| regulation of intracellular adenosine cyclic 3':5'-monophosphate levels in escherichia coli and salmonella typhimurium. evidence for energy-dependent excretion of the cyclic nucleotide. | sugars and other energy sources were found to lower intracellular concentrations of adenosine 3':5'-monophosphate (cyclic amp) in strains of escherichia coli and salmonella typhimurium which were deficient for cyclic amp phosphodiesterase. this effect required the presence of the specific transport system responsible for entry of that sugar into the cell and depended on the intracellular catabolic enzymes. metabolizable sugars were more effective than nonmetabolizable sugars in reducing cellular ... | 1975 | 170265 |
| active site stoichiometry of l-phenylalanine: trna ligase from escherichia coli k(-10). | the existence of two active siter per molecule of l-phenylalanine:trna ligase from escherichia coli k(-10) has been demonstrated by isolation of the e-aminoacyl adenylate and tel filtration and the nitrocellulose filter assay at ph 5.0 revealed the same stoichiometry for the e-trnaphe comples as protection against degradation by snake venom phosphodiesterase and equilibrium gel filtration at ph 7.5. using a fluorescence titration technique, it was found that the dissociation constant for ligase- ... | 1975 | 170267 |
| studies on the regulation of the three enzymes of the leloir pathway in cultured mammalian cells. ii. a search for quantitative interrelationships between the three enzyme activities. | studies on a normal human diploid cell strain revealed that the specific activity of the cell protein, for each of the three enzymes of the leloir pathway, changed significantly as the cells grew. the kinetics of change in specific activity varied according to the enzyme being studied, and the kinetics for each enzyme varied from experiment to experiment. within each experiment, there was no consistent correlation between specific activity for any one enzyme and specific activity for the other t ... | 1975 | 170290 |
| studies on the regulation of the three enzymes of the leloir pathway in cultured mammalian cells. i. effect of substitution of galactose for glucose as the sole hexose in the medium in human diploid cell strains and in a rat hepatoma line. | in human diploid cell strains, the substitution of galactose for glucose as the sole hexose in the medium had no measurable effect on the specific activity of the cell protein for any of the three enzymes of the leloir pathway. these enzymes are galactokinase, alpha-d-galactose-1-phosphate: udp glucose uridyl transferase and udp galactose 4-epimerase. a cell strain from a patient with galactosemia had no detectable activity for the transferase. the substitution of galactose for glucose in the me ... | 1975 | 170294 |
| the role of cyclic amp in the chemotactic responsiveness and spontaneous motility of rabbit peritoneal neutrophils. the inhibition of neutrophil movement and the elevation of cyclic amp levels by catecholamines, prostaglandins, theophylline and cholera toxin. | agents known to affect intracellular levels of cyclic amp in many diverse systems have been tested for their effect on the chemotaxis induced by escherichia coli culture filtrates, spontaneous motility and cyclic amp levels of rabbit peritoneal neutrophils. prostaglandin e1 and a1 but not prostaglandin f2alpha increased neutrophil cyclic amp levels and, correspondingly, only the former two prostaglandins inhibited chemotaxis. nevertheless, a quantitative relationship between prostaglandin stimul ... | 1975 | 170335 |
| the synthesis of beta-galactosidase by constitutive and other regulatory mutants of escherichia coli in chemostat culture. | the synthesis of beta-galactosidase by an e. coli constitutive mutant was examined in a chemostat using glucose-, glycerol-, succinate- or n-limited growth media. except for glucose-grown bacteria, the steady-state intracellular level of beta-galactosidase was maximal at dilution rates between 0-2 and 0-3 h-1. at higher dilution rates enzyme synthesis was reduced by catabolite repression, which could be relieved by the addition of cyclic amp. with a catabolite-resistant mutant (uv5c), no decreas ... | 1975 | 170362 |
| letter: the isolation and properties of the specific binding sites for escherichia coli rna polymerase on t4 and t7 bacteriophage dnas. | | 1975 | 170407 |
| relationship of the first step in protein synthesis to ppgpp: formation of a(5')ppp(5')gpp. | in the presence of purified escherichia coli lysyl-trna synthetase [l-lysine:trnalys ligase (amp-forming) ec 6.1.1.6], l-lysine, and atp, addition of the nucleotide ppgpp results in formation of a unique product-a(5')ppp(5') gpp. the same compound is also formed very rapidly in a cell-free protein-synthesizing system when ppgpp is added. the possible significance of this reaction in the rapid turnover of ppgpp and as a more general mechanism by which an amp residue is activated and introduced on ... | 1975 | 170611 |
| [determination of the penicillin acylase activity of e. coli cultures using a method of gas-liquid chromatography]. | penicillinacylase activity was determined in e. coli by the product of benzylpenicillin destruction, i.e. phenylacetic acid formed under the effect of the enzyme. the determination was performed on a chromatograph. the immobile phase consisted of 10 per cent of ethylenglycol edipate on chromosorb a, modified with 2 per cent h3po4. nitrogen was used as the gaseous carrier. the method is rapid and handy for mass testing of the cultures with a purpose of detecting penicillinacylase-producing strain ... | 1975 | 170853 |
| bactericidal activity of superoxide anion and of hydrogen peroxide: investigations employing dialuric acid, a superoxide-generating drug. | the addition of dialuric acid (a superoxide-generating drug) to a suspension of resting human neutrophils resulted in a stimulation of cellular hexose monophosphate shunt activity. measurement of oxygen consumption demonstrated a rapid rate of oxygen uptake by the drug alone in aqueous solution. the subsequent addition of catalase (but not of superoxide dismutase) resulted in a substantial release of oxygen, indicating that h(2)o(2) was accumulating in the media. the generation of o(2) (-) by th ... | 1975 | 170855 |
| mecillinam (fl 1060), a 6beta-amidinopenicillanic acid derivative: bactericidal action and synergy in vitro. | a newly described 6beta-amidinopenicillanic acid derivative, mecillinam (formerly called fl 1060), showed a high in vitro activity against enterobacteriaceae. the effect on escherichia coli was bactericidal and was due to lysis of the cells. the longer the culture grew under the influence of mecillinam or the lower the inoculum, the greater the bactericidal effect. the morphology of the cells changed towards large spheric forms (2 to 5 mum) under the influence of mecillinam. consequently a great ... | 1975 | 170856 |
