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8096212 | Cloning and sequencing of the Escherichia coli panB gene, which encodes ketopantoate hydroxymethyltransferase, and overexpression of the enzyme. | The panB gene from Escherichia coli, encoding the first enzyme of the pantothenate biosynthesis pathway, ketopantoate hydroxymethyltransferase (KPHMT), has been isolated by functional complementation of a panB mutant strain with an E. coli genomic library. The gene is 792 bp long, encoding a protein of 264 amino acids ... |
8458846 | Analysis of the promoter and regulatory sequences of an oxygen-regulated bch operon in Rhodobacter capsulatus by site-directed mutagenesis. | The biosynthesis of pigments (carotenoids and bacteriochlorophylls) in the photosynthetic bacterium Rhodobacter capsulatus is regulated by the oxygen concentration in the environment. However, the mechanism of this regulation has remained obscure. In this study, transcriptional fusions of the bchCXYZ promoter region to... |
8455607 | Relatedness of an RNA-binding motif in human immunodeficiency virus type 1 TAR RNA-binding protein TRBP to human P1/dsI kinase and Drosophila staufen. | TRBP is a human cellular protein that binds the human immunodeficiency virus type 1 TAR RNA. Here, we show that the intact presence of amino acids 247 to 267 in TRBP correlates with its ability to bind RNA. This region contains a lysine- and arginine-rich motif, KKLAKRNAAAKMLLRVHTVPLDAR. A 24-amino-acid synthetic pepti... |
7681044 | Evidence that lipopolysaccharide and pertussis toxin bind to different domains on the same p73 receptor on murine splenocytes. | In previous studies, we used a photoactivable, radioiodinated lipopolysaccharide (LPS) derivative to define and characterize a specific bacterial endotoxic LPS-binding protein (p73) on mammalian lymphoreticular cells, including B and T lymphocytes and macrophages. More recently, using the same methodology, we character... |
7680391 | Definition of a minimal optimal cytotoxic T-cell epitope within the hepatitis B virus nucleocapsid protein. | Residues 11 to 27 of the hepatitis B virus nucleocapsid antigen contain a cytotoxic T-cell epitope that is recognized by cytotoxic T cells from virtually all HLA-A2-positive patients with acute hepatitis B virus infection. Using panels of truncated and overlapping peptides, we now show that the optimal amino acid seque... |
8095307 | Different requirements for membrane fusion mediated by the envelopes of human immunodeficiency virus types 1 and 2. | CD4+ cells derived from the human cell lines U87MG and SCL1 cannot be infected by human immunodeficiency virus type 1 (HIV-1) or fuse with cells expressing the HIV-1 envelope. This block was complemented in heterokaryons with HeLa cells and probably reflects the absence of cellular factors necessary for membrane fusion... |
8383239 | WIN 52035-2 inhibits both attachment and eclipse of human rhinovirus 14. | WIN compounds inhibit attachment of human rhinovirus 14 by binding to a hydrophobic pocket within the capsid and inducing conformational changes in the canyon floor, the region that binds the cellular receptor. To study the basis of drug resistance, we isolated and characterized a family of human rhinovirus 14 mutants ... |
8383233 | Role of maturation cleavage in infectivity of picornaviruses: activation of an infectosome. | Maturation of picornaviruses involves assembly of a "provirion," which undergoes an autocatalytic cleavage of VP0 to VP2 plus VP4. RNA transcripts from a cDNA clone of human rhinovirus 14 mutated at asparagine 68, one of the residues in the maturation cleavage site, generated normal yields of 150S particles which were ... |
8383228 | Physical and functional characterization of transcriptional control elements in the equine infectious anemia virus promoter. | Equine infectious anemia virus (EIAV) is a lentivirus that causes a chronic disease of horses characterized by cyclic episodes of fever, anemia, and viremia. Although the genome and promoter of EIAV are much less complex than those of its relatives the primate immunodeficiency viruses, the cellular proteins that activa... |
8383219 | Expression of human papillomavirus type 11 L1 protein in insect cells: in vivo and in vitro assembly of viruslike particles. | The L1 coat protein of human papillomavirus type 11 (HPV-11) was expressed in Sf-9 insect cells with the recombinant baculovirus vector Ac11L1. Viruslike particles (VLPs) were identified by electron microscopy in the nucleus and cytoplasm of Sf-9 cells infected with Ac11L1. The L1 protein was purified from Ac11L1-infec... |
19431886 | Raman dispersion spectroscopy probes heme distortions in deoxyHb-trout IV involved in its T-state Bohr effect. | The depolarization ratios of heme protein Raman lines arising from vibrations of the heme group exhibit significant dependence on the excitation wavelength. From the analysis of this depolarization ratio dispersion, one obtains information about symmetry-lowering distortions deltaQ(Gamma) of the heme group that can be ... |
18965656 | Spectrophotometric study of Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and Pb(II) complexes with some crown ethers in dimethylsulphoxide solution using murexide as a metallochromic indicator. | The complexation reactions between Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and Pb(II) ions and benzo-15-crown-5, dicyclohexyl-18-crown-6, dibenzo-18-crown-6 and 1,10-diaza-18-crown-6 have been studied in dimethylsulphoxide solution at 25 degrees by means of a competitive spectrophotometric method using murexide as a met... |
