| the use of avidin-biotin interaction in immunoenzymatic techniques. | biotin was covalently attached to antibodies, antigens and enzymes, and the effects of this labeling on the antigen and antibody binding capacity and on enzymatic activity were tested. based on avidin-biotin interaction, the labeled proteins were used in quantitative enzyme-immunoassay and enzyme-immunohistochemical staining procedures. two procedures were developed. in the first procedure, named the bridged avidin-biotin (brab) technique four steps were used sequentially in order to quantify or ... | 1979 | 90074 |
| condensation--inhibition by 33258-hoechst of centromeric heterochromatin in prematurely condensed mouse chromosomes. | | 1979 | 91529 |
| concert chromatography purification of mouse interferon [proceedings]. | | 1979 | 92244 |
| [epidemiological study on beta hemolytic streptococci among healthy school children in toda city, saitama (author's transl)]. | | 1978 | 101618 |
| inhibition of acetylcholinesterase from foetal and maternal tissues after oral intake of carbaryl (1-naphthyl-n-methyl-carbamate) by pregnant rats. | | 1978 | 103555 |
| an unstable donor-recipient dna complex in transformation of bacillus subtilis. | in re-extracted dna obtained shortly after uptake of transforming dna by bacillus subtilis, increased amounts of donor dna radioactivity banding at the position of donor-recipient dna complex (drc) are observed in cscl gradients, if the cells are irradiated with high doses of uv prior to reextraction of the dna. qualitatively, the same phenomenon is observed if lysates of transforming cells are irradiated. uv-irradiation of lysates of competent cells to which single-stranded dna is added after l ... | 1978 | 106232 |
| pericarditis due to mycobacterium tuberculosis and mycobacterium fortuitum: a case report. | in this case study, pericarditis results from mycobacterium tuberculosis and mycobacterium fortuitum. both organisms were isolated from three different clinical specimens: a pericardial fluid, pericardium, and a thoracentesis fluid. a mixed mycobacterial culture was initially suspected upon examining ziehl-neelsen stained smears prepared from the primary cultures following seven to ten days of incubation. dilutions and subcultures were subsequently performed, confirming the presence of two diffe ... | 1979 | 106725 |
| [homologous transplants in the middle ear (author's transl)]. | the original concept of tympanoplasty included besides the closure of the middle ear, the removal of pathological middle ear components leaving intact the functional and healthy components. the special conditions that prevail in the middle ear (aeration, absence of intrinsic trauma) allow the reconstruction of the middle ear mechanics to a great extent. animal experiments and clinical experience reveal good transplantation properties of denatured and preserved ear ossicles. they are partly repla ... | 1975 | 123985 |
| [letter: study of anthropometric characteristics and of dermatoglyphics in the parents of children with 21 trisomy]. | | 1975 | 126416 |
| the possible role of tightly bound adenine nucleotides in oxidative and photosynthetic phosphorylation. | the tightly bound nucleotides of the beff-heart mitochondrial atpase are released during cold inactivation followed by ammonium sulfate precipitation. during incubation at 0 degrees c the sedimentation coefficient (s20w) of the atpase first declines from 12.1s to 9s. prolonged incubation or precipitation with ammonium sulfate leads to dissociation of the 9s component into subunits with s20w of 3.5s. the 9s component still bears bound nucleotides which exchange more extensively and rapidly with a ... | 1975 | 127089 |
| letter: light induced change in rod outer segment membrane fluidity. | | 1975 | 165628 |
| behavioral effects of dibutyryl cyclic 3'5'amp and biogenic amines in rats. | white male wistar rats were injected intraventricularly with 200 mug of dibutyryl cyclic 3'5'amp (damp. 30 min later part of animals was injected intraventricularly with 10 mug of dopamine (da), 10 mug of 5-hydroxytryptamine (5-ht) or 50 mug of acetylcholine (ach). immediately after injection of the amines the time of walking, convulsions, immobility and number of jumps during 10 min periods of observation was measured. damp induced excitation of animals expressed by convulsions, jumping and sho ... | 1975 | 165657 |
| properties of adenylate cyclase solubilized from rat adrenal membranes: effects of acth and other stimulators on solubilization. | we have solubilized adenylate cyclase in a relatively stable form from rat adrenal membranes. the solubilized enzyme elutes on a column of sepharose 4br as a distinct peak with a higher molecular weight than the soluble fractions which bind 125i-acth. both the soluble and membrane bound enzymes are activated by naf and gpp(nh)p, and both have similar affinities for mgatp. while the membrane bound enzyme is activated similarly by either mg2+ or mn2+, the soluble enzyme is more fully activated by ... | 1977 | 201680 |
| multiple rearrangements and activated expression of c-myc induced by woodchuck hepatitis virus integration in a primary liver tumour. | woodchuck hepatitis virus (whv) is a small, partially double-stranded dna virus. like the related human hepatitis b virus (hbv), whv induces acute and chronic hepatitis and hepatocellular carcinoma (hcc) in its natural host. whv dna integration into c-myc and n-myc, resulting in deregulated expression of these genes, has been described previously in woodchuck hcc. we have analysed a woodchuck liver tumour in which whv dna was integrated in the c-myc gene. the virus insertion provoked multiple al ... | 1992 | 1317604 |
| phylogenetic and chemotaxonomic characterization of acidaminococcus fermentans. | the phylogenetic position of acidaminococcus fermentans was determined by comparative sequence analysis of the 16s rrna. this gram-negative bacterium is a member of the sporomusa cluster that is defined by other gram-negative bacteria, i.e. sporomusa, megasphaera, selenomonas, butyrivibrio, pectinatus, and zymophilus. the branching point of this group within the radiation of gram-positive bacteria of the clostridium/bacillus subphylum and adjacent to peptococcus niger could be confirmed. chemota ... | 1992 | 1385264 |
