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3663831 | Molecular aggregation characterized by high order autocorrelation in fluorescence correlation spectroscopy. | The use of high order autocorrelation in fluorescence correlation spectroscopy for investigating aggregation in a sample that contains fluorescent molecules is described. Theoretical expressions for the fluorescence fluctuation autocorrelation functions defined by gm,n(tau) = [(delta fm(t + tau)delta fm(t] - (delta Fm(... |
2822159 | Hydrophobic molecules in lecithin-water systems. I. Formation of reversed hexagonal phases at high and low water contents. | The system dioleoylphosphatidylcholine (DOPC)-n-dodecane-2H2O was investigated with different nuclear magnetic resonance (NMR) techniques: (a) a tentative phase diagram was determined by 2H- and 31P-NMR, (b) translational diffusion coefficients were determined for the three components with the pulsed magnetic field gra... |
3663196 | Amino acid sequence of acyl-CoA-binding protein from cow liver. | Acyl-CoA-binding protein from bovine liver was purified with the use of reverse-phase h.p.l.c. in the final step. The complete amino acid sequence was determined by using a combination of gas-phase Edman degradation and electron-impact and fast-atom-bombardment mass spectrometry. The sequence was confirmed by determina... |
3652660 | Characterization of acid-soluble type I collagen in solution by viscosity measurements. I. Some evidence about adsorption on the glass material and about electrostatic and ionic bondings in the molecular self assembly process. | The evidence of a adsorption phenomenon of the acid-soluble collagen molecules on the glass material is shown. A way of calculation is proposed from viscosimetric measurements. It could be pointed out that a small amount corresponding to 4 to 5% of the collagenous concentration is involved in such a adsorption process,... |
3624311 | Low ionic strength solubility of myosin in sea urchin egg extracts is mediated by a myosin-binding protein. | We identify a novel myosin-binding protein, designated 53K, which appears to mediate the low ionic strength solubility of myosin in extracts of unfertilized sea urchin eggs. The protein possesses a subunit molecular mass on SDS-PAGE of 53 kD, an S value of 7, may be organized into disulfide-linked oligomers, and is ass... |
3040773 | Complete nucleotide sequence and deduced polypeptide sequence of a nonmuscle myosin heavy chain gene from Acanthamoeba: evidence of a hinge in the rodlike tail. | We have completely sequenced a gene encoding the heavy chain of myosin II, a nonmuscle myosin from the soil ameba Acanthamoeba castellanii. The gene spans 6 kb, is split by three small introns, and encodes a 1,509-residue heavy chain polypeptide. The positions of the three introns are largely conserved relative to char... |
3305518 | Effects of inhibition of proteoglycan synthesis on the differentiation of cultured rat Schwann cells. | Schwann cells synthesize two heparan sulfate proteoglycans, one that is a component of the Schwann cell basement membrane and a smaller one that is an integral component of the Schwann cell plasma membrane. To determine the functions of these molecules, Schwann cell-nerve cell cultures were grown in medium containing a... |
3039492 | Characterization of a mammalian mutant with a camptothecin-resistant DNA topoisomerase I. | DNA topoisomerase I was purified to near homogeneity from a clonal line of human lymphoblastic leukemia cells, RPMI 8402, that is resistant to camptothecin, a cytotoxic alkaloid from Camptotheca acuminata, and compared with that of the parent wild-type cells. As assayed by relaxation of the supercoiled plasmid DNA and ... |
3039139 | X-ray crystal structure of the opioid ligand naltrexonazine. | The anti-anti isomer of naltrexonazine (1) was synthesized, and its configuration was confirmed by X-ray crystallography. The syn-anti isomer is readily converted to 1 under acidic conditions. The apparent equal receptor binding of 1 and syn-anti isomer indicates that isomerization of the azine moiety may take place un... |
2441012 | Complete amino acid sequence and in vitro expression of rat NF-M, the middle molecular weight neurofilament protein. | A lambda gtII expression library was prepared from rat brain and screened with a polyclonal antiserum, which recognizes both NF-H and NF-M. An NF-M cDNA clone (pNF-M3C = 1.6 kb) was isolated and characterized. The fusion protein of NF-M3C, when used as an affinity matrix for the anti-neurofilament serum, isolated a sub... |
3611357 | Abnormal oxidant sensitivity and beta-chain structure of spectrin in hereditary spherocytosis associated with defective spectrin-protein 4.1 binding. | Hereditary spherocytosis (HS) is an inherited disorder of erythrocyte shape associated with spectrin deficiency and hemolytic anemia. In a subset of patients with the autosomal dominant form of HS, spectrin displays a reduced capacity to bind protein 4.1 and, therefore, actin; both functions that are critical to the me... |
3112124 | Nucleotide sequence of the Rickettsia prowazekii citrate synthase gene. | The Rickettsia prowazekii citrate synthase (gltA) gene, previously cloned in Escherichia coli, was localized to a 2.0-kilobase chromosomal fragment. DNA sequence analysis of a portion of this fragment revealed an open reading frame of 1,308 base pairs that encodes a protein of 435 amino acids with a molecular weight of... |