18601281 | Affinity precipitation of proteins by polyligands. | A novel technique for affinity precipitation has been developed in which multimeric target proteins are precipitated as a result of network formation by polymer-conjugated ligands (polyligands). A polyligand precipitant for avidin was synthesized by conjugation of biotin to a polyacrylamide-based backbone. The effects ... |
8477740 | Identification of novel phosphorylation sites in murine A-type lamins. | We report the distribution of phosphorylation sites in murine lamins A and C (A-type lamins) in vitro and in vivo followed by reverse-phase high-performance liquid chromatography and microsequencing of peptides spanning the almost complete lamin sequence. We show that two distinct protein kinases, cell-division-cycle-2... |
8475121 | Probability model for molecular recognition in biological receptor repertoires: significance to the olfactory system. | A generalized phenomenological model is presented for stereospecific recognition between biological receptors and their ligands. We ask what is the distribution of binding constants psi(K) between an arbitrary ligand and members of a large receptor repertoire, such as immunoglobulins or olfactory receptors. For binding... |
8097321 | Outer-membrane PapC molecular usher discriminately recognizes periplasmic chaperone-pilus subunit complexes. | P pili are highly ordered composite structures consisting of thin fibrillar tips joined end-to-end to rigid helical rods. The production of these virulence-associated structures requires a periplasmic chaperone (PapD) and an outer membrane protein (PapC) that is the prototype member of a newly recognized class of prote... |
8475107 | Structure-based inhibitor design by using protein models for the development of antiparasitic agents. | The lack of an experimentally determined structure of a target protein frequently limits the application of structure-based drug design methods. In an effort to overcome this limitation, we have investigated the use of computer model-built structures for the identification of previously unknown inhibitors of enzymes fr... |
7682699 | Spontaneous assembly of a self-complementary oligopeptide to form a stable macroscopic membrane. | A 16-residue peptide [(Ala-Glu-Ala-Glu-Ala-Lys-Ala-Lys)2] has a characteristic beta-sheet circular dichroism spectrum in water. Upon the addition of salt, the peptide spontaneously assembles to form a macroscopic membrane. The membrane does not dissolve in heat or in acidic or alkaline solutions, nor does it dissolve u... |
7682697 | Pattern formation and handedness in the cytoskeleton of human platelets. | The cytoskeletal patterns of human platelets spread on a glass surface are analyzed. F-actin is arranged in patterns of parallel microfilaments, microfilaments forming triangles, or microfilaments radiating tangentially from a central ellipse or circle. Vinculin, a cytoskeletal protein, is located at both ends of the f... |
8251191 | Using a neural network to identify potential HLA-DR1 binding sites within proteins. | The presentation by antigen-presenting cells of immunodominant peptide segments in association with major histocompatibility complex (MHC) encoded proteins is fundamental to the efficacy of a specific immune response. One approach used to identify immunodominant segments within proteins has involved the development of ... |
8251190 | Design of novel cationic ligands for the purification of trypsin-like proteases by affinity chromatography. | A number of new cationic ligands have been designed and synthesized for the selective resolution and purification of the trypszin-like proteases. A series of ligands based on 4-[2'-methyl-4'-(2'',4''-dichloro-1'',3'',5''-triazin-6-ylamino ) phenylazo]benzamidine were able to bind to trypsin and the trypsin-like proteas... |
8251189 | Chiral separation using molecularly imprinted heteroaromatic polymers. | Novel molecularly imprinted polymer systems utilizing 4-vinylpyridine and 1-vinylimidazole as functional monomers have been developed for enantioselective recognition of carboxylic and N-protected amino acids. Non-covalent interactions between the functional monomers and the template molecules were the source of the su... |
8210677 | Release of lipopolysaccharide during Bordetella pertussis growth. | The effect of the addition of (2,6-O-dimethyl)-beta-cyclodextrin (Me beta CD) during growth of Bordetella pertussis in synthetic Stainer-Scholte liquid medium (SS) on lipopolysaccharide (LPS; endotoxin) release was investigated. The Me beta CD concentration used (3 mg/ml) was chosen according to the optimal level found... |
8357150 | [The current state of adjuvant treatment in carcinoma of the resected colon]. | After radical surgery for colo-rectal cancer, the prevention of local recurrence and/or distant metastasis, represents the key factor of the active measures adopted by surgeons and oncologists. Recent trends of the research in this field, show that an effective chemotherapy is the goal to achieve. Our review of the lit... |
8325235 | Site-specific cleavage of basement membrane collagen IV during Drosophila metamorphosis. | Breakdown of basement membranes is an important step in the controlled rearrangement of cells during metamorphosis, cell migration, and metastatic spread of tumor cells. One of our two laboratories found a unique collagenous peptide that only appears during metamorphosis of Drosophila melanogaster. The other laboratory... |
