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18963655 | Extraction of potassium p-nitrophenoxide with macrocyclic crown ethers and cryptands from aqueous medium into diverse organic solvents: a systematic evaluation. | A systematic study has been made of the extraction of potassium p-nitrophenoxide from aqueous medium into a number of organic solvents that are immiscible or partly miscible with water, in the presence of several macrocyclic crown ether and cryptand complexing agents. The efficiency of extraction varies extremely widel... |
6494226 | Cyclodextrin polymer, a new tablet disintegrating agent. | Cyclodextrin (CD) polymer, a type of crosslinked cyclodextrin, has been evaluated as a new tablet disintegrating agent in comparison with four common disintegrants (crosslinked polyvinylpyrrolidone, crosslinked carboxymethyl cellulose, formaldehyde casein and corn starch). Physical properties of the disintegrants have ... |
6490608 | Kinetic study of beta-cyclodextrin-dye system by high-pressure temperature-jump method. | The pressure dependence of the formation and dissociation rate constants of the inclusion reaction between beta-cyclodextrin and phenolphthalein was investigated with a newly constructed high-pressure temperature-jump apparatus. The jump height of temperature was 2.8 degrees C within 1 microsecond under pressure up to ... |
6091782 | [ A selective filter model of the potassium channel]. | A model based on analogy between filter and crown-ether molecule in a two-phase system organic solvent-water is proposed for potassium channel selective filter. The selectivity of K+-channel can be quantitatively described by this model. |
6480773 | Simultaneous separation and sensitive determination of free fatty acids in blood plasma by high-performance liquid chromatography. | Fatty acids are separated by reversed-phase high-performance liquid chromatography after derivatization with a fluorescence reagent, 4-bromomethyl-7-acetoxycoumarin. Each derivative eluted from a column is successively hydrolysed by mixing it with an alkaline solution, and the produced fluorescence is detected. The der... |
6478462 | Synthesis of the trisaccharide moiety of gangliotriosylceramide (asialo GM2). | The synthesis of the trisaccharide methyl glycoside beta-D-GalNAc-(1----4)-beta-D-Gal-(1----4)-beta-D-Glc-OMe, which corresponds to the carbohydrate portion of gangliotriosylceramide (asialo GM2), was accomplished by the reaction of 4-O-acetyl-3,6-di-O-benzoyl-2-deoxy-2-phthalimido-D-galactopyranosyl bromide (18) with ... |
6477637 | Predominance of beta-structure in solubilized zona pellucida from porcine ova. | The isolated zona pellucida from porcine ova was effectively solubilized in water at 60 degrees C within one hour. The circular dichroic spectra of zona in water with and without dithiothreitol showed the beta-form. Although sodium dodecyl sulfate partially induced helical structure, the beta-form was considerably reta... |
6473721 | [Changes in the composition of phospholipids bound to supramolecular DNA of the thymus and liver in gamma-irradiated rats]. | The composition of supramolecular DNA (SM DNA)-bound phospholipids (PL) of thymus and liver of intact rats and those 2 min, 2, 6 and 24 h after gamma-irradiation (9,7 Gy) was studied. In norm, supramolecular DNA of the thymus was shown to contain 6.7 micrograms PL/mg DNA, and that of the liver, 6.1 micrograms PL/mg DNA... |
6469902 | Liquid chromatographic method for quantitative determination of free fatty acids in butter. | A liquid chromatographic method has been developed for the determination of free fatty acids in butter. The fatty acids are converted to the p-bromophenacyl esters, via a crown ether-catalyzed reaction, without separation from the other butter components. The esters are separated on a C18-bonded silica column by using ... |
6087976 | Adrenergic transmission in hippocampus-locus coeruleus double grafts in oculo: demonstration by in vivo electrochemical detection. | In vivo electrochemical detection was used to study transmitter release from a synaptically or pharmacologically stimulated noradrenergic isolated pathway formed by double in oculo brain tissue grafts. Retinal illumination, which activates cholinergic nerve fibers that grow into intraocular grafts from the autonomic gr... |
6589601 | Structure of the cholesteryl ester core of human plasma low density lipoproteins: selective deuteration and neutron small-angle scattering. | The structural arrangement of cholesteryl esters in human plasma low density lipoproteins (LDL) has been studied by selective deuteration and neutron small-angle scattering. LDL were labeled by in vitro exchange with two different kinds of deuterated cholesteryl esters, one labeled in the fatty acyl chain (cholesteryl ... |
6379600 | H1a, an E. coli DNA-binding protein which accumulates in stationary phase, strongly compacts DNA in vitro. | We characterize a component of the E. coli bacterial nucleoid H1a, which accumulates in stationary phase. This protein, identical with the major component of a plasmid-protein complex previously isolated in our laboratory, has a pI close to 7.5. Acrylamide gel electrophoresis and sedimentation in sucrose gradient have ... |
6379417 | Membrane attack by complement. | Membrane attack by complement involves the self-assembly on membranes of five hydrophilic proteins (C5b, C6, C7, C8 and C9) to an amphiphilic tubular complex comprising approximately 20 subunits. The hydrophilic-amphiphilic transition of the precursor proteins is achieved by restricted unfolding and exposure of previou... |
