by applying d-tubocurarine (dtc) chronically to embryos during the period when sensory-motor connec... |
2026656 | Two type XII-like collagens localize to the surface of banded collagen fibrils. | Two recently identified collagen molecules, termed twelve-like A and twelve-like B (TL-A and TL-B) have properties similar to type XII collagen. These molecules have been localized in human and calf tissues by immunoelectron microscopy. The observations strongly suggest that both molecules are located along the surface... |
1709167 | Keratin incorporation into intermediate filament networks is a rapid process. | The properties of keratin-containing intermediate filament (IF) networks in vivo were studied following the microinjection of biotinylated keratin. Keratin-IFs were biotinylated, disassembled, and separated into type I and type II proteins by ion exchange chromatography. Recombination of these derivatized type I and ty... |
2023942 | Chlamydia trachomatis developmentally regulated protein is homologous to eukaryotic histone H1. | Chlamydiae are prokaryotic obligate intracellular parasites that undergo a biphasic life cycle involving an infectious, extracellular form known as elementary bodies and an intracellular, replicating form termed reticulate bodies. We have purified from Chlamydia trachomatis a very basic elementary body-specific protein... |
2023914 | Alpha B-crystallin is a small heat shock protein. | Sequence similarity between alpha B-crystallin and small heat shock proteins (HSPs) has prompted us to investigate whether alpha B-crystallin expression is induced by heat shock. Indeed, accumulation of alpha B-crystallin was detected immunologically in NIH 3T3 cells after incubation at elevated temperatures and after ... |
2023263 | "Soft docking": matching of molecular surface cubes. | Molecular recognition is achieved through the complementarity of molecular surface structures and energetics with, most commonly, associated minor conformational changes. This complementarity can take many forms: charge-charge interaction, hydrogen bonding, van der Waals' interaction, and the size and shape of surfaces... |
2022726 | Expression of mRNA for interleukin-5 in mucosal bronchial biopsies from asthma. | We have attempted to identify mRNA for IL-5 in endobronchial mucosal biopsies from asthmatics and controls, using the technique of in situ hybridization. Bronchial biopsies were obtained from 10 asthmatics and 9 nonatopic normal controls. A radio-labeled cRNA probe was prepared from an IL-5 cDNA and hybridized to perme... |
1902483 | Sublingual administration of testosterone-hydroxypropyl-beta-cyclodextrin inclusion complex simulates episodic androgen release in hypogonadal men. | In search of a more physiological testosterone (T) replacement therapy for hypogonadal states, we evaluated an inclusion complex of T with 2-hydroxypropyl-beta-cyclodextrin (HPBCD). HPBCD enhances T solubility and absorption, but HPBCD is not absorbed. Five hypogonadal men (mean age, 32.4 +/- 2.3 yr) with serum T level... |
1850403 | Transcription of the myxobacterial hemagglutinin gene is mediated by a sigma 54-like promoter and a cis-acting upstream regulatory region of DNA. | Myxobacterial hemagglutinin (MBHA) is a major developmentally induced protein that accumulates during the period of cellular aggregation of the fruiting bacterium Myxococcus xanthus. In this study, DNA sequences mediating the transcriptional regulation of mbhA have been identified. Examination of nucleotide sequences u... |
1708385 | Characterization of a neopullulanase and an alpha-glucosidase from Bacteroides thetaiotaomicron 95-1. | Previously, we constructed a gene disruption in the pullulanase I gene of Bacteroides thetaiotaomicron 5482A. This mutant, designated B. thetaiotaomicron 95-1, had a lower level of pullulanase specific activity than did wild-type B. thetaiotaomicron but still exhibited a substantial amount of pullulanase activity. Char... |
2019561 | New structural features of the flagellar base in Salmonella typhimurium revealed by rapid-freeze electron microscopy. | The structure of the flagellar base in Salmonella typhimurium has been studied by rapid-freeze techniques. Freeze-substituted thin sections and freeze-etched replicas of cell envelope preparations have provided complementary information about the flagellar base. The flagellar base has a bell-shaped extension reaching a... |