8317356 | [Application of cyclosporin for cornea graft]. | This study aimed to determine the optimal concentration rate of clinically effective Cyclosporin (CYA). Exchange penetrating keratoplasties were performed on 30 albino rabbits divided into 3 groups of ten, Groups I, II, and III, using 7 mm. trephine. In Group I 0.025% CYA drops were administered 4 times per day for 50 ... |
8506803 | [Intracavernous injection of lipo prostaglandin E1 for the diagnosis of impotence: a comparative study with prostaglandin E1-CD]. | Intracavernous injection of 20 micrograms prostaglandin E1-CD (PGE1-CD, 8 cases), 5 micrograms lipo prostaglandin E1 (Lipo PG-E1, 8 cases) or 10 micrograms Lipo PGE1 (9 cases) was performed in patients with functional impotence in order to comparatively analyze the diagnostic efficacy of these drugs. Full erection was ... |
8098529 | The general concept of molecular chaperones. | This introductory article proposes a conceptual framework in which to consider the information that is emerging about the proteins called molecular chaperones, and suggests some definitions that may be useful in this new field of biochemistry. Molecular chaperones are currently defined in functional terms as a class of... |
8485321 | Dynamics of microtubules from erythrocyte marginal bands. | Microtubules can adjust their length by the mechanism of dynamic instability, that is by switching between phases of growth and shrinkage. Thus far this phenomenon has been studied with microtubules that contain several components, that is, a mixture of tubulin isoforms, with or without a mixture of microtubule-associa... |
8097690 | Metabolism and disposition of a thiazolobenzimidazole active against human immunodeficiency virus-1. | This study was undertaken to evaluate the disposition of the thiazolobenzimidazole, 1-(2,6-difluorophenyl)-1H,3H-thiazolo[3,4-a]benzimidazole (TZB), which has promising antiviral activity. For mice, the maximum tolerated intravenous dose of TZB was 50 mg/kg. An HPLC procedure developed for TZB was used to determine the... |
8480998 | Distribution of viral abundance in the reef environment of Key Largo, Florida. | The distribution of viral and microbial abundance in the Key Largo, Fla., reef environment was measured. Viral abundance was measured by transmission electron microscope direct counts and plaque titer on specific bacterial hosts in water and sediment samples from Florida Bay (Blackwater Sound) and along a transect from... |
8472260 | Inclusion complexes of cyclomaltoheptaose (beta-cyclodextrin) and its methylated derivatives with the main components of the pheromone of the olive fruit fly. | The inclusion complexes of cyclomaltoheptaose (beta CD) and heptakis(2,3,6-tri-O-methyl)cyclomaltoheptaose (TM-beta CD) with the four major components of the pheromone of the olive fruit fly (Dacus oleae), namely 1,7-dioxaspiro[5.5]undecane, (-)-alpha-pinene, nonanal, and ethyl dodecanoate, and the complex of heptakis(... |
8471732 | Analysis of ordered arrays of adsorbed lysozyme by scanning tunneling microscopy. | Scanning tunneling microscopy (STM) has been used to observe lysozyme at a graphite surface directly in order to gain mechanistic information about the molecular events involved in protein adsorption. The experiments were performed using an insulated tip in an aqueous protein solution, allowing the time course of the a... |
8471727 | Nucleation and growth phases in the polymerization of coat and scaffolding subunits into icosahedral procapsid shells. | The polymerization of protein subunits into precursor shells empty of DNA is a critical process in the assembly of double-stranded DNA viruses. For the well-characterized icosahedral procapsid of phage P22, coat and scaffolding protein subunits do not assemble separately but, upon mixing, copolymerize into double-shell... |
8097117 | Site-directed mutagenesis of alpha-tubulin. Reductive methylation studies of the Lys 394 region. | Previous studies have implicated at least two regions in alpha-tubulin that are important for the regulation of microtubule assembly. These regions include a cluster of basic residues consisting of Arg 390, His 393, and Lys 394 and the highly acidic carboxyl terminus. Lys 394 is highly reactive to HCHO and NaCNBH3. The... |
8464727 | A study into the effects of protein binding on nucleotide conformation. | In this study, we examine the effects of binding to protein upon nucleotide conformation, by the comparison of X-ray crystal structures of free and protein-bound nucleotides. A dataset of structurally non-homologous protein-nucleotide complexes was derived from the Brookhaven Protein Data Bank by a novel protocol of du... |
8385311 | Retroviral vectors displaying functional antibody fragments. | We have made retrovirus particles displaying a functional antibody fragment. We fused the gene encoding an antibody fragment directed against a hapten with that encoding the viral envelope protein (Pr80env) of the ecotropic Moloney murine leukemia virus. The fusion gene was co-expressed in ecotropic retroviral packagin... |
8464405 | Pathogenesis of human immunodeficiency virus infection. | The lentivirus human immunodeficiency virus (HIV) causes AIDS by interacting with a large number of different cells in the body and escaping the host immune response against it. HIV is transmitted primarily through blood and genital fluids and to newborn infants from infected mothers. The steps occurring in infection i... |