6235234 | Respective roles of centrosomes and chromatin in the conversion of microtubule arrays from interphase to metaphase. | We report the results of studies in which partially purified centrosomes, nuclei, and DNA were injected into frog's eggs, which are naturally arrested in metaphase or interphase. These results have led to an independent assessment of the contributions of the centrosome and the chromatin to the formation of the mitotic ... |
6746728 | Water near intracellular surfaces. | In this paper we make the following points: Water is perturbed within several angstroms of the surfaces of soluble molecules. Removal of this water can require significant amounts of work, seen as an exponentially varying "hydration force" with respect to molecular separation. The favorable and specific attractions tha... |
6235122 | Crown ethers which influence cardiac and respiratory muscle contractility. | Guinea-pig tracheal smooth muscle and heart muscle demonstrated a variety of in vitro positive and negative inotropic responses to concentrations of crown ethers in the nmole/1 to mumole/1 range. It is suggested that these ionophoretic compounds have potential as therapeutic agents. |
6588384 | Lignoceric acid is oxidized in the peroxisome: implications for the Zellweger cerebro-hepato-renal syndrome and adrenoleukodystrophy. | The deficient oxidation and accumulation of very-long-chain fatty acids in the Zellweger cerebro-hepato-renal syndrome (CHRS) and X chromosome-linked adrenoleukodystrophy (ALD), coupled with the observation that peroxisomes are lacking in CHRS, prompted us to investigate the subcellular localization of the catabolism o... |
6234380 | Phase II study of methyl-CCNU, vincristine, 5-fluorouracil, and streptozotocin in advanced colorectal cancer. By the Gastrointestinal Tumor Study Group. | In an attempt to confirm the previously reported response rates with methyl-CCNU, vincristine, 5-fluorouracil, and streptozotocin (MOF-strep) (34%) in advanced colorectal cancer, the Gastrointestinal Tumor Study Group used the identical treatment schedule in 40 good performance status patients who had received no prior... |
6376619 | Use of immunogold electron microscopy and monoclonal antibodies in the identification of nuclear substructures. | A cytochemical technique for the ultrastructural localization of unique nuclear antigens is reported. Using a post-embedding indirect immunogold labeling procedure, nuclear antigens in electron-dense regions of the nucleus are localized with a minimum of nonspecific staining. Using this technique and indirect immunoflu... |
6330173 | Lipoprotein metabolism by rat hepatomas. Studies on the etiology of defective dietary feedback inhibition of cholesterol synthesis. | In contrast to normal liver, it is known that in vivo hepatomas fail to decrease their rate of cholesterol biosynthesis in response to increased dietary cholesterol. From a consideration of the available data it has been hypothesized that the defect might lie in the delivery of cholesterol to the hepatoma cell. To stud... |
6539784 | Colchicine-binding activity distinguishes sea urchin egg and outer doublet tubulins. | The colchicine-binding activity of tubulin has been utilized to distinguish the tubulins from two distinct microtubule systems of the same species, the sea urchin Strongylocentrotus purpuratus. We have analyzed the colchicine-binding affinities of highly purified tubulins from the unfertilized eggs and from the flagell... |
6330030 | Porin from Rhodopseudomonas sphaeroides. | A protein homooligomer was purified from both the cell envelope fractions and the saline extracts of Rhodopseudomonas sphaeroides cells. This oligomer exhibited strong porin activity when reconstituted into proteoliposomes with egg phosphatidylcholine. In the saline extracts of both chemotrophically and phototrophicall... |
22557447 | Potential of herbal medicines in modern medical therapy. | The author discusses in this paper the potentialities of Herbal medicine in modern therapy. Also he throws some light on the importance of natural drugs which bring about cure without generation side-effects. |
16593492 | Statistical thermodynamics of amphiphile chains in micelles. | The probability distribution of amphiphile chain conformations in micelles of different geometries is derived through maximization of their packing entropy. A lattice model, first suggested by Dill and Flory, is used to represent the possible chain conformations in the micellar core. The polar heads of the chains are a... |
16346587 | Interaction of Pseudomonas solanacearum Lipopolysaccharide and Extracellular Polysaccharide with Agglutinin from Potato Tubers. | In vitro binding assays were used to study the possible role of a cell wall agglutinin in the attachment to plant cell walls of avirulent strains of the wilt pathogen, Pseudomonas solanacearum. In a nitrocellulose filter assay, radioactively labeled lipopolysaccharide (LPS) from the virulent strain, K60, and the avirul... |
6476380 | A fluorometric method for the specific determination of serum arginine with 2,3-naphthalenedicarbaldehyde. | A specific and simple fluorometric method for the determination of serum arginine was developed which consists of (1) deproteinization of serum sample with 10% perchloric acid, (2) blocking thiol compounds with N-ethylmaleimide, (3) fluorescence reaction with 2,3-naphthalenedicarbaldehyde in 0.2 M borate buffer, pH 9.3... |