| 2-hydroxyglutaryl-coa dehydratase from fusobacterium nucleatum (subsp. nucleatum): an iron-sulfur flavoprotein. | anaerobically prepared cell-free extracts from fusobacterium nucleatum contain 2-hydroxyglutaryl-coa dehydratase with a specific activity of 20 nkat mg-1. the enzyme was purified 24-fold to a specific activity of 480 nkat mg-1 by anion exchange chromatography, gel filtration and chromatography on blue-sepharose. the activity of the purified enzyme was strictly dependent on the reductant ti(iii)citrate and stimulated 25-fold by 0.15 mm atp and 5 mm mgcl2. atp is hydrolysed to adp during incubatio ... | 1992 | 1417419 |
| regulations for implementing the clinical laboratory improvement amendments of 1988: a summary. | in 1988, congress passed the clinical laboratory improvement amendments (clia), which set standards to improve the quality of clinical laboratory testing in all laboratories in the nation that conduct testing on human specimens for health assessment or for the diagnosis, prevention, or treatment of disease. this report summarizes the final regulations for implementing clia and provides an overview of each section, specifying laboratory standards and requirements. | 1992 | 1538689 |
| presence of paf-acether in rheumatic diseases. | paf-acether (paf) is a naturally occurring phospholipid involved in inflammatory processes. the presence of paf, its precursor lyso paf, and lipo-paf has been determined in blood and synovial fluid from 13 patients with rheumatoid arthritis (ra), 11 with spondylarthropathies, eight with other inflammatory rheumatisms, 13 with chondrocalcinosis, 15 with osteoarthritis, and also in blood from nine healthy subjects. paf and lipo-paf were measured by rabbit platelet aggregation after isolation by hi ... | 1992 | 1540032 |
| susceptibilities of anaerobic bacteria isolated from animals with ovine foot rot to 28 antimicrobial agents. | the agar dilution method was used to determine the inhibitory activities of 28 antimicrobial agents against 35 strains of the genus peptostreptococcus, 4 strains of the species peptococcus niger, 20 strains of the species megasphaera elsdenii, 7 strains from the species acidaminococcus fermentans, 8 strains of the genus clostridium, 11 strains of the genus eubacterium, and 1 strain of the species propionibacterium acidipropionici, all of which were isolated from 125 clinical cases of ovine foot ... | 1992 | 1590689 |
| synthesis and properties of (r)-2-hydroxyglutaryl-1-coa. (r)-2-hydroxyglutaryl-5-coa, an erroneous product of glutaconate coa-transferase. | 1) (r)-2-hydroxyglutaryl-1-coa was synthesised starting from (r)-5-oxotetrahydrofuran-2-carboxylic acid (gamma-lactone of (r)-2-hydroxyglutarate) which was converted to the acylchloride and condensed with n-capryloylcysteamine. the lactone ring of the resulting thiolester was opened by acid hydrolysis and the coa derivative was obtained by transesterification. 2) pure glutaconate coa-transferase from acidaminococcus fermentans catalysed the formation of the 1- and the 5-isomer of (r)-2-hydroxygl ... | 1991 | 1872995 |
| clonal variation of dna repair in a human glioma cell line. | clonal heterogeneity in response to ionizing radiation was found for a human glioma cell line, in859. we have investigated the most sensitive clone, the most resistant clone and the parent line for differences in dna repair fidelity using the method of plasmid reconstitution. significant differences in repair fidelity were found between the two clones, and between the sensitive clone and the parent line. the resistant clone and the parent line showed the greater repair fidelity. a comparison of ... | 1991 | 1924859 |
| radioimmunotargeting of human tumour cells in immunocompetent animals. | a tumour model system is reported that for many purposes may be an alternative to xenografted nude mice. the model allows immunotargeting of human tumour cells in immunocompetent animals. the target cells are contained in i.p. diffusion chambers (dc) with micropore membrane walls that are permeable to molecules, including the cell specific monoclonal antibodies (moab), but impermeable to cells. thus, the tumour cells are protected from the host immunocompetent cells. in the work here presented t ... | 1990 | 2223574 |
| the biotin-dependent sodium ion pump glutaconyl-coa decarboxylase from fusobacterium nucleatum (subsp. nucleatum). comparison with the glutaconyl-coa decarboxylases from gram-positive bacteria. | membrane preparations of fusobacterium nucleatum grown on glutamate contain glutaconyl-coa decarboxylase at a high specific activity (13.8 nkat/mg protein). the enzyme was solubilized with 2% triton x-100 in 0.5 m nacl and purified 63-fold to a specific activity of 870 nkat/mg by affinity chromatography on monomeric avidin-sepharose. the activity of the decarboxylase was strictly dependent on na+ (km = 3 mm) and was stimulated up to 3-fold by phospholipids. the glutaconyl-coa decarboxylases from ... | 1990 | 2244788 |
| carbon-13 labelled biotin--a new probe for the study of enzyme catalyzed carboxylation and decarboxylation reactions. | [2'-13c]biotin was incorporated into avidin (egg white), glutaconyl-coa decarboxylase (ec 4.1.1.70) from acidaminococcus fermentans and the biotin carrier of transcarboxylase from propionibacterium freudenreichii (ec 2.1.3.1). 13c-nmr measurements showed an upfield shift of the carbonyl carbon of 3.1 and 2.0 ppm for both enzymes, whereas binding to avidin induced no significant change of the chemical shift as compared to free biotin. the data indicate that the enzymes provide an electronic envir ... | 1990 | 2269346 |
| the sodium pump glutaconyl-coa decarboxylase from acidaminococcus fermentans. specific cleavage by n-alkanols. | glutaconyl-coa decarboxylase from acidaminococcus fermentans was inactivated by incubation with n-alkanols at 37 degrees c. the concentration of the alcohol required for complete inactivation decreased with increasing chain length; e.g. 2 m ethanol was as potent as 2 mm hexanol or 0.5 mm decanol. the data indicate a binding of the alcohol to the enzyme with an energy of about 4 kj/methylene group. sodium ions prevented the inactivation (50% at 30 mm nacl). k+, nh4+, cs+ and mg2+ had no influence ... | 1986 | 2422027 |