8464403 | Protein secretion in Bacillus species. | Bacilli secrete numerous proteins into the environment. Many of the secretory proteins, their export signals, and their processing steps during secretion have been characterized in detail. In contrast, the molecular mechanisms of protein secretion have been relatively poorly characterized. However, several components o... |
8464402 | Bacillus subtilis sporulation: regulation of gene expression and control of morphogenesis. | Bacillus subtilis sporulation is an adaptive response to nutritional stress and involves the differential development of two cells. In the last 10 years or so, virtually all of the regulatory genes controlling sporulation, and many genes directing the structural and morphological changes that accompany sporulation, hav... |
8464348 | Hypolipidemic effects of beta-cyclodextrin in the hamster and in the genetically hypercholesterolemic Rico rat. | The effect of increasing amounts of a cyclic oligosaccharide, beta-cyclodextrin (BCD), included in the diet on plasma cholesterol and triglycerides, was investigated in two animal models, namely in male genetically hypercholesterolemic Rico rats and in male Syrian hamsters. The distribution of bile acids in the gastroi... |
8461030 | Protection of erythrocytes against hemolytic agents by cyclodextrin polysulfate. | Cyclodextrins generally exhibit hemolytic activity, some at concentrations as low as 1-10 mg/mL or lower. However, we found previously that a highly polysulfated cyclodextrin has no demonstrable hemolytic activity (Macarak et al., Biochem Pharmacol 42: 1502-1503, 1991). In the present study, we determined that, in fact... |
8460151 | Inhibitors of human immunodeficiency virus integrase. | In an effort to further extend the number of targets for development of antiretroviral agents, we have used an in vitro integrase assay to investigate a variety of chemicals, including topoisomerase inhibitors, antimalarial agents, DNA binders, naphthoquinones, the flavone quercetin, and caffeic acid phenethyl ester as... |
8459852 | Thermodynamic beta-sheet propensities measured using a zinc-finger host peptide. | The three-dimensional structures of proteins reveal that the distribution of amino acids within the major classes of secondary structure is not random but that each amino acid has its own preferred secondary structural arrangements. Propensity scales for residues in alpha-helices have been generated through the use of ... |
8458895 | Identification and quantitation of intact diastereoisomeric benzodiazepine glucuronides in biological samples by high-performance liquid chromatography. | A rapid and simple high-performance liquid chromatographic method for the simultaneous detection of intact glucuronides of different benzodiazepines is described. Separation of the diastereomers of the following benzodiazepine glucuronides can be achieved on a reversed-phase column (octadecyl or select B): oxazepam, no... |
8096174 | Initiation of assembly and association of the structural elements of a bacterial pilus depend on two specialized tip proteins. | Uropathogenic Escherichia coli produce heteropolymeric surface fibers called P pili, which present an adhesin at their tip that specifically recognizes globoside receptors on the host uroepithelium. The initial attachment step is thought to be essential for pathogenesis. P pili are composite fibers consisting of a thin... |
8384550 | Analysis of strand exchange and DNA binding of enhancer-independent Gin recombinase mutants. | The Gin recombination system of phage Mu mediates inversion of the DNA sequence between two sites (gix). In addition to Gin protein and gix sites, recombination requires an enhancer bound by the host factor FIS. We analyzed mutants of Gin that function in the absence of the enhancer and FIS and mediate deletion and int... |
8384446 | The role of inorganic metals and metalloporphyrins in the induction of haem oxygenase and heat-shock protein 70 in human hepatoma cells. | The role of inorganic metals and metalloporphyrins in the induction of mRNAs for haem oxygenase and heat-shock protein 70 (hsp70), the two heat-shock proteins, was examined in human HepG2 and Hep3B hepatoma cells. SnCl2, but not Sn-protoporphyrin, was found to be a potent inducer of both haem oxygenase and hsp70 mRNAs.... |
8456938 | Extracellular matrix components induce endocrine differentiation in vitro in NCI-H716 cells. | Endocrine cells occur in +/- 30% of colorectal adenocarcinomas. The significance of this phenomenon in terms of tumor behavior is still controversial. Endocrine differentiation in colorectal cancer cell lines is almost confined to tumor xenografts in vivo, suggesting that endocrine differentiation might be regulated by... |
8453379 | Bacterial expression and photoaffinity labeling of a pheromone binding protein. | The first high-level production of a binding-active odorant binding protein is described. The expression cassette polymerase chain reaction was used to generate a DNA fragment encoding the pheromone binding protein (PBP) of the male moth Antheraea polyphemus. Transformation of Escherichia coli cells with a vector conta... |
8453377 | Unnatural amino acid packing mutants of Escherichia coli thioredoxin produced by combined mutagenesis/chemical modification techniques. | We have produced several mutants of Escherichia coli thioredoxin (Trx) using a combined mutagenesis/chemical modification technique. The protein C32S, C35S, L78C Trx was produced using standard mutagenesis procedures. After unfolding the protein with guanidine hydrochloride (GdmCl), the normally buried cysteine residue... |