3609224 | Trypanosoma rhodesiense: antigenicity and immunogenicity of flagellar pocket membrane components. | A low density membrane fraction, isolated from the bloodstream stage of Trypanosoma rhodesiense and enriched in flagellar pocket membrane, was characterized with regard to antigenicity using antibodies raised against purified flagellar pocket membrane. Mild trypsinolysis of flagellar pocket membrane released two small ... |
3110373 | Alkylation of free sulfhydryls fortifies electroplax subsynaptic structures. | The cysteine-rich 43,000-dalton peripheral membrane protein, nu 1, is localized at the cytoplasmic face of electroplax and muscle cholinergic synapses, where it is thought to play an important role in the endplate supramolecular structure. The peripheral membrane protein properties of nu 1 are inferred by its removal f... |
3508280 | The design of a biochip: a self-assembling molecular-scale memory device. | A design for a biochip memory device based on known materials and existing principles is presented. The fabrication of this memory system relies on the self-assembly of the nucleic acid junction system, which acts as the scaffolding for a molecular wire consisting of polyacetylene-like units. A molecular switch to cont... |
18581379 | Enzyme-entrapping behaviors in alginate fibers and their papers. | Enzyme immobilization in the form of fiber and paper was easily achieved by wet spinning of aqueous admixture of sodium alginate and enzymes into divalent metallic ion solution as a coagulating bath, followed by paper making of resultant shortly cut fibers. Entrapment yields of enzymes used, e.g., glucoamylase, cyclode... |
16593868 | Self-assembly of proglycinin and hybrid proglycinin synthesized in vitro from cDNA. | An in vitro system was developed that results in the self-assembly of subunit precursors into complexes that resemble those found naturally in the endoplasmic reticulum. Subunits of glycinin, the predominant seed protein of soybeans, were synthesized from modified cDNAs using a combination of the SP6 transcription and ... |
3694434 | Effects of beta- and gamma-cyclodextrins on the pharmacokinetic behavior of prednisolone after intravenous and intramuscular administrations to rabbits. | The effects of beta- and gamma-cyclodextrins (CyDs) on the pharmacokinetic behavior of prednisolone after intravenous or intramuscular administration in rabbits were investigated. The serum levels of prednisolone after intravenous administration were little affected by the two CyD complexes. This might have been due to... |
3694430 | The use of beta-cyclodextrin in lymphocyte culture. Induction of the primary antibody response in vitro in calf serum- or newborn bovine serum-containing culture medium. | In order to induce the primary antibody response to sheep erythrocytes in vitro in murine lymphocytes, the cells are usually cultured in RPMI-1640 medium containing 10% fetal calf serum (FCS). When FCS was replaced by calf serum (CS) or newborn bovine serum (NBS), the antibody response was poor compared with that obtai... |
3680430 | Chiral-phase high-performance liquid chromatography of rotenoid racemates. | The high-performance liquid chromatographic (HPLC) behavior of parent rotenoids (type I) and the hydroxy-analogues (type II) on three different chiral stationary phases (CSPs) was studied. Separations of optical isomers were achieved in various degrees depending largely upon the rotenoidal structures and the CSP types ... |
3314864 | Participation of ATP in the binding of a yeast replicative complex to DNA. | The activity that replicates yeast DNA in vitro can be isolated from cells of the budding yeast Saccharomyces in a high-Mr (approximately 2 X 10(6] form. Several lines of evidence indicate that this fraction contains a multiprotein replicative complex. A functional assay has been developed for the analysis of the inter... |
3670300 | Identification of the principal promoter sequence of the c-H-ras transforming oncogene: deletion analysis of the 5'-flanking region by focus formation assay. | A number of deletion mutants were isolated, including 5', 3', and internal deletions in the 5'-flanking region of the human cellular oncogene related to the Harvey sarcoma virus (c-H-ras), and their transforming activities were examined in NIH 3T3 cells. DNA sequences which could not be detected without losing transfor... |
2822395 | Escherichia coli integration host factor bends the DNA at the ends of IS1 and in an insertion hotspot with multiple IHF binding sites. | The integration host factor of Escherichia coli (IHF) is a small, histone-like protein which participates in the integration of bacteriophage lambda into the E. coli chromosome and in a number of regulatory processes. Our recent footprinting analysis has shown that IHF binds specifically to the ends of the transposable... |
3117049 | Detection of 23-27 kDa GTP-binding proteins in platelets and other cells. | Membrane proteins from rabbit and human platelets were separated by SDS/polyacrylamide-gel electrophoresis and the resolved polypeptides blotted on nitrocellulose. A family of GTP-binding proteins, termed Gn proteins, was detected by incubation of these blots with [alpha-32P]GTP in the presence of Mg2+. A major Gn prot... |
3310882 | Degradation of the framework of the Chlamydomonas cell wall by proteases present in a commercially available alpha-amylase preparation. | A commercially available alpha-amylase derived from Bacillus licheniformis contained an enzymatic activity able to degrade the inner portion or framework of the cell wall of Chlamydomonas reinhardtii. Both the wall-degrading activity and the contaminating protease were destroyed by heating the alpha-amylase preparation... |