| substrate stereochemistry of the biotin-dependent sodium pump glutaconyl-coa decarboxylase from acidaminococcus fermentans. | the steric course of the decarboxylation of glutaconyl-coa to crotonyl-coa, catalysed by the biotin-dependent sodium pump glutaconyl-coa decarboxylase from acidaminococcus fermentans, was elucidated using the sequence: chiral acetate----citrate----glutamate----glutaconyl-coa----crotonyl-coa ----chiral acetate. since glutaconyl-coa or glutaconate labeled at c-4 was subjected to rapid chemical or enzymatic exchanges, glutamate was fermented to acetate by growing cells of a. fermentans. the analysi ... | 1986 | 2422028 |
| anomalous drainage of the inferior vena cava into a left atrial connection: a case report involving a 41-year-old man. | a 41-year-old man had an anomalous inferior vena cava directly connected to the left atrium demonstrated by contrast echocardiography, magnetic resonance imaging, angiography, and at operation. the anomaly is due to developmental failure of the right sinus venosus valve, septum secundum, and dorsal portion of the atrial septum. | 1989 | 2650882 |
| cloning and sequencing of the genes of 2-hydoxyglutaryl-coa dehydratase from acidaminococcus fermentans. | two genomic libraries from acidaminococcus fermentans dna constructed with the lambda vectors gt11 and embl 3 were screened with antisera raised against 2-hydroxyglutaryl-coa dehydratase. two clones giving the strongest reaction in the immunoassay were analyzed further, one was a lambda gt11 clone with an insert of 2050 bp and one was a lambda embl-3 clone with an insert of approximately 11,000 bp. escherichia coli cells infected with the lambda gt11 clone expressed the alpha subunit of the dehy ... | 1989 | 2659350 |
| equilibrium constants of several reactions involved in the fermentation of glutamate. | the equilibrium constants of the reactions catalysed by (s)-citramalate lyase and (r)-2-hydroxyglutarate dehydrogenase were determined using the purified enzymes from clostridium tetanomorphum and acidaminococcus fermentans, respectively. the former constant had to be determined at high ionic strength (i). therefore it was corrected to i = 0.1 m by applying single-ion activity coefficients estimated from literature data. the result (kapp = 4.31 +/- 0.07 m-1; direction of citramalate formation) a ... | 1987 | 2883006 |
| ischaemic mouse thigh model for evaluation of pathogenicity of non-clostridial anaerobes. | a mouse thigh model has been devised in which the growing culture of non-clostridial anaerobe in the ischaemic tissue produces inflammatory swelling and death. the swelling of the right thigh served as an index of pathogenicity of the test strain in comparison to the negatively reacting left thigh which received injection of the control strain of bifidobacterium infantis. actinomyces naeslundii exceptionally caused death in all animals within 24 h. mortality and thigh swelling were pronounced (g ... | 1989 | 2914729 |
| high-level production of the ecori endonuclease under the control of the pl promoter of bacteriophage lambda. | escherichia coli strains overproducing the ecori restriction endonuclease have been constructed, using lambda pl promoter expression vectors. in a first step we constructed endri::lacz gene fusions by fusing the n-terminal part of the endri gene with a lacz gene fragment, whereafter the hybrid gene was positioned randomly under the control of the pl promoter to optimize the level of expression. these plasmids direct the synthesis of large amounts of fusion protein approaching 30% of the total ce ... | 1985 | 2996986 |
| autoradiographic mapping of substance p receptors in lung. | | 1986 | 3019735 |
| autoradiographic mapping of substance p receptors in lung. | | 1986 | 3019735 |
| mechanism of decreased vascular response to angiotensin ii in renal vascular hypertension. | compared to many forms of hypertension, vascular reactivity to angiotensin ii (aii) is decreased in the early phase of two-kidney, one clip (2-k, 1c) renovascular hypertension (rvh). to determine the role of the aii receptor, we examined vascular responsiveness and 125i-aii binding to mesenteric artery membrane fractions after three weeks of 2-k, 1c rvh. systolic blood pressure was 165 +/- 8 in rvh and 105 +/- 4 mm hg in controls, p less than 0.001. plasma renin activity was 4.2 +/- 0.6 in rvh a ... | 1987 | 3035267 |
| diabetic embryopathy and fuel-mediated organ teratogenesis: lessons from animal models. | the growing recognition that faulty maternal metabolism during early organogenesis may be implicated in the increased incidence of birth defects in pregnancies complicated by diabetes has prompted worldwide efforts to institute improved preconceptional metabolic regulation. however, the failure to identify the periods of greatest risk for diabetic embryopathy, the mediating teratogen(s), and the underlying mechanisms have complicated attempts to establish precise therapeutic guidelines and targe ... | 1988 | 3053387 |
| delayed-amelanotic (dam or smyth) chicken: melanocyte dysfunction in vivo and in vitro. | chickens of the autoimmune delayed-amelanotic (dam or smyth) line develop postnatal feather amelanosis and severe visual defects, both of which are presumed to be due to a dysfunction of melanocytes and a subsequent autoimmune response that eliminates pigment cells. in this report we elucidate further the melanocytic defect. we present a morphologic analysis of the mildly affected erratic (edam) group of smyth chicken whose partial depigmentation and lack of visual impairment resemble human viti ... | 1986 | 3091704 |
| lethal and sublethal effects of the combination of doxorubicin and the bisdioxopiperazine, (+)-1,2,-bis (3-5-dioxopiperazinyl-1-yl) propane (icrf 187), on murine sarcoma s180 in vitro. | doxorubicin and the bisdioxopiperazine, icrf 187, synergistically inhibit proliferation of murine sarcoma s180 cells in vitro. cell cycle analysis was employed to help discriminate cytokinetic from lethal effects of the drug combination. twenty-four-hour incubation with either agent produced dose-dependent partial g2m arrest. at high doses, icrf 187 produced partial g2m arrest, inhibition of cell division, and continued dna synthesis at a higher ploidy, resulting in a second g2m arrest of an 8n ... | 1987 | 3107574 |