8453373 | Ribonuclease S-peptide as a carrier in fusion proteins. | S-peptide (residues 1-20) and S-protein (residues 21-124) are the enzymatically inactive products of the limited digestion of ribonuclease A by subtilisin. S-peptide binds S-protein with high affinity to form ribonuclease S, which has full enzymatic activity. Recombinant DNA technology was used to produce a fusion prot... |
8095833 | Conformational change of chaperone Hsc70 upon binding to a decapeptide: a circular dichroism study. | The conformation of bovine Hsc70, a 70-kDa heat shock cognate protein, and its conformational change upon binding to decapeptides, was studied by CD spectroscopy and secondary structure prediction (Chou, P.Y. & Fasman, G.D., 1974, Biochemistry 13, 222-245). The CD spectra were analyzed by the LINCOMB method, as well as... |
7680901 | Evidence for the lumenal location of the 53 kDa glycoprotein of sarcoplasmic reticulum. | The 53 kDa glycoprotein from sarcoplasmic reticulum was shown to be protected from proteolysis by trypsin, V8 proteinase and proteinase K in intact vesicles yet readily digested in the presence of the non-denaturing detergent C12E8. Competitive ELISAs with a library of seven monoclonal antibodies raised against the 53 ... |
8452544 | Nucleotide sequence and over-expression of morphine dehydrogenase, a plasmid-encoded gene from Pseudomonas putida M10. | Pseudomonas putida M10 was originally isolated from factory waste liquors by selection for growth on morphine. The NADP(+)-dependent morphine dehydrogenase that initiates morphine catabolism is encoded by a large plasmid of 165 kb. Treatment of P. putida M10 with ethidium bromide led to the isolation of a putative plas... |
8452521 | Further observations on the Mg-protoporphyrin IX monomethyl ester (oxidative) cyclase system. | The Mg-protoporphyrin IX monomethyl ester (oxidative) cyclase was strongly inhibited by CN- and N3- in a reconstituted system, but was inhibited slightly or not at all by the same reagents in intact developing chloroplasts. Known inhibitors of cytochrome P-450 processes showed no consistent effect. Benzoquinone and qui... |
8095695 | Compartmentation of receptors and guanine nucleotide-binding proteins in NG108-15 cells: lack of cross-talk in agonist binding among the alpha 2-adrenergic, muscarinic, and opiate receptors. | Many different types of receptors couple to the inhibitory guanine nucleotide-binding protein (G protein) Gi. In NG108-15 neuroblastoma-glioma cells, alpha 2b-adrenergic, m4 muscarinic, and delta-opiate receptors all use Gi as a transducer. According to the ternary complex model of receptor-G protein interactions, agon... |
7680663 | Higher-affinity oligosaccharide ligands for E-selectin. | A series of synthetic oligosaccharides based on sialyl Lewis x (sLex; Neu5Ac alpha 2-3Gal beta 1-4[Fuc alpha 1-3]GlcNAc) and sialyl Lewis a (sLea; Neu5Ac alpha 2-3Gal beta 1-3[Fuc alpha 1-4]GlcNAc) was used to study the binding interactions of selectins. E-selectin-immunoglobulin fusion protein (E-selectin-Ig) bound to... |
8449867 | DNA binding and bending are necessary but not sufficient for Fis-dependent activation of rrnB P1. | The Escherichia coli Fis protein binds to three sites in the upstream activation region of the rrnB P1 promoter and enhances transcription 5- to 10-fold in vivo. In this report, we investigate the mechanism of Fis-dependent activation of transcription. We show that stimulation of rrnB P1 transcription by Fis can occur ... |
8449096 | Immunologic therapy for ARDS, septic shock, and multiple-organ failure. | Advances in cytokine biology and molecular biology have led to the development of novel immunologic approaches to the treatment of septic shock, ARDS, and MOF. These advances are necessary since improvements in supportive care clearly fall short of the hoped-for reductions in mortality associated with these disorders. ... |
8095403 | Binding and hydrolysis of nucleotides in the chaperonin catalytic cycle: implications for the mechanism of assisted protein folding. | Cpn60 was labeled with pyrene maleimide in order to follow structural rearrangements in the protein triggered by the binding of nucleotides and cpn10. The conjugate binds ATP, AMP-PNP, and ADP(P(i)) with pyrene fluorescence enhancements of 60%, 60%, and 15%, respectively. In each case, binding is cooperative with half-... |
8448106 | 5-hydroxytryptophan as a new intrinsic probe for investigating protein-DNA interactions by analytical ultracentrifugation. Study of the effect of DNA on self-assembly of the bacteriophage lambda cI repressor. | Pairwise cooperativity between proteins bound to DNA is believed to be important in governing the transcriptional regulation of numerous genes. However, the spectral overlap of normal proteins and DNA has blocked the study of these interactions by many physical methods. As shown recently by Ross et al. (in press), lamb... |
8444809 | Derepression of LamB protein facilitates outer membrane permeation of carbohydrates into Escherichia coli under conditions of nutrient stress. | The level of LamB protein in the outer membrane of Escherichia coli was derepressed in the absence of a known inducer (maltodextrins) under carbohydrate-limiting conditions in chemostats. LamB protein contributed to the ability of the bacteria to remove sugar from glucose-limited chemostats, and well-characterized lamB... |
8441415 | Alpha B-crystallin expression in mouse NIH 3T3 fibroblasts: glucocorticoid responsiveness and involvement in thermal protection. | alpha B-crystallin, a major soluble protein of vertebrate eye lenses, is a small heat shock protein which transiently accumulates in response to heat shock and other kinds of stress in mouse NIH 3T3 fibroblasts. Ectopic expression of an alpha B-crystallin cDNA clone renders NIH 3T3 cells thermoresistant. alpha B-crysta... |
