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8177173 | Gas vesicles. | The gas vesicle is a hollow structure made of protein. It usually has the form of a cylindrical tube closed by conical end caps. Gas vesicles occur in five phyla of the Bacteria and two groups of the Archaea, but they are mostly restricted to planktonic microorganisms, in which they provide buoyancy. By regulating thei... |
8154590 | Effects of cations and charge types on the metastable decay rates of oligosaccharides. | Metastable decay rates of alpha-cyclodextrin and maltohexaose coordinated to proton and alkali metal ions were determined from ions produced by liquid secondary ion mass spectrometry in an external source Fourier transform mass spectrometry instrument. For both oligosaccharide compounds the decay rates of the protonate... |
8152909 | DNA looping by the HMG-box domains of HMG1 and modulation of DNA binding by the acidic C-terminal domain. | We have compared HMG1 with the product of tryptic removal of its acidic C-terminal domain termed HMG3, which contains two 'HMG-box' DNA-binding domains. (i) HMG3 has a higher affinity for DNA than HMG1. (ii) Both HMG1 and HMG3 supercoil circular DNA in the presence of topoisomerase I. Supercoiling by HMG3 is the same a... |
8149029 | Pulmonary failure and the production of leukotrienes. | The activation of neutrophils and elaboration of leukotrienes has a role in the pathophysiologic factors of many of the disease states seen by surgeons and nonsurgical counterparts. Although direct evidence of cause and effect is lacking, there is a growing array of literature proving the importance of neutrophils and ... |
8146136 | Genital human papillomavirus infection. | Genital human papillomavirus (HPV) infection is a common sexually transmitted disease that at the present time is not effectively controlled or treated. Many infections are inapparent and transient. However, some HPV infections result in persistent lesions that in some cases undergo carcinogenic progression. A subset o... |
7511798 | The endogenous oestrogen metabolite 2-methoxyoestradiol inhibits angiogenesis and suppresses tumour growth. | The formation of new blood vessels (angiogenesis) is critical for the growth of tumours and is a dominant feature in various angiogenic diseases such as diabetic retinopathy, arthritis, haemangiomas and psoriasis. Recognition of the potential therapeutic benefits of controlling pathological angiogenesis has led to a se... |
8145312 | Dynamics of interleukin 1, 2, and 6 and tumor necrosis factor alpha in multiple trauma patients. | The involvement of cytokines in trauma still has not been satisfactorily elucidated. The development of multiorgan failure, the very serious complication of multiple trauma with high mortality, should also be controlled by cytokines, endotoxin, and other mediators. We therefore prospectively studied 42 consecutive pati... |
8141789 | Component analysis and characterization of a nuclear deoxyribonucleotidase. | We have previously reported the identification of a novel activity residing in the nuclear fraction of mammalian cells that selectively binds and hydrolyses deoxyribonucleoside triphosphates. Incubation of this protein with [alpha-32P]dATP leads to the appearance of a retarded band relative to free dATP when the reacti... |
8141787 | The region around residue 115 of human bactericidal/permeability-increasing protein is not involved in lipopolysaccharide binding or bactericidal activity. Chemical synthesis and expression of a gene coding for the active domain and characterization of recombinant proteins. | Bactericidal/permeability-increasing protein (BPI) is a potent antimicrobial agent produced by polymorphonuclear leucocytes that specifically interacts with and kills Gram-negative bacteria. An 825 bp gene determining the bactericidal N-terminal domain of human BPI was chemically synthesized and expressed as inclusion ... |
7907994 | beta-Cyclodextrin interacts with the Alzheimer amyloid beta-A4 peptide. | Electrospray ionisation mass spectrometry has been used to show that the synthetic 40 amino acid beta-amyloid peptide (beta 1-40) interacts with the cyclic oligosaccharide beta-cyclodextrin. This interaction, presumably with the hydrophobic aromatic moieties on the peptide, has been shown to diminish substantially the ... |
8135774 | Regulation of undulin synthesis and gene expression in human fat-storing cells by acetaldehyde and transforming growth factor-beta 1: comparison with fibronectin. | Undulin and fibronectin (FN) are large extracellular matrix (ECM) glycoproteins possibly involved in cell-matrix interactions. In this study we analyzed the effect of acetaldehyde and transforming growth factor-beta 1 (TGF-beta 1) on undulin and FN synthesis in cultured fat-storing cells (FSC) isolated from wedge secti... |
8135736 | Enzyme-enzyme interactions and metabolite channelling: alternative mechanisms and their evolutionary significance. | Metabolite channelling may result from different kinetic mechanisms in which enzyme-enzyme interactions occur, so that intermediates are not released into the bulk solution and cannot be used by enzymes outside the channel. From an evolutionary point of view, the emergence of such mechanisms may provide new functional ... |
8134834 | Functional polymers and dendrimers: reactivity, molecular architecture, and interfacial energy. | The interaction of polymers with their environment depends largely on the functional groups they carry. Interfaces between different polymers or between polymers and other surfaces can be strengthened through the design of molecular interactions such as hydrogen bonding and through the control of polymer architecture. ... |