| surgical cannulation of a hepatic vein in dairy cows utilizing diagnostic ultrasound. | use of a diagnostic ultrasonography unit in the placement of hepatic vein catheters is described. diagnostic ultrasound proved to be a safe and rapid means of identifying the hepatic venous circulation. it provided a clear visual guide in an otherwise blind surgical procedure and allowed for a precise determination of catheter placement. thus, the method could be used to advantage in other types of catheterizations. use of ultrasonography reduced the duration of surgery by 50 to 75%, thereby min ... | 1987 | 3294948 |
| stereological analysis of synaptogenesis in the molecular layer of piriform cortex in the prenatal rat. | the development of synapses in the molecular layer of the rat piriform cortex was studied at embryonic days 15, 17, 19, and 21. the present study has sought to extend past studies of synaptogenesis by identifying not only changes in numbers of synapses, but also changes in numbers of potential precursors of synapses. a stereological method (cruz-orive, '80) was used to make volumetric estimations of the numbers of synapses, axonal puncta, vesicle-associated puncta, and unapposed postsynaptic spe ... | 1987 | 3624545 |
| purification of 2-hydroxyglutaryl-coa dehydratase from acidaminococcus fermentans. an iron-sulfur protein. | 1. the (r)-2-hydroxyglutaryl-coa dehydratase system from acidaminococcus fermentans was separated by chromatography of cell-free extracts on q-sepharose into two components, an activator and the actual dehydratase. the latter enzyme was further purified to homogeneity by chromatography on blue-sepharose. it is an iron-sulfur protein (mr 210,000) consisting of two different polypeptides (alpha, mr 55,000, and beta, mr 42,000) in an alpha 2 beta 2 structure with probably two [4fe-4s] centers. afte ... | 1987 | 3691501 |
| in vivo stability of in vitro labelled 99tcm-red blood cells for radionuclide determination of left ventricular ejection fractions and volumes. | serial determination of radionuclide left ventricular ejection fraction and volumes require a label that remains highly stable after introduction into the human circulation. we have evaluated the in vivo stability of 99tcm-red blood cells (99tcm-rbc) labelled in vitro by preparation with small amounts of a stannous agent in 19 patients with coronary artery disease. the distribution volume of 99tcm-rbc was virtually identical to that of rbc labelled with 51cr. labelling efficiency expressed as th ... | 1986 | 3774253 |
| protein sparing in skeletal muscle during prolonged starvation. dependence on lipid fuel availability. | previous studies indicated that protein sparing in skeletal muscle during prolonged starvation depends on the availability of lipid fuels. to test this relationship further, fasted rats conserving protein were treated in vivo for 6-8 h with the antilipolytic agent nicotinic acid (na) or with tetradecylglycidate (tdgd), an inhibitor of long-chain fatty acid oxidation. after treatment, protein synthesis and degradation in skeletal muscle were evaluated with the perfused rat hindquarter. na treatme ... | 1987 | 3792662 |
| the in vivo effect of indomethacin on ex vivo functioning of cyclo-oxygenase in dental pulp. | | 1985 | 3931072 |
| a sodium ion gradient as energy source for peptostreptococcus asaccharolyticus. | the determination of enzymatic activities in cell-free extracts of acidaminococcus fermentans and peptostreptococcus asaccharolyticus led to a refined scheme for the pathway of glutamate fermentation via (r)-2-hydroxyglutarate to acetate and butyrate. from the ratio of these products the amount of atp generated by substrate level phosphorylation was calculated. growth experiments with the organisms including clostridium symbiosum and clostridium tetanomorphum indicated that a sodium gradient con ... | 1985 | 4037980 |
| effect of polynucleotides on aminoacyl transfer ribonucleic acid synthetases. 3. inhibition of glutamyl transfer ribonucleic acid synthetase by natural polynucleotides. | | 1968 | 4299520 |
| metabolic interlock. regulatory interactions exerted between biochemical pathways. | | 1969 | 4306282 |
| [determination of glutathione reductase activity in normal epidermis]. | | 1972 | 4403523 |
| [anti-complement activity of clofibrinic acid. research in vitro and in vivo]. | | 1974 | 4477476 |
| [clinical and experimental studies on tracheobronchial collapse syndrome (author's transl)]. | | 1974 | 4478896 |
| isolation of acidaminococcus fermentans and megasphaera elsdenii from normal human feces. | fecal bacterial cultures from 40 normal humans yielded megasphaera elsdenii from four individuals and acidaminococcus fermentans from 10 individuals, with two individuals having both organisms. | 1974 | 4589136 |
| two pathways of glutamate fermentation by anaerobic bacteria. | two pathways are involved in the fermentation of glutamate to acetate, butyrate, carbon dioxide, and ammonia-the methylaspartate and the hydroxyglutarate pathways which are used by clostridium tetanomorphum and peptococcus aerogenes, respectively. although these pathways give rise to the same products, they are easily distinguished by different labeling patterns of the butyrate when [4-(14)c]glutamate is used as substrate. schmidt degradation of the radioactive butyrate from c. tetanomorphum yie ... | 1974 | 4813895 |
| acidaminococcus gen. n., acidaminococcus fermentans sp. n., anaerobic gram-negative diplococci using amino acids as the sole energy source for growth. | acidaminococcus gen. n. and the type species acidaminococcus fermentans sp. n. were described. amino acids, of which glutamic acid is the most important, could serve as the sole energy source for growth. acetic and butyric acids and co(2) were produced; propionic acid and hydrogen were not produced. amino acid media supporting growth and the amino acid and vitamin requirements were described. glucose was frequently not fermented or was weakly catabolized. derivative products from glucose autocla ... | 1969 | 5784223 |
| a biotin-dependent sodium pump: glutaconyl-coa decarboxylase from acidaminococcus fermentans. | the decarboxylation of glutaconyl-coa to crotonyl-coa in the anaerobic bacterium acidaminococcus fermentans is catalysed by a membrane-bound, biotin-dependent enzyme which requires na+ for activity. inverted vesicles from a. fermentans accumulated na+ only if glutaconyl-coa was decarboxylated. the na+ uptake was inhibited by avidin but not by the avidin biotin complex. detergents and ionophores such as monensin also prevented the na+ transport. the results indicate that the enzyme is able to con ... | 1982 | 6293874 |