| mode of action of polymyxin b: physiological studies with bacillus subtilis-resistant mutant. | polymyxin b resistance in bacillus subtilis can be suppressed by the synergistic action of lysozyme or of an analogous cell wall lytic activity released by b. subtilis spores during germination. such a synergistic effect is probably due to partial cell-wall digestion by lysozyme that allows polymyxin to reach its site of action and is therefore distinct from the analogous synergistic effect described by other authors in escherichia coli. in the latter case polymyxin b probably damaged the outer ... | 1975 | 170857 |
| interaction of normal and tumor transfer rna methyltransferases with ethionine-induced methyl-deficient rat liver transfer rna. | the trna methyltransferases from normal rat liver and novikoff hepatoma have been compared with respect to their base specificity, capacity to methylate, and reaction kinetics, using mixed escherichia coli b transfer rna (trna) and ethionine-induced partially methyl-deficient rat liver trna. the pattern of base methylation of the two substrates is different with the use of enzymes from either source. in particular, n1-methylguanine methylation is much greater in the methyl-deficient rat liver tr ... | 1975 | 171059 |
| replication of colicinogenic factor e1 dna in plasmolysed escherichia coli cells. coupling of dna replication and rna synthesis. | plasmolysed chloramphenicol-treated escherichia coli cells carrying the colicinogenic factor e1 utilize deoxynucleoside triphosphates for the semi-conservative synthesis of col e1 dna. col e1 dna replication in plasmolysed cells can be dissociated into two temporally separated processes: (a) a rifampicin-sensitive rna synthesis, which is stimulated by adenosine 3':5'-monophosphate (cyclic amp) and requires all four ribonucleoside triphosphates and (b) an atp-dependent dna synthesis, which is inh ... | 1975 | 171157 |
| altered hexose transport and salt sensitivity in cyclic adenosine 3',5'-monophosphate-deficient escherichia coli. | a cyclic adenosine 3',5'-monophosphate (camp)-deficient mutant strain of escherichia coli k-12 was studied to determine the effect this cyclic nucleotide has on the overall growth and metabolism of this organism. deficient cells were found to be more susceptible to growth inhibition by salts than were their camp-sufficient counterparts. the deficient cells transported alpha-methylglucoside by passive diffusion, whereas the parental cells or mutant cells grown in the presence of exogenous camp we ... | 1975 | 171252 |
| identification of an outer membrane protein of escherichia coli, with a role in the coordination of deoxyribonucleic acid replication and cell elongation. | protein g of molecular weight 15,000 is the fourth commonest protein in the outer membrane of escherichia coli b/r. from experiments described here on the relationship of protein g production to cell elongation and septation, the hypothesis is proposed that protein g is a structural protein of cell elongation. furthermore, a surplus of protein g is produced when deoxyribonucleic acid synthesis is arrested and septation is thereby prevented. thus protein g may be an important coordination protein ... | 1975 | 171254 |
| multiple regulation of nucleoside catabolizing enzymes: regulation of the deo operon by the cytr and deor gene products. | the protein and repressor nature of two regulatory gene products in e. coli has been demonstrated, employing mutants with either amber or thermosensitive mutations. the regulatory genes are the cytr and the deor genes, both of which contribute to the regulation of the synthesis of nucleoside catabolizing enzymes. enzyme levels in strains with concurrent mutations in both regulatory genes are considerably higher than the sum of the levels in strains with a cytr or a deor mutation alone, indicatin ... | 1975 | 171553 |
| reversible effects of chaotropic agents on the proton permeability of escherichia coli membrane vesicles. | extraction of e. coli ml 308-225 membrane vesicles with chaotropic agents causes the vesicles to become specifically permeable to protons. as a result, the vesicles no longer generate a membrane potential, interior negative, and they do not catalyze respiration-dependent lactose or proline transport. treatment of the extracted vesicles with various carbodiimides decreases the permeability of the vesicle membrane to protons, causing them to regain their ability to generate a membrane potential. b ... | 1975 | 171661 |
| convenient non-chromatographic assays for the microbial deconjugation and 7alpha-oh bioconversion of taurocholate. | we described two convenient assay methods to estimate bile acid deconjugation and bile acid bioconversion at the 7alpha-oh position by individual microorganisms grown in media containing taurocholic acid. the methods are based on (i) a selective chemical assay for taurine conjugates previously described and (ii) the use of a cell-free preparation of 7alpha-hydroxysteroid dehydrogenase from escherichia coli to directly quantify 7alpha-oh groups. these non-chromatographic approaches have been appl ... | 1975 | 172011 |
| maintenance of dna and repair of apurinic sites. | escherichia coli cells contain an enzyme which hydrolyzes a phosphodiester bond near each apurinic site in double-stranded dna. this endonuclease is specific for apurinic sites; it has no effect on normal dna, and its action on alkylated dna is restricted to apurinic sites. in vitro incubation with the endonuclease for apurinic sites, dna polymerase i, and ligase permits repair of dna containing apurinic sites. the endonuclease for apurinic sites might thus play a role in cell survival after a t ... | 1975 | 172058 |
| granulocyte function in chronic granulocytic leukaemia. i. bactericidal and metabolic capabilities during phagocytosis in isolated granulocytes. | the ingestion, bactericidal activity and metabolism of isolated mature neutrophil leucocytes during phagocytosis was studied in 17 patients with chronic granulocytic leukaemia (cgl) with the simultaneous use of normal controls. seven patients had received no treatment and the others had been treated previously with busulphan. the phagocytic indices for killed yeast cells did not differ from those of the controls. a diminished bactericidal activity against e. coli was found in nine cgl cases. the ... | 1975 | 172109 |
| partial myeloperoxidase deficiency in a case of preleukaemia. ii. defects of degranulation and abnormal bactericidal activity of blood neutrophils. | a patient with a refractory anaemia preceding acute myeloblastic leukaemia had an increased susceptibility to infection due to staphylococcus aureus. 36% of neutrophils lacked myeloperoxidase (mpo) activity and, in vitro, these polymorphonuclear neutrophils (pmn) had a defect of bactericidal activity against staphylococcus aureus. cytochemical studies of phagocytosis with the electron miscroscope have shown that the degranulation of primary granules (mpo+ or mpo-) was normal after phagocytosis o ... | 1975 | 172112 |
| membrane potential and active transport in membrane vesicles from escherichia coli. | | 1975 | 172125 |