8134358 | RNA polymerase binding using a strongly acidic hydrophobic-repeat region of sigma 54. | sigma 54 is a rare bacterial protein that substitutes for sigma 70 in the case of Escherichia coli genes transcribed by certain activators with enhancer protein-like properties. It contains a strongly acidic region of previously unknown function. Gel mobility-shift assays using sigma 54 deletion mutants show that this ... |
8133516 | Crystallization and preliminary X-ray studies of cyclodextrin glucanotransferase from alkalophilic Bacillus sp. 1011. | Large crystals of cyclodextrin glucanotransferase (CGTase) from alkalophilic Bacillus sp. 1011, a typical alkalophilic enzyme, have been obtained at room temperature using polyethylene glycol 3000 and 2-propanol as precipitant. They belong to the triclinic space group P1 with the following unit cell constants: a = 64.9... |
8133032 | Evidence for a direct physical interaction of membrane IgM, IgD, and IgG with the B29 gene product. | The B cell Ag-receptor complex is composed of membrane immunoglobulin (mIg) and the mb-1/B29 heterodimer. In order to obtain insight into the architecture of the B cell receptor complex, we have looked for conditions that disrupt all disulfide bridges in the complex without affecting the noncovalent interaction between... |
8132760 | Deletions in the COL4A5 collagen gene in X-linked Alport syndrome. Characterization of the pathological transcripts in nonrenal cells and correlation with disease expression. | The type IV collagen alpha 5 chain (COL4A5) gene of 88 unrelated male patients with X-linked Alport syndrome was tested for major gene rearrangements by Southern blot analysis, using COL4A5 cDNA probes. 14 different deletions were detected, providing a 16% deletion rate in the COL4A5 gene in the patient population. The... |
7510712 | Integrin cytoplasmic domains mediate inside-out signal transduction. | We analyzed the binding of fibronectin to integrin alpha 5 beta 1 in various cells; in some cells fibronectin bound with low affinity (e.g., K562 cells) whereas in others (e.g., CHO), it bound with high affinity (Kd approximately 100 nM) in an energy-dependent manner. We constructed chimeras of the extracellular and tr... |
8132579 | Limited proteolysis and active-site studies of the first multienzyme component of the erythromycin-producing polyketide synthase. | The domain structure of the 6-deoxyerythronolide B synthase 1 component of the erythromycin-producing polyketide synthase from Saccharopolyspora erythraea has been investigated using limited proteolysis and active-site labeling. Trypsin, elastase, endoproteinase Glu-C, and endoproteinase Arg-C were used to cleave the m... |
8131735 | Three-dimensional structure of the rotavirus haemagglutinin VP4 by cryo-electron microscopy and difference map analysis. | The three-dimensional structure of the rotavirus spike haemagglutinin viral protein 4 (VP4) has been determined to a resolution of 26 A by cryo-electron microscopy and difference analysis of intact virions and smooth (spikeless) particles. Native and spikeless virions were mixed prior to cryo-preservation so that both ... |
8130189 | Solubilizing buried domains of proteins: a self-assembling interface domain from glutathione reductase. | In the dimeric glutathione reductase (GR) from Escherichia coli, the interface domain is largely surrounded by the other three domains in each subunit of the protein. Subgenes encoding three forms of the interface domain have been expressed in E. coli and the products purified from inclusion bodies: INT is the excised ... |
8128221 | Differential adhesion of cells to enantiomorphous crystal surfaces. | Interactions during cell adhesion to external surfaces may reach the level of discrimination of molecular chirality. Cultured epithelial cells interact differently with the [011] faces of the (R,R) and (S,S) calcium tartrate tetrahydrate crystals. In a modified version of the classical Pasteur experiment, the enantiomo... |
8127917 | Ceramide structure predicts tumor ganglioside immunosuppressive activity. | Molecular determinants of biological activity of gangliosides are generally believed to be carbohydrate in nature. However, our studies of immunomodulation by highly purified naturally occurring tumor gangliosides provide another perspective: while the immunosuppressive activity of gangliosides requires the intact mole... |
7510408 | Enthalpy of hydrogen bond formation in a protein-ligand binding reaction. | Parallel measurements of the thermodynamics (free-energy, enthalpy, entropy and heat-capacity changes) of ligand binding to FK506 binding protein (FKBP-12) in H2O and D2O have been performed in an effort to probe the energetic contributions of single protein-ligand hydrogen bonds formed in the binding reactions. Changi... |
8127880 | The formation of mitochondrial ribonucleoprotein complexes involving guide RNA molecules in Trypanosoma brucei. | Transcripts from mitochondrial (maxicircle) genes of kinetoplastid organisms undergo RNA editing characterized by a series of reactions that insert and delete uridine nucleotides within the sequence of the pre-mRNAs. Guide RNAs, which complement fully edited mRNAs, provide the information for the edited sequence by an ... |