3310868 | In vitro and in vivo antibacterial activities of CS-807, a new oral cephalosporin. | CS-807 is a new oral prodrug of R-3746, a cephalosporin derivative, with potent in vitro and in vivo antibacterial activity against both gram-positive and gram-negative bacteria. The susceptibility of about 1,200 clinical isolates to R-3746 was determined by the agar dilution method. Ninety percent or more of pathogens... |
2820716 | The origin of bidirectional DNA replication in polyoma virus. | The nucleotide locations of RNA-p-DNA covalent linkages in polyoma virus (PyV) replicating DNA were mapped in the region containing the genetically required origin of DNA replication (ori). These linkages mark the initiation sites for RNA-primed DNA synthesis. A clear transition was identified between the presence of t... |
3653072 | Deriving the generic structure of the fibronectin type II domain from the prothrombin Kringle 1 crystal structure. | The proposed homology between the fibronectin type II domain and the Kringle domains of blood clotting and fibrinolytic proteins has been examined in three dimensions by substituting the type II sequence into the bovine prothrombin Kringle 1 tertiary structure, determined by X-ray crystallographical methods at 3.8 A. S... |
3305538 | Chromatography of complex protein mixtures. | This review has shown that a variety of chromatographic techniques are available for fractionating proteins. Fortunately, high-quality columns of every type described in this review are commercially available. Most water-soluble proteins may be eluted from size-exclusion, hydrophobic-interaction, ion-exchange, metal ch... |
3114196 | Inhibition of experimental and spontaneous pulmonary metastasis of murine RCT (+) sarcoma by beta-cyclodextrin-benzaldehyde. | The effect of beta-cyclodextrin-benzaldehyde (CDBA) on pulmonary metastasis in C3H/He mice was examined. In experimental metastasis that was induced by iv injection of 1 X 10(6) RCT (+) cells, the highest inhibition was observed in the mice that were treated daily with CDBA (5 mg/day) for 1 week before tumor cell inocu... |
3620656 | [Principle of the supramolecular stacking of the cellular deoxyribonucleoprotein complex]. | Using cytofluorimetry with acridine orange staining and a modified thermal denaturation technique of cellular DNP, it has been shown that chromatin melting profiles of normal human nuclei (from lymphocytes and granulocytes) have distinct regularities. It is believed that these regularities reflect specific supramolecul... |
3304388 | Human breast cancer cells share antigens with the myeloid monocyte lineage. | We have examined the expression of several myeloid cell associated antigens, some of which are involved in myelomonocyte adhesion, in seven well characterized human breast cancer cell lines, since common properties of adhesiveness and migration are found in haemopoietic cells and epithelial cancer cells. Five of these ... |
3615204 | Thermodynamics of B-Z transition in supercoiled DNA. | The nature of the possible supercoil-induced B-Z transition has been analyzed from the thermodynamical point of view, by taking into account the effects of the twisting as well as the writhing components of the supercoiling free energy. The cooperative aspects of the transition, as predicted by theory, agrees well with... |
3612879 | Intracellular fate of a multivalent ligand covalently bound to cell surface components. An electron microscopic study. | The electron dense tracer ferritin hydrazide (FH) was covalently attached to sialoglycoconjugates of the luminal surface of capillary endothelium in rat pancreas, after chemical modification of sialyl residues. Mild oxidation of the vasculature by perfusion with 1 mM sodium periodate was followed by a 30-90 min incubat... |
2440895 | Changes in villin synthesis and subcellular distribution during intestinal differentiation of HT29-18 clones. | Brush border in enterocytes is a cell surface specialization intimately associated with terminal differentiation of these cells. HT29-18, a clone derived from the HT-29 human colonic adenocarcinoma cell line, and HT29-18-C1, a subclone from HT29-18 described in the companion paper (Huet, C., C. Sahuquillo-Merino, E. Co... |
2956268 | Assembly of the intestinal brush border: appearance and redistribution of microvillar core proteins in developing chick enterocytes. | The assembly of the intestinal microvillus cytoskeleton during embryogenesis in the chick was examined by immunochemical and light microscopic immunolocalization techniques. For these studies, affinity-purified antibodies reactive with three major cytoskeletal proteins of the adult intestinal microvillus, fimbrin, vill... |
3037532 | Phencyclidine is a negative allosteric modulator of signal transduction at two subclasses of excitatory amino acid receptors. | Phencyclidine (PCP) and some of its pharmacological congeners inhibit the signal transduction at specific excitatory amino acid receptors of cerebellar granule cells in primary cultures. These drugs do not bind to the transmitter recognition sites, and affinity of this specific binding site is increased by the presence... |
3037518 | Origins of netropsin binding affinity and specificity: correlations of thermodynamic and structural data. | We report complete thermodynamic profiles for netropsin binding to an oligomeric and to several polymeric DNA host duplexes. These data allow us to reach the following conclusions: netropsin binding by deep penetration into the minor groove is overwhelmingly enthalpy driven and exhibits a very high binding affinity (K ... |