| endotoxic lipopolysaccharides stimulate steroidogenesis and adenylate cyclase in adrenal tumor cells. | lipopolysaccharides (endotoxins) from escherichia coli, serratia marcesens and salmonella typhosa stimulated steroid production in y-1 adrenal tumor cells in culture with a latent period of 3-4 h. lipid a, derived from escherichia coli lipopolysaccharide, also stimulated steroidogenesis. lipopolysaccharides and lipid a also stimulate adenylate cyclase activity and cause rounding of the cells. in contrast, lipopolysaccharides do not stimulate steroidogenesis in receptor-deficient adrenal tumor ce ... | 1975 | 172155 |
| rna sulfurtransferase activity in rat liver and chemically induced hepatomas. | rna sulfurtransferase activity has been detected in rat liver and in hepatomas from rats fed a diet containing 0.06% 3'-methyl-4-dimethylaminoazobenzene for 14 to 18 weeks. the reaction measured was the transfer of sulfur from cysteine to acceptor sites in escherichia coli b transfer rna (trna). specific activities of the enzymes in liver and hepatoma supernatant fractions were similar, as were the rates and extents of sulfur transfer to trna. deae-cellulose chromatography of digests of the [35s ... | 1975 | 172228 |
| [rna fragments rich in g and a nucleotides obligatory for in vitro dna replication of phages phi-x 174 and lambda]. | evidence was presented that in vitro conversion of single-stranded dna of phage phi x 174 to the double-stranded replicative form by partially purified dna-dependent dna polymerase i requires a specific rna fragment acting as primer (25-50 nucleotides). rna fragments highly rich in nucleotides a and g were obtained by partial degradation of e. coli m 500 sho-r ribosomal rna with pancreatic ribonuclease. they become covalently bound to the newly synthesized dna chain of the replicative form of ph ... | 1975 | 172251 |
| [localization of polyphosphatase in cells of escherichia coli with repressed and derepressed biosynthesis of this enzyme]. | | 1975 | 172303 |
| on the mechanism of inhibition of enzyme induction in escherichia coli by distamycin a. | the mechanism of the interference of the antiviral antibiotic distamycin a with the bacterial cell has been investigated. labelled distamycin a is firmly bound by e. coli cells and the binding process does not require metabolic energy as indicated by the use of inhibitors. the antibiotic does not induce gross alteration in the cell membrane but inhibits cyclic amp accumulation in the cells exposed to a glucose-free medium. this inhibition is concomitant with that exerted on the synthesis of an i ... | 1975 | 172369 |
| effect of shigella enterotoxin on electrolyte transport in rabbit ileum. | shigella dysenteriae i is one of several bacteria which produces an enterotoxin capable of stimulating intestinal water and electrolyte secretion. unlike cholera and escherichia coli enterotoxins which have been shown to increase intracellular cyclic adenosine monophosphate levels in the small intestine, the mechanism by which shigella enterotoxin causes intestinal secretion is not known. to study shigella enterotoxin-stimulated intestinal secretion, rabbit ileal mucosa exposed in vivo to shigel ... | 1975 | 172398 |
| histopathological effect of clostridium perfringens enterotoxin in the rabbit ileum. | highly purified enterotoxin from clostridium perfringens was found to have histopathological activity in the rabbit ileum. unlike the action of cholera, escherichia coli, and shigella enterotoxins, epithelium was denuded from the tips of ileal villi at concentrations of the enterotoxin necessary to induce fluid accumulation in the rabbit. whether or not this observed histopathology is essential for the diarrheal syndrome associated with clostridium perfringens food poisoning remains unclear. | 1975 | 172454 |
| operator-constitutive mutants in the threonine operon of escherichia coli k-12. | three escherichia coli k-12 mutant strains resistant to dl-alpha-amino-beta-hydroxyvaleric acid were isolated in which the expression of the thr operon is constitutive. the localization and dominance properties of the mutations involved, called thro, are those of operator mutations. the gene sequence is oabc as suggested by earlier studies. | 1975 | 172487 |
| competitive inhibition of transformation in group h streptococcus strain challis by heterologous deoxyribonucleic acid. | glucosylated deoxyribonucleic acid (dna) from phages t4 and t6 competes poorly with homologous dna causing only a slight decrease of transformation in group h streptococcus strain challis. other types of heterologous dnas (micrococcus luteus, clostridium perfringens, escherichia coli, calf thymus and non-glucosylated phage t6 dna), in contrast to glucosylated t4 and t6 dnas, compete with transforming dna to the normal, high extent. these results indicate that as in transformation of bacillus sub ... | 1975 | 172490 |
| reconstitution of bacillus stearothermophilus 50 s ribosomal subunits from purified molecular components. | bacillus stearothermophilus 50 s ribosomal subunits have been reconstituted from a mixture of purified rna and protein components. the protein fraction of 50 s subunits was separated into 27 components by a combination of various methods including ion exchange and gel filtration chromatography. the individual proteins showed single bands in a variety of polyacrylamide gel electrophoresis systems, and nearly all showed single spots on two-dimensional polyacrylamide gels. the molecular weights of ... | 1976 | 172511 |
| genes involved in the uptake and catabolism of gluconate by escherichia coli. | the isolation and properties of a mutant of escherichia coli k12 that is totally unable to take up and utilize gluconate are described. genetical analysis shows this phenotype to be associated with two lesions. one phenotype, designated gntm-, is the result of a mutation in a gene co-transducible with mala; the other, designated gnts-, is the result of a mutation in a gene (gnts) co-transducible with fdp. the gnts--phenotype differs little from that of wild-type cells, but gntm- gnts+ organisms ... | 1975 | 172599 |
| the activity of polymyxins against dense populations of escherichia coli. | the activities of polymyxin b sulphate, colistin (polymyxin e) sulphate and their sulphomethyl derivatives were compared by continuous turbidimetric monitoring of dense cultures of an escherichia coli strain exposed to these agents. judged by the concentration of antibiotic which caused a rapid fall in opacity of the culture, polymyxin b sulphate and colistin sulphate had similar activities, but the sulphomethyl compounds differed considerably: sulphomyxin sodium induced lysis of the culture at ... | 1975 | 172601 |
| properties of the escherichia coli dna-binding (unwinding) protein interaction with nucleolytic enzymes and dna. | | 1975 | 172646 |
| effects of estrogen on gene expression in chick oviduct: nuclear receptor levels and initiation of transcription. | estrogen (diethylstilbesterol) was administered in vivo to chicks for various time periods. chromatin was then prepared from oviduct nuclei and assayed for its capacity to support initiation of rna chain synthesis in vitro in the presence of saturating levels of escherichia coli rna polymerase (rna nucleotidyltransferase; nucleosidetriphosphate:rna nucleotidyltransferase; ec 2.7.7.6). these same nuclei were also assayed by a [3h]estradiol exchange assay for their endogenous receptor content. the ... | 1975 | 172899 |
