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6571728 | Genetic transformation of Streptococcus pneumoniae by DNA cloned into the single-stranded bacteriophage f1. | A Staphylococcus aureus plasmid derivative, pFB9, coding for erythromycin and chloramphenicol resistance was cloned into the filamentous Escherichia coli phage f1. Recombinant phage-plasmid hybrids, designated plasmids, were isolated from E. coli and purified by transformation into Streptococcus pneumoniae. Single-stra... |
16453471 | The Balbiani ring 2 gene in Chironomus tentans is built from two types of tandemly arranged major repeat units with a common evolutionary origin. | The internal structure of the 37 kb long Balbiani ring 2 (BR 2) gene in Chironomus tentans has been studied by analysis of a collection of cloned cDNA sequences and in genomic Southern blot analysis with the cDNA sequences used as probes. The BR 2 gene contains two types of tandemly arranged major repeat units 200 bp l... |
16453463 | Genes and transcripts for the polypeptides of the cytochrome b6/f complex from spinach thylakoid membranes. | Cytochrome b6/f complex was prepared from washed thylakoid membranes by a procedure involving detergent treatment and centrifugation in sucrose gradients. The complex is composed of at least four polypeptide species, cytochrome f which occurs in two variant forms (mol. wt. 34/33 kd), cytochrome b6 (23 kd), the high-pot... |
6532523 | Dendritic membrane from insect olfactory hairs: isolation method and electron microscopic observations. | Sensory hairs from antennae of male saturniid moths (Antheraea polyphemus) were separated while deep-frozen by shaking antennal branches with glass beads. The hairs were collected through their differential adhesion to the surface of a petri dish. The yield, determined by the length of the isolated hair fragments, was ... |
6531392 | Simulation of pharmacokinetic behaviour of drug-cyclodextrin complexes. | Complexation with cyclodextrin decreases the hydrophobicity of poorly soluble drugs and results in enhanced dissolution rates and higher solubility. In vivo experiments showed that this "molecular encapsulation" of drugs leads to enhanced bioavailability, which is controlled by the solubilities, stability constants of ... |
6530440 | High-performance liquid chromatography of dicarboxylic porphyrins and metalloporphyrins: retention behaviour and biomedical applications. | The retention behaviour of the main dicarboxylic porphyrins, haemato-, deutero-, meso- and protoporphyrins, together with the Fe, Co, Cu and Zn complexes of meso- and protoporphyrins have been systematically studied. Hydrophobic chromatography with methanol-ammonium acetate buffer systems on reversed-phase columns prov... |
6570189 | Sequence-specific binding of simian virus 40 A protein to nonorigin and cellular DNA. | The simian virus 40 A protein (T antigen) recognized and bound to the consensus sequence 5'-GAGGC-3' in DNA from many sources. Sequence-specific binding to single pentanucleotides in randomly chosen DNA predominated over binding to nonspecific sequences. The asymmetric orientation of protein bound to nonorigin recognit... |
6527255 | Improved competitive indicator methods for the study of alpha-cyclodextrin complexes. | The competitive indicator method for studying molecular complexes is extended to systems forming 1:1 (SL) and 1:2 (SL2) complexes of substrate (S) and ligand (L). A modification is described for slightly soluble substrates, in which the presence of solid substrate establishes a constant concentration of uncomplexed sub... |
6084595 | Characterization of bovine keratin genes: similarities of exon patterns in genes coding for different keratins. | Four different genomic clones which contain the genes coding for epidermal keratins Ia (mol. wt. approximately 68 000), Ib (68 000), III (60 000) and VIb (54 500) have been selected using cDNA probes and identified by hybrid-selection translation. The genes vary considerably in length, primarily due to differences in i... |
6543118 | Purification and characterization of glutathione S-transferases P, S and N. Isolation from rat liver of Yb1 Yn protein, the existence of which was predicted by subunit hybridization in vitro. | The glutathione S-transferases are dimeric proteins and comprise subunits of Mr 25 500 (Ya), 26 500 (Yn), 27 000 (Yb1 and Yb2) and 28 500 (Yc). Enzymes containing Ya and/or Yc subunits have been isolated as have forms containing binary combinations of Yn, Yb1 and Yb2 subunits. To date only one enzyme, transferase S, ha... |
6394911 | Interaction between elastin and elastases and its role in the aging of the arterial wall, skin and other connective tissues. A review. | Elastic fibers are progressively lysed during maturation and aging and in an accelerated fashion in several aging diseases such as diabetes, arteriosclerosis, emphysema and several skin diseases. Several enzymes (elastase-type proteases) were isolated in recent years in our laboratory which appear to be involved in the... |
6440907 | Evaluation of a C-reactive protein latex agglutination detection test with sera from patients with sexually transmitted diseases. | A total of 149 sera, including 79 pre- and posttreatment sera from 33 patients with disseminated gonococcal infections, 18 from patients with uncomplicated gonococcal infections, 6 from patients with pelvic inflammatory disease, 4 from patients with genital Chlamydia trachomatis infections, and 42 from normal volunteer... |