7680094 | Abnormal muscle development in the heldup3 mutant of Drosophila melanogaster is caused by a splicing defect affecting selected troponin I isoforms. | The troponin I (TnI) gene of Drosophila melanogaster encodes a family of 10 isoforms resulting from the differential splicing of 13 exons. Four of these exons (6a1, 6a2, 6b1, and 6b2) are mutually exclusive and very similar in sequence. TnI isoforms show qualitative specificity whereby each muscle expresses a selected ... |
8441383 | Isolation and characterization of DNA sequences that are specifically bound by wild-type p53 protein. | Wild-type p53 was shown to function as a transcription factor. The N-terminal region of the protein contains the transcription activation domain, while the C terminus is responsible for DNA binding. Localization of the DNA-binding domain of the p53 protein to the highly conserved carboxy-terminal region suggests that t... |
8441057 | Scintigraphic methods for detecting vascular thrombus. | Vascular thrombosis is a common and potentially life-threatening condition, but objective diagnosis is highly desirable before anticoagulant therapy is instituted. Existing nonscintigraphic modalities such as contrast venography and ultrasonography can image venous morphology but cannot reliably indicate the hematologi... |
8441052 | From monoclonal antibodies to peptides and molecular recognition units: an overview. | Various antigen-specific monoclonal antibodies (Mabs) are now being used clinically. Applications include in vitro testing (radioimmunoassay) and in vivo imaging (radioimmunoscintigraphy) for the early detection and staging of disease. Mabs can also be used as vehicles for delivering therapy (radioimmunotherapy) or to ... |
8382315 | Purification and characterization of the DNA-binding activity of the Epstein-Barr virus DNA polymerase accessory protein BMRF1 gene products, as expressed in insect cells by using the baculovirus system. | A recombinant baculovirus containing the complete sequence for the Epstein-Barr virus (EBV) BMRF1 gene product, the EBV DNA polymerase accessory protein, under the control of the polyhedrin promoter was constructed. Insect cells infected with the recombinant virus produced two phosphoproteins of 52 and 50 kDa and one u... |
8382302 | Cooperation of structural proteins during late events in the life cycle of polyomavirus. | The polyomavirus minor late capsid antigen, VP2, is myristylated on its N-terminal glycine, this modification being required for efficient infection of mouse cells. To study further the functions of this antigen, as well as those of the other minor late antigen, VP3, recombinant baculoviruses carrying genes for VP1, VP... |
8094718 | Structurally related class I and class II receptor protein tyrosine kinases are down-regulated by the same E3 protein coded for by human group C adenoviruses. | Receptor tyrosine kinases (RTKs) are grouped into subcategories based on shared sequence and structural features. Human group C adenoviruses down-regulate EGF receptors, which are members of the class I family of RTKs, during the early stages of infection. Adenovirus appears to utilize a nonsaturable intracellular path... |
8436589 | A 27,000-D core of the Dictyostelium 34,000-D protein retains Ca(2+)-regulated actin cross-linking but lacks bundling activity. | Actin cross-linking proteins are important for formation of isotropic F-actin networks and anisotropic bundles of filaments in the cytoplasm of eucaryotic cells. A 34,000-D protein from the cellular slime mold Dictyostelium discoideum mediates formation of actin bundles in vitro, and is specifically incorporated into f... |
8432611 | Characterization of specific binding of a human immunoglobulin M monoclonal antibody to lipopolysaccharide and its lipid A domain. | The human immunoglobulin M monoclonal antibody HA-1A was first described as an antibody which bound specifically to the lipid A region of lipopolysaccharide (LPS) (N. N. H. Teng, H. S. Kaplan, J. M. Herbert, C. Moore, H. Douglas, A. Wunderlich, and A. Braude, Proc. Natl. Acad. Sci. USA 82:1790-1794, 1985) and provided ... |
8094384 | Proteus mirabilis fimbriae: N-terminal amino acid sequence of a major fimbrial subunit and nucleotide sequences of the genes from two strains. | Proteus mirabilis, a common cause of urinary tract infection in hospitalized and catheterized patients, produces mannose-resistant/klebsiella-like (MR/K) and mannose-resistant/proteus-like (MR/P) hemagglutinins. The gene encoding the major structural subunit of a fimbria, possibly MR/K, was identified in two strains. A... |
24234853 | Gas-phase complexation of polyethers with halide ions. | Gas-phase complexes of halide anions with a variety of crown ethers and acyclic analogs are formed by ion-molecule reactions in the chemical ionization source of a triple-quadrupole mass spectrometer. The ether complexes of iodide, bromide, and chloride dissociate on collisional activation by cleavage of the halide-eth... |
24234849 | "Slow" metastable decomposition of oligosaccharide cations produced in an external source fourier transform mass spectrometer. | Unimolecular metastable decomposition of cucyclodextrin cations is observed in a fast-atom bombardment Fourier transform mass spectrometry instrument. Cleavage reactions occur at the glycosidic bonds to produce oligomeric fragment ions. The first-order rate constant for the decay of the protonated parent was measured a... |