8127871 | Structure of the Escherichia coli Fis-DNA complex probed by protein conjugated with 1,10-phenanthroline copper(I) complex. | The Escherichia coli Fis (factor for inversion stimulation) protein functions in many diverse biological systems including recombination, transcription, and DNA replication. Although Fis is a site-specific DNA-binding protein, it lacks a well-defined consensus recognition sequence. The electrophoretic mobility of Fis-D... |
7510405 | Nitric oxide: a mediator in rat tubular hypoxia/reoxygenation injury. | Nitric oxide (NO), among several other functions, may play a role in hypoxia and reoxygenation injury due to its free radical nature and high reactivity with the superoxide radical to yield peroxynitrite, an oxidant molecule. The present study was undertaken to evaluate a potential role for NO, either endogenous or exo... |
8126735 | The use of composite crystal-field environments in molecular recognition and the de novo design of protein ligands. | Small molecule crystal data have been retrieved from the Cambridge Crystallographic Database to compile composite crystal-field environments about different functional groups, which also occur in proteins and nucleotides. Their spatial distribution can be used to map-out putative interaction sites, e.g. about amino aci... |
8126549 | Self-recognition: a constraint on the formation of electrical coupling in neurons. | Electrical coupling between specific neurons is important for proper function of many neuronal circuits. Identified cultured neurons from the snail Helisoma show a strong correlation between electrical coupling and presence of gap junction plaques in freeze-fracture replicas. Gap junction plaques, however, were never s... |
7510096 | Distribution of substance P immunoreactive nerve fibers in the tracheal submucosal gland of cats. | Immunohistochemistry combined with electron microscopy was employed to investigate the distribution of substance P-immunoreactive (SP-IR) nerve fibers in the tracheal submucosal gland of cats. The SP-IR nerve fibers were found to form a network around the glands. Numerous varicosities were also detected within the base... |
8120886 | Molecular recognition in proteins. Simulation analysis of substrate binding by a tyrosyl-tRNA synthetase mutant. | Alchemical molecular dynamics simulations are performed to determine the difference in the free energy of binding of the tyrosine substrate between the wild type of tyrosyl-tRNA synthetase (TyrRS) from Bacillus stearothermophilus and the mutant Tyr169-->Phe. The results are of general interest because the Tyr169 hydrox... |
8120090 | A triggered mechanism retrieves membrane in seconds after Ca(2+)-stimulated exocytosis in single pituitary cells. | In neuroendocrine cells, cytosolic Ca2+ triggers exocytosis in tens of milliseconds, yet known pathways of endocytic membrane retrieval take minutes. To test for faster retrieval mechanisms, we have triggered short bursts of exocytosis by flash photolysis of caged Ca2+, and have tracked subsequent retrieval by measurin... |
8119176 | Characterization of the 3 beta-hydroxysteroid dehydrogenase activity associated with bovine adrenocortical mitochondria. | The enzymatic activity of 3 beta-hydroxysteroid dehydrogenase (3 beta HSD/I) constitutes an essential step in the biosynthesis of active steroid hormones such as progesterone, mineralo- and gluco-corticoids, estrogens, and androgens. Its subcellular localization in steroidogenic tissues is usually considered to be main... |
7509450 | Methylation of single sites within the herpes simplex virus tk coding region and the simian virus 40 T-antigen intron causes gene inactivation. | In order to determine whether partial methylation of the herpes simplex virus (HSV) tk gene prevents tk gene expression, the HSV tk gene was cloned as single-stranded DNA. By in vitro second-strand DNA synthesis, specific HSV tk gene segments were methylated, and the hemimethylated DNA molecules were microinjected into... |
8113176 | Determinants of affinity and mode of DNA binding at the carboxy terminus of the bacteriophage SPO1-encoded type II DNA-binding protein, TF1. | The role of the carboxy-terminal amino acids of the bacteriophage SPO1-encoded type II DNA-binding protein, TF1, in DNA binding was analyzed. Chain-terminating mutations truncating the normally 99-amino-acid TF1 at amino acids 96, 97, and 98 were constructed, as were missense mutations substituting cysteine, arginine, ... |
7509321 | Pentoxifylline and CD14 antibody additively inhibit priming of polymorphonuclear leukocytes for enhanced release of superoxide by lipopolysaccharide: possible mechanism of these actions. | Lipopolysaccharide (LPS) primes human polymorphonuclear leukocytes (PMN) for enhanced O2- production in response to stimulation by N-formyl-methionyl-leucyl-phenylalanine (fMet-Leu-Phe). Serum factor is essential for priming at lower concentrations of LPS. Complexes of LPS and LPS-binding protein are recognized by CD14... |
8112848 | Heparin-inhibitable lectin activity of the filamentous hemagglutinin adhesin of Bordetella pertussis. | Bordetella pertussis, the etiologic agent of whooping cough, produces an outer membrane-associated filamentous hemagglutinin (FHA) which is the major adhesin of this organism. FHA exhibits a lectin-like activity for heparin and dextran sulfate. By using in vitro adherence assays to cultured epithelial cells, the attach... |