6518251 | Lipid exchange between membranes. | The exchange of lipid molecules between vesicle bilayers in water and a monolayer forming at the water surface was investigated theoretically within the framework of thermodynamics. The total number of exchanged molecules was found to depend on the bilayer curvature as expressed by the vesicle radius and on the boundar... |
6097223 | Binding in vitro to rat liver receptors does not correlate with activities in vivo of bovine somatotropin. Use of chemically modified derivatives as probes. | Bovine somatotropin with an increasing number of its carboxylate groups modified by reaction with glycine methyl ester in the presence of a water-soluble carbodi-imide was tested for its activity in different bioassays. Only those derivatives which were known to be active in the body-weight-increase bioassay were able ... |
6549121 | Enzymatic heme oxygenase activity in soluble extracts of the unicellular red alga, Cyanidium caldarium. | Extracts of the phycocyanin-containing unicellular red alga, Cyanidium caldarium, catalyzed enzymatic cleavage of the heme macrocycle to form the linear tetrapyrrole bilin structure. This is the key first step in the branch of the tetrapyrrole biosynthetic pathway leading to phycobilin photosynthetic accessory pigments... |
6096857 | 15N electron nuclear double resonance of the primary donor cation radical P+.865 in reaction centers of Rhodopseudomonas sphaeroides: additional evidence for the dimer model. | Four 15N hyperfine coupling constants, including signs, have been measured by electron nuclear double resonance (ENDOR) and electron nuclear nuclear triple resonance (TRIPLE) for the bacteriochlorophyll a radical cation, BChla+., in vitro and for the light-induced primary donor radical cation, P+.865, in reaction cente... |
6096808 | Structure of the spinach chloroplast genes for the D2 and 44 kd reaction-centre proteins of photosystem II and for tRNASer (UGA). | We have determined the sequence of the spinach (Spinacia oleracea) chloroplast genes for the photosystem II proteins, D2 and the 44 kd reaction-centre, chlorophyll a-binding protein, and for tRNASer (UGA). The 3' end of the D2 gene overlaps the first 50 bp of the 5' end of the gene for the 44 kd protein. Northern RNA h... |
6096475 | Priming of neutrophils for enhanced release of oxygen metabolites by bacterial lipopolysaccharide. Evidence for increased activity of the superoxide-producing enzyme. | We investigated the capacity of bacterial endotoxin (lipopolysaccharide, LPS) to modify the oxidative metabolic response to membrane stimulation of human neutrophils. Neutrophils were pretreated for 60 min with LPS, 10 ng/ml, then stimulated by exposure to fixed immune complexes, the chemotactic peptide formyl-methiony... |
6549007 | Proposed structure for the noncovalently associated heme prosthetic group of dissimilatory nitrite reductases. Configuration of substituents of acrylochlorin. | The configuration of the substituents around the macrocycle core has been determined for acrylochlorin, the reduced porphyrin that is the iron-free form of heme d1. This has been accomplished by two independent techniques. Nuclear Overhauser enhancements on the proton resonances of acrylochlorin d3-methyl ester were me... |
6334579 | Inhibition of interleukin-2 production by adherent cell factors from lepromatous leprosy patients. | Twenty-four hour supernatants (MoF) were obtained from monocyte rich 2 h adherent cells of 19 leprosy patients and four healthy contacts. MoF from borderline and lepromatous patients produced 52-61% inhibition of human interleukin-2 (IL-2) production by a PHA conditioned T cell line (Jurkat). Non-adherent cell supernat... |
6594697 | Isolation of the heterogeneous nuclear RNA-ribonucleoprotein complex (hnRNP): a unique supramolecular assembly. | The packaging of heterogeneous nuclear RNA (hnRNA), the fate of hnRNA in the nucleus, and the conversion of hnRNA to mRNA are believed to occur as the hnRNA transcript is associated with specific proteins to form a ribonucleoprotein complex termed the hnRNP complex. The identity and organization of the protein constitu... |
6502590 | Synthesis and evaluation of furan, thiophene, and azole bis[(carbamoyloxy)methyl] derivatives as potential antineoplastic agents. | A series of bis(hydroxymethyl)-substituted heterocycles were synthesized and converted to the corresponding bis(methylcarbamate) derivatives. The heterocyclic systems studied were based on 2-phenyl-3-methylfuran (2-4), 1-phenylpyrazole (5-7), 1-phenyl-5-methylpyrazole (9-11), 1-phenyl-5-methylthiophene (13), 1-phenyl-1... |
6094807 | Design, synthesis, and testing of potential antisickling agents. 5. Disubstituted benzoic acids designed for the donor site and proline salicylates designed for the acceptor site. | This paper reports the discovery of a new class of potent antigelling agents. The new compounds, disubstituted benzoic acid derivatives, were designed by using molecular modeling experiments. These molecules contain functional groups positioned to interact with several polar amino acid residues near the Val-6 beta muta... |
6548528 | Three monoclonal antibodies against measles virus F protein cross-react with cellular stress proteins. | In a group of 11 monoclonal antibodies specifically reacting with the measles virus fusion protein, three antibodies also immunoprecipitated other proteins, in particular a 79,000-molecular-weight protein from virus-infected cells. The cross-reacting 79,000-molecular-weight protein was shown to be a virus-induced host ... |