1840573 | Genetic analysis of homology between the virulence plasmids of Salmonella dublin and Yersinia pseudotuberculosis. | Two segments within the virulence region of Salmonella dublin plasmid pSDL2 that were homologous to regions on Yersinia pseudotuberculosis plasmid pIB1 were located with regard to the four known genes (vsdA, vsdB, vsdC, and vsdD) of pSDL2. One segment mapped upstream of vsdA within an insertion element related to IS630... |
2017176 | A single base pair dominates over the novel identity of an Escherichia coli tyrosine tRNA in Saccharomyces cerevisiae. | The Escherichia coli su+3 tyrosine tRNA was shown recently to be a leucine-specific tRNA in Saccharomyces cerevisiae. This finding raises the possibility that some determinants for tRNA identity in E. coli may be different in S. cerevisiae. To investigate whether the fungal system is sensitive to the major determinant ... |
2016342 | Ontogenesis of glomerular basement membrane: structural and functional properties. | Protein A-gold immunocytochemistry was applied in combination with morphometrical approaches to reveal the alpha 1(IV), alpha 2(IV), and alpha 3(IV) chains of type IV collagen as well as entactin on renal basement membranes, particularly on the glomerular one, during maturation. The results have indicated that a hetero... |
2016335 | The Saccharomyces cerevisiae MYO2 gene encodes an essential myosin for vectorial transport of vesicles. | After the initiation of bud formation, cells of the yeast Saccharomyces cerevisiae direct new growth to the developing bud. We show here that this vectorial growth is facilitated by activity of the MYO2 gene. The wild-type MYO2 gene encodes an essential form of myosin composed of an NH2-terminal domain typical of the g... |
11538377 | Origin of amphiphilic molecules and their role in primary structure formation. | Attempts to solve two fundamental questions are described: the first concerns which mechanisms were responsible for the self-assembly of membrane structures on the prebiotic Earth, and the second concerns the routes by which considerable amounts of membrane amphiphiles formed from simpler hydrocarbons. The physicoche... |
1821702 | Molecular structure and dynamics of tricyclic antidepressant drugs. | The molecular structure, electrostatic potentials and dynamics of imipramine, chlorimipramine, amitriptyline and nortriptyline were examined by computer graphics, molecular mechanical energy calculations and molecular dynamics simulations, using the AMBER all atom force field. Starting coordinates for amitriptyline and... |
1781286 | [Effect of enhancers on cutaneous permeation of piroxicam in vitro]. | Enhancing effects on the permeation of piroxicam (Pir) through excised hairless mouse (inbred HRS mice) skin were investigated by measuring flux. Azone 1% was found to be the most effective enhancer studied, increasing the flux about 21 times. The effect of Azone was enhanced by the presence of propylene glycol. Oleic ... |
29865505 | Choanocyte-like cells in the digestive system of the starfish Marthasterias glacialis (Echinodermata). | Two types of choanocyte-like cells have been found in the digestive tract of the starfish. Type I choanocytes are in the lining epithelium of all organs of the digestive system. These are narrow, columnar cells strongly anchored basally and expanded apically into a protuberance projecting into the lumen. A prominent fl... |
24425017 | Effect of methyl-cyclodextrin on adenylate cyclase activity of Bordetella pertussis. | The activity of Bordetella pertussis extracytoplasmic adenylate cyclase (AC) decreased during decelerating growth phase in a Stainer-Scholte medium. Neither proteolytic activity nor virulence variation (phase variation; antigenic modulation) appears to be responsible for the observed activity fall. The addition of meth... |
19431792 | Polarized fluorescence measurements on ordered photosynthetic antenna complexes: Chlorosomes of Chloroflexus aurantiacus and B800-B850 antenna complexes of Rhodobacter sphaeroides. | We have used a new and relatively easy approach to study the pigment-organization in chlorosomes from the photosynthetic bacterium Chloroflexus aurantiacus and in B800-850 antenna complexes of the photosynthetic purple bacterium Rhodobacter sphaeroides. These particles were embedded in compressed and uncompressed gels ... |