8107889 | Stereoselectivity of DNA catenane fusion by resolvase. | Communications between distant sites on DNA often depend on the way in which the sites are connected. For example, site-specific recombination catalysed by Tn3 resolvase is most efficient when the 114-base-pair res recombination sites are directly repeated in the same DNA molecule. In vitro a supercoiled plasmid substr... |
8107240 | Viral multiplicity of attachment and its implications for human immunodeficiency virus therapies. | The multiplicity of attachment (MOA) of a virion in any particular time interval is the average number of cellular attachment opportunities that must be blocked to keep the virion in suspension. MOA is usually proportional to incubation time and cell concentration. Low MOA (like low multiplicity of infection) is requir... |
8107216 | Transcription inhibition and other properties of matrix proteins expressed by M genes cloned from measles viruses and diseased human brain tissue. | Ribonucleoprotein (RNP) cores extracted from virions of wild-type (Edmonston strain) measles virus (MV) or obtained from MV-infected cells (cRNP) were shown to be capable of transcribing RNA in vitro but at relatively low efficiency. The tightly bound matrix (M) protein could be effectively removed from virion RNP (vRN... |
8107207 | Down-regulation of HLA antigens by the adenovirus type 2 E3/19K protein in a T-lymphoma cell line. | Adenoviruses of subgroup C can establish persistent infections in human beings. The exact site of persistence has not been established, but lymphoid tissues are certainly one reservoir. Experimental evidence suggests that early transcription unit 3 (E3) of the virus is involved in this phenomenon. In particular, the mo... |
8107199 | Neutralization sensitivity of human immunodeficiency virus type 1 is determined in part by the cell in which the virus is propagated. | Neutralizing antibody responses to human immunodeficiency virus type 1 (HIV-1) vary widely and have not been reproducibly associated with prognosis or disease progression. We have found that both low-passage clinical isolates and laboratory-adapted strains of HIV-1 have different sensitivities to neutralization by the ... |
24233296 | Time-resolved fluorescence of crown ether styrul dyes. | Photophsical processes are studied in a new class of dyes contining a chromophoric part and a crown ether part. Fluorescence decays were oebserved to be strongly dependent on temperature in the range from 294 to 4 K. Photoinduced isomerization and electron transfer are considered as possible mechanisms to explain the r... |
24233289 | Environmentally shifted fluorescence lifetimes for multicomponent phase-modulation fluorimetric analysis. | Several cyclodextrins, surfactants, and a series of three organic solvents-methanol, isoamylic alcohol, and hexanol-with different polarities and viscosities, were used to study the influence of the microenvironment on the fluorescent behavior of three diuretics-furosemide, triamterene, and piretanide. We concluded tha... |
9422129 | Early intubation in severely injured patients. | In a prospectively studied trauma population from 1986 to 1991 the influence of early intubation (EI) within 2 h after the accident on post-traumatic (multiple) organ failure (M)OF was compared with delayed intubation (DI) in 131 patients with multiple injuries (Injury severity score (ISS) 37). Indications for intubati... |
8086033 | Boron neutron capture therapy of primary and metastatic brain tumors. | Boron neutron capture therapy (BNCT) is based on the nuclear reaction that occurs when a stable isotope, boron-10, is irradiated with low energy (0.025 eV) thermal neutrons (nth) to yield alpha (4He) particles and 7Li nuclei (10B+nth-->[11B]-->4He + 7Li + 2.79 MeV). The success of BNCT as a tumoricidal modality is depe... |
8019007 | Microtubule flux in mitosis is independent of chromosomes, centrosomes, and antiparallel microtubules. | We investigated the mechanism of poleward microtubule flux in the mitotic spindle by generating spindle subassemblies in Xenopus egg extracts in vitro and assaying their ability to flux by photoactivation of fluorescence and low-light multichannel fluorescence video-microscopy. We find that monopolar intermediates of i... |
8019002 | Phosphorylation of native and reassembled neurofilaments composed of NF-L, NF-M, and NF-H by the catalytic subunit of cAMP-dependent protein kinase. | Phosphorylation of neurofilament-L protein (NF-L) by the catalytic subunit of cAMP-dependent protein kinase (A-kinase) inhibits the reassembly of NF-L and disassembles filamentous NF-L. The effects of phosphorylation by A-kinase on native neurofilaments (NF) composed of three distinct subunits: NF-L, NF-M, and NF-H, ho... |
8013554 | Chronic adenosine A1 receptor agonist and antagonist: effect on receptor density and N-methyl-D-aspartate induced seizures in mice. | The effect of chronic administration of the adenosine A1 receptor agonist N6-cyclopentyladenosine (CPA) and the adenosine A1 antagonist 8-cyclopentyl-1,3-dipropylxanthine (CPX) on N-methyl-D-aspartate (NMDA)-evoked seizures was studied in C57BL/6 mice (20/group). Animals were injected i.p. for 9 days with either 1.0 mg... |
8013064 | Effect of glucocorticoid receptor (GR) blockade on endotoxemia in rats. | To study the clinical significance of the decrease of glucocorticoid receptor (GR) in stress and shock, GR was blocked about 80% by mifepristone (RU38486), and the effects of the blockade on the pathological changes of endotoxemia were studied in rats. The results revealed that GR blockade may exacerbate the pathologic... |