6092717 | Isolation and characterization of monoclonal antibodies to structural and nonstructural herpesvirus saimiri proteins. | An improved screening procedure was applied to identify hybridomas secreting antibodies to herpesvirus saimiri-specified polypeptides among the products of fusions between SP2/0 myeloma cells and spleen cells from mice immunized with purified virus particles or virus-specific DNA-binding proteins. Twenty-four monoclona... |
6208382 | Cleavage of nascent reovirus mRNA by localized activation of the 2'-5'-oligoadenylate-dependent endoribonuclease. | Addition of cell extracts prepared from untreated or interferon-treated cells reduced the yield of reovirus RNA synthesized in transcription reactions with purified virions. The reduction observed with the extract of interferon-treated cells was greater than that observed with the extract of untreated cells. The yield ... |
6092707 | Multiple binding sites for polyomavirus large T antigen within regulatory sequences of polyomavirus DNA. | Polyomavirus large T antigen binds specifically to multiple sites within the regulatory region of the viral genome. Experiments done with crude extracts from wild-type virus-infected mouse cells and immunoprecipitation of protein-DNA complexes localized two high-affinity binding sites on the early region side of the DN... |
18963740 | Alkali-metal ion complexation with lariat ethers possessing a chromogenic group. | The extraction and complexation abilities of chromogenic alkyl crown-ether reagents were compared with those of their chromogenic benzo crown ether analogues. Improvements in the extraction efficiency and stability of the complexes were observed, and can be attributed to various factors such as increased lipophilic cha... |
6084878 | The use of backscattered electrons to examine selectively stained nerve fibers in the scanning electron microscope. | Selective staining of neuronal tissues using standard light microscopic techniques has been combined with backscattered electron scanning electron microscopy. This technique allows neurons to be readily distinguished from their surrounding tissues and examined at high resolution. The technique overcomes some of the pro... |
6520327 | Polarimetric determination of substitution of oxirane groups on epoxy-activated Sepharose 6B gel by cyclodextrins. | A method is described for direct monitoring of extent of coupling of cyclodextrins to Epoxy-activated Sepharose 6B gel by polarimetry. The extent of coupling of cyclodextrin to Epoxy gel can be quantitatively monitored by this method. |
6520078 | Liquid chromatographic determination of sodium fluoroacetate (Compound 1080) in meat baits and formulations. | A liquid chromatographic (LC) method is described for the determination of sodium fluoroacetate in meat baits and formulations. Baits were extracted with water, ultrafiltered, partitioned into butanone, back-partitioned into dilute base, and diluted with acetonitrile. Aqueous formulations of 1080 were diluted with acet... |
6392560 | The application of EDXS to the biological sciences. | The distribution of chemical elements in soft tissues may be faithfully preserved by very rapid freezing. Most often the material is then cryosectioned and the sections frozen-dried prior to analysis, but direct analysis in the hydrated state is an established alternative. For bulk specimens, the shape of the analysed ... |
6510409 | Xenopus hsp 70 genes are constitutively expressed in injected oocytes. | Xenopus heat-shock genes are transiently heat-inducible in somatic cells, but they are also subject to a long-term developmental control in oogenesis and early embryogenesis. In order to understand whether different genes or different promoter elements are involved in the two types of control, several genomic clones co... |
6389600 | Degradation of sulfated proteoglycans in the subendothelial extracellular matrix by human platelet heparitinase. | Cultured vascular and corneal endothelial cells produce an underlying extracellular matrix (ECM) which induces platelet adherence, aggregation, and release reaction. Incubation of a metabolically (35S)O = 4-labeled ECM with platelet-rich plasma or washed platelets, but not with platelet-poor plasma, resulted in degrada... |
6150007 | Exclusive presence of lactose-sensitive fimbriae on a typical strain (WVU45) of Actinomyces naeslundii. | Lactose-sensitive fimbriae were identified as the only fimbriae present on Actinomyces naeslundii WVU45 (ATCC 12104). A single antigen reactive with antiserum against WVU45 cells was detected by cross immunoelectrophoresis of isolated fimbriae, and a monospecific antiserum against this antigen reacted with all fimbriae... |
6500696 | Isolation and identification of two hemolytic forms of streptolysin-O. | Streptolysin-O was isolated from culture supernatants of group-A beta-hemolytic streptococci (Richards strain) by ammonium sulfate and polyethylene glycol precipitation, DEAE-ion exchange chromatography, preparative isoelectric focusing, and chromatography on Sephacryl S-300. Two forms of the toxin possessing similar h... |
6498276 | Kinetics of nucleation-controlled polymerization. A perturbation treatment for use with a secondary pathway. | We present a perturbation method for analyzing nucleation-controlled polymerization augmented by a secondary pathway for polymer growth. With this method, the solution to the kinetic equations assumes a simple analytic closed form that can easily be used in fitting data. So long as the formation of polymers by the seco... |