18965183 | A fiber-optic cyclodextrin-based sensor. | This paper describes the development of a fiber-optic cyclodextrin-based (FCD) sensor. The device uses laser excitation and fluorescence detection with beta-cyclodextrin as the reagent phase, immobilized at the tip of an optical fiber. The sensitivity of the FCD sensor is 14 times as great as that of a bare optical fib... |
17746667 | Molecular self-assembly of two-terminal, voltammetric microsensors with internal references. | Self-assembly of a ferrocenyl thiol and a quinone thiol onto Au microelectrodes forms the basis for a new microsensor concept: a two-terminal, voltammetric microsensor with reference and sensor functions on the same electrode. The detection is based on measurement of the potential difference of current peaks for oxidat... |
16348489 | Ultrastructural changes in an obligately barophilic marine bacterium after decompression. | The bacterial isolate MT-41 from 10,476 m, nearly the greatest ocean depth, is obligately barophilic. The purpose of this study was to describe the morphological changes in MT-41 due to nearly isothermal decompression followed by incubation at atmospheric pressure. Two cultures were grown at 103.5 MPa and 2 degrees C a... |
1939452 | Random decarboxylation of uroporphyrinogen III by human hepatic uroporphyrinogen decarboxylase. | The type III heptacarboxylic porphyrinogens derived from enzymic decarboxylation of an acetic acid substituent on uroporphyrinogen III to a methyl group by human hepatic uroporphyrinogen decarboxylase has been analysed by reversed-phase high-performance liquid chromatography with electrochemical detection. The results ... |
1888141 | Effect on protein synthesis and cell survival of the benzaldehyde derivatives sodium benzylidene ascorbate (SBA) and the deuterated compound zilascorb(2H). | Three different benzaldehyde derivatives (viz. beta-cyclodextrin benzaldehyde inclusion compound (CDBA), 4, 6-O-benzylidene-D-glucose (BG) and sodium benzylidene-ascorbate (SBA) have been shown to exert anticancer effects in patients without causing side effects. The anticancer effects are, however, variable and in man... |
1886043 | Solubilities of trimethoprim and sulfamethoxazole at various pH values and crystallization of trimethoprim from infusion fluids. | Solubilities of sulfamethoxazole (SMX) and trimethoprim (TMP) have been measured in the absence and presence of various concentrations of hydroxypropyl beta-cyclodextrin (HPCD) in buffers over a range of pH values. The solubilities of TMP increased linearly in the presence of HPCD at pH values of 7.0, 7.5, 8.9, and 9.9... |
1883776 | Long duration local anesthesia with lecithin-coated microdroplets of methoxyflurane: studies with human skin. | Lecithin-coated microdroplets of methoxyflurane (MOF) have been reported to produce local anesthesia of long duration in rats. The present study was conducted in two phases. The first phase was open label studies in two human volunteers aimed at determining the effective concentration of MOF in human skin. Over the con... |
1883775 | Long duration local anesthesia with lecithin-coated microdroplets of methoxyflurane: studies with rat skin. | Lecithin-coated microdroplets of methoxyflurane (MOF) are shown to produce local anesthesia of three- to six-day duration in the skin with a single intradermal injection in rats. Anesthesia was quantitated by elevation of the threshold (milliampere) for shock vocalization with intradermal electrodes. Intradermal inject... |
1880191 | Chiral high-performance liquid chromatography of aromatic cyclic dipeptides using cyclodextrin stationary phases. | A series of enantiomers of cyclic and linear dipeptides containing aromatic amino acids was prepared and chromatographed on beta- and gamma-cyclodextrin (CD) columns. The retention times, separation factor alpha and resolution values were calculated. The relevance of the distance of the chiral center from the phenyl ri... |
1874860 | High-performance liquid chromatographic separation of bile acid pyrenacyl esters with cyclodextrin-containing mobile phase. | The high-performance liquid chromatographic separation of bile acid pyrenacyl esters with cyclodextrin-containing mobile phase is presented. Compared with conventional methods, inclusion chromatography gives much more satisfactory separation of derivatized bile acids in a short time. The application of this method to t... |