8012567 | Two-dimensional gas chromatography for the enantiomeric separation of ephedrine and phenaminum and their metabolites. | Two-dimensional gas chromatography was used for enantiomeric separation of ephedrine, phenaminum and their metabolites in human urine. The main column was coated with a 2,6-di-O-pentyl-3-O-trifluoroacetylated-alpha-cyclodextrin and an SE-54 phase column was used as precolumn. The results showed that two-dimensional chr... |
8003954 | Crystal structure of cholera toxin B-pentamer bound to receptor GM1 pentasaccharide. | Cholera toxin (CT) is an AB5 hexameric protein responsible for the symptoms produced by Vibrio cholerae infection. In the first step of cell intoxication, the B-pentamer of the toxin binds specifically to the branched pentasaccharide moiety of ganglioside GM1 on the surface of target human intestinal epithelial cells. ... |
8206876 | Dynamic properties of nucleic acids in biosupramolecular systems, as studied by 31P NMR. | The dynamic properties of nucleic acids in five different types of intact supramolecular systems, namely, chicken erythrocyte chromatin, the wild type and a deletion mutant of the lambda phage, lipid-containing phage PM2, and Alteromonas espejiana ribosomes, were investigated by means of 31P solid-state NMR. The nuclei... |
8204217 | Structure and self assembly of a retrovirus (FeLV) proline rich neutralization domain. | The 60 amino acid proline-rich neutralization domain of the external surface unit glycoprotein of feline leukemia virus was chemically synthesized in total and in fragments. We examined the ability of these retroviral peptides to form ordered conformations using 1H-NMR, circular dichroism spectroscopy, and intrinsic vi... |
8192469 | Saperconazole therapy of murine disseminated candidiasis: efficacy and interactions with amphotericin B. | The efficacy of a new triazole antifungal agent, saperconazole, in a murine model of disseminated candidiasis was studied. Mice were intravenously infected with Candida albicans blastoconidia and treated for 14 days with oral saperconazole, intraperitoneal amphotericin B, or a combination of these. Amphotericin B alone... |
8191415 | Potential etiologic role of PAF in two major septic complications; disseminated intravascular coagulation and multiple organ failure. | A possible role of platelet-activating factor (PAF) in the occurrence of the two septic complications, i.e., disseminated intravascular coagulation (DIC) and multiple organ failure (MOF) was investigated, employing a rabbit model and a novel PAF antagonist E5880. By an instillation of fecal suspension into the common b... |
8180997 | Syntheses of all the possible monomethyl ethers and several deoxyhalo analogues of methyl beta-lactoside as ligands for the Ricinus communis lectins. | The synthesis of all the possible monomethyl ethers of methyl beta-lactoside (1) has been performed from 1 in a straightforward way, making use of the different reactivity of the hydroxyl groups in alkylation and stannylation reactions. In addition, the deoxyfluoro derivatives of 1 at positions, 6,3',4',epi-4', and 6' ... |
8180980 | Separation and characterization of five positional isomers of trimaltosyl-cyclomaltoheptaose (trimaltosyl-beta-cyclodextrin). | Trace amounts of trimaltosyl-cyclomaltoheptaoses (trimaltosyl-beta-cyclodextrins, trimaltosyl-beta CDs) were found in a mixture of maltosyl-cyclomaltoheptaoses (maltosyl-beta-cyclodextrins, maltosyl-beta CDs) prepared from maltose and cyclomaltoheptaose (beta-cyclodextrin, beta CD) through the reverse action of Klebsie... |
7764720 | Replacement of an amino acid residue of cyclodextrin glucanotransferase of Bacillus ohbensis doubles the production of gamma-cyclodextrin. | Cyclodextrin glucanotransferase (CGTase; EC 2.4.1.19) produces cyclodextrin (CD) from starch through an intramolecular transglucosylation reaction. To obtain a better understanding of the amylolytic and cyclization mechanisms of CGTase, and furthermore to improve the production of gamma-CD, mutant CGTases were construc... |
8169790 | A new approach in the synthesis of immunotoxins: ribosome inactivating protein noncovalently bound to monoclonal antibody. | This study describes the synthesis of a new generation of immunotoxins made by a noncovalent interaction between a monoclonal antibody derivatized with a dichlorotriazinic dye and the ribosomal inhibitor protein gelonin. The scheme of preparation has several advantages with respect to the traditional methods, which use... |
8169787 | Safety of oral cyclodextrins: effects of hydroxypropyl cyclodextrins, cyclodextrin sulfates and cationic cyclodextrins on steroid balance in rats. | Derivatives of beta-cyclodextrin differing in the length of a hydroxyalkyl substituent (CH2CH2OH, CH2CHOHCH3, CH2CHOHCH2CH2CH2CH3) or in the electrical charge of the substituents (SO4-, CH2CHOHCH2N(CH3)3+) and hydroxypropyl derivatives (CH2CHOHCH3) of alpha-, beta-, and gamma-cyclodextrin were compared, individually an... |
8165197 | Fluorometric study of the molecular states of 2,5-diphenyloxazole in ground mixtures with gamma-cyclodextrin. | Molecular states of 2,5-diphenyloxazole (PPO) were investigated in ground mixtures with gamma-cyclodextrin (gamma-CD). Crystalline PPO gradually became amorphous upon grinding in the presence of gamma-CD. Solid-state fluorescence spectra of the ground mixtures showed that the fluorescence emission peak due to PPO cryst... |