3299271 | Construction of bacteriophage T7 late promoters with point mutations and characterization by in vitro transcription properties. | This paper describes the construction of 18 cloned bacteriophage T7 late promoters with single point mutations. In vitro transcription experiments were used to characterize the properties of these promoters. Since the mutated promoters are cloned into identical backgrounds, differences seen in the transcription assays ... |
3601675 | Hybridization properties of immobilized nucleic acids. | The 5'-end attachment of oligonucleotides to dextran supports facilitates the study of the hybridization properties of an immobilized oligonucleotide system. The hybridization properties which were studied include: hybridization capacity and kinetics, hybridization-complex stability, and reagents influencing hybridizat... |
3600614 | Stimulation of adenylate cyclase by water-soluble analogues of forskolin. | Analogues of forskolin that are more soluble in water than forskolin have been synthesized and tested for their ability to interact with adenylate cyclase. These analogues are esterified with various heterocyclic amino acids at the 6 beta-hydroxyl position of forskolin or at the 6 beta-hydroxyl or 7 beta-hydroxyl posit... |
3298524 | Protection of bone marrow transplant recipients from lethal doses of methotrexate by the generation of methotrexate-resistant bone marrow. | To develop a highly efficient means for generating methotrexate resistant (MTXr) hematopoietic cells in vivo, a recombinant retroviral genome was constructed that encodes a MTXr dihydrofolate reductase (DHFRr). Cell lines producing high titers of virus capable of transmitting the DHFR gene were generated and used to in... |
3597773 | Mutant forms of spectrin alpha-subunits in hereditary elliptocytosis. | Two variant spectrins have been described in hereditary elliptocytosis (HE) and pyropoikilocytosis (HPP). Both are characterized by increased susceptibility of the alpha I (N-terminal) 80-kD domain to mild tryptic digestion, yielding peptides of 46-50 or 65-68 kD (T50a and T68 in our terminology). In this report we add... |
2439510 | Photoaffinity labeling of T4 bacteriophage 32 protein. | With a view toward the determination of nucleic acid binding domains and sites on nucleic acid helix-destabilizing (single strand-specific) proteins (HDPs), we have studied the interactions of the copolymer polynucleotide photoaffinity label, poly(adenylic, 8-azidoadenylic acid), (poly(A,8-N3A] with the T4 bacteriophag... |
3036774 | Cobalamin (vitamin B12) biosynthetic genes of Salmonella typhimurium. | The enteric bacterium Salmonella typhimurium synthesizes cobalamin (vitamin B12) de novo only under anaerobic growth conditions. We initiated a genetic analysis of the cobalamin biosynthetic (cob) gene cluster, Stable cob::lac operon fusions were generated by insertions of a transposition-defective derivative of bacter... |
3596801 | Purification and partial characterization of the capsular polymer of Haemophilus pleuropneumoniae serotype 5. | The capsular polymer (CP) of Haemophilus pleuropneumoniae serotype 5 was purified, and its chemical composition was analyzed. Radioimmunoassay experiments showed that the maximum amount of CP could be obtained from broth cultures of bacteria in the late stationary phase, rather than from bacteria washed off agar plates... |
3109487 | Characterization of the aflatoxin B1-binding site of rat albumin. | A fluorescence-enhancement method was used to investigate the non-covalent interaction between aflatoxin B1 and rat albumin. Solvent-induced shifts in the emission spectrum of aflatoxin B1 provided evidence that the aflatoxin B1-binding site of rat albumin is a highly nonpolar environment. A dissociation constant of 20... |
3035209 | Oligomerization and origin DNA-binding activity of simian virus 40 large T antigen. | Simian virus 40 (SV40) large tumor antigen (T antigen) exists in multiple molecular forms, some of which are separable by zone velocity sedimentation of soluble extracts from infected monkey cells. Three subclasses of this antigen from SV40-infected monkey cells have been separated and characterized: the 5S, 7S, and 14... |
16347393 | Production of Thermostable alpha-Amylase, Pullulanase, and alpha-Glucosidase in Continuous Culture by a New Clostridium Isolate. | The production of alpha-amylase, pullulanase, and alpha-glucosidase and the formation of fermentation products by the newly isolated thermophilic Clostridium sp. strain EM1 were investigated in continuous culture with a defined medium and an incubation temperature of 60 degrees C. Enzyme production and excretion were g... |
3325759 | Metabolic activation of 3-nitroperylene in the Salmonella/S9 assay. | The mutagenicity of 3-nitroperylene (nitroPer), a nitrated polycyclic aromatic hydrocarbon (PAH) has been extensively studied using the Ames Salmonella test. In accord with previous work, nitroPer proved to be a potent frameshift mutagen which requires activation by mixed function oxidases (MFOs) in the microsomes of r... |
3656780 | The use of beta-cyclodextrin-containing culture medium for in vitro evaluation of immunomodulating agents. | We have devised a new culture medium that is made of RPMI-1640 medium, 500 micrograms/ml beta-cyclodextrin (beta-CD) and 1% fetal calf serum (FCS) (beta-CD medium). Murine lymphocytes stimulated with sheep erythrocytes in vitro developed antibody-forming cells in beta-CD medium as efficiently as in 10% FCS-containing R... |