6437334 | Collagen fibrillogenesis in vitro: comparison of types I, II, and III. | The self-assembly of pepsin-extracted types I, II, and III collagen was studied to determine how differences in the triple-helical structure between collagen types influence in vitro collagen fibrillogenesis. Collagen types I, II, and III were extracted and purified from bovine sources, and were studied in solution by ... |
6092698 | Epstein-Barr virus-transformed lymphocytes produce monoclonal autoantibodies that react with antigens in multiple organs. | Peripheral blood lymphocytes from normal individuals and patients with autoimmune abnormalities such as insulin-dependent diabetes mellitus and thyroiditis were infected with Epstein-Barr virus, and the culture supernatants were tested for autoantibodies that reacted with normal tissues. Between 58 and 86% of Epstein-B... |
6238120 | Inhibition of complement activation on the surface of cells after incorporation of decay-accelerating factor (DAF) into their membranes. | Decay-accelerating factor (DAF), extracted from the stroma of human erythrocytes, was purified to homogeneity and incorporated into the membrane of sheep red cell complement intermediates, where its functional properties were analyzed. Incorporation of DAF into the cell membranes was temperature dependent, took place o... |
6208310 | Monoclonal antibody with hemagglutination, immobilization, and neutralization activities defines an immunodominant, 47,000 mol wt, surface-exposed immunogen of Treponema pallidum (Nichols). | Radioimmunoprecipitation (RIP) analyses performed on 125I-surface-labeled Treponema pallidum cells using various immune sera revealed the presence of six major surface antigens (immunogens) with apparent molecular weights of 47 K, 36 K, 34 K, 32 K, 29 K, and 13 K. Among these, the 47 K surface antigen was most abundant... |
6333482 | Trichomonas vaginalis is dependent on uptake and degradation of human low density lipoproteins. | Human plasma low density lipoprotein uptake by the urogenital pathogen, Trichomonas vaginalis, was examined. Rapid binding and internalization of 125I-labeled low density lipoproteins by live T. vaginalis was observed at 37 degrees C. Data showing parasite degradation of the internalized apoproteins and lipid accumulat... |
6490722 | Biologically active synthetic peptides as probes of embryonic development: a competitive peptide inhibitor of fibronectin function inhibits gastrulation in amphibian embryos and neural crest cell migration in avian embryos. | We describe a new method for analyzing embryonic events dependent on a specific peptide recognition signal. A short, specific amino acid sequence in fibronectin has been implicated as a recognition site in fibronectin-mediated interactions. Fibroblast adhesion to fibronectin is competitively inhibited by certain synthe... |
6386826 | Subunit structure of junctional feet in triads of skeletal muscle: a freeze-drying, rotary-shadowing study. | Isolated heavy sarcoplasmic reticulum vesicles retain junctional specializations (feet) on their outer surface. We have obtained en face three-dimensional views of the feet by shadowing and replicating the surfaces of freeze-dried isolated vesicles. Feet are clearly visible as large structures located on raised platfor... |
6386825 | Structural domains of clathrin heavy chains. | We used a combination of electron microscopy and proteolytic dissection to study the substructure of the clathrin trimer. The fragments of a heavy chain generated by limited proteolysis of cages were examined by rotary shadowing after disassembly. Correlation of lengths and molecular weights allowed us to map certain c... |
6208200 | Reconstitution of cytokeratin filaments in vitro: further evidence for the role of nonhelical peptides in filament assembly. | The in vitro renaturation and assembly of cytokeratin molecules to form intermediate filaments (IF) illustrates that these molecules contain all of the structural information necessary for IF information. These molecules contain nine structural domains: the amino- and carboxyterminal extra helical regions, and three co... |
6238033 | Phytanic acid alpha-oxidation in rat liver. Requirement of cytosolic factor. | The alpha-oxidation of [1-14C]phytanic acid of high specific activity was studied in postnuclear and various subcellular fractions from rat liver. alpha-Oxidation in the postnuclear fraction required ATP, Mg2+, nicotinamide, and molecular oxygen for activity. alpha-Oxidation was inhibited by iron-specific chelating age... |
18963717 | The solubility of alkali-metal fluorides in non-aqueous solvents with and without crown ethers, as determined by flame emission spectrometry. | The solubilities of LiF, NaF, KF, RbF and CsF in acetonitrile, acetone, tetrahydrofuran, dimethylformamide, benzene and cyclohexane have been determined with and without a crown ether (usually 0.1 M 18-crown-6) present. Flame emission spectrometry was the determination method. Three procedures, selected according to th... |
16663898 | Regulatory effect of cytokinin on secondary xylem fiber formation in an in vivo system. | The regulatory effect of cytokinin on the formation of secondary xylem fibers was studied in the hypocotyl of young Helianthus annuus L. plants. Positive correlation was found between the kinetin supplied (0.25-0.5 micrograms/gram) to the growth medium and the rate of fiber formation within and between the vascular bun... |