| translation of rna that contains polyadenylate from yeast mitochondria in an escherichia coli ribosomal system. | rna that contains poly(a) [poly(a)-rna] has been isolated from yeast mitochondria by poly(u) sepharose-4b column chromatography. pulse-labeled poly(a)-rna shows 8-10 discrete peaks by acrylamide gel electrophoresis. the specific activity of mitochondrial poly(a)-ran is six to eight times greater than that of mitochondrial rrna after pulse labeling of protoplasts with [3h-]uridine. ethidium bromide inhibits incorporation by over 90%. the total mitochondrial rna preparation was contaminated with 5 ... | 1975 | 172902 |
| in vitro synthesis of a constitutive enzyme of escherichia coli, 6-phosphogluconate dehydrogenase. | enzymes of central intermediary metabolism are among the constitutive proteins of escherichia coli. 6-phosphogluconate dehydrogenase [6-phospho-d-gluconate: nicotinamide adenine dinucleotide phosphate 2-oxidoreductase (decarboxylating), ec 1.1.1.44-a1, an enzyme of the hexose monophosphate shunt, was synthesized in vitro in a coupled transcription-translation system directed by dna from a specialized transducing phage carrying gnd, the structural gene. enzyme synthesized in vitro was detected by ... | 1975 | 172907 |
| [membrane vesicles prepared by different procedures from escherichia coli: orientation of membrane vesicles and coupling of energy to transport into membrane vesicles (author's transl)]. | | 1975 | 172977 |
| metabolic regulation of beta-galactosidase synthesis in escherichia coli. a test for constitutive ribosome synthesis. | the rate of differential synthesis of beta-galactosidase (alphalac) was measured in maximally induced cultures of escherichia coli b/r with 0.01 m-inducer and 0.01 m-cyclic amp. the value of alphalac decreases with growth rate (60% between 0.67 and 2.1 doublings/h) and after a nutritional shift-up. this decrease is presumed to reflect a decrease in the intracellular concentration of free active rna polymerase after a shift-up, which implies that the increase in ribosome synthesis after a shift-u ... | 1975 | 173297 |
| utilization of gluconate by escherichia coli. a role of adenosine 3':5'-cyclic monophosphate in the induction of gluconate catabolism. | 1. cultures of escherichia coli growing on gluconate use both gluconate and glucose when glucose is added. 2. glycerol-grown cells adapt to gluconate utilization even in media containing glucose as well as gluconate. 3. the rates of gluconate utilization by cells growing on a mixture of glucose and gluconate, and the specific activities of the gluconate uptake system and of gluconate kinase, are greater if adenosine 3':5'-cyclic monophosphate (cyclic amp) is present in the medium than in its abs ... | 1975 | 173298 |
| diverse directional changes of cgmp relative to camp in e. coli. | | 1975 | 173303 |
| initiation of transcription is temperature-dependent in an e. coli mutant with ts adenylate kinase. | | 1975 | 173310 |
| [biosynthesis of escherichia coli polyphosphatases under control of the regulatory genes usual for alkaline phosphatase]. | | 1975 | 173506 |
| adp-ribosylation of dna-dependent rna polymerase of escherichia coli by an nad+: protein adp-ribosyltransferase from bacteriophage t4. | a protein from bacteriophage t4 responsible for the alteration of host dna-dependent rna polymerase and absent in t4 alt- phage was purified from t4 phage and enriched from t4-infected cells. it is injected during infection together with the known internal proteins. it has a molecular weight of about 70000 and catalyses the release of nicotinamide and the transfer of the adp-ribosyl moiety from nad+ to arginyl residues of various proteins including itself. rna polymerase from escherichia coli ac ... | 1975 | 173540 |
| effect of desdanine on nucleoside diphosphate kinase and pyruvate kinase of escherichia coli. | kinetic analysis demonstrated that the irreversible inhibition of nucleoside diphosphate kinase of escherichia coli by desdanine proceeds via a reversible enzyme-inhibitor complex. it is known that pyruvate kinase of e. coli becomes inactive upon prolonged dialysis in the absence of a reducing reagent, such as dithiothreitol and that the inactive enzyme is reactivated if dithiothretiol is added. desdanine inhibits this reactivation process. the effect is discussed in relation to inhibition in re ... | 1975 | 173700 |
| specific inhibition of phospholipid synthesis in plsa mutants of escherichia coli. | plsa mutants of escherichia coli are temperature-sensitive strains which possess two enzymes of abnormal thermolability, sn-glycerol 3-phosphate acyltransferase and adenylate kinase. phospholipid synthesis is inhibited after shift of plsa mutants to temperatures at the lower end of the nonpermissive temperature range. this inhibition is not due to inactivation of the adenylate kinase activity since nucleic acid (and hence adenosine 5'-triphosphate) synthesis is inhibited only slightly. these res ... | 1976 | 173704 |
| properties of adenyl cyclase and cyclic adenosine 3',5'-monophosphate receptor protein-deficient mutants of escherichia coli. | several spontaneous cya and crp mutants of escherichia coli have been selected as clones simultaneously resistant to phage lambda and nalidixic acid and characterized. both cya and crp mutants have been found to grow as cocci with increased doubling times. they have increased resistance to some mutagens (methylmethanesulfonate, ultraviolet light, gamma rays), antibiotics (nalidixic acid, ampicillin), phages (lambda, t6), sublethal heat and hypotonic shock, and decreased resistance to neutral det ... | 1976 | 173710 |
| suppressor-induced structural changes in a missense l-ribulokinase of escherichia coli. | a suppressor mutation specific for a missense codon in the l-ribulokinase structural gene of the l-arabinose operon of escherichia coli b/r enhanced l-arabinose utilization by the strain containing the missense codon. electrophoretic comparisons of the wild-type, missense, and suppressed missense l-ribulokinases indicated that the suppressor changed the structure of the missense kinase, thereby increasing its catalytic activity. hyperinducibility imposed on an operator-distal gene by the missens ... | 1976 | 173711 |
| transformation of escherichia coli by chromosomal deoxyribonucleic acid from salmonella typhi. | the genetic transformation of escherichia coli k-12 with chromosomal deoxyribonucleic acid purified from salmonella typhi is described. | 1976 | 173714 |
| mutations in escherichia coli that relieve catabolite repression of tryptophanase synthesis. mutations distant from the tryptophanase gene. | two mutants are described in which the synthesis of tryptophanase is unusually insensitive to catabolite repression. neither mutation is linked by transduction to the tryptophane structural gene, neither mutation renders the synthesis of beta-galactosidase insensitive to catabolite repression, and the mutations do not permit tryptophanase to be synthesized in strains deficient in adenyl cyclase. during growth in glucose-minimal medium the mutants maintained a similar intracellular concentration ... | 1976 | 173793 |