3627092 | [Endotoxemia after surgery in digestive diseases]. | The blood level of endotoxin after operations in patients with digestive diseases, mainly liver cirrhosis and obstructive jaundice, and the complications most likely related to the presence of endotoxemia were investigated. Twenty-seven patients without either liver cirrhosis or obstructive jaundice showed a minimal el... |
3616264 | [Two cases of severe acute pancreatitis-CT scan was useful to the assessment]. | We report two cases of severe acute pancreatitis; a 53-year-old man (Case 1) and a 60-year-old woman (Case 2). Case 1 was classified as "severe" according to the Ranson's criteria and he died of MOF on the 21st hospital day. Case 2 was classified as "moderate", but a large pancreatic abscess was observed by CT scan. Sh... |
2440977 | Batrachotoxin-modified sodium channels in planar lipid bilayers. Ion permeation and block. | Batrachotoxin-modified, voltage-dependent sodium channels from canine forebrain were incorporated into planar lipid bilayers. Single-channel conductances were studied for [Na+] ranging between 0.02 and 3.5 M. Typically, the single-channel currents exhibited a simple two-state behavior, with transitions between closed a... |
3111937 | Partial correction of structural defects in alcohol dehydrogenase through interallelic complementation in Drosophila melanogaster. | Alcohol dehydrogenases (ADH) from the F1 progeny of all pairwise crosses between 12 null-activity mutants and crosses between these mutants and four active variants, ADHn5 ADHF, ADHD and ADHS, were analyzed for the presence of active or inactive heterodimers. Gels were stained for ADH enzyme activity, and protein blots... |
2440487 | Uniformly oriented gramicidin channels embedded in thick monodomain lecithin multilayers. | Phosphatidylcholine multilayers, containing 20% water by total sample weight and gramicidin/lipid molar ratios up to 1:40 were aligned by low temperature annealing (less than 60 degrees C) and mechanical stressing. We were able to obtain large (greater than 80 micron thick X 40 mm2 area) monodomain defect-free multilay... |
3607215 | Acanthamoeba profilin binding to fluorescein-labeled actins. | The binding constants of Acanthamoeba profilin to fluorescein-labeled actin from Acanthamoeba and from rabbit skeletal muscle have been determined by measuring the reduction in the actin tracer diffusion coefficients, determined by fluorescence photobleaching recovery, as a function of added profilin concentration. Dat... |
3607213 | Interpretation of fluorescence decays in proteins using continuous lifetime distributions. | The decay of the tryptophanyl emission in proteins is often complex due to the sensitivity of the tryptophan excited state to its surroundings. The traditional analysis of the decay curve using exponential components is based on the identification of each component with a particular protein conformation. An alternative... |
2439371 | Covalent and non-covalent interaction of chymotrypsin with alpha 2-macroglobulin. | The pattern of covalent crosslinking between human alpha 2-macroglobulin (alpha 2M) and chymotrypsin has been investigated by chromatography and polyacrylamide gel electrophoresis in denaturing medium. Reaction with a single mol of chymotrypsin per mol alpha 2M results in the formation of a 95% covalent 1:1 chymotrypsi... |
3495664 | Inhibition of the mammalian beta-lactamase renal dipeptidase (dehydropeptidase-I) by (Z)-2-(acylamino)-3-substituted-propenoic acids. | The title enzyme deactivates the potent carbapenem antibiotic imipenem in the kidney, producing low antibiotic levels in the urinary tract. A series of (Z)-2-(acylamino)-3-substituted-propenoic acids (3) are specific, competitive inhibitors of the enzyme capable of increasing the urinary concentration of imipenem in vi... |
3584471 | Specific affinity between fibronectin and the epidermolysis bullosa acquisita antigen. | Autoantibodies in the skin and sera of patients with epidermolysis bullosa acquisita bind to a large matrix molecule within the lamina densa region of skin basement membrane. At the site of these immune complexes, the epidermis separates from the dermis, which creates a subepidermal blister just below the lamina densa.... |
3294857 | Posttranslational modifications of alpha-tubulin: acetylated and detyrosinated forms in axons of rat cerebellum. | The distribution of acetylated alpha-tubulin in rat cerebellum was examined and compared with that of total alpha-tubulin and tyrosinated alpha-tubulin. From immunoperoxidase-stained vibratome sections of rat cerebellum it was found that acetylated alpha-tubulin, detectable with monoclonal 6-11B-1, was preferentially e... |
3584073 | Bordetella parapertussis and Bordetella bronchiseptica contain transcriptionally silent pertussis toxin genes. | Pertussis toxin, the major virulence factor of Bordetella pertussis, is not produced by the closely related species Bordetella parapertussis and Bordetella bronchiseptica. It is shown here that these two species possess but do not express the complete toxin operon. Nucleotide sequencing of an EcoRI fragment of 5 kiloba... |
2438270 | Promoter of the pertussis toxin operon and production of pertussis toxin. | Pertussis toxin (PT), the major virulence factor of Bordetella pertussis, is composed of five different subunits whose genes are organized as an operon. We report the mapping of the promoter region of the PT operon and show that this promoter is only weakly active in Escherichia coli. Bordetella parapertussis and Borde... |