6522449 | Suppositories containing beta-cyclodextrin complexes. Part 1: Stability studies. | Application of beta-cyclodextrin complexes of volatile substances in suppositories improves the mechanical properties and stability of suppositories. The incompatibility between the volatile components and suppository bases can be eliminated. |
6542568 | High-performance liquid chromatographic assay for prostaglandin E1 in various ointment vehicles. Separation and stability testing. | A high-performance liquid chromatographic method for the determination of prostaglandin E1 (PGE1) incorporated in white petrolatum, white ointment, hydrophilic petrolatum and Plastibase was investigated. The prostaglandin was separated from the oleaginous vehicles with n-hexane-aqueous acetonitrile. Most of white petro... |
6391377 | Production of polyhedrin monoclonal antibodies for distinguishing two Orgyia pseudotsugata baculoviruses. | Monoclonal antibodies were produced to polyhedrins from Orgyia pseudotsugata multicapsid nuclear polyhedrosis virus (OpMNPV) and single-capsid nuclear polyhedrosis virus (OpSNPV). Although the polyhedrins are closely related, antibodies were selected which allowed differentiation between the two viruses. In an indirect... |
6095050 | Formation of vesicular stomatitis virus nucleocapsid from cytoskeletal framework-bound N protein: possible model for structure assembly. | The pathway of vesicular stomatitis virus N protein from synthesis to assembly into capsids was studied by use of detergent extraction of infected HeLa cells together with protein cross-linking. One half of the newly synthesized N protein was extracted with the soluble cell proteins and, when cross-linked, never formed... |
6389321 | [Immunodiagnosis of kidney tubular cell injuries using specific anti-membrane antibodies]. | In contrast to healthy persons, microvillous antigens of the proximal tubule were excreted at an increased rate in patients with kidney diseases as could be shown using specific antisera against brush border (BB) fragments (tissue-proteinuria, histuria). These urinary membrane components were immunologically completely... |
6389118 | The 43-K protein, v1, associated with acetylcholine receptor containing membrane fragments is an actin-binding protein. | Acetylcholine receptor enriched membrane fragments were obtained from the electric organs of Torpedo marmorata. The purified membrane fragments contained several proteins in addition to the acetylcholine receptor subunits. One of these was shown to be actin by means of immune blotting with a monoclonal antibody. Brief ... |
6497848 | The evolution of enzyme kinetic power. | Evolution of the kinetic potential of enzyme reactions is discussed. Quantitative assessment of the evolution of enzyme action has usually focused on optimization of the parametric ratio kcat./Km, which is the apparent second-order rate constant for the reaction of free substrate with free enzyme to give product. We pr... |
6593717 | Theory of the intermediate rippled phase of phospholipid bilayers. | A mathematical model of the periodic, rippled P beta' phase of phosphatidylcholine is described. In this model the P beta' phase shows a periodic variation in membrane properties corresponding to a lateral periodic variation between fluid-like and crystal-like states. The model is based on a curvature-dependent Landau-... |
6493847 | Freeze-etching and biochemical analysis of human fetal erythrocyte membranes. | In order to test the hypothesis that there are ultrastructural and supramolecular differences between fetal and adult erythrocyte membranes that are manifested in their functional characteristics, the cells were studied by freeze-etching and transmission microscopy and biochemical methods. Freeze-etching and transmissi... |
6385005 | Involvement of the carboxyl-terminal domain of tubulin in the regulation of its assembly. | Limited proteolysis of phosphocellulose-purified tubulin with subtilisin resulted in cleavage of both alpha and beta tubulin subunits, with the formation of two major fragments (S alpha, and S beta, 48 kDa) and a small peptide (4 kDa) containing the carboxyl-terminal region of tubulin. Interestingly, tubulin cleaved un... |
6384271 | Human multiple organ-reactive monoclonal autoantibody recognizes growth hormone and a 35,000-molecular weight protein. | By fusing peripheral leukocytes from a patient with insulin-dependent diabetes with mouse myeloma cells, a heterohybridoma was isolated that, for over one year, has secreted a human monoclonal autoantibody, designated MOR-h1 (multiple organ-reactive human 1). This antibody reacts with antigens in several endocrine orga... |
6434549 | Intermediate-sized filaments in Drosophila tissue culture cells. | In using a monoclonal antibody against a major cytoplasmic protein of 46,000 mol wt, we have characterized an intermediate-sized (10 nm) filamentous cytoskeleton in Drosophila melanogaster tissue culture cells. Indirect immunofluorescence, immunoelectron microscopy, and protein blotting show that this cytoskeleton exhi... |
6090424 | Genetic system for analyzing Escherichia coli thymidylate synthase. | Random in vitro mutagenesis of the thyA gene is being used to delineate its regulatory elements as well as the functional domains of its product, thymidylate synthase (EC 2.1.1.45). Streamlined procedures have been developed for the isolation and characterization of the mutants. Positive selection for synthase-deficien... |