1868163 | Differential scanning calorimetry studies of NaCl effect on the inverse temperature transition of some elastin-based polytetra-, polypenta-, and polynonapeptides. | Differential scanning calorimetry studies of the effect of NaCl on protein-based polymer self-assembly has been carried out on six elastin-based synthetic sequential polypeptides--i.e., the polypentapeptide (L-Val1-L-Pro2-Gly3-L-Val4-Gly5)n and its more hydrophobic analogues (L-Leu1-L-Pro2-Gly3-L-Val4-Gly5)n and (L-Val... |
1865341 | Oversaturated solutions of drug in hydroxypropylcyclodextrins: parenteral preparation of pancratistatin. | The effect of 15 cyclodextrin derivatives (polar-electroneutral, cationic, anionic, and lipophilic) and of three 2-hydroxypropyldigitonins on the solubility of pancratistatin, an anticancer drug, was evaluated. The direct solubilizations into aqueous solutions were invariably low (0.1-1.2 mg/mL compared with 50 microgr... |
1865340 | Development of aqueous parenteral formulations for carbamazepine through the use of modified cyclodextrins. | The poor aqueous solubility of carbamazepine was dramatically increased via complexation with various chemically modified beta-cyclodextrins and gamma-cyclodextrins. A preparation of carbamazepine and 2-hydroxypropyl-beta-cyclodextrin was found to be stable to steam sterilization and to storage under a variety of condi... |
1859209 | Effect of beta-cyclodextrin on mucochloric acid and 3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone. | Cyclodextrins form inclusion complexes with a wide range of guest molecules which wholly, or in part, fit into their hydrophobic cavity. Since no covalent bonds are formed in this complexation, the guests can subsequently be eluted. The possibility of such complexation was envisioned as a means of removing chlorinated ... |
2065191 | Carboxy Mb at pH 3. Time-resolved resonance Raman study at cryogenic temperatures. | Cryogenic samples of MbCO at pH3 are studied using nanosecond and picosecond time-resolved resonance Raman spectroscopy. It is observed that under excitation conditions sufficient to completely photodissociate MbCO at pH7, the pH3 sample at 10 ns remains substantially unphotolyzed even at 15 K. The similarity in the op... |
1648415 | Structural investigation of the covalent and electrostatic binding of yeast cytochrome c to the surface of various ultrathin lipid multilayers using x-ray diffraction. | X-Ray diffraction was used to characterize the profile structures of ultrathin lipid multilayers having a bound surface layer of cytochrome c. The lipid multilayers were formed on an alkylated glass surface, using the Langmuir-Blodgett method. The ultrathin lipid multilayers of this study were: five monolayers of arach... |
2059041 | Growth and survival of Bordetella bronchiseptica in natural waters and in buffered saline without added nutrients. | Bordetella bronchiseptica showed increases in viable count when incubated in phosphate-buffered saline (PBS), in reagent-grade water, and in local lake and pond waters, all without added nutrients. Within 48 to 72 h at 37 degrees C in PBS and in lake and pond waters, stationary-phase populations of around 2.7 x 10(6) C... |
2041799 | Compilation of DNA sequences of Escherichia coli (update 1991). | We have compiled the DNA sequence data for E. coli available from the GENBANK and EMBL data libraries and over a period of several years independently from the literature. This is the third listing replacing and increasing the former listing roughly by one fifth. However, in order to save space this printed version con... |
2027777 | Interactions of nucleic acids with distamycins. Binding of Dst-3 to d(CGTTTAAACG)2 and d(CGTACGTACG)2. | The binding between Distamycin 3 and the palindromic duplexes d(CGTTTAAACG)2 and d(CGTACGTACG)2 was investigated by two independent techniques: UV-Vis absorption in the Job's plot approach and Induced Circular Dichroism. Both decamers bind two molecules of peptide per duplex, with close overall affinities. This result ... |
1709115 | Topographical and enzymatic characterization of amylases from the extremely thermophilic eubacterium Thermotoga maritima. | The hyperthermophilic eubacterium Thermotoga maritima uses starch as a substrate, without releasing amylase activity into the culture medium. The enzyme is associated with the 'toga'. Its expression level is too low to allow the isolation of the pure enzyme. Using cycloheptaamylose and acarbose affinity chromatography ... |