| interferon treatment of ehrlich ascites tumor cells: effects on exogenous mrna translation and trna inactivation in the cell extract. | we reported earlier that in cell extracts that were prepared from interferon-treated ehrlich ascites tumor cells and preincubated and passed through sephadex g-25 (s60int), the translation of exogenous mrna (viral and host) was impaired and the impairment could be overcome to a large extent by adding a crude trna preparation from ehrlich ascites tumor cells but not from escherichia coli. we find now that the rate of inactivation of some trna's (especially those specific for leucine, lysine, and ... | 1975 | 173882 |
| orientation of the complementary strands of polyoma virus dna with respect to the dna physical map. | the chemical polarities of the two strands of polyoma virus dna with respect to the dna physical map have been determined by hybridization of restriction endonuclease fragments specifically labeled with [125i]dcmp at their 3' termini to asymmetric polyoma complementary rna (the product of in vitro transcription of viral dna by escherichia coli rna polymerase). the orientations of the polyoma-specific stable rna transcripts present in the cytoplasm of productively linfected mouse cells have been ... | 1975 | 173885 |
| human papillomavirus dna: physical map. | human papillomavirus (hpv) dna form i (supercoiled) was prepared from plantar warts. hpv dna was cleaved with restriction enzymes obtained from the following sources: escherichia coli (ecori), hemophilus influenzae strain rd (both unfractionated hind and aeparated hindii and hindiii enzymes) and hemophilus parainfluenzae (hpai). the cleavage products were analyzed by polyacrylamide gradient slab gel electrophoresis and electron microscopy. hpv dna was cleaved into two fragments by ecori (87% and ... | 1975 | 174077 |
| energy-dependent binding of dansylgalactoside to the lac carrier protein: direct binding measurements. | high specific activity 6'-n-[3h]dansyl)aminohexyl 1-thio-beta-d-galactopyranoside (dns6-gal) has been synthesized, and its binding to escherichia coli membrane vesicles measured directly by flow dialysis. with ml 308-225 vesicles containing the lac carrier protein, specific binding is not detected in the absence of d-lactate or reduced phenazine methosulfate. in the presence of these electron donors, binding is observed, and the binding constant and number of binding sites are approximately 4 mu ... | 1976 | 174094 |
| "early" simian-virus-40-specific rna contains information for tumor antigen formation and chromatin replication. | simian virus 40 (sv40) induces tumor (t)-antigen formation, chromatin replication, and mitosis in primary mouse kidney cells arrested in g0 phase of the mitotic cycle. the temporal and quantitative relation between these early virus-specific reactions led to the hypothesis that the early sv40 mrna contains information necessary for t-antigen formation and induction of cellular dna synthesis. to get direct experimental evidence for this hypothesis, the early strand of sv40 dna was transcribed in ... | 1976 | 174105 |
| coordinated, coenzyme q reversible, 2,5-dibromothymoquionine inhibition of electron transport and atpase in escherichia coli. | | 1976 | 174563 |
| synchronous digestion of sv40 dna by exonuclease iii. | we have established an optimal condition for the synchronous digestion of sv40 dna with escherichia coli exonuclease iii. electron microscopy and polyacrylamide gel electrophoresis were used to obtain accurate measurements on the lengths of dna before and after exonuclease iii digestion. based on this finding, a new method for determining the sequence of long duplex dna can be realized. it involves (a) the synchronous digestion of the dna from the 3' ends with exonuclease iii, followed by (b) re ... | 1976 | 174717 |
| partial purification and properties of a dna-binding protein from nuclei of cells infected with polyoma virus. | a dna-binding protein has been purified from nuclei of 3t3 cells infected with polyoma virus. the assay used to detect this activity measures the amount of double-stranded dna retained on a nitrocellulose membrane filter in the presence of binding protein. the interaction between dna and protein is salt dependent and occurs optimally at 0.8 m nacl. the isolated protein can bind to both circular and linear duplex dna. incubation of the binding protein with pm2 or polyoma dna results in the format ... | 1976 | 174725 |
| kinetic studies on the reaction catalyzed by polynucleotide kinase from phage t4-infected escherichia coli. | kinetic properties of polynucleotide kinase (ec 2.7.1.78) isolated from escherichia coli cells infected with phage t4 were investigated. the reaction depends on the concentration of mgatp, while free atp or free mg2+ have neither inhibitory nor accelerating effect. the initial reaction velocity was plotted against variable concentrations of atp as the phosphate donor at various fixed concentrations of 5'-hydroxyl-dna or -oligo(ra) as the phosphate acceptor in the presence or absence of products. ... | 1976 | 174738 |
| regulation of penicillin acylase in escherichia coli by cyclic amp. | 1. cyclic amp was found to stimulate penicillin acylase activity. 2. it also overcame the repression of glucose and restored enzyme synthesis to the non-repressed levels. 3. the conversion of inactive enzyme precursor into active enzyme was not stimulated by cyclic amp in cells in which protein synthesis was inhibited by chloramphenicol. 4. cyclic amp failed to stimulate enzyme production in cells in which messenger rna synthesis was arrested by rifampicin or inducer removal. 5. cyclic amp appea ... | 1976 | 174748 |
| base composition studies on mitochondrial 4 s rna from rat liver and morris hepatomas 5123d and 7777. | the major and modified base composition of mitochondrial 4 s rna from rat liver and from morris hepatomas 5123d and 7777 has been determined for 16 constituents using a chemical tritium-derivative method. the base composition of these mitochondrial 4 s rna preparations was compared with the base composition of cytoplasmic and bacterial (escherichia coli b and bacillus subtilis) 4-s rnas. the results of these studies are: 1. when compared with cytoplasmic 4 s rna, the liver and hepatoma mitochond ... | 1976 | 174749 |
| [bactericidal dosie-activity relationships with e. coli, k. pneumoniae and staph. aureus (author's transl)]. | in investigations into the dosis-activity relationships of bactericidal antibiotics used against e. coli, k. pneumoniae and staph. aureus four types of activity could be demonstrated. the penicillin type shows almost no improvement in bactericidal activity despite increasing the dosage above a certain level. an increase in concentration of aminoglycoside antibiotics led to a more rapid killing of the bacteria. in cefalotin there was a linear dosis-activity relationship: rising concentrations of ... | 1976 | 174881 |