6469455 | Preparation of maltosyl, beta-cyclodextrinyl, glucosaminyl, and glucosamineoctaosyl derivatives of beta-lactoglobulin. | beta-Lactoglobulin was modified to various degrees with maltose or beta-cyclodextrin using the cyclic carbonate method and with glucosamine or glucosamine-octaose using the carbodiimide method. Up to 65% of the amino or the carboxyl groups of b-LG were glycosylated using the two methods, respectively. Up to 32 maltose ... |
6547605 | Triacylglycerol synthesis in goat mammary gland. The effect of ATP, Mg2+ and glycerol 3-phosphate on the esterification of fatty acids synthesized de novo. | Goat mammary-gland microsomal fraction by itself induces synthesis of medium-chain-length fatty acids by goat mammary fatty acid synthetase and incorporates short- and medium-chain fatty acids into triacylglycerol. Addition of ATP in the absence or presence of Mg2+ totally inhibits triacylglycerol synthesis from short-... |
6204448 | In vitro assembly of poliovirus empty capsids: antigenic consequences and immunological assay of the morphopoietic factor. | The assembly of poliovirus 14 S particles into empty capsids was studied without cell extract (self-assembly) and in extracts of infected or uninfected HeLa cells. The products were analyzed using monoclonal antibodies specific for N1, N2, or H epitopes. The empty capsids formed in infected cell extract, and only those... |
6330977 | Reversible restriction of vesicular stomatitis virus in permissive cells treated with inhibitors of prostaglandin biosynthesis. | Indomethacin, a potent nonsteroidal inhibitor of prostaglandin synthetase (cyclooxygenase) reduced yields of infectious vesicular stomatitis virus in HEp-2 cells more than 99% if added to cultures at levels of 10(-3)M either before or after infection. Other permissive cell lines differed according to the treatment peri... |
6375978 | Neural retinas promote cell division and fibre differentiation in lens epithelial explants. | Histological analysis of lens epithelial cells from newborn rats co-cultured with neural retinas over a 12 day period showed stimulation of cell division and fibre differentiation. Cell division increased to a peak of 0.54 +/- 0.13% at 6 days and then decreased to near zero at 12 days. Early signs of differentiation at... |
6329204 | Experimental simulation of the environment of the delta opioid receptor. A 500 MHz study of enkephalins in CDCl3. | Complexes of [Met5] and [Leu5]enkephalin amides with 18-crown-6-ether have been studied in CDCl3 solution by means of 500 MHz NMR spectroscopy, in order to simulate two of the features of the opioid receptor: the apolar environment and the binding of the charged N atom. Contrary to all previous studies in polar solvent... |
6587784 | Clinical application of prostaglandin E1 (PGE1) upon orthodontic tooth movement. | Chemically produced prostaglandin E1 (PGE1) was administered in clinical cases of orthodontic tooth movement. In the first phase, lingual arch springs were applied on both sides of the maxilla to upper first premolars which were scheduled for extraction. One side received submucosal injections of PGE1 and the other rec... |
6427775 | Rapid mutational analysis of regulatory loci in Escherichia coli K-12 using bacteriophage M13. | A derivative of bacteriophage M13mp8 , designated M13mp8 /P, was prepared in which the promoter and NH2-terminal codons of bacterial genes may be fused to a portion of beta-galactosidase, resulting in an easily scorable phenotype. Because transcription from the inserted promoter remains responsive to the host regulator... |
6587383 | Titin is an extraordinarily long, flexible, and slender myofibrillar protein. | " Titin " is a term used to describe a pair of closely related megadalton polypeptides that together are the third most abundant myofibrillar protein in a wide range of striated muscles. It has been proposed that titin and another giant protein, nebulin , are the major components of an elastic cytoskeletal lattice with... |
6587352 | A simple topological method for describing stereoisomers of DNA catenanes and knots. | Although linking number is an effective topological invariant for describing supercoiled DNA, it is inadequate for the additional interwinding in catenated or knotted DNA. We explain how the two-bridge theory of Schubert provides a powerful yet simple method for analyzing these forms by associating them with two integr... |
6328509 | Bis[cyclo(histidylhistidine)]copper(II) complex that mimicks the active center of superoxide dismutase has its catalytic activity. | The formation of copper complexes with bis[cyclo( histidylhistidine )] copper(II) was determined potentiometrically; the maximum coordination number was four deprotonated histidine residues per Cu(II) ion. This complex mimicks the active center of Cu/Zn superoxide dismutase (superoxide:superoxide oxidoreductase, EC 1.1... |
6539380 | Location of DNA-binding proteins and disulfide-linked proteins in vaccinia virus structural elements. | Treatment with sodium dodecyl sulfate (SDS) converted the vaccinia virus strain IHD-J into particles of two types: (i) ghosts which possessed a thin-membrane vesicle derived from basement part of the virus membrane with attached lateral bodies and a membranous structure derived from the core wall and (ii) aggregates of... |