8477506 | Direct injection analysis of atenolol enantiomers in plasma using an achiral/chiral coupled column HPLC system. | A novel HPLC system was developed with an achiral/chiral coupled column for the direct injection analysis of atenolol (AT) enantiomers in plasma. The system consists of a size-exclusion column, an ODS silica column and a newly developed beta-cyclodextrin perphenylcarbamate(ph-beta-CD)-bonded silica column connected in ... |
8477005 | Chemical characterization and toxicity of dihydro derivatives of nodularin and microcystin-LR, potent cyanobacterial cyclic peptide hepatotoxins. | Dihydro derivatives of nodularin (1) and microcystin-LR (4), potent cyclic peptide hepatotoxins isolated from Nodularia spumigena and Microcystis aeruginosa, respectively, were prepared by sodium borohydride reduction of the dehydroamino acid residues. The two stereoisomers of both dihydronodularin (2 and 3) and dihydr... |
11607365 | Modeling the complexation of substituted benzenes by a cyclophane host in water. | Monte Carlo statistical mechanics simulations have been used to study the complexation of disubstituted benzenes by Diederich's octamethoxy tetraoxaparacyclophane host. Relative free energies of binding were obtained in water at 25 degrees C for benzene, p-xylene, p-cresol, p-dicyanobenzene, and hydroquinone from stati... |
8392462 | Antisense inhibition of AMEL translation demonstrates supramolecular controls for enamel HAP crystal growth during embryonic mouse molar development. | During tooth development, enamel organ epithelial cells express a tissue-specific gene product (amelogenin) which presumably functions to control calcium hydroxyapatite crystal growth patterns during enamel biomineralization. The present studies were designed to test the hypothesis that amelogenin as a supramolecular a... |
8495216 | The generation of stable CHO cell lines expressing very high levels of complement C5A receptors and subsequent modulation of binding affinity for C5A. | A single gene fragment encoding for the C5a receptor was produced by reverse transcription of mRNA isolated from differentiated U937 cells and subsequently amplified by means of the polymerase chain reaction. This fragment was introduced into the mammalian expression vector pEE6hCMV.neo and used to transfect a CHO cell... |
8460527 | A H1 hemagglutinin of a human influenza A virus with a carbohydrate-modulated receptor binding site and an unusual cleavage site. | Two receptor binding variants of the influenza virus A/Tübingen/12/85 (H1N1) were separated by their different plaque formation in MDCK cells. Hemagglutination of variant I was restricted to red blood cells of guinea pigs, whereas variant II also hemagglutinated chicken cells. The variants differed also in their abilit... |
8384500 | Charge transport by ion translocating membrane proteins on solid supported membranes. | A new method for the investigation of ion translocating membrane proteins is presented. Protein containing membrane fragments or vesicles are adsorbed to a solid supported membrane. The solid supported membrane consists of a lipid monolayer on a gold evaporated or gold sputtered glass substrate which is coated with a l... |
8384365 | Preparation of heptakis(2,6-di-O-ethyl)-beta-cyclodextrin and its nuclear magnetic resonance spectroscopic characterization. | Heptakis(2,6-di-O-ethyl)-beta-cyclodextrin (DE-beta-CyD) was prepared and its 1H and 13C nuclear magnetic resonance (NMR) signals in DMSO-d6 were unequivocally assigned by two-dimensional COSY and ROESY. The results on 1H coupling constants indicated that all ethylated glucose units are in a 4C1 chair conformation. The... |
8456063 | Applications of capillary electrophoresis in pharmaceutical analysis. | The role of capillary electrophoresis (CE) in the analysis of peptide/proteins, chiral pharmaceuticals, and other small-molecule drugs has been reviewed. Potential uses of CE range from purity and structural confirmation to a micropreparative technique. Strategies for the prevention of protein wall adsorption include t... |
8383931 | Enantioselective enzymatic biotransformation of 2'-deoxy-3'-thiacytidine (BCH 189) monitored by capillary electrophoresis. | Concentrations of the enantiomers of 2'-deoxy-3'-thiacytidine (BCH 189) have been monitored during enantiospecific biotransformation catalyzed by cytidine deaminase. This enzymatic reaction is monitored by capillary electrophoresis (CE) over a 51-h time period. The use of dimethyl-beta-cyclodextrin as a chiral electrol... |
8383840 | Interactions between HIV-1 nucleocapsid protein and viral DNA may have important functions in the viral life cycle. | In the virion core of retroviruses, the genomic RNA is tightly associated with nucleocapsid (NC) protein molecules, forming the nucleocapsid structure. NC protein, a highly basic protein with two zinc fingers, is indispensable for RNA dimerization, encapsidation and the initiation of reverse transcription in avian, mur... |
8450564 | Surface behavior of axolemma monolayers: physico-chemical characterization and use as supported planar membranes for cultured Schwann cells. | The axolemma membrane forms a stable and reproducible monomolecular layer at the air-aqueous interface. The major lipids and proteins are present in this monolayer in molar ratios similar to the original membrane. Acetylcholinesterase and Na-K-ATPase activities are preserved in the monolayer to levels of 64% and 25%, r... |