| characteristics of cells present in peritoneal fluids of mice injected intraperitoneally with bordetella pertussis. | peritoneal fluids obtained from mice after the intraperitoneal administration of bordetella pertussis vaccine, heated vaccine, an extract of the organisms, killed escherichia coli, or thioglycolate medium were examined in terms of total cells and percentage that adhered to glass cover slips during 2-h incubation period. all these substances were found to increase the number of leukocytes in peritoneal fluid within 1 to 2 days after the injection. this increase appeared to be due to an influx of ... | 1976 | 175017 |
| the distribution of pyrophosphatidic acid in nature. | the occurrence of a novel phospholipid, pyrophosphatidic acid, in the lipid extracts of yeasts (23 species), bacteria (e. coli), algae (chlorella), mammalia (human, rabbit, guinea pig, and mouse), insect (cockroach), fish (carp), mollusc (clam), and spermatophyta (spinach) was investigated. pyrophosphatidic acid was found exclusively in the lipid extracts of several kinds of yeast species, but not in other normal living species (animals, plants, and microorganisms) so far investigated. all of th ... | 1975 | 175047 |
| effect of glucose and cyclic adenosine 3',5'-monophosphate on the synthesis of succinate dehydrogenase and isocitrate lyase in escherichia coli. | repressed respiration of escherichia coli cells grown in the presence of 2% glucose was derepressed when the cells were incubated in a buffer containing casamino acids. the glucose-repressed cells were deficient in succinate dehydrogenase [ec 1.3.99.1] and isocitrate lyase [ec 4.1.3.1] activities, which increased during the incubation. the increases in respiratory activity and enzyme activity on incubation were repressed by glucose, but except for isocitrate lyase these repressions could be rest ... | 1975 | 175051 |
| studies on a thermophilic rna polymerase which is active only on poly d(a-t) and poly dadt. | two types of rna polymerases [ec 2.7.7.6], polymerases a and b, exist in thermophilic bacteria, thermus thermophilus hb8. polymerase b is apparently like the core enzyme of polymerase a but is active only when an alternating copolymer of deoxyadenylic and deoxythymidylic acids (poly d(a-t)) or a mixture of homopolymers of deoxyadenylic acid and deoxythymidylic acid (poly dadt) is used as a template. polymerase b was further characterized to elucidate its relation to polymerase a and to determine ... | 1975 | 175054 |
| effect of alcohols on polypeptide chain elongation and aminoacyl-trna formation. | the effect of alcohols (methanol, ethanol, and propanol) on polypeptide chain elongation was studied. in the e. coli and rat liver cell-free systems, the optimal concentration of mg2+ decreased with increase of ethanol concentration, although the maximum polyphenylalanine synthesis decreased. methanol had almost the same effect as ethanol. propanol decreased the optimal magnesium concentration, but polyphenylalanine synthetic activity was markedly decreased. the shift of optimal mg2+ concentrati ... | 1975 | 175055 |
| total synthesis of the structural gene for the precursor of a tyrosine suppressor transfer rna from escherichia coli. 3. synthesis of deoxyribopolynucleotide segments corresponding to the nucleotide sequence 27-51. | chemical syntheses of the four deoxyribodecanucleotides, d(t-c-g-a-a-g-t-c-g-a), d(c-g-t-c-a-t-c-g-a-c), d(t-g-a-c-g-g-c-a-g-a), and d(c-t-a-a-a-t-c-t-g-c) are described. these polynucleotides form, respectively, segments 7 to 10 in the plan adopted for the total synthesis of the dna corresponding to the precursor for the escherichia coli tyrosine trna. the syntheses used the principles of stepwise addition of protected mono- and oligonucleotides to the 3'-hydroxyl end of growing oligonucleotide ... | 1976 | 175056 |
| total synthesis of the structural gene for the precursor of a tyrosine suppressor transfer rna from escherichia coli. 10. enzymatic joining of chemically synthesized segments to form the dna duplex corresponding to the nucleotide sequence 86-126. | the polynucleotide ligase-catalyzed joining of the eight chemically synthesized deoxypolynucleotides (segments 19 to 26), comprising the nucleotide sequence 86-126 of the dna corresponding to the escherichia coli tyrosine trna precursor has been investigated. joining was studied using various combinations of 3, 4, or larger number of segments at a time. the extent of joining was in general low (0 to 40%) for the three-component as well as for the four-component systems. joining of the five- and ... | 1976 | 175057 |
| total synthesis of the structural gene for the precursor of a tyrosine suppressor transfer rna from escherichia coli. 11. enzymatic joining to form the total dna duplex. | the dna duplex corresponding to the entire length (126 nucleotides) of the precursor for an escherichia coli tyrosine trna has been synthesized. duplex [i] (sekiya, t., besmer, p., takeya, t., and khorana, h. g.(1976) j. biol. chem. 251, 634-641), corresponding to the nucleotide sequence 1-26, containing single-stranded ends and carrying one appropriately labeled 5'-phosphate group, was joined to duplex [ii] (loewen, p. c., miller, r. c., panet, a., sekiya, t., and khorana, h. g. (1976) j. biol. ... | 1976 | 175058 |
| total synthesis of the structural gene for the precursor of a tyrosine suppressor transfer rna from escherichia coli. 12. synthesis of a dna duplex corresponding to a sequence of 23 nucleotide units adjoining the c-c-a end. | in continuing the work on the total synthesis of the gene for an escherichia coli tyrosine suppressor trna (accompanying papers) and as a part of a study of the mechanism of transcription of this gene, a 23-nucleotide unit-long dna corresponding to the previously determined (loewen, p., sekiya, t., and khorana, h. g. (1974) j. biol. chem. 249, 217) sequence has been synthesized. the synthesis was carried out by dividing the total duplex into the following five deoxyribooligonucleotide segments, ... | 1976 | 175059 |
| an epidemic of diarrhoea in human neonates involving a reovirus-like agent and 'enteropathogenic' serotypes of escherichia coli. | during december 1974, an epidemic of diarrhoea occurred in the royal children's hospital, melbourne, in a ward caring for neonates with acute or chronic medical and surgical problems. electron microscopy of diarrhoeal faeces revealed a reovirus-like particle ('duovirus' or 'rotavirus') known to cause acute enteritis in older children. this virus is considered to have been primarily involved in the aetiology of the epidemic. in addition, three 'enteropathogenic' serotypes of escherichia coli were ... | 1976 | 175099 |
| specificity of the stimulation of in vitro ribonucleic acid synthesis by guanosine 5'-diphosphate 3'-diphosphate. | the in vitro synthesis of ribonucleic acid (rna) by s-30 extracts of escherichia coli k-12 is stimulated from two-to fourfold by 0.16 mm to 0.32 mm guanosine 5'-diphosphate 3'-diphosphate (ppgpp) when either gammaci857st68h80 deoxyribonucleic acid (gammah80 dna), gammah80dilv dna or gammah80dlac dna are employed as templates. hybridization analysis of the 3h-rna product transcribed from gammah80dilv dna in the presence of ppgpp indicates that both bacteriophage- and bacterial-specific transcript ... | 1975 | 175258 |