6427352 | Rat monoclonal antibodies. II. A rapid and efficient method of purification from ascitic fluid or serum. | A technique for purifying rat monoclonal antibodies from ascitic fluid or serum is described which is based on 2 facts. First, approximately 95% of rat immunoglobulin light chains are of the kappa type. Second, an allotypy in the rat species is located on the constant part of the kappa light chain. By use of a mouse mo... |
6725555 | A molecular defect of spectrin in a subset of patients with hereditary elliptocytosis. Alterations in the alpha-subunit domain involved in spectrin self-association. | Hereditary elliptocytosis (HE) is a clinically and biochemically heterogenous group of diseases characterized by elliptically shaped erythrocytes and an autosomal dominant mode of inheritance. Whereas the self-association of spectrin heterodimers to tetramers is defective in a subpopulation of HE patients, designated H... |
6373789 | In vivo co-distribution of fibronectin and actin fibers in granulation tissue: immunofluorescence and electron microscope studies of the fibronexus at the myofibroblast surface. | The fibronexus ( FNX ), a very close transmembrane association of individual extracellular fibronectin fibers and actin microfilaments, was found previously at the substrate-binding surface of fibroblasts in tissue culture (Singer, 1. 1., 1979, Cell, 16:675-685). To determine whether the fibronexus might be involved in... |
6327697 | Mössbauer, EPR, and optical studies of the P-460 center of hydroxylamine oxidoreductase from Nitrosomonas. A ferrous heme with an unusually large quadrupole splitting. | Hydroxylamine oxidoreductase from Nitrosomonas europeae catalyzes the oxidative conversion of NH2OH to NO-2. The enzyme, Mr = 220,000, has an (alpha beta)3 subunit structure with each alpha beta subunit containing 7-8 c-type hemes and one unusual prosthetic group, termed P-460. The P-460 is also found in a Mr approxima... |
6327634 | Effects of deletion of the gene for the development-specific protein S on differentiation in Myxococcus xanthus. | A deletion mutation of the gene for protein S (tps), a development-specific protein of Myxococcus xanthus, was constructed. No significant differences in the process of fruiting body formation or the yield of myxospores were observed between mutant and wild-type cells. On the other hand, when the tps gene was deleted t... |
6373609 | Characterization of nonfimbrial mannose-resistant protein hemagglutinins of two Escherichia coli strains isolated from infants with enteritis. | Escherichia coli strains 444-3 and 469-3, isolated from patients with severe infantile enteritis, are able to adhere to and penetrate human epithelial cells in culture. In addition to type 1 fimbriae and glycocalyces , both strains elaborate mannose-resistant nonfimbrial protein hemagglutinins specific for human erythr... |
6427012 | Aspartic acid-121 functions at the active site of bovine pancreatic ribonuclease. | The fully active semisynthetic enzyme formed by the non-covalent interaction of residues 1-118 of bovine pancreatic ribonuclease and a synthetic tetradecapeptide containing residues 111-124 of the enzyme has allowed a direct test of the role of aspartic acid-121 in the functioning of the molecule. Replacement of this r... |
18553375 | Immobilized cyclomaltodextrin glucanotransferase of an alkalophilic Bacillus sp. No. 38-2. | Cyclomaltodextrin glucanotransferase [1,4-alpha-D-glucan-4-alpha-D-(1,4-alpha-D-glucano)-transferase (cyclizing), E.C.-2.4.1.19] of an alkalophilic Bacillus sp. No. 38-2 (ATCC 21783), which contains three types of enzymes (acid, neutral, and alkaline enzymes), was immobilized on synthetic adsorption resin. No distingui... |
6093394 | The GABA hypothesis of the pathogenesis of hepatic encephalopathy: current status. | Gamma-aminobutyric acid (GABA), the principal inhibitory neurotransmitter of the mammalian brain, can induce coma. Outside the central nervous system it is synthesized by gut bacteria and catabolized largely in the liver. GABA and its agonists, as well as benzodiazepines and barbiturates, induce neural inhibition as a ... |
6466721 | [Changes in the electrical and visco-elastic properties of bilayer lipid membranes during interaction with proteins and lipoproteins]. | A method for simultaneous registration of planar bilayer lipid membrane (BLM) DC conductance G, capacitance C, surface potential difference delta phi and transversal elasticity module E is developed. C, delta phi and E are proportional to the amplitude of the first, second and third harmonics of capacitance current res... |
6743242 | Magnetic alignment of collagen during self-assembly. | Magnetically induced birefringence is used to monitor the thermally induced self-assembly of collagen fibrils from a solution of molecules. The magnetic torque alone can, at best, only orient the fibrils into planes normal to the field direction. Nevertheless, the gels formed have a high degree of uniaxial alignment, p... |
6329743 | The supercoil-stabilised cruciform of ColE1 is hyper-reactive to osmium tetroxide. | Supercoiled pColIR215 contains a site of pronounced hyper-reactivity towards modification by osmium tetroxide, a reagent known to be single-strand-selective. The site of hypersensitivity has been mapped to the ColE1 inverted repeat, believed to extrude a cruciform in supercoiled DNA. Linear or relaxed plasmids are not ... |