3584071 | Charge distribution on the S layer of Bacillus stearothermophilus NRS 1536/3c and importance of charged groups for morphogenesis and function. | The distribution and functional significance of charged groups on the outer and inner faces of the S layer from Bacillus stearothermophilus NRS 1536/3c was investigated. Chemical modification of the exposed amino or carboxyl groups was performed on whole cells, isolated S layers self-assembled in vitro, and cell wall f... |
3473063 | Bradyrhizobium japonicum mutants defective in nitrogen fixation and molybdenum metabolism. | Bradyrhizobium japonicum JH mutants deficient in molybdenum metabolism into the enzymes nitrogenase and nitrate reductase were isolated by using the vector pSUP1011, which carries transposon Tn5 (streptomycin and kanamycin resistance). Mutants in Mo metabolism were obtained at a frequency of 3.6 X 10(-3) (per Kan Strr ... |
16453768 | Chalcone isomerase cDNA cloning and mRNA induction by fungal elicitor, wounding and infection. | The environmentally regulated synthesis of phenylpropanoid natural products was studied by examining the expression of the gene encoding chalcone isomerase (CHI). This enzyme catalyzes a step common to the synthesis of flavonoid pigments and isoflavonoid phytoalexins. A lambdagt11 library was constructed using mRNA fro... |
3446177 | Anti-actin antibodies. An immunological approach to the myosin-actin and the tropomyosin-actin interfaces. | The topography of the rigor complex between subfragment-1 (S-1) of myosin and actin was investigated by using several specific antibodies directed to well-located sequences in actin. A major contact area for S-1 was characterized in the hydrophilic 18-28 constant sequence, and the variable 1-7 sequence was only found t... |
3663111 | Substrate-derived two-protonic-state electrophiles as sensitive kinetic specificity probes for cysteine proteinases. Activation of 2-pyridyl disulphides by hydrogen-bonding. | 1. 2-(N'-Acetyl-L-phenylalanylamino)ethyl 2'-pyridyl disulphide [compound (III)] and 2-(acetamido)ethyl 2'-pyridyl disulphide [compound (IV)] were synthesized by acylation of the common intermediate, 2-aminoethyl 2'-pyridyl disulphide, to provide examples of chromogenic thiol-specific substrate-derived two-protonic-sta... |
3617222 | [Effect of elastic properties of the crab axon sheath on the movement of nerve fibers at the action potential]. | The shear modulus (nu) of single giant axon of the crab Carcinus maenas was determined by measuring the axon elastic stretching up to 1-10%. The value obtained for nu (5-7 X 10(3) dn X cm) is more than that for sheaths of reptilian and mammalian red blood cells by 10(4)-10(6) times. Proteolysis of the axon sheath by pr... |
3038516 | Cell type-specificity elements of the immunoglobulin heavy chain gene enhancer. | A strong transcriptional enhancer was created by oligomerization of a short segment from the immunoglobulin heavy chain (IgH) enhancer. This segment was analyzed in parallel for biological activity in vivo and factor binding in vitro. In transfection experiments the oligomerized segment stimulates transcription in a ce... |
3607226 | Basic kinetics of binding and incorporation with supramolecular aggregates. | Supramolecular particles of spherical shape (such as micelles, vesicles, etc.) are imagined to interact with small (bio)molecules so that either binding or incorporation occurs. This is generally described as an association process whose rate is determined by appropriate diffusion and actual transformation steps. Along... |
3110598 | Primary structure of human nuclear ribonucleoprotein particle C proteins: conservation of sequence and domain structures in heterogeneous nuclear RNA, mRNA, and pre-rRNA-binding proteins. | In the eucaryotic nucleus, heterogeneous nuclear RNAs exist in a complex with a specific set of proteins to form heterogeneous nuclear ribonucleoprotein particles (hnRNPs). The C proteins, C1 and C2, are major constituents of hnRNPs and appear to play a role in RNA splicing as suggested by antibody inhibition and immun... |
3593926 | [Metabolism of the inhibitor of fibrin self-assembly in rats]. | It has been shown that the application of the labelled preparation in physiologically normal white rats and in animals with experimental hyper- and hypothrombinemia leads to the rapid exchange of the peptide self-assembly inhibitor between the blood and extravascular space. The constant level of the inhibitor in the bl... |
3592668 | Reduction of the C2 and C4 vinyl groups of Sn-protoporphyrin to form Sn-mesoporphyrin markedly enhances the ability of the metalloporphyrin to inhibit in vivo heme catabolism. | Sn (tin)-mesoporphyrin (Sn-protoporphyrin in which the vinyl groups at C2 and C4 have been reduced to ethyl groups) when incubated with rat splenic microsomal heme oxygenase proved to be a potent competitive inhibitor of enzyme activity in vitro, with a Ki of 0.014 microM. Sn-mesoporphyrin (1 mumol/kg body wt) also inh... |
3585469 | Synaptic potentials of primary afferent fibers and motoneurons evoked by single intermediate nucleus interneurons in the cat spinal cord. | Spike-triggered averaging of dorsal and ventral root potentials was used in anesthetized cats to disclose possible synaptic connections of spinal interneurons in the intermediate nucleus with afferent fibers and/or motoneurons. With this method we have been able to document the existence of a distinct group of interneu... |