6384043 | Tubulin and high-molecular-weight polypeptides as Giardia lamblia antigens. | We determined the antigenic specificities of nine murine monoclonal antibodies to Giardia lamblia. Four distinct antibody reaction patterns were detected by immunofluorescence with G. lamblia trophozoites. Four monoclonal antibodies which reacted with the body but not the flagella of the whole trophozoites recognized t... |
6540798 | Actin-based gelation of cytoplasmic extracts from brain tissue. | Incubation of rat brain cytoplasmic extracts under the conditions described in this paper results in the formation of three-dimensional gels. Ultrastructurally, these gels correspond to complex supramolecular structures formed by single microfilaments and by microfilament bundles. Analysis of protein composition indica... |
6400936 | Electronmicroscopy and circular dichroism of the dynamics of the formation and dissolution of supramolecular forms of Z-DNA. | Previous electronmicroscopic studies had shown that N-acetylaminofluorene (AFF)-substituted poly(dG-dC)-poly(dG-dC) in the Z conformation, in 10mM Mg++, condensed into periodically banded, branched structures. We now show that similar structures are seen when poly(dG-dC)-poly(dG-dC) is converted to the Z conformation b... |
16617474 | Binding of 16S rRNA to chloroplast 30S ribosomal proteins blotted on nitrocellulose. | Protein-RNA associations were studied by a method using proteins blotted on a nitrocellulose sheet. This method was assayed with Escherichia Coli 30S ribosomal components. In stringent conditions (300 mM NaCl or 20 degrees C) only 9 E. coli ribosomal proteins strongly bound to the 16S rRNA: S4, S5, S7, S9, S12, S13, S1... |
6438486 | [Nutritional management of anastomotic leakage after gastrointestinal surgery--with special reference to the serious cases]. | Effects of intravenous hyperalimentation (IVH) were studied in 38 patients with anastomotic leakage following gastrointestinal surgery. Spontaneous closure of the leakage were found in 23 patients (60%), and surgical closure were needed in 9 patients (24%). The duration required for spontaneous closure was 5 weeks on t... |
6238839 | [Search for and study of antiarrhythmic substances among crown ethers]. | The authors studied antiarrhythmic properties of macrocyclic polyesters. Some of the esters exhibited antiarrhythmic activity coupled with low toxicity. It was found that antiarrhythmic action of these substances is not mediated via acetylcholine and/or catecholamine system responsible for nervous regulation of the car... |
6238621 | Sarcoplasmic reticulum adenosinetriphosphatase phosphorylation from inorganic phosphate. Theoretical and experimental reinvestigation. | Pi phosphorylation of sarcoplasmic reticulum (SR) vesicles in the absence of Ca was reinvestigated. Theoretical analysis shows that, for various substrate concentrations, the time dependence of phosphoenzyme formation does not allow determination of an unambiguous reaction scheme or estimation of the stoichiometry of t... |
6149576 | Mechanism of complement cytolysis and the concept of channel-forming proteins. | Complement damages membranes via the terminal reaction sequence that leads to the formation of membrane-bound, macromolecular C5b-9(m) protein complexes. These complexes represent C5b-8 monomers to which varying numbers of C9 molecules can be bound. Complexes carrying high numbers of C9 (ca. 6/8-12/16?) exhibit the mor... |
6493232 | Griseofulvin resistance mutation of Chinese hamster ovary cells that affects the apparent molecular weight of a congruent to 200,000-dalton protein. | A single-step griseofulvin-resistant mutant (GrsR-4) of CHO cells which exhibit very specific cross-resistance towards certain microtubule inhibitors showed the absence of a protein of molecular weight congruent to 200,000 (designated P5) and the concomitant presence of a new protein spot, M5, of lower molecular weight... |
6386867 | Monoclonal antibodies to Bacteroides fragilis lipopolysaccharide. | Monoclonal antibodies (MoAbs) to the lipopolysaccharide (LPS) of Bacteroides fragilis were produced by immunizing mice before hybridization with bacterial outer membranes solubilized with Triton X-100. Nineteen stabile clones were established. They all produced antibodies that reacted more strongly with purified B. fra... |
6092061 | Formation of covalently closed heteroduplex DNA by the combined action of gyrase and RecA protein. | The concerted action of DNA gyrase and RecA protein of Escherichia coli on intact and gapped homologous or partially homologous plasmid DNA molecules leads to the formation of covalently closed DNA containing one strand of each parental molecule. Large regions of non-homology can be incorporated into the closed circula... |
6090398 | Construction of a promoter-probe vector for a Bacillus subtilis host by using the trpD+ gene of Bacillus amyloliquefaciens. | The trp gene cluster of Bacillus amyloliquefaciens was found to be structurally similar to that of the Enterobacteriaceae. The translation termination codon of the putative trpE gene and the initiation codon for the putative trpD gene overlap at the trpE-trpD junction, and a promoter for the putative trpC gene is sugge... |
6383473 | Organic ion transport during seven decades. The amino acids. | The amino acids are ions of various charge combinations, and one can argue that historically they were the first ions for which the ongoing problem of membrane transport was presented; also that among transported ions these may undergo a highly detailed molecular recognition. Furthermore, the distribution of charge on ... |