| catabolism of diadenosine 5',5"'-p1,p4-tetraphosphate in procaryotes. purification and properties of diadenosine 5',5"'-p1,p4-tetraphosphate (symmetrical) pyrophosphohydrolase from escherichia coli k12. | enzymatic activity which hydrolyzes diadenosine 5',5"'-p1,p4-tetraphosphate (ap4a) yielding adp has been identified in extracts of eubacteria, escherichia coli and acidaminococcus fermentans, and of a highly thermophilic archaebacterium, pyrodictum occultum. specific ap4a (symmetric) pyrophosphohydrolase from escherichia coli k12 has been purified almost 400-fold. the preparation was free of phosphatase, atpase, phosphodiesterase, amp-nucleosidase, and adenylate kinase. the ap4a pyrophosphohydro ... | 1983 | 6317672 |
| [cefotiam passage into the maxillary sinus tissues]. | clinical study was made on cefotiam (ctm) and the following results were obtained. tissue concentrations of ctm were determined 1 hour after intravenous injection (ctm 1 g) in chronic sinusitis and maxillary cyst. concentrations of ctm were 16.53 micrograms/g, 13.26 micrograms/g in mucosa of the maxillary sinus, maxillary cyst, respectively. antibacterial activity of ctm was measured on escherichia coli, staphylococcus epidermidis, aerococcus, acidaminococcus fermentans, peptostreptococcus anaer ... | 1983 | 6325743 |
| on the dehydration of (r)-lactate in the fermentation of alanine to propionate by clostridium propionicum. | all the enzymes of the pathway of (s)-alanine fermentation to acetate and propionate were detected in cell-free extracts of clostridium propionicum . among these (s)-glutamate dehydrogenase (nad), (r)-lactate dehydrogenase (nad) and propionate coa-transferase were purified to apparent homogeneity. their structures were presumably alpha 6, alpha 2 and alpha 4, respectively. the latter enzyme was specific for short-chain monocarboxylic acids with a pronounced preference for (r)-lactate over the (s ... | 1984 | 6586495 |
| purification, characterisation and reconstitution of glutaconyl-coa decarboxylase, a biotin-dependent sodium pump from anaerobic bacteria. | glutaconyl-coa decarboxylase from acidaminococcus fermentans is a biotin enzyme, which is integrated into membranes. it is activated by triton x-100 and inhibited by avidin. the results obtained by a combination of both agents indicate that biotin and the substrate-binding site are located on the same side of the membrane. the decarboxylase was solubilized with triton x-100 and purified by affinity chromatography on monomeric avidin-sepharose. the enzyme is composed of three types of polypeptide ... | 1983 | 6628393 |
| glutaconate coa-transferase from acidaminococcus fermentans. | 1. glutaconate coa-transferase catalyses the transfer of coas- from acetyl-coa preferentially to (e)-glutaconate, but glutarate, (r)-2-hydroxyglutarate, acrylate and propionate are also good acceptors. no reaction was observed with (z)-glutaconate and c4-dicarboxylic acids. 2. the product of the reaction of acetyl-coa with (e)-glutaconate is the 1-isomer of glutaconyl-coa, i.e. the thiol ester is conjugated with the double bond. other results indicate, however, that with (r)-2-hydroxyglutarate a ... | 1981 | 6945182 |
| the reversible dehydration of (r)-2-hydroxyglutarate to (e)-glutaconate. | 1. during fermentation with whole cells of acidaminococcus fermentans or clostridium microsporum the pro-3s hydrogen of (r)-2-hydroxyglutarate or of its precursor (s)-glutamate is eliminated stereospecifically. since (e)-glutaconate but not its z isomer is fermented by whole cells or cell-free extracts of a. fermentans, the overall dehydration of (r)-2-hydroxyglutarate to (e)-glutaconate can be described as syn. 2. the fermentation of (e)-glutaconate required acetyl phophate, coa and nad, that o ... | 1980 | 7398622 |
| activation of (r)-2-hydroxyglutaryl-coa dehydratase from acidaminococcus fermentans. | (r)-2-hydroxyglutaryl-coa dehydratase (hgdab) from acidaminococcus fermentans catalyses the reversible dehydration of its substrate to glutaconyl-coa. the enzyme has to be activated by atp, mgcl2, and ti(iii)citrate by an activator protein (hgdc) that is present in the organism at very low concentrations. cell-free extracts of a recombinant escherichia coli strain, in which hgdc was expressed, contained the activator with a specific activity of up to 45 u'/mg protein (1 u' is the amount of activ ... | 1995 | 7607244 |
| identification of glutamate beta 54 as the covalent-catalytic residue in the active site of glutaconate coa-transferase from acidaminococcus fermentans. | in the course of glutamate fermentation by acidaminococcus fermentans glutaconate coenzyme a-transferase catalyzes the transfer of coas- from acetyl-coa to (r)-2-hydroxyglutarate, forming (r)-2-hydroxyglutaryl-coa. glutamate (e) 54 of the beta-subunit was postulated to be directly involved in catalysis by formation of a coash ester intermediate [(1994) eur. j. biochem., in press]. in order to prove this preliminary result, the following mutations, beta e54a, beta e64a, beta e54q and beta e54d, w ... | 1995 | 7805881 |
| posex: vectors for osmotically controlled and finely tuned gene expression in escherichia coli. | expression of the prou operon of escherichia coli is directly proportional to the osmolarity of the growth medium. the basal level of prou transcription is very low, but a large increase is triggered by a sudden rise in the external osmolarity. this increased expression is maintained for as long as the osmotic stimulus persists. we have capitalized upon these regulatory features of the prou operon and have constructed a series of expression vectors (posex) permitting osmotically controlled expre ... | 1994 | 7828862 |
| location of the two genes encoding glutaconate coenzyme a-transferase at the beginning of the hydroxyglutarate operon in acidaminococcus fermentans. | glutaconate coenzyme a-transferase (gct) from acidaminococcus fermentans consists of two subunits (gcta, 35725 da and gctb, 29168 da). the n-termini sequences of both subunits were determined. dna sequencing of a subgenomic fragment of a. fermentans revealed that the genes encoding glutaconate coa-transferase (gctab) are located upstream of a gene cluster formed by gcda, hgdc, hgda and hgdb in this order. further upstream of gcta, a dna sequence was detected showing significant similarities to s ... | 1994 | 7957258 |