6733723 | Hexadeoxycycloheptaamylose-pyridoxamine, an artificial transaminase with a "deeper" binding pocket. | Cycloheptaamylose was converted in four steps into a monosulfonylated, hexadeoxy derivative that, on treatment with pyridoxaminethiol, provided an artificial transaminase with activity similar to that found in the nondeoxygenated analogue. Characterization of the intermediate hexadeoxycycloheptaamylose was facilitated ... |
6587349 | Epoxidation of olefins by cytochrome P-450 model compounds: mechanism of oxygen atom transfer. | The mechanism of the Mn(III) porphyrin-catalyzed epoxidation of olefins by lithium hypochlorite is examined. The active oxidant is thought to be a high-valent manganese-oxo complex. It is shown that a relatively stable intermediate is reversibly formed upon interaction of the olefin and the oxo complex. The decompositi... |
6374617 | Secondary structure of mouse 28S rRNA and general model for the folding of the large rRNA in eukaryotes. | We present a secondary structure model for the entire sequence of mouse 28S rRNA (1) which is based on an extensive comparative analysis of the available eukaryotic sequences, i.e. yeast (2, 3), Physarum polycephalum (4), Xenopus laevis (5) and rat (6). It has been derived with close reference to the models previously ... |
6327614 | Oxygen-dependent proton efflux in cyanobacteria (blue-green algae). | The oxygen-dependent proton efflux (in the dark) of intact cells of Anabaena variabilis and four other cyanobacteria (blue-green algae) was investigated. In contrast to bacteria and isolated mitochondria, an H+/e ratio (= protons translocated per electron transported) of only 0.23 to 0.35 and a P/e ratio of 0.8 to 1.5 ... |
6326673 | HMG17 protein facilitates the DNA catenation reaction catalyzed by DNA topoisomerases. | HMG17 protein is shown to greatly facilitate the catention of double-stranded DNA rings catalyzed by DNA topoisomerases. Even at low DNA concentrations such that catenanes are not observable in the absence of HMG17, the addition of the protein promotes the catenation of greater than 95% of the input DNA into networks t... |
6143785 | Gonococcal pili. Primary structure and receptor binding domain. | The complete amino acid sequence of pilin from gonococcal strain MS11 and the sequence of constant and variable regions from strain R10 pilin have been determined in order to elucidate the structural basis for adherence function, antigenic diversity, and polymeric structure. The MS11 pilin sequence consists of 159 amin... |
6325504 | Silica-stimulated monocytes release fibroblast proliferation factors identical to interleukin 1. A potential role for interleukin 1 in the pathogenesis of silicosis. | Previous study strongly suggests that silicotic fibrosis is mediated by macrophages and their soluble mediators. The biochemical properties of the mediators involved in silicotic fibrosis, however, are as yet ill defined. The current study, therefore, determined whether human monocyte-macrophages treated with fibrogeni... |
6370865 | Isolation of a major cell envelope protein from Fusobacterium nucleatum. | A major, heat-modifiable cell envelope protein was identified in Fusobacterium nucleatum FDC 364 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. This protein, designated HM-1, had apparent molecular weights of 38,500 and 50,000 when heated in sodium dodecyl sulfate at 50 and 100 degrees C, respectively. W... |
6323765 | Differential phosphorylation of cytoplasmic and nuclear variants of simian virus 40 large T antigen encoded by simian virus 40-adenovirus 7 hybrid viruses. | The phosphorylation patterns of cytoplasmic and nuclear forms of simian virus 40 large T antigen encoded by simian virus 40-adenovirus 7 hybrid viruses were analyzed by two-dimensional peptide mapping. The PARA(cT) mutant which encodes a large T antigen defective for nuclear transport was used as source for cytoplasmic... |
6323746 | An oligomeric form of simian virus 40 large T-antigen is immunologically related to the cellular tumor antigen p53. | The cellular tumor antigen p53 is bound to the simian virus 40 (SV40) large T-antigen in SV40-infected and -transformed cells. As a result, p53 can in general be immunoprecipitated by either monoclonal or polyclonal antibodies that react with large T-antigen. Despite extensive immunological characterization of both the... |
6740761 | [Sugar transport regulation in vitro by new calcium ionophores]. | The influence of calcium ionophores--tenoyltrifluoroacetate (TTFA) and divaleryldibenzo-18-crown-6(divaleryl) on the glucose consumption, D-xylose transport and glycogen content in rat diaphragm was studied. TTFA caused a clear dose-dependent inhibition of carbohydrate transport and glycogenolysis stimulation. Divalery... |
6736921 | Sporulation of Bacillus sphaericus 2297: an electron microscope study of crystal-like inclusion biogenesis and toxicity to mosquito larvae. | Sporulation of Bacillus sphaericus strain 2297 in a synchronous liquid culture was studied by electron microscopy. The t0 of sporulation occurred 7 h after the beginning of the lag phase. Crystal-like inclusions first appeared at t2 and reached their final size between t5 and t6. The release of the spore/inclusion comp... |