6382262 | Catalytic consequences of oligomeric organization: kinetic evidence for "tethered" acto-heavy meromyosin at low ATP concentrations. | The influence of the supramolecular organization of myosin on its ATPase activity was investigated at a range of ATP concentrations, using as a model system subfragment 1 (S1) and heavy meromyosin (HMM), which are respectively monomeric and dimeric proteolytic fragments of myosin. At low ATP levels in the presence of a... |
6381756 | Subcellular localization of glycoproteins encoded by the viral oncogene v-fms. | The McDonough strain of feline sarcoma virus encodes a polyprotein that is cotranslationally glycosylated and proteolytically cleaved to yield transforming glycoproteins specified by the viral oncogene v-fms. The major form of the glycoprotein (gp120fms) contains endoglycosidase H-sensitive, N-linked oligosaccharide ch... |
6236232 | Defective binding of spectrin to ankyrin in a kindred with recessively inherited hereditary elliptocytosis. | The interaction of spectrin with spectrin-depleted inside-out membrane vesicles was studied in a kindred with an atypical variant of hereditary elliptocytosis inherited in a recessive manner. The probands are characterized by prominent elliptocytosis, decreased erythrocyte thermal stability, an altered limited tryptic ... |
6470047 | A 45,000-mol-wt protein-actin complex from unfertilized sea urchin egg affects assembly properties of actin. | A one-to-one complex of a 45,000-mol-wt protein and actin was purified from unfertilized eggs of the sea urchin, Hemicentrotus pulcherrimus, by means of DNase l-Sepharose affinity and gel filtration column chromatographies. Effects of the complex on the polymerization of actin were studied by viscometry, spectrophotome... |
6470045 | Identification and extraction of proteins that compose the triad junction of skeletal muscle. | Treatment of both transverse tubules and terminal cisternae with a combination of Triton X-100 and hypertonic K cacodylate causes dissolution of nonjunctional proteins and selective retention of membrane fragments which are capable of junction formation. Treatment of vesicles with Triton X-100 and either KCl or K gluco... |
6540785 | Interaction of fluorescently-labeled contractile proteins with the cytoskeleton in cell models. | To determine if a living cell is necessary for the incorporation of actin, alpha-actinin, and tropomyosin into the cytoskeleton, we have exposed cell models to fluorescently labeled contractile proteins. In this in vitro system, lissamine rhodamine-labeled actin bound to attachment plaques, ruffles, cleavage furrows an... |
6381508 | Localization of actin and myosin for the study of ameboid movement in Dictyostelium using improved immunofluorescence. | The distribution of actin and myosin in Dictyostelium amebae at different developmental stages was studied by improved immunofluorescence ("agar-overlay" technique). Both were localized at the cortical region of amebae in all early developmental stages. In amebae with polarized morphology, bright fluorescence with anti... |
6540783 | Polymerization of ADP-actin. | Using hexokinase, glucose, and ATP to vary reversibly the concentrations of ADP and ATP in solution and bound to Acanthamoeba actin, I measured the relative critical concentrations and elongation rate constants for ATP-actin and ADP-actin in 50 mM KCl, 1 mM MgCl2, 1 mM EGTA, 0.1 mM nucleotide, 0.1 mM CaCl2, 10 mM imida... |
6470037 | Rapid rate of tubulin dissociation from microtubules in the mitotic spindle in vivo measured by blocking polymerization with colchicine. | At metaphase, the amount of tubulin assembled into spindle microtubules is relatively constant; the rate of tubulin association equals the rate of dissociation. To measure the intrinsic rate of dissociation, we microinjected high concentrations of colchicine, or its derivative colcemid, into sea urchin embryos at metap... |
6432699 | Effect of Pseudomonas aeruginosa cytotoxin on thymidine incorporation by murine splenocytes. | The interaction of highly purified Pseudomonas aeruginosa cytotoxin (PAC) with murine splenocytes was examined. Added at culture initiation, PAC (0.1 to 0.5 microgram/ml) inhibited subsequent [3H]deoxythymidine incorporation measured between 42 to 48 h. Incorporation of [3H]deoxythymidine was inhibited 50% in lipopolys... |
6504980 | Cyclodextrin-stabilized volatile substances for inhalation therapy. | Diapulmon (Chinoin) which comprise camphor, 1-menthol, eucalyptus oil and quinine dissolved in sunflower oil (Oleum helianthi) is marketed in ampoules of 2 ml but utilized almost exclusively for inhalation therapy. Complexing the active ingredients of Diapulmon with beta-cyclodextrin (beta-CD) a stable non hygroscopic ... |
6239050 | Studies on experimental immune complex nephritis (3). Therapeutic effect of prostaglandin E1 alpha-cyclodextrin host molecule (PGE1 . CD) on serum sickness nephritis in rats. | The effect of prostaglandin E1 alpha-cyclodextrin host molecule (PGE1 . CD) was estimated by using a model of immune complex glomerulonephritis induced in rats by i.v. injection of 1 mg of rabbit serum albumin every other day. PGE1 . CD was given subcutaneously for 10 days after nephritis was definitely induced and res... |
6499803 | Acute and subchronic toxicity of ethylene glycol monobutyl ether. | The available information on the acute and subchronic toxicity of ethylene glycol monobutyl ether is reviewed. Data from animal studies have been examined from the standpoint of dose-response relationships and the sensitivity of various animal species, including man, to the effects of this chemical. In view of recent f... |