| rapid diagnosis of anaerobic gram-positive cocci by salt tolerance. | the maximum salt tolerance was 2.5% in cases of peptostreptococcus anaerobius and peptococcus prevotii, 3% in ruminococcus albus, 4% in acidaminococcus fermentans, peptococcus niger and megasphaera elsdenii and 5% in peptococcus magnus. the biochemical tests being largely inactive and time consuming the findings of salt tolerance if combined with those of morphological data provide clue to the rapid identification of gram-positive anaerobic cocci. | 1994 | 7963612 |
| emendation of the description of acidaminococcus fermentans, a trans-aconitate- and citrate-oxidizing bacterium. | ruminal fluid which was enriched with trans-aconitate yielded a gram-negative diplococcus (strain ao) which was identified by 16s ribosomal dna sequence analysis as acidaminococcus fermentans. in contrast to the original description, the a. fermentans type strain and strain ao were found to utilize citrate as an energy source and to produce hydrogen and hydrogen sulfide. the descriptions of the genus and species are emended accordingly. | 1994 | 8068544 |
| ability of acidaminococcus fermentans to oxidize trans-aconitate and decrease the accumulation of tricarballylate, a toxic end product of ruminal fermentation. | mixed ruminal bacteria convert trans-aconitate to tricarballylate, a tricarboxylic acid which chelates blood divalent cations and decreases their availability (j. b. russell and p. j. van soest, appl. environ. microbiol. 47:155-159, 1984). decreases in blood magnesium in turn cause a potentially fatal disease known as grass tetany. trans-aconitate was stoichiometrically reduced to tricarballylate by selenomonas ruminantium, a common ruminal bacterium in grass-fed ruminants (j. b. russell, appl. ... | 1994 | 8074529 |
| identification of the gene encoding the activator of (r)-2-hydroxyglutaryl-coa dehydratase from acidaminococcus fermentans by gene expression in escherichia coli. | (r)-2-hydroxyglutaryl-coa dehydratase (hgda/b) from acidaminococcus fermentans requires an activator protein for activity. this activator (hgdc) has not yet been purified from its natural source due to its low concentration combined with an extreme sensitivity towards oxygen. gene expression in escherichia coli identified an open reading frame (780 bp) as the gene encoding hgdc. dehydratase activity was stimulated at least tenfold by cell-free extracts of e. coli cells transformed with a plasmid ... | 1993 | 8365476 |
| cloning, sequencing and expression of the gene encoding the carboxytransferase subunit of the biotin-dependent na+ pump glutaconyl-coa decarboxylase from acidaminococcus fermentans in escherichia coli. | 1. the primary sodium-ion pump glutaconyl-coa decarboxylase (gcd) from acidaminococcus fermentans is composed of four subunits: gcda, the carboxytransferase (65 kda), gcdb, the carboxylyase (36 kda), gcdc, the biotin carrier (24 kda) and gcdd (14 kda) of unknown function. a genomic library of a. fermentans was screened with an antiserum raised against whole gcd. a clone giving the strongest reaction in an immunoassay contained a 12-kbp genomic fragment from a. fermentans and was analysed further ... | 1993 | 8382157 |
| non-sporing anaerobes in certain surgical group of patients. | the magnitude of non-sparing anaerobic (nsa) infections has been defined in the postoperative wounds on colorectum in children (57.1%), general surgery (0%), abdominoperineal and uterocervical operations (11-45%) in gynaecologic and obstetrical cases and perforative peritonitis (25.8-32.3%). children below the 6 months age group bear less risk of acquiring nsa infection. under certain situations, metronidazole combats nsa infections in a better way than other antibacterials. the bacteriology of ... | 1995 | 8648152 |
| fermentation of trans-aconitate via citrate, oxaloacetate, and pyruvate by acidaminococcus fermentans. | growing cells of acidaminococcus fermentans (dsm 20731 and atcc 25085) fermented trans-aconitate via citrate, oxaloacetate, and pyruvate to approximately 2 co2, 1.8 acetate, 0.1 butyrate and 0.9 h2. the carbon and electron recoveries were close to 100%. on citrate no growth was observed and washed cells were unable to ferment this tricarboxylate. in cell-free extracts, however, citrate as well as trans-aconitate were readily fermented to co2 and acetate. under these conditions, also cis-aconitat ... | 1996 | 8929281 |
| sodium ion-dependent hydrogen production in acidaminococcus fermentans. | acidaminococcus fermentans is able to ferment glutamate to ammonia, co2, acetate, butyrate, and h2. the molecular hydrogen (approximately 10 kpa; e' = -385 mv) stems from nadh generated in the 3-hydroxybutyryl-coa dehydrogenase reaction (e degrees ' = -240 mv) of the hydroxyglutarate pathway. in contrast to growing cells, which require at least 5 mm na+, a na+-dependence of the h2-formation was observed with washed cells. whereas the optimal glutamate fermentation rate was achieved already at 1 ... | 1996 | 8929282 |
| re-face stereospecificity at c4 of nad(p) for alcohol dehydrogenase from methanogenium organophilum and for (r)-2-hydroxyglutarate dehydrogenase from acidaminococcus fermentans as determined by 1h-nmr spectroscopy. | the two diastereotopic protons at c4 of nad(p)h are seen separately in 1h-nmr spectra. this fact was used to determine the stereospecificity at c4 of nad(p) for the nadp-dependent alcohol dehydrogenase from methanogenium organophilum and for the nad-dependent (r)-2-hydroxyglutarate dehydrogenase from acidaminococcus fermentans. the reduction of nadp+ with [2h6]ethanol was found to yield (4r)-[4-2h1]nadph and the oxidation of (4r)-[4-2h1]nadh with 2-oxoglutarate to yield unlabelled [4-1h]nad+. th ... | 1996 | 8980127 |