7512830 | The barrel-stave model as applied to alamethicin and its analogs reevaluated. | Alamethicin and its analogs from cation selective, multi-conductance channels in lipid bilayers. The conductance levels have been thought to be due to a barrel-stave structure where conducting pores (barrels) are formed by the self-assembly of a variable number of alpha-helical rods (staves). The conductance transition... |
8161680 | Structure and selectivity of a monovalent cation binding site in cubic insulin crystals. | Cubic insulin crystals contain a binding site for monovalent cations in a cavity of the crystal dyad in which the bound cation is ligated by protein atomic dipoles and water molecules. These types of interaction are analogous to interactions that occur in small cation-selective carrier and channel molecules. X-ray diff... |
7512676 | The quaternary structures of untransformed steroid hormone receptors: an open issue. | Oligomeric forms of steroid hormone receptors have been observed since the original detection of these proteins in cytosols from target tissues, and the capacity of receptors to arrange in supramolecular entities was found to be related to their functional untransformed states of low affinity for nuclear acceptor sites... |
8150941 | Norwalk virus-associated gastroenteritis traced to ice consumption aboard a cruise ship in Hawaii: comparison and application of molecular method-based assays. | Investigation of an outbreak of acute nonbacterial gastroenteritis on a cruise ship provided an opportunity to assess new molecular method-based diagnostic methods for Norwalk virus (NV) and the antibody response to NV infection. The outbreak began within 36 h of embarkation and affected 30% of 672 passengers and crew.... |
8149461 | Preparation of 6(1),6n-di-O-(tert-butyldimethylsilyl)-cyclomalto-octaoses. | Four positional isomers of 6(1),6n-di-O-(tert-butyldimethylsilyl)- cyclomalto-octaose (n = 2-5) were prepared by reaction of cyclomalto-octaose (1, cG8) with tert-butyldimethylsilyl chloride in pyridine, and were isolated by high-performance liquid chromatography. The regiochemical determination of those positional iso... |
8148875 | Extensin: repetitive motifs, functional sites, post-translational codes, and phylogeny. | Homologous hydroxyproline-rich glycoproteins (HRGPs) of the plant extracellular matrix include extensins, repetitive proline-rich proteins (RPRPs), some nodulins, gum arabic glycoprotein (GAGP), arabinogalactan-proteins (AGPs), and chimeric proteins such as potato lectin which contain an extensin module fused to a lect... |
8148074 | The significance of changes in serum tumour necrosis factor (TNF) activity in severely burned patients. | In order to explore the pathogenesis of postburn internal organ injury (OI) and multiple organ failure (MOF), serum TNF activity was measured by biological assay in 24 severely burned patients. Parameters related to internal organ functions were simultaneously measured. The results showed an obvious increase in serum T... |
8136914 | High-performance liquid chromatographic separation of cis-trans isomers of proline-containing peptides. II. Fractionation in different cyclodextrin systems. | beta-Cyclodextrin-bonded silica is demonstrated to be a suitable stationary phase for high-performance liquid chromatography of conformational isomers of proline-containing peptides. In contrast to reversed-phase chromatography, the principle of inclusion complexation shows significant selectivities in conformer resolu... |
8136571 | Monitoring of the cellular immune system in patients with biventricular assist devices awaiting cardiac transplantation. | Lack of objective parameters to predict the clinical course and outcome are a major problem in managing the patients selected for BVAD-support as a bridge to heart transplantation. This study was intended to assess whether cellular immune parameters have a predictive value for the clinical result of VAD-support. Variou... |
8135514 | Engineering and production of streptokinase in a Bacillus subtilis expression-secretion system. | Streptokinase is one of the major blood-clot-dissolving agents used in many medical treatments. With the cloned streptokinase gene (skc) available, production of the secreted streptokinase from various Bacillus subtilis strains was studied. The use of the six-extracellular-protease-deficient strain, WB600, greatly impr... |
8129728 | Synthesis of recombinant human procollagen II in a stably transfected tumour cell line (HT1080). | Apparently because the biosynthetic pathways involve eight or more highly specific post-translational enzymes, it has been difficult to obtain expression of genes for fibrillar collagens in recombinant systems. Here two constructs of the human gene for procollagen II (COL2A1) were prepared, one with about 0.5 kb of a p... |
8129710 | alpha-Actinin from chicken gizzard: at low temperature, the onset of actin-gelling activity correlates with actin bundling. | The effect of alpha-actinin from chicken gizzard on the properties of F-actin solutions at 37 degrees C and at 4 degrees C was investigated. Beside the well-known increase of the gelling activity of alpha-actinin, it was found that lowering temperature to 4 degrees C: (a) modifies the shape of the alpha-actinin-F-acti... |
8129708 | Site and significance of chemically modifiable cysteine residues in glutamate dehydrogenase of Clostridium symbiosum and the use of protection studies to measure coenzyme binding. | Protein chemical studies of NAD(+)-dependent glutamate dehydrogenase (GDH; EC 1.4.1.2) from Clostridium symbiosum indicate only two cysteine residues/subunit, in good agreement with the gene sequence. Experiments with various thiol-modifying reagents reveal that in native clostridial GDH only one of these two cysteines... |