8445248 | Application of polymer beta-cyclodextrin-treated fetal calf serum to in vitro antibody production. | In order to induce an optimal plaque-forming cell response to sheep red blood cells (anti-SRBC PFC response) in vitro, murine splenocytes have been cultured in RPMI 1640 medium containing 10% fetal calf serum (FCS). In this paper, we report that 10% intact FCS in such a conventional medium can be replaced by 2% modifie... |
8443596 | Characterization and 2D NMR study of the stable [9-21, 15-27] 2 disulfide intermediate in the folding of the 3 disulfide trypsin inhibitor EETI II. | The three disulfide Ecballium elaterium trypsin inhibitor II (EETI II) reduction with dithiothreitol (DTT) and reoxidation of the fully reduced derivative have been examined. A common stable intermediate has been observed for both processes. Isolation and sequencing of carboxymethylated material showed that the interme... |
8382799 | The DNA binding domain of the varicella-zoster virus gene 62 protein interacts with multiple sequences which are similar to the binding site of the related protein of herpes simplex virus type 1. | Varicella-zoster virus gene 62 encodes a protein with predicted Mr of 140,000D (VZV 140k) that shares extensive predicted amino acid sequence homology with the major immediate early (IE) transcriptional regulator protein of herpes simplex virus type 1 (HSV-1) Vmw175. The integrity of highly conserved region 2 is essent... |
8440248 | The RNA binding site of bacteriophage MS2 coat protein. | The coat protein of the RNA bacteriophage MS2 binds a specific stem-loop structure in viral RNA to accomplish encapsidation of the genome and translational repression of replicase synthesis. In order to identify the structural components of coat protein required for its RNA binding function, a series of repressor-defec... |
8382606 | The absence of supercoiling in kinetoplast DNA minicircles. | Crithidia fasciculata kinetoplast DNA is a mitochondrial DNA composed of 5000 minicircles and approximately 25 maxicircles, all catenated into a giant network. By comparing the linking number of minicircles released from the network by limited sonication with that of control minicircles, we demonstrate that not only do... |
8439298 | Studies on the inhibitory mechanism of iodonium compounds with special reference to neutrophil NADPH oxidase. | Diphenyleneiodonium (DPI) and its analogues have been previously shown to react via a radical mechanism whereby an electron is abstracted from a nucleophile to form a radical, which then adds back to the nucleophile to form covalent adducts [Banks (1966) Chem. Rev. 66, 243-266]. We propose that the inhibition of neutro... |
8439297 | Ionization characteristics of the Cys-25/His-159 interactive system and of the modulatory group of papain: resolution of ambiguity by electronic perturbation of the quasi-2-mercaptopyridine leaving group in a new pyrimidyl disulphide reactivity probe. | 1. A new thiol-specific reactivity probe 4,4'-dipyrimidyl disulphide [compound (VII), m.p. 110 degrees C, pKa of its monohydronated form 0.91] was synthesized and used to resolve the ambiguity of interpretation of the behaviour of papain (EC 3.4.22.2) in alkaline media known to depend to varying extents on two ionizati... |
8439296 | Purification and characterization of 5-aminolaevulinic acid dehydratase from Escherichia coli and a study of the reactive thiols at the metal-binding domain. | 5-Aminolaevulinic acid dehydratase (ALAD) from a recombinant strain of Escherichia coli was purified to homogeneity. The enzyme is a homo-octamer of subunit M(r) 36554 +/- 17. Enzyme activity was dependent on the presence of Zn2+ ions and an exogenous thiol. Two molar equivalents of Zn2+ are bound/mol of subunit under ... |
8439280 | L-mandelate dehydrogenase from Rhodotorula graminis: comparisons with the L-lactate dehydrogenase (flavocytochrome b2) from Saccharomyces cerevisiae. | L-Lactate dehydrogenase (L-LDH) from Saccharomyces cerevisiae and L-mandelate dehydrogenase (L-MDH) from Rhodotorula graminis are both flavocytochromes b2. The kinetic properties of these enzymes have been compared using steady-state kinetic methods. The most striking difference between the two enzymes is found by comp... |
8437360 | [Evaluation of blood purification in perioperative acute renal failure]. | The technical aspects of blood purification have made a great progress during 1980's. We reviewed our experiences of blood purification for the past six years. Between 1986 to 1991, we treated 48 perioperative patients with acute renal failure (ARF). Four were intraoperative cases and 46 were postoperative cases. Three... |
8436121 | Purification, characterization, crystallisation and X-ray analysis of selenomethionine-labelled hydroxymethylbilane synthase from Escherichia coli. | Hydroxymethylbilane synthase (HMBS) catalyses the conversion of porphobilinogen into hydroxymethylbilane, a linear tetrapyrrolic intermediate in the biosynthesis of haems, chlorophylls, vitamin B12 and related macrocycles. In the course of an investigation of the crystal structure of this enzyme, we intended to follow ... |
8382047 | Cytochrome bo from Escherichia coli: identification of haem ligands and reaction of the reduced enzyme with carbon monoxide. | Inner membranes were prepared from Escherichia coli strain RG 145, which is deficient in cytochrome bd, but overexpresses cytochrome bo [Au and Gennis (1987) J. Bacteriol. 169, 3237-3242]. The latter was purified 7-fold by extracting the membranes with octyl beta-D-glucopyranoside, followed by chromatography on DEAE-Se... |
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