3472223 | Spontaneous assembly of double-stranded helicates from oligobipyridine ligands and copper(I) cations: structure of an inorganic double helix. | Two oligobipyridine ligands containing two and three 2,2'-bipyridine subunits separated by 2-oxapropylene bridges have been synthesized and some of their complexation properties with metal ions have been investigated. In particular, with copper(I) they form, respectively, a dinuclear and a trinuclear complex containing... |
2883653 | Isolation and characterization of the alpha-sialyl-beta-2,3-galactosyl-specific adhesin from fimbriated Escherichia coli. | The alpha-sialyl-beta-2,3-galactosyl-specific adhesin (S adhesin) was isolated from cells of a recombinant Escherichia coli K-12 strain expressing the S-fimbrial adhesin complex. A crude cell extract was partially dissociated into fimbriae and an adhesin-enriched fraction by heating to 70 degrees C. From the latter, ad... |
2952887 | Determination of bacteriophage lambda tail length by a protein ruler. | How the size and shape of living structures are determined by genetic information is one of the fundamental problems in biology. Here I describe a study in which the size of a biological supramolecular structure was changed in a predictable way by in vitro genetics, with the size both before and after manipulation bein... |
3033298 | Functional expression of a cloned herpes simplex virus type 1 DNA polymerase gene. | A vector which expresses the herpes simplex virus type 1 (HSV-1) (strain 17) DNA polymerase gene was constructed by ligating two separately cloned HSV DNA restriction fragments into an intermediate plasmid and then mobilizing the intact polymerase gene-encoding sequence into a pSV2 derivative. The expression vector (pD... |
3033283 | Multiple tandemly repeated binding sites for cellular nuclear factor 1 that surround the major immediate-early promoters of simian and human cytomegalovirus. | We show that the large DNA genomes of human and simian cytomegaloviruses (HCMV and SCMV, respectively) each contain multiple binding sites for purified cellular nuclear factor 1 (NF1) protein. Examination of the major immediate-early (IE) gene region in the HindIII H fragment of SCMV (Colburn) by filter binding assays ... |
3033276 | Synthesis and immunogenicity of the rotavirus major capsid antigen using a baculovirus expression system. | Rotaviruses are the major pathogens that cause life-threatening diarrhea in young children and animals. We inserted a simian rotavirus SA11 gene 6 cDNA into the genome of the baculovirus Autographa californica nuclear polyhedrosis virus adjacent to the strong polyhedrin promoter. The major capsid antigen (VP6) was expr... |
3033269 | Identification of gp350 as the viral glycoprotein mediating attachment of Epstein-Barr virus (EBV) to the EBV/C3d receptor of B cells: sequence homology of gp350 and C3 complement fragment C3d. | The major Epstein-Barr virus (EBV) envelope glycoprotein, gp350, was purified from the B95-8 cell line and analyzed for its ability to mediate virus attachment to the isolated EBV/C3d receptor (CR2) of human B lymphocytes. Purified gp350 and EBV, but not cytomegalovirus, exhibited dose-dependent binding to purified CR2... |
2883299 | Alpha-1 adrenergic coupling events induced by full and partial agonists in rabbit aorta. | Differences in the ability of full vs. partial agonists to initiate alpha-1 adrenergic receptor-mediated coupling events were studied in isolated segments of rabbit aorta. Mono- and dimethoxysubstituted tolazolines produced contractile responses which, at their maximum, were 27 to 100% of the response produced by the f... |
3106556 | A major immunogen in Schistosoma mansoni infections is homologous to the heat-shock protein Hsp70. | A 70,000 mol wt protein of Schistosoma mansoni was shown to be a major immunogen that invariably elicited an antibody response in infected humans. The universality of the response to this abundant antigen was confirmed in experimental animals and included the antibody response associated with the protective irradiated ... |
3033026 | Variation of erythroid and myeloid precursors in the marrow and peripheral blood of volunteer subjects infected with human parvovirus (B19). | Infection of normal individuals with human parvovirus (B19) results in a mild disease (erythema infectiosum) but gives rise to aplastic crises in patients with chronic hemolytic anemias. The effects of this disease on hemopoiesis were investigated following intranasal inoculation of the virus into three volunteers. A t... |
2437126 | Monoclonal antibodies identify a group of nuclear pore complex glycoproteins. | Using monoclonal antibodies we identified a group of eight polypeptides of rat liver nuclear envelopes that have common epitopes. Most or all of these proteins are structurally distinct, as shown by tryptic peptide mapping and analysis with polyclonal antibodies. While these polypeptides are relatively tightly bound to... |
3032913 | Regulation of cobalamin biosynthetic operons in Salmonella typhimurium. | Transcription of cobalamin (cob) biosynthetic genes in Salmonella typhimurium is repressed by cobalamin and by molecular oxygen. These genes seem to be subject to catabolite repression, and they are maximally expressed under conditions of anaerobic respiration of glycerol-fumarate. A 215-fold increase in the expression... |