8127704 | Identification of cis- and trans-acting elements involved in the expression of cold shock-inducible TIP1 gene of yeast Saccharomyces cerevisiae. | Northern blot hybridization analysis of a series of 5' end, 3' end and internal deletions has revealed that at least four different regions are involved in the regulation of the expression of TIP1, a cold shock-inducible gene of Saccharomyces cerevisiae. One of these four regions has negative effect on the expression o... |
8127692 | Dynamics of transfer RNAs analyzed by normal mode calculation. | Normal mode calculation is applied to tRNAPhe and tRNAAsp, and their structural and vibrational aspects are analyzed. Dihedral angles along the phosphate-ribose backbone (alpha, beta, gamma, epsilon, zeta) and dihedral angles of glycosyl bonds (chi) are selected as movable parameters. The calculated displacement of eac... |
7907417 | Mutation of a single lysine residue severely impairs the DNA recognition and regulatory functions of the VZV gene 62 transactivator protein. | The product of varicella-zoster virus gene 62 (VZV 140k) is a potent transactivator protein. We have identified a region within the DNA binding domain of VZV 140k that shows a striking similarity to the DNA recognition helix of the homeodomain, with an especially highly conserved quartet of residues, WLQN. The 140k pro... |
8121390 | [The beneficial effects of PGI2 analogue (OP-41483-alpha-CD) on hepatic dysfunction after warm ischemic damage]. | The purpose of the experimental study was to investigate the beneficial effects of aPGI2 analogue (OP-41483-alpha-CD; aPGI2) on hepatic dysfunction after warm ischemia and reperfusion. Hepatic warm ischemia was produced by temporary clamping of the portal vein and hepatic artery. Experimental groups were divided into t... |
8121178 | Phospholipase A2 regulates critical inflammatory mediators of multiple organ failure. | PLA2 is a family of regulatory enzymes that control eicosanoid synthesis and PAF production. PLA2 must be tightly regulated within the cell or cell destruction results. Circulatory release of PLA2 occurs in states of profound illness including sepsis, shock, severe injury, and pancreatitis, all of which are linked to t... |
8119401 | pH-dependent formation of ethylenediaminetetraacetic acid supramolecular aggregates. | Pure ethylenediaminetetraacetic acid tetrasodium salt (EDTA.Na4) in water showed a pH-dependent change of optical density detected in the ultraviolet region. The most important change was found between pH 4 and 8, corresponding to the deprotonation of the third ionizable group having a pK of 6.2. The absorbance change ... |
8119360 | Genetic relationships between foot-and-mouth disease type Asia 1 viruses. | The sequence of 165 nucleotides at the 3' end of the 1D (VP1) gene of foot-and-mouth disease (FMD) virus was determined for 44 type Asia 1 strains isolated from throughout Asia between 1954-92. Analysis of the relationships between the virus genomes showed epidemiological links not previously evident. The possible orig... |
8114089 | Molecular recognition of the identity-determinant set of isoleucine transfer RNA from Escherichia coli. | Molecular recognition of Escherichia coli tRNA(Ile) by the cognate isoleucyl-tRNA synthetase (IleRS) was studied by analyses of chemical footprinting with N-nitroso-N-ethylurea and aminoacylation kinetics of variant tRNA(Ile) transcripts prepared with bacteriophage T7 RNA polymerase. IleRS binds to the acceptor, dihydr... |
7509279 | Dissociation of TNF-alpha cytotoxic and proinflammatory activities by p55 receptor- and p75 receptor-selective TNF-alpha mutants. | Human tumour necrosis factor alpha (TNF-alpha) is a pleiotropic cytokine capable of killing mammalian tumour cells in vitro and in vivo, and of enhancing the proinflammatory activity of leucocytes and endothelium, the latter effects limiting its usage as an antitumour agent in humans. Using TNF-alpha mutants with a sel... |
8110818 | Polymorphic phase behavior of perfluoroalkylated phosphatidylcholines. | The polymorphic phase behavior of the F-alkyl modified phosphatidylcholines FnCmPC with Fn = CnF2n + 1 and Cm = -(CH2)m- and the physicochemical properties of their aqueous dispersions have been investigated. We show that the supramolecular assemblies formed by F4C4PC, F6C4PC, F8C4PC and F4C10PC dispersed in water cons... |
8110205 | Substrate analogues as probes of the catalytic mechanism of L-mandelate dehydrogenase from Rhodotorula graminis. | A detailed kinetic analysis of the oxidation of mono-substituted mandelates catalysed by L-(+)-mandelate dehydrogenase (L-MDH) from Rhodotorula graminis has been carried out to elucidate the role of the substrate in the catalytic mechanism. Values of Km and kcat. (25 degrees C, pH 7.5) were determined for mandelate and... |
8107802 | Self-assembly of a double-helical complex of sodium. | Spontaneous self-organization of helical and multiple-helical molecular structures occurs on several levels in living organisms. Key examples are alpha-helical polypeptides, double-helical nucleic acids and helical protein structures, including F-actin, microtubules and the protein sheath of the tobacco mosaic virus. A... |
8107143 | Nucleotide sequence and X-ray structure of cyclodextrin glycosyltransferase from Bacillus circulans strain 251 in a maltose-dependent crystal form. | The cyclodextrin glycosyltransferase (CGTase, EC 2.4.1.19) gene from Bacillus circulans strain 251 was cloned and sequenced. It was found to code for a mature protein of 686 amino acid residues, showing 75% identity to the CGTase from B. circulans strain 8. The X-ray structure of the CGTase was elucidated in a maltodex... |