6732906 | [Gynecomastia. Apropos of 122 cases]. | Pathological data from 122 cases of gynecomastia are studied. According to the importance of epithelial hyperplasia and of specialised stroma, 3 types are described. Every type is compared with the age of patients, the duration of the illness and occasional etiologic circumstances. It is concluded that these 3 types ar... |
6722266 | A model of dynamic quenching of fluorescence in globular proteins. | A model is presented for the quenching of a fluorophore in a protein interior. At low quencher concentration the quenching process is determined by the acquisition rate of quencher by the protein, the migration rate of quencher in the protein interior, and the exit rate of quencher from the protein. In cases where the ... |
6371806 | Use of prokaryotic-derived probes to identify poly(sialic acid) in neonatal neuronal membranes. | Three prokaryotic-derived probes to identify and study the temporal expression of polysialosyl units in neuronal tissue have been developed. A polyclonal antibody, a bacteriophage-derived endo-neuraminidase, and an Escherichia coli K1 sialyltransferase are all specific for either recognizing or synthesizing poly(sialic... |
6326093 | DNA binding activity of polyoma virus large tumor antigen. | Polyoma virus large tumor antigen from productively infected mouse cells has been purified to greater than 50% homogeneity by a simple immunoaffinity procedure using monoclonal antibodies. A radioimmunoreaction was devised for assaying purity. The purified large tumor antigen retained its antigenicity and its ability t... |
6717441 | Tubulin heterogeneity in the trypanosome Crithidia fasciculata. | The interphase cell of Crithidia fasciculata has three discrete tubulin populations: the subpellicular microtubules, the axonemal microtubules, and the nonpolymerized cytoplasmic pool protein. These three tubulin populations were independently and selectively purified, yielding, in each case, microtubule protein capabl... |
6712235 | Self-association and oxygen-binding characteristics of the isolated subunits of Limulus polyphemus hemocyanin. | The hemocyanin of the horseshoe crab Limulus polyphemus is characteristic of arthropod hemocyanins in that it is a high-molecular-weight oligomer composed of functionally and structurally distinct subunits. The protein forms a 48-subunit complex, the largest form of arthropod hemocyanin, whose oxygen-binding characteri... |
6323884 | On reaction of sterol hydroperoxides with superoxide. | Reduction of sterol hydroperoxides 3 beta-hydroxy-5 alpha-cholest-6-ene-5-hydroperoxide and cholesterol 7 alpha-hydroperoxide by KO2 (or other strong base in air) solubilized by crown ether in dimethylsulfoxide gave only corresponding alcohols, but in the presence of cholesterol (or other sterols) gave 3 beta-hydroxych... |
6323014 | Balbiani ring 6 gene in Chironomus tentans: a diverged member of the Balbiani ring gene family. | We describe the internal organization of a large part of the Balbiani ring (BR) 6 gene in Chironomus tentans. The BR6 gene is a diverged member of the BR gene family. It displays the characteristic hierarchic organization of repetitive sequences, but in the constant region of the repeat units the overall sequence homol... |
6142766 | Histopathological and biochemical analyses of transplantable renal adenocarcinoma in rats induced by N-ethyl-N-hydroxyethylnitrosamine. | Transplantable renal adenocarcinoma can be readily induced in Wistar strain male rats by initiation with N-ethyl-N-hydroxy-ethylnitrosamine followed by promotion with beta-cyclodextrin. The transplantability rates of the tumors by s.c. inoculation in newborn rats were 33 and 50%, respectively, for tumors of the first a... |
6200146 | Actin polymerization induced by pulsed electric stimulation of bone cells in vitro. | Electric field pulses, capacitively applied to tissue cultures of embryonic bone cells, were shown to induce changes in the state of cellular actin. Three actin states could be defined by DNAase I inhibition. A rapidly (20-30 s) inhibiting fraction, attributed to monomeric G-actin, amounts to 55% of total actin in nons... |
6321781 | DNA-binding activity of simian virus 40 large T antigen correlates with a distinct phosphorylation state. | The state of phosphorylation and the relationship of various subclasses of simian virus 40 large T antigen (large T) differing in DNA-binding activity, degree of oligomerization, age, and subcellular distribution were investigated. Young large T (continuously labeled for 4 h late in infection) comprised about 20% of th... |
16593459 | Rotational barrier of a molybdenum-molybdenum quadruple bond. | The synthesis and characterization of molybdenum(II) porphyrin dimers containing unbridged metal-metal quadruple bonds are presented. Variable temperature 300 MHz (1)H NMR studies of meso-substituted derivatives provide novel solution evidence for both the existence of quadruple bonds and for a barrier to rotation abou... |
16346515 | Analysis of an Effective Antibiotic (Chaetomacin) Isolated from a Thermophilic Bacillus sp. Against Olive Green Mold. | Successful methods to control the damaging weed mold Chaetomium olivaceum (olive green mold) in mushroom beds are not known. An effective antibiotic (named chaetomacin) against C. olivaceum was isolated from a thermophilic Bacillus sp. This compound was shown to be an extremely potent and stable antibiotic, effective o... |