6237681 | Anthracenyl crown ethers and cryptands as fluorescent probes for solid-phase transitions of phosphatidylcholines: syntheses and phospholipid membrane studies. | Three structurally related crown compounds and cryptands have been synthesized that differ by the number and linkage of coronand units and anthracene moieties. The interaction of the fluorescent dyes with sonicated dimyristoylphosphatidylcholine (DMPC) vesicles is characterized by the relative quantum yields, uptake ki... |
6433896 | Modification of hydroxymethylbilane synthase (porphobilinogen deaminase) by pyridoxal 5'-phosphate. Demonstration of an essential lysine residue. | When hydroxymethylbilane synthase (porphobilinogen deaminase) from Euglena gracilis is incubated with pyridoxal 5'-phosphate at pH 7.0 and 0 degree C, it rapidly loses part of its activity. The proportion of activity that remains decreases as the concentration of the modifier increases up to approx. 2mM, above which no... |
6477506 | The brain isoform of a key ATP-regulating enzyme, creatine kinase, is a phosphoprotein. | Two-dimensional electrophoretic analysis of crude microtubule preparations from the rat brain revealed the presence of three polypeptides in positions corresponding to those of the isovariants of purified rat brain creatine kinase (CK-BB). By the use of [gamma-32P]ATP, the two more acidic forms of these polypeptides we... |
6473106 | Viroid replication: equilibrium association constant and comparative activity measurements for the viroid-polymerase interaction. | The binding and replication of purified potato spindle tuber viroid (PSTV) by DNA-dependent RNA polymerase II from wheat germ was studied in analytical ultracentrifugation experiments and in vitro transcription assays. The equilibrium association constant for the viroid-polymerase interaction is 1.9 X 10(7) M-1. Both u... |
6469964 | Proteoglycans synthesized by rat ovarian granulosa cells in culture. Isolation, fractionation, and characterization of proteoglycans associated with the cell layer. | Rat ovarian granulosa cells were isolated from immature female rats after stimulation with pregnant mare's serum gonadotropin and maintained in culture. Proteoglycans were labeled with [35S]sulfate, [3H]glucosamine, or [3H]serine as precursors. Proteoglycans associated with the cell layer were extracted with 4 M guanid... |
6087953 | [Effect of the macrocyclic polyether 15-crown-5 on the ionic permeability of excitable membranes]. | The macrocyclic polyether 15-crown-5 at a concentration of 5 . 10(-5)-10(-3) M reduced the frequency of the contractions of an isolated rat auricle, increasing the refractory period of the contractions. The polyether lowered the rate of activation of the slow input current of rat spinal ganglionic neurons and blocked t... |
6589625 | Macroscopic models for studies of electrostatic interactions in proteins: limitations and applicability. | The validity of macroscopic models for calculations of electrostatic energies in proteins is examined. The Tanford-Kirkwood (TK) model is extended to include the self energy of the ionized groups. It is shown that ionized groups cannot exist inside nonpolar regions of proteins and argued that the experimental finding o... |
6087342 | Rapid purification of a cloned gene product by genetic fusion and site-specific proteolysis. | We have developed a rapid and general technique for purification of a protein encoded by a cistron contained in a recombinant DNA clone. The technique consists of fusing the target cistron DNA in the correct reading frame to a marker cistron via a piece of DNA that codes for a linker peptide. The target cistron in the ... |
6746743 | Basal lamina formation by cultured microvascular endothelial cells. | The production of a basal lamina by microvascular endothelial cells (MEC) cultured on various substrata was examined. MEC were isolated from human dermis and plated on plastic dishes coated with fibronectin, or cell-free extracellular matrices elaborated by fibroblasts, smooth muscle cells, corneal endothelial cells, o... |
6235235 | Biosynthesis of heparan sulfate proteoglycan by human colon carcinoma cells and its localization at the cell surface. | After 24 h of continuous labeling with radioactive precursors, a high molecular weight heparan sulfate proteoglycan (HS-PG) was isolated from both the medium and cell layer of human colon carcinoma cells (WiDr) in culture. The medium HS-PG eluted from a diethylaminoethyl anion exchange column with 0.45-0.50 M NaCl, had... |
6146599 | Organization and expression of genes responsible for type 1 piliation in Escherichia coli. | The genetic organization of a segment of recombinant DNA conferring the capacity of synthesize E. coli type 1 pili was examined. This 11.2-kilobase (kb) segment of DNA, derived from a clinical isolate, conferred a piliated phenotype (Pil+) on a nonpiliated (Pil-) strain of E. coli K-12 that lacked DNA homologous to the... |
6401129 | Neutron diffraction of alpha, beta and gamma cyclodextrins: hydrogen bonding patterns. | Cyclodextrins (CD's) have proved useful as model systems for the study of hydrogen bonding. They are torus-shaped molecules composed of six(alpha), seven(beta) or eight(gamma) (1----4) linked glucoses. Because of their particular geometry, they are able to act as a "host" to form inclusion complexes with "guest" molecu... |
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