| glutaconate coa-transferase from acidaminococcus fermentans: the crystal structure reveals homology with other coa-transferases. | coenzyme a-transferases are a family of enzymes with a diverse substrate specificity and subunit composition. members of this group of enzymes are found in anaerobic fermenting bacteria, aerobic bacteria and in the mitochondria of humans and other mammals, but so far none have been crystallized. a defect in the human gene encoding succinyl-coa: 3-oxoacid coa-transferase causes a metabolic disease which leads to severe ketoacidosis, thus reflecting the importance of this family of enzymes. all co ... | 1997 | 9083111 |
| conversion of glutaconate coa-transferase from acidaminococcus fermentans into an acyl-coa hydrolase by site-directed mutagenesis. | the heterooctameric (alphabeta)4 glutaconate coa-transferase (ec 2.8.3.12) from the anaerobic bacterium acidaminococcus fermentans catalyses the transfer of coash from acetyl-coa to the 1-carboxylate of glutaconate. during this reaction the glutamate residue 54 of the beta-subunit (betae54) forms a coa-ester. the single amino acid replacement betae54d resulted in a drastic change of enzymatic function. the coa-transferase activity decreased from 140 to less than 0.01 s(-1), whereas the acyl-coa ... | 1997 | 9089292 |
| genes coding for the benzoyl-coa pathway of anaerobic aromatic metabolism in the bacterium thauera aromatica. | many aromatic compounds are anaerobically oxidized to co2 via benzoyl-coa as the common aromatic intermediate. in thauera aromatica, the central benzoyl-coa pathway comprises the atp-driven two-electron reduction of the benzene ring; this reaction uses a ferredoxin as electron donor and is catalyzed by benzoyl-coa reductase. the first intermediate, cyclohex-1,5-diene-1-carboxyl-coa, is subsequently hydrated by dienoyl-coa hydratase to 6-hydroxycyclohex-1-ene-1-carboxyl-coa. formation of the main ... | 1998 | 9746358 |
| the sodium ion translocating glutaconyl-coa decarboxylase from acidaminococcus fermentans: cloning and function of the genes forming a second operon. | glutaconyl-coa decarboxylase from acidaminococcus fermentans (clostridal cluster ix), a strict anaerobic inhabitant of animal intestines, uses the free energy of decarboxylation (delta g(o) approximately -30 kj mol-1) in order to translocate na+ from the inside through the cytoplasmic membrane. the proton, which is required for decarboxylation, most probably comes from the outside. the enzyme consists of four different subunits. the largest subunit, alpha or gcda (65 kda), catalyses the transfer ... | 1999 | 10027965 |
| oxygen exchange between acetate and the catalytic glutamate residue in glutaconate coa-transferase from acidaminococcus fermentans. implications for the mechanism of coa-ester hydrolysis. | the exchange of oxygen atoms between acetate, glutaryl-coa, and the catalytic glutamate residue in glutaconate coa-transferase from acidaminococcus fermentans was analyzed using [(18)o(2)]acetate together with matrix-assisted laser desorption/ionization time of flight mass spectrometry of an appropriate undecapeptide. the exchange reaction was shown to be site-specific, reversible, and required both glutaryl-coa and [(18)o(2)]acetate. the observed exchange is in agreement with the formation of a ... | 1999 | 10409616 |
| succinispira mobilis gen. nov., sp. nov., a succinate-decarboxylating anaerobic bacterium. | a succinate-decarboxylating anaerobic bacterium, designated strain 19gly1t, was previously isolated from a mixed culture growing with glycolate. the almost complete sequence of the 16s rrna gene (1495 nt) was determined for this strain. on the basis of 16s rrna gene sequence homology, strain 19gly1t was identified as a member of the sporomusa sub-branch of the 'low g+c' gram-positive bacteria. phylogenetic analysis showed that strain 19gly1t was most closely related to succiniclasticum ruminis, ... | 1999 | 10425757 |
| 2-hydroxyglutaryl-coa dehydratase from clostridium symbiosum. | component d (hgdab) of 2-hydroxyglutaryl-coa dehydratase from clostridium symbiosum was purified to homogeneity. it is able to use component a from acidaminococcus fermentans (hgdc) to initiate catalysis together with atp, mg2+ and a strong reducing agent such as ti(iii)citrate. component d from c. symbiosum has a 6 x higher specific activity compared with that from a. fermentans and contains a second [4fe-4s] cluster but the same amount of riboflavin 5'-phosphate (1.0 per heterodimeric enzyme, ... | 1999 | 10491198 |
| the involvement of coenzyme a esters in the dehydration of (r)-phenyllactate to (e)-cinnamate by clostridium sporogenes. | phenyllactate dehydratase from clostridium sporogenes grown anaerobically on l-phenylalanine catalyses the reversible syn-dehydration of (r)-phenyllactate to (e)-cinnamate. purification yielded a heterotrimeric enzyme complex (130 +/- 15 kda) composed of flda (46 kda), fldb (43 kda) and fldc (40 kda). by re-chromatography on q-sepharose, the major part of flda could be separated and identified as oxygen insensitive cinnamoyl-coa:phenyllactate coa-transferase, whereas the transferase depleted tri ... | 2000 | 10849007 |
| comparative in vitro activities of ertapenem (mk-0826) against 1,001 anaerobes isolated from human intra-abdominal infections. | by using an agar dilution method, the comparative in vitro activities of ertapenem (mk-0826) were studied against 1,001 anaerobes isolated from human intra-abdominal infections in 17 countries worldwide. mk-0826 was uniformly active against all isolates, including all bacteroides fragilis group species isolates, with the exception of 12 of 61 (20%) strains of bilophila wadsworthia, 3 strains of lactobacilli, and 1 isolate of acidaminococcus fermentans. geographical variation in activity was not ... | 2000 | 10952584 |
| succinyl-coa:3-ketoacid coa transferase (scot): cloning of the human scot gene, tertiary structural modeling of the human scot monomer, and characterization of three pathogenic mutations. | the activity of succinyl-coa:3-ketoacid coa transferase (scot; locus symbol oxct; ec 2.8.3.5) is the main determinant of the ketolytic capacity of tissues. hereditary scot deficiency causes episodic ketoacidosis. here we describe the human scot gene, which spans more than 100 kb and contains 17 exons, on chromosome 5p13. we report pathogenic missense mutations in three scot-deficient patients designated gs04, 05, and 06. gs04 is a g219e/g324e compound; gs05 is a v221m homozygote, and gs06 is a g ... | 2000 | 10964512 |