3106320 | Functional expression of plastid allophycocyanin genes in a cyanobacterium. | In Cyanophora paradoxa, the allophycocyanin apoprotein subunits, alpha and beta, are encoded in the cyanelle (plastid) genome. These genes were transferred to the cyanobacterium Synechococcus sp. PCC 7002 on a plasmid replicon. Phycobilisomes isolated from transformed cyanobacteria were found to contain C. paradoxa all... |
3106037 | Purification and characterization of extracellular alpha-amylase and glucoamylase from the yeast Candida antarctica CBS 6678. | An alpha-amylase and a glucoamylase were purified to homogeneity from the culture fluid of beta-cyclodextrin-grown Candida antarctica CBS 6678 by protamine sulfate treatment, ammonium sulfate precipitation, gel filtration (Sephadex G-75 sf, Ultrogel AcA 54), DEAE-Sephacel chromatography, hydroxyapatite chromatography a... |
3032409 | Characterization of the cyclic adenosine 3':5'-monophosphate effector system in hormone-dependent and hormone-independent rat mammary carcinomas. | We have compared the properties of cyclic adenosine 3':5'-monophosphate (cAMP)-dependent protein kinases I and II in hormone-dependent/cAMP-sensitive (DMBA tumor) and hormone-independent/cAMP-resistant (DMBA 1 tumor) rat mammary carcinomas. cAMP-resistance was not due to less total kinase in the hormone-independent tum... |
2952186 | Platelets express a membrane protein complex immunologically related to the fibroblast fibronectin receptor and distinct from GPIIb/IIIa. | We have previously identified and characterized a membrane glycoprotein complex (GP150/135) that functions as fibronectin receptor (FN-R) in fibroblast adhesion. Here we report that an immunologically related protein complex is expressed at the surface of human platelets. Antibodies monospecific for the smaller subunit... |
3566931 | A morphological study of the effect of the Cavitron ultrasonic surgical aspirator system near human peripheral nerves. | The Cavitron ultrasonic surgical aspirator system was used to clear superficial tissue from the greater auricular nerve in four human subjects. Following stimulation, the nerves were removed together with an untreated section and processed for examination by light microscopy. Significant damage had been sustained by th... |
3509341 | Enhanced percutaneous absorption of homogenized tolnaftate/beta-cyclodextrin polymer ground mixture. | The absorption of tolnaftate after external application of tolnaftate-cyclodextrin polymer homogenized ground mixtures was investigated in comparison with that of tolnaftate alone and non-homogenized mixtures. To evaluate their percutaneous absorption, samples were applied to the shaved back skin of mice. It was found ... |
18964347 | Transport of alkali-metal picrates through liquid membranes: Coupled action of w/o microemulsion droplets and lipophilic crown-ether carriers. | The transport of potassium and sodium picrates is measured by a liquid membrane technique in the presence of two mobile carriers: water-in-oil microemulsion droplets and lipophilic crown-ethers. The fluxes are compared for two cases: (i) the crown-ether (dicyclohexano-18-crown-6 is assumed to be independent of the micr... |
17010281 | Influence of solvent, anion and presence of nitrogen in the ring structure on the mechanism of complexation of alkali metal cations with crown ethers. | The mechanism of complexation of alkali metal cations with macrocyclic ligands such as the simple crown ethers and the role of desolvation vs. ligand rearrangement are discussed. The unique role of water solvent in the rate-determining step of complexations in aqueous solutions is brought into focus. The competitive ro... |
16593826 | Bacteriopheophytin g: Properties and some speculations on a possible primary role for bacteriochlorophylls b and g in the biosynthesis of chlorophylls. | Bacteriopheophytin g and small amounts of bacteriochlorophyll g have been obtained in high purity from the recently discovered photosynthetic bacterium Heliobacterium chlorum. Preparative methods and precautions in handling these sensitive compounds are described. The compounds have been characterized by californium-25... |
16347352 | Characterization of Pyoverdin(pss), the Fluorescent Siderophore Produced by Pseudomonas syringae pv. syringae. | Pseudomonas syringae pv. syringae B301D produces a yellow-green, fluorescent siderophore, pyoverdin(pss), in large quantities under iron-limited growth conditions. Maximum yields of pyoverdin(pss) of approximately 50 mug/ml occurred after 24 h of incubation in a deferrated synthetic medium. Increasing increments of Fe(... |
2440450 | [A new primer for sequencing DNA fragments cloned in M13mp vectors]. | Tridecadeoxyribonucleotide d(CCAGGGTTTTCCC) was prepared by solid phase crown-ether-catalyzed phosphotriester method and proposed a new sequencing primer. This primer expands capacities of the Sanger dideoxy-chain-terminating method to solve various sequencing problems as compared to well-known universal primers. Crite... |
3111460 | The partial amino acid sequence of bovine cartilage proteoglycan, deduced from a cDNA clone, contains numerous Ser-Gly sequences arranged in homologous repeats. | We have determined the sequence of a partial cDNA clone encoding the C-terminal region of bovine cartilage aggregating proteoglycan core protein. The deduced amino acid sequence contains a cysteine-rich region which is homologous with chicken hepatic lectin. This lectin-homologous region has previously been identified ... |
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