6372684 | In vitro antifungal activities of amphotericin B and liposome-encapsulated amphotericin B. | The in vitro activities of liposome-encapsulated amphotericin B and free amphotericin B against Candida albicans 336 were comparable. Amphotericin B concentrations 12-fold and greater than 50-fold higher were required to kill the same organism when cholesterol and ergosterol were incorporated into the liposomes. The ad... |
6585547 | Inclusion complexation of prostaglandin F2 alpha with gamma-cyclodextrin in solution and solid phases. | A solid complex of prostaglandin F2 alpha (dinoprost) with gamma-cyclodextrin in a molar ratio of 1:1 was obtained on the basis of the BS-type phase solubility diagram. The mode of interaction in the solid state was studied by powder X-ray diffractometry, thermal analysis, and carbon-13 cross polarization/magic angle s... |
6709499 | Synthesis, complete 1H assignments and conformations of the self-complementary hexadeoxyribonucleotide [d(CpGpApTpCpG)]2 and its fragments by high field NMR. | The two deoxyribonucleotides [d(CpGpApTpCpG)]2 and [d(CpGpCpG)]2 were synthesized by the phosphotriester method. Their duplex form under the conditions of the 1H-nmr experiments was proven by end 32P labeling with T4 polynucleotide kinase followed by butt end joining employing the absolute specificity of T4 ligase for ... |
6366245 | Formation of the prohead core of bacteriophage T4 in vivo. | Formation of the prohead core of bacteriophage T4 was not dependent on shell assembly. In mutant infections, where the production or assembly of active shell protein was not possible, naked core structures were formed. The particles were generally attached to the bacterial inner membrane and possessed defined prolate d... |
6321754 | Oligomerization of simian virus 40 large T antigen is not necessarily repressed by temperature-sensitive A gene lesions. | Simian virus 40 large T antigen is a multifunctional protein which exists in different molecular weight forms. According to several reports, T antigen encoded by temperature-sensitive simian virus 40 A locus mutants (tsA) is unable to oligomerize into high-molecular-weight species. To try to correlate structural and fu... |
6699087 | Analysis of myofibrillar structure and assembly using fluorescently labeled contractile proteins. | To study how contractile proteins become organized into sarcomeric units in striated muscle, we have exposed glycerinated myofibrils to fluorescently labeled actin, alpha-actinin, and tropomyosin. In this in vitro system, alpha-actinin bound to the Z-bands and the binding could not be saturated by prior addition of exc... |
6421741 | A macromolecular structure produced by Pseudomonas aeruginosa is recognized by antibody to exotoxin A. | Organized particulate structures (rods) identified in purified preparations of exotoxin A from culture supernatants of Pseudomonas aeruginosa PA103 were found to be immunochemically cross-reactive with exotoxin A. The rods were visualized by electron microscopy after negative staining as hollow tubes or sheaths (45 by ... |
16593428 | Structural studies of the primary donor cation radical P(870) in reaction centers of Rhodospirillum rubrum by electron-nuclear double resonance in solution. | The light-induced cation radical of the primary electron donor, P(870) (+.), in photosynthetic reaction centers from Rhodospirillum rubrum G-9, has been investigated by electron-nuclear double resonance (ENDOR) in liquid aqueous solution. The measured hyperfine coupling constants are assigned to specific molecular posi... |
6707528 | A facile route to semi-synthesis of acetyl glycerylether phosphoethanolamine and its choline analogue. | A facile route to the semi-synthesis of acetyl glycerylether phosphoethanolamine and, subsequently, its choline analogue (platelet-activating factor) has been developed. In essence, this technique takes advantage of the fact that the phosphatidylethanolamine fraction of bovine erythrocytes contains 75-80% of a 1-O-alky... |
6704996 | Myristoyl esters of lactose. | Whereas lactose did not undergo a base-catalyzed transesterification with methyl esters of fatty acids, methyl beta-lactoside reacted under identical conditions to give mono- and di-myristates. This difference in behavior is explained in terms of the formation of an unreactive, internally chelated potassium-lactose com... |
6142488 | Collagen: the organic matrix of bone. | Collagen is the principal organic matrix in bone. The triple helical region of the molecule is 1014 amino acids long. In fibrils these molecules are staggered axially by integers of 234 residues or 68 nm (D). This axial shift occurs by self-assembly and can be understood in terms of a periodicity in the occurrence of a... |
6230671 | Interaction of the bacteriophage P1 recombinase Cre with the recombining site loxP. | The interaction between the P1 recombinase protein Cre and the DNA site at which it acts, loxP, has been studied by using nuclease protection techniques. The region of DNA protected by Cre against nuclease attack by DNase I or neocarzinostatin is a 34-base-pair (bp) region containing two 13-bp inverted repeats separate... |
6700589 | Activity of human growth hormone and related polypeptides on the adipose conversion of 3T3 cells. | A culture system is described for the study of cellular responsiveness to growth hormone. The hormone acts directly on an established line of preadipose 3T3 cells and promotes their differentiation into adipose cells. This response is the basis of a sensitive and specific assay and does not depend on the participation ... |