| aci-1 from acidaminococcus fermentans: characterization of the first beta-lactamase in anaerobic cocci. | acidaminococcus fermentans belongs to the group of strictly anaerobic gram-negative cocci. all previously described acidaminococcus strains are susceptible to beta-lactam antibiotics. an a. fermentans strain (ryc-mr95) resistant to penicillin and expanded-spectrum cephalosporin (amoxicillin and cefotaxime mics, 64 microgram/ml) was isolated from a human perianal abscess. a fragment encoding a beta-lactamase from genomic dna was cloned in escherichia coli k-12 strain hb101, and the recombinant st ... | 2000 | 11036038 |
| fermentation of 4-aminobutyrate by clostridium aminobutyricum: cloning of two genes involved in the formation and dehydration of 4-hydroxybutyryl-coa. | clostridium aminobutyricum ferments 4-aminobutyrate via succinic semialdehyde, 4-hydroxybutyrate, 4-hydroxybutyryl-coa and crotonyl-coa to acetate and butyrate. the genes coding for the enzymes that catalyse the interconversion of these intermediates are arranged in the order abfd (4-hydroxybutyryl-coa dehydratase), abft (4-hydroxybutyrate coa-transferase), and abfh (nad-dependent 4-hydroxybutyrate dehydrogenase). the genes abfd and abft were cloned, sequenced and expressed as active enzymes in ... | 2000 | 11041350 |
| the iron-sulfur clusters in 2-hydroxyglutaryl-coa dehydratase from acidaminococcus fermentans. biochemical and spectroscopic investigations. | the reversible dehydration of (r)-2-hydroxyglutaryl-coa to (e)-glutaconyl-coa is catalysed by the combined action of two oxygen-sensitive enzymes from acidaminococcus fermentans, the homodimeric component a (2 x 27 kda) and the heterodimeric component d (45 and 50 kda). component a was purified to homogeneity (specific activity 25-30 s-1) using streptavidin-tag affinity chromatography. in the presence of 5 mm mgcl2 and 1 mm adp or atp, component a could be stabilized and stored for 4-5 days at 4 ... | 2000 | 11106419 |
| crystal structure of the acidaminococcus fermentans 2-hydroxyglutaryl-coa dehydratase component a. | acidaminococcus fermentans degrades glutamate via the hydroxyglutarate pathway, which involves the syn-elimination of water from (r)-2-hydroxyglutaryl-coa in a key reaction of the pathway. this anaerobic process is catalyzed by 2-hydroxyglutaryl-coa dehydratase, an enzyme with two components (a and d) that reversibly associate during reaction cycles. component a (compa), a homodimeric protein of 2x27 kda, contains a single, bridging [4fe-4s] cluster and uses the hydrolysis of atp to deliver an e ... | 2001 | 11243821 |
| sodium ion-translocating decarboxylases. | the review is concerned with three na(+)-dependent biotin-containing decarboxylases, which catalyse the substitution of co(2) by h(+) with retention of configuration (deltag degrees '=-30 kj/mol): oxaloacetate decarboxylase from enterobacteria, methylmalonyl-coa decarboxylase from veillonella parvula and propiogenium modestum, and glutaconyl-coa decarboxylase from acidaminococcus fermentans. the enzymes represent complexes of four functional domains or subunits, a carboxytransferase, a mobile al ... | 2001 | 11248185 |
| propionate coa-transferase from clostridium propionicum. cloning of gene and identification of glutamate 324 at the active site. | propionate coa-transferase from clostridium propionicum has been purified and the gene encoding the enzyme has been cloned and sequenced. the enzyme was rapidly and irreversibly inactivated by sodium borohydride or hydroxylamine in the presence of propionyl-coa. the reduction of the thiol ester between a catalytic site glutamate and coa with borohydride and the cleavage by hydroxylamine were used to introduce a site-specific label, which was followed by maldi-tof-ms. this allowed the identificat ... | 2002 | 11784332 |
| molecular characterization of phenyllactate dehydratase and its initiator from clostridium sporogenes. | the heterotrimeric phenyllactate dehydratase from clostridium sporogenes, fldabc, catalyses the reversible dehydration of (r)-phenyllactate to (e)-cinnamate in two steps: (i) coa-transfer from the cofactor cinnamoyl-coa to phenyllactate to yield phenyllactyl-coa and the product cinnamate mediated by flda, a (r)-phenyllactate coa-transferase; followed by (ii) dehydration of phenyllactyl-coa to cinnamoyl-coa mediated by heterodimeric fldbc, a phenyllactyl-coa dehydratase. phenyllactate dehydratase ... | 2002 | 11967068 |
| adenosine triphosphate-induced electron transfer in 2-hydroxyglutaryl-coa dehydratase from acidaminococcus fermentans. | 2-hydroxyglutaryl-coa dehydratase from acidaminococcus fermentans catalyzes the chemical difficult elimination of water from (r)-2-hydroxyglutaryl-coa to glutaconyl-coa. the enzyme consists of two oxygen-sensitive protein components, the homodimeric activator (a) with one [4fe-4s]1+/2+ cluster and the heterodimeric dehydratase (d) with one nonreducible [4fe-4s]2+ cluster and reduced riboflavin 5'-monophosphate (fmnh2). for activation, atp, mg2+, and a reduced flavodoxin (16 kda) purified from a. ... | 2002 | 11980491 |
| ammonia production by ruminal microorganisms and enumeration, isolation, and characterization of bacteria capable of growth on peptides and amino acids from the sheep rumen. | excessive nh(3) production in the rumen is a major nutritional inefficiency in ruminant animals. experiments were undertaken to compare the rates of nh(3) production from different substrates in ruminal fluid in vitro and to assess the role of asaccharolytic bacteria in nh(3) production. ruminal fluid was taken from four rumen-fistulated sheep receiving a mixed hay-concentrate diet. the calculated rate of nh(3) production from trypticase varied from 1.8 to 19.7 nmol mg of protein(-1) min(-1) dep ... | 2002 | 12324340 |
| diet influences the ecology of lactic acid bacteria and escherichia coli along the digestive tract of cattle: neural networks and 16s rdna. | in this manuscript, the authors have sought to gain a better understanding of the interactions between escherichia coli and lactic acid bacteria (lab) isolated from rogossa mrs agar along the digestive tract of grain- and forage-fed cattle. e. coli from cattle receiving a high-grain diet were more numerous (p<0.05) than from the high-forage diet and the highest numbers were in the faeces. isolates on rogossa mrs agar were always greater in the high-grain diet (p<0.05) and contained a significant ... | 2003 | 12