8107128 | Holliday junction crossover topology. | The Holliday junction is a key intermediate in genetic recombination. It consists of four strands of DNA that associate to form four double-helical arms. Studies over the past decade with asymmetric analogs of Holliday junctions have shown that the four arms stack to generate two stacking domains. This arrangement of a... |
8107106 | Structural dependence of post-translational modification and reductive acetylation of the lipoyl domain of the pyruvate dehydrogenase multienzyme complex. | The lipoyl domain of the dihydrolipoyl acetyltransferase (E2) component of the pyruvate dehydrogenase multienzyme complex is recognized specifically by the lipoylating enzyme(s) in the cell and by the pyruvate dehydrogenase (E1) component in the parent complex. Highly conserved aspartic acid and alanine residues flank ... |
8107099 | Interrelations of secondary structure stability and DNA-binding affinity in the bacteriophage SPO1-encoded type II DNA-binding protein TF1. | TF1, a homodimeric DNA-binding and -bending protein with a preference for hydroxymethyluracil-containing DNA is the Bacillus subtilis-encoded homolog of the bacterial HU proteins and of the E. coli integration host factor. A temperature-sensitive mutation at amino acid 25 of TF1 (L25-->A) and two intragenic second site... |
8107092 | Refined molecular structure of pig pancreatic alpha-amylase at 2.1 A resolution. | The structure of pig pancreatic alpha-amylase has been determined by X-ray diffraction analysis using multiple isomorphous replacement in a crystal of space group P2(1)2(1)2(1) (a = 70.6 A, b = 114.8 A, c = 118.8 A) containing nearly 75% solvent. The structure was refined by simulated annealing and Powell minimization,... |
8106548 | Assembly of body wall muscle and muscle cell attachment structures in Caenorhabditis elegans. | C. Elegans has four muscle quadrants that are used for locomotion. Contraction is converted to locomotion because muscle cells are anchored to the cuticle (the outer covering of the worm) by a specialized basement membrane and hemidesmosome structures in the hypodermis (a cellular syncytium that covers the worm and sec... |
7508686 | Induction of interleukin-8 synthesis from monocytes by human C5a anaphylatoxin. | Interleukin-8 (IL-8) is an important mediator of inflammation and has been shown to be a potent chemotactic/cell activator for polymorphonuclear neutrophils (PMNs). T lymphocytes, and basophils. Cellular sources of IL-8 include monocytes, PMNs, endothelial cells, epithelial cells, and keratinocytes when stimulated by f... |
8310402 | Immunologic assessment of host defense impairment in patients with septic multiple organ failure: relationship between complement activation and changes in neutrophil function. | <h4>Background</h4>The pathogenesis of gram-negative sepsis-induced multiple organ failure (MOF) remains to be elucidated.<h4>Methods</h4>Blood samples were obtained from eleven patients with septic MOF, three patients with sepsis, three patients who underwent operation, and three healthy volunteers. In these patients ... |
8307187 | Receptor-mediated endocytosis of plasminogen activators and activator/inhibitor complexes. | Recent findings have elucidated the mechanism for clearance from the extracellular space of the two types of plasminogen activators, urokinase-type plasminogen activator (u-PA) and tissue-type plasminogen activator (t-PA), and their type-1 inhibitor (PAI-1). Activator/PAI-1 complexes and uncomplexed t-PA bind to the mu... |
8306260 | A comparative study of copper-67 radiolabeling and kinetic stabilities of antibody-macrocycle chelate conjugates. | <h4>Background</h4>The development of new chelating agents and radiolabeling protocols is essential to progress in radioimmunotherapy with antibody-chelate conjugates.<h4>Methods</h4>Immunoconjugates of four polyazamacrocycles with N-bonded acetate groups were prepared by conjugation via 2-iminothiolane to Lym-1, a mur... |
8302874 | Supramolecular organization of the mammalian translation system. | Although evidence suggests that the protein synthetic machinery is organized within cells, this point has been difficult to prove because any organization that might exist is lost upon preparation of the cell-free systems usually used to study translation in vitro. To examine this process under conditions more represen... |
8302868 | Candida albicans estrogen-binding protein gene encodes an oxidoreductase that is inhibited by estradiol. | Candida albicans, the most common fungal pathogen of humans, possesses an estrogen-binding protein (EBP) that binds mammalian estrogens with high affinity. We report here the cloning and complete nucleotide sequence of a gene encoding a C. albicans EBP. Amino acid sequences obtained from cyanogen bromide fragments of p... |
8302865 | Evidence for a non-alpha-helical DNA-binding motif in the Rel homology region. | The Rel family of transcription factors serve as terminal messengers in a variety of developmental and receptor-mediated signaling pathways. These proteins are related by a domain of approximately 280 amino acids, the Rel homology region, which mediates dimerization and sequence-specific binding to DNA. Here we report ... |
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