| [specific modification of phenylalanine:trna-ligases of e. coli mre-600 with n-chlorambucilyl-14c-phenylalanyl-trna]. | n-chlorambucilyl-[14c]phenylalanyl-trna was used for the affinity modification of phenylalanine : trna-ligase from e. coli mre-600. it has been found that n-chlorambucilyl-[14c]phenylalanyl-trna selectively inactivates phenylalanine : trna-lagase that results in formation of a covalent bond between the trna derivative and the enzyme at ph 5.8, 25 degrees c. the rate fall of the aminoacylation of trna with [14c]phenylalanine was observed after the enzyme incubation with n-chlorambucilyl-[14c]phen ... | 1975 | 175264 |
| specific spin-labeling of transfer ribonucleic acid molecules. | the spin labels anhydride (asl), bromoacetamide (bsl) and carbodiimide (csl) were used to label selectively trnaglu, trna fmet and trnaphe from e. coli. the preparation and characterization of the sites of labeling of eight new spin-labeled trnas are described. the sites of labeling are: s2u using asl, bsl and cls and trnaglu; s4u using asl and bsl on trnafmet and trnaphe; u-37 with csl on trnfmet; u-33 with csl on trnaphe. the rare base x at position 47 of trnaphe has been acylated with a spin- ... | 1976 | 175353 |
| a spin label study of the thermal unfolding of secondary and tertiary structure in e. colic transfer rnas. | the molecular mechanism of thermal unfolding of e. coli trnaglu, trnafmet and trnaphe (in 0.02m tris-hc1, ph 7.5. 10 mm mg c12) has been examined by the spin-labeling technique. the rate of tumbling of the spin label has been measured as a function of temperature for ten different selectively spin-labeled trnas. only spin labels at position s4u-8 were able to probe the tertiary structure. evidences are presented which support the hypothesis that the thermal denaturation of the three species of t ... | 1976 | 175354 |
| specific oligoribonucleotide synthesis using primer-independent polynucleotide phosphorylase. | oligoribonucleotides of a predetermined base sequence beginning with adenylyl-3', 5'-adenosine at the 5' end have been synthesized in yields varying between 13% and 42%. the synthesis was carried out using primer-independent polynucleotide phosphorylase from e. coli in the presence of high concentrations of primer and of sodium chloride. | 1975 | 175364 |
| studies on the energetic metabolism of shigella flexneri x escherichia coli hybrids devoid of penetration ability. iii. catalase and phosphatase activity. | the catalase and phosphatase activity of avirulent by keratoconjunctival test of guinea pigs lac+, kcp- hybrids that have lost their ability of penetrating in the epithelium, received from virulent strains shigella flexneri (sh. flexneri 222 5a and sh. flexneri m42-43) and donor strains escherichia coli (e. coli k-12, p4x and e. coli h) was investigated. it was established that there is no any dependence between the lost of virulence of the hybrids and the level of the catalase activity. during ... | 1975 | 175614 |
| localization of selenium in bacterial cells using tem and energy dispersive x-ray analysis. | bacteria isolated from lake sediment samples reduced sodium selenite to elemental selenium. finestructural observations were made on a number of different bacterial species cultured in the presence of sodium selenite. examination of escherichia coli and a pseudomonas species revealed electron-dense deposits of irregular shape, composed of smaller units, within the cytoplasm but not on the cell wall and cell membrane. cells of aeromonas and flavobacterium species exhibited conspicuous intranuclea ... | 1976 | 175749 |
| accumulation of cyclic guanosine 3':5'-monophosphate in the culture medium of growing cells of escherichia coli. | | 1976 | 175794 |
| isolation of viral specific rna from sv40 infected cells by viral dna chemically linked to a cellulose matrix. | sv40 dna fragments chemically attached to neutral cellulose powder with a water-soluble carbodiimide have been used to isolate late lytic viral specific rna from virus infected cells. exhaustive hybridization to sv40 dna reveals that virtually all of the isolated rna molecules contain sv40 specific sequences. comparison with sv40 crna prepared with purified escherichia coli rna polymerase and a sv40 dna i template suggests that the purity of the isolated sv40 specific rna is very close to 100%. ... | 1976 | 175823 |
| a ribosome-independent, soluble stringent factor-like enzyme isolated from a bacillus brevis. | a ribosome-independent synthesis of guanosine 5',3'-polyphosphates has been found in the soluble fraction of bacillus brevis (atcc 8185) extracts. the partially purified enzyme catalyzes the formation of both guanosine 5'-diphosphate 3'-diphosphate and guanosine 5'-triphosphate 3'-diphosphate, does not require 20% methanol to stimulate the rate of reaction, and is not stimulated by complexing with ribosomes of either escherichia coli or b. brevis. the b. brevis enzyme system is not inhibited by ... | 1976 | 175825 |
| random cleavage of superhelical sv 40 dna s1 nuclease. | sv40 dna fo i is randomly cleaved by s1 nuclease both at moderate (50 mm) and higher salt concentrations (250 mm nac1). full length linear s1 cleavage products of sv40 dna when digested with various restriction endonucleases revealed fragments that were electrophoretically indistinguishable from the products found after digestion of superhelical sv40 dna fo i with the corresponding enzyme. concordingly, when the linear s1 generated duplexes were melted and renatured, circular duplexes were forme ... | 1976 | 175852 |
| on the monomeric structure and proposed regulatory properties of phosphoenolpyruvate carboxykinase of escherichia coli. | phosphoenolpyruvate carboxykinase (atp:oxaloacetate carboxy-lyase (transphosphorylating)) (ec 4.1.1.49) has been purified to homogeneity from escherichia coli. the enzyme shows the same molecular weight (ca. 65000) either by sedimentation equilibrium under nondenaturing conditions or by polyacrylamide gel electrophoresis in the presence of detergent, indicating that the enzyme has a monomeric structure. we have confirmed the previous observation that nadh is an inhibitor of this enzyme, but we h ... | 1976 | 175900 |
| mechanism of activation adenylate cyclase in vitro by polymyxin-released, heat-labile enterotoxin of escherichia coli. | heat-labile enterotoxic material released from escherichia coli by polymyxin b activates the adenylate cyclase of pigeon erythrocyte ghosts in a time- and concentration-dependent manner. the activation requires nicotinamide adenine dinucleotide, adenosine triphosphate, and another component of the erythrocyte supernatant. the active species has a molecular weight of about 23,000-24,000 daltons, is inhibited by antibodies to the toxin of vibrio cholerae, and is not irreversibly denatured by sodiu ... | 1976 | 176279 |
| purification of the polymyxin-released, heat-labile enterotoxin of escherichia coli. | the heat-labile enterotoxin of escherichia coli strain h-10407 has been purified by use of a commercially available affinity gel (affi-gel 202). this gel possesses a strong and highly specific affinity for the enterotoxin released from intact e. coli cells by polymyxin b. the polymyxin-release technique could be used with fermenter-size batches of e. coli cells grown in a casamino acids-yeast extract medium. with a simple (nh4)2so4 back-extraction step prior to affinity chromatography, large bat ... | 1976 | 176284 |