2025226 | Studies on the mechanism of hydroxymethylbilane synthase concerning the role of arginine residues in substrate binding. | The role of conserved arginine residues in hydroxymethylbilane synthase was investigated by replacing these residues in the enzyme from Escherichia coli with leucine residues by using site-directed mutagenesis. The kinetic parameters for these mutant enzymes and studies on the formation of intermediate enzyme-substrate... |
2025222 | Comparison of the activities of protein disulphide-isomerase and thioredoxin in catalysing disulphide isomerization in a protein substrate. | 1. The activities of protein disulphide-isomerase (PDI) and thioredoxin in catalysing disulphide bond isomerization in a protein substrate were compared by using the standard assay, namely the re-activation of 'scrambled' RNAase. 2. The specific activity of PDI was 25-fold greater than that of thioredoxin. 3. The great... |
1827254 | Staurosporine both activates and inhibits serine/threonine kinases in human platelets. | The effects of staurosporine on a selection of protein kinases were investigated with thrombin-stimulated and control human blood platelets. The results demonstrate that staurosporine (1 microM) can lead to activation of certain protein kinases in intact platelets and has a general inhibitory effect on the renaturable ... |
2021617 | Contribution to the thermodynamics of protein folding from the reduction in water-accessible nonpolar surface area. | Protein folding and the transfer of hydrocarbons from a dilute aqueous solution to the pure liquid phase are thermodynamically similar in that both processes remove nonpolar surface from water and both are accompanied by anomalously large negative heat capacity changes. On the basis of a limited set of published surfac... |
2021537 | Application of boronated anti-CEA immunoliposome to tumour cell growth inhibition in in vitro boron neutron capture therapy model. | An immunoliposome containing a 10B-compound has been examined as a selective drug delivery system in boron neutron-capture therapy. Liposomes, conjugated with monoclonal antibodies specific for carcinoembryonic antigen (CEA) were shown to bind selectively to cells bearing CEA on their surface. The immunoliposomes attac... |
2021532 | The influence of chronic anaemia on the radiosensitivity of two mouse tumours. | There is clear clinical evidence that tumours in anaemic patients are difficult to control with radiotherapy. We have studied the radiosensitivity of two transplantable mouse tumours, the SCCVII/St carcinoma and the KHT sarcoma in hosts made anaemic either with an iron poor diet or as a result of tumour growth. The hae... |
2021531 | The effects of intra-arterial vasoconstrictors on the distribution of a radiolabelled low molecular weight marker in an experimental model of liver tumour. | Regional chemotherapy for colorectal liver metastases has not demonstrated a convincing survival benefit over systemic chemotherapy. This may be due to poor delivery of chemotherapeutic drugs to hypovascular liver tumour. Since vasoactive agents may influence hepatic blood flow this study investigated the effects of sy... |
2019567 | The regulation of intermediate filament reorganization in mitosis. p34cdc2 phosphorylates vimentin at a unique N-terminal site. | The disassembly of vimentin-containing intermediate filament (IF) networks during mitosis in BHK-21 cells is accompanied by increased phosphorylation of vimentin (Chou, Y.-H., Rosevear, E., and Goldman, R. D. (1989) Proc. Natl. Acad. Sci. U. S. A. 86, 1885-1889). We have recently identified p34cdc2 as the catalytic sub... |
1708234 | Soluble fibrin preparations inhibit the reaction of plasmin with alpha 2-macroglobulin. Comparison with alpha 2-antiplasmin and leupeptin. | The kinetics of plasmin inhibition by alpha 2-antiplasmin (alpha 2AP), alpha 2-macroglobulin (alpha 2M) and leupeptin were studied in the presence of fibrin monomer (Fn) and CNBr fragments of fibrinogen (Fg-CNBr). Active plasmin was detected in continuous and discontinuous assays using the chromogenic substrate D-Val-L... |
2016747 | Generation of infectious nucleocapsids by in vitro assembly of the shell protein on to the polymerase complex of the dsRNA bacteriophage phi 6. | A method for the in vitro uncoating of the phi 6 nucleocapsid (NC) was developed. The resulting particle, designated as the NC core, containing the genomic double-stranded (ds) RNA segments and the proteins P1, P2, P4 and P7, was not infectious but had a highly enhanced in vitro transcriptase activity compared to that ... |
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