6698967 | Isolation and preliminary characterization of proteoglycan aggregates from cultured dermal fibroblasts. | A1 proteoglycan fractions were prepared by isopycnic cesium chloride density gradient centrifugation from early passage cultured fibroblasts derived from the skin of human infants. In five different fibroblast strains, A1 preparations from the medium and the cells, respectively, contained 36-63% and 59-79% of the sulfa... |
6363428 | Immunocytochemical localization of microtubule-associated protein 1 in rat cerebellum using monoclonal antibodies. | Immunohistochemical staining with monoclonal antibodies showed that microtubule-associated protein 1 (MAP1) has a restricted cellular distribution in the rat cerebellum. Anti-MAP1 staining was found only in neurons, where it was much stronger in dendrites than in axons. There were striking variations in the apparent co... |
6537953 | Hagfish slime gland thread cells. II. Isolation and characterization of intermediate filament components associated with the thread. | The slime glands of hagfish have two major cell types, gland thread cells (GTCs) and gland mucous cells (GMCs), both of which upon contact with water contribute to the formation of an abundant quantity of viscous mucus. In previous studies we reported a method for the isolation of GTCs and showed that each ellipsoidal ... |
6420411 | Proposed structure for the noncovalently associated heme prosthetic group of dissimilatory nitrite reductases. Identification of substituents. | The substituents of the noncovalently associated heme prosthetic group of the bacterial nitrite reductase-cytochrome oxidase (EC 1.9.6.1 or EC 1.9.3.2.) from Pseudomonas aeruginosa (ATCC 19429) and Paracoccus denitrificans (ATCC 13456) have been identified. This was accomplished by 1H NMR, infrared, visible, and mass s... |
6693353 | Components of the regular surface array of Aquaspirillum serpens MW5 and their assembly in vitro. | The two-layered regular surface array of Aquaspirillum serpens MW5 was removed from cell envelopes and dissociated into subunits by treatment with 6 M urea. The surface components reassembled onto an outer membrane surface and self-assembled into planar sheets in vitro in the presence of Ca2+ or Sr2+. The two layers we... |
6319363 | Characterization of the cloned fip gene and its product. | A DNA fragment encoding the fip (filamentous phage production) gene from Escherichia coli, when cloned in a filamentous phage vector, restored to the phage ability to assemble progeny in fip mutant hosts. The fip gene was located just upstream of and transcribed in the same direction as the rho gene. Minicells containi... |
6363289 | Role of cellular lipoteichoic acids in mediating adherence of serotype III strains of group B streptococci to human embryonic, fetal, and adult epithelial cells. | Lipoteichoic acids (LTA) of serotype III strains of group B streptococci (GBS) were shown to mediate adherence of these organisms to human embryonic (HEC), fetal (HFC), and adult buccal (HBEC) epithelial cells. The binding of GBS was temperature dependent, and maximum attachment occurred at 37 degrees C. HEC, HFC, and ... |
16593417 | Electron nuclear double resonance evidence supporting a monomeric nature for P700 in spinach chloroplasts. | Proton electron nuclear double resonance (ENDOR) spectra of P700(+) in spinach chloroplasts and in photosystem I particles have been obtained and compared with the corresponding ENDOR spectrum of monomeric chlorophyl a(+) (Chla(+)) cation radical. The hyperfine couplings for P700(+) can be interpreted in terms of those... |
6545822 | Synaptic junctions between the adrenergic axon varicosity and the pinealocyte in the rat. | Intercellular relationships of sympathetic nerve fibers and cells in pineal glands of Long-Evans rats and yellow-bellied country rats (Rattus losea Swinhoe) were studied with conventional electron microscopy. Typical synapses were found between adrenergic axon varicosities and pinealocytes. The synaptic cleft was 20-30... |
6398455 | Perireceptor and receptor events in vertebrate olfaction. | In this article we have summarized the basic information which identifies several key issues in the study of perireceptor and receptor events in vertebrate olfaction. We have emphasized the biophysical and biochemical data which have established a pivotal role for the olfactory mucus in the access of odorants to recept... |
6240955 | The production of alpha-cyclodextrin by enzymatic degradation of starch. | The maximum concentration of alpha-cyclodextrin for the enzymatic degradation of starch is limited to about 13.5 g X 1(-1). By addition of decanol, the equilibrium of the reaction system can be shifted towards an alpha-cyclodextrin yield of 50% even at high substrate concentrations. The main variables of the decanol pr... |
6098160 | A unique ATP-dependent DNA topoisomerase from trypanosomatids. | Crithidia fasciculata DNA topoisomerase (22) has been purified to near homogeneity from trypanosomatid cell extracts. The purified enzyme catalyzes the reversible interconversion of monomeric duplex DNA circles and catenanes in an ATP dependent reaction. Reversible catenane formation is affected by the ionic strength a... |
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