| level of specific prereplicative mrna's during bacteriophage t4 rega-, 43- and t4 43- infection of escherichia coli b. | the role of the t4 bacteriophage rega gene in stabilizing early mrna was investigated by assaying the level of functional mrna from eight prereplicative genes (56 [dcmp hydroxymethylase], cd [dcmp deaminase], 1 [deoxynucleotide kinase], riia, riib, 46 [dna arrest], and 45) during extended infection of escherichia coli b with t4 rega-, 43- and t4 43- bacteriophage. the above gene-specific transcripts in rna isolated from infected cells were quantitated by translation with an e. coli b cell-free s ... | 1976 | 176430 |
| simian virus 40 dna replication: characterization of gaps in the termination region. | a class of precursor dna (pdna) ii molecules has been identified as the immediate precursor of simian virus 40 dna i. a pdna ii molecule contains a strand of newly synthesized dna with an interruption located in the region where dna synthesis terminates (4). these pdna ii molecules have been isolated and further characterized. they are converted to covalently closed structures (simian virus 40 dna i) only when they are treated in vitro with both t4 dna polymerase and escherichia coli ligase. aft ... | 1976 | 176434 |
| proposed structure of two defective viral dna oligomers produced in 3t3 cells transformed by the ts-a mutant of polyoma virus. | the various oligomeric viral dna species produced at 32 c by two related syblines of ts-a-transformed mouse 3t3 cells were characterized. results from the analysis of the cleavage products observed after digestion with restriction endonucleases from haemophilus parainfluenzae, escherichia coli ri, and haemophilus suis are consistent with the assumption that in both sublines, the major oligomeric component is a dimer from which a segment of different length is deleted. the major oligomeric (27s) ... | 1976 | 176437 |
| protein synthesis in bacteriophage ghost-infected cells. | escherichia coli b infected with t4 phage ghosts at 10 mm mg2+ regains its protein synthesizing activity upon addition of atp, gtp, and their generator to approximately 2% of the intact exponentially growing cells. in contrast to amino acid incorporation by intact cells, this system is sensitive to edta or low mg2+. on the other hand, this system, differing from the regular cell-free system, does not respond to addition of soluble protein and ribonuclease. the ghost-infected cells were able to s ... | 1976 | 176455 |
| early events after infection of escherichia coli by bacteriophage t5. ii. control of the bacteriophage-induced 5'-nucleotidase activity. | the control of activity of the bacteriophage t5-induced 5'-nucleotidase is dependent upon the amount of t5 parental dna injected into the cell and expressed. when only the first-step transfer dna is injected and expressed the amount of 5'-nucleotidase activity observed is two to three times the maximum amount observed after normal t5 infection, and inactivation of the enzyme does not occur. enzyme inactivation occurs only after the remaining dna is injected, but only limited expression of this d ... | 1976 | 176472 |
| orphan airlift. enteric pathogens isolated from vietnamese children immigrating to the united states. | isolation studies for bacterial and parasitic agents were carried out on stool specimens from vietnamese infants at the time of their mass airlift to the united states. one or more bacterial pathogens were found in 49% of the 367 stool specimens cultured. the isolates included enteropathogenic escherichia coli (161), shigella (16), salmonella (15), but no salmonella typhi or vibrio cholerae. parasites identified in 88 stool specimens included giardia lamblia (10), ascaris lumbricoides (7), and e ... | 1976 | 176481 |
| defects in granulocyte function in various chromosome abnormalities (down's-, edwards'-, cri-du-chat syndrome). | in five infants with autosomal aberrations and diminished resistance to infection (in spite of intact humoral and cellular immune mechanisms) several granulocyte functions (chemotaxis, phagocytosis, intracellular killing and metabolism of killing) were measured. a serum-dependent or a cell-dependent disturbance of phagocytosis of candida albicans was found in two infants with cat-cry syndrome and one with trisomy 18. in one of these children there was an additional serum dependent defect of the ... | 1976 | 176505 |
| human reovirus-like agent as the major pathogen associated with "winter" gastroenteritis in hospitalized infants and young children. | we found a human reovirus-like agent in the stools of 42 per cent of 143 infants and young children hospitalized with acute gastroenteritis between january, 1974, and june, 1975. half the patients studied by electron microscopy and serologic technics had evidence of infection with the agent. the infection had a seasonal pattern: 59 per cent of those admitted during the cooler months (november to april) shed the agent, with a peak of 78 per cent in december, 1974, and january, 1975, combined. non ... | 1976 | 176586 |
| function of granulocytes with deficient myeloperoxidase-mediated iodination in a patient with generalized pustular psoriasis. | the granulocytes of a patient with generalized pustular psoriasis (gpp) were found to have impaired ability to fix iodine after ingestion of yeast particles. since hexose monophosphate shunt (hms) activity was increased and the contents of 3 other lysosomal enzymes, beta-glucuronidase, n-acetyl-beta-glucosaminidase and lysozyme, were within normal range, the impaired iodination appeared to be due to a selective defect of myeloperoxidase (mpo) activity within the phagocytic cells. the deficient i ... | 1976 | 176720 |
| [obtaining the beta-globulin fractions from swine and cattle sera and a study of their immunological activity]. | the rivanol precipitation was used to obtain beta-globulin fractions from specific swine sera against edema disease, paratyph and aujeszky's disease as well as from normal ovine and swine sera. agar electrophoresis revealed that the preparations produced contained beta-globulin (86 per cent), gamma-globulin (5 per cent), and alpha2-globulin (9 per cent). the beta-globulin preparations were studied for the presence of antibodies against e. coli, salmonellae, staphylococci, myxovirus parainfluenza ... | 1976 | 176771 |
| studies on the kinetic mechanism and the phosphoryl-enzyme compound of the escherichia coli acetate kinase reaction. | | 1976 | 176952 |
| homoserine kinase from escherichia coli k12. | homoserine kinase was purified to apparent homogeneity from a derepressed strain of escherichia coli k12, using standard fractionation techniques. it is a dimer (mr = 60000) composed of apparently identical polypeptide chains (mr = 29000). its amino acid composition and n-terminal sequence have been determined. l-threonine is a competitive inhibitor of the substrate l-homoserine; this inhibition is straighforward and shows no sign of co-operativity. evidence is presented that homoserine and thre ... | 1976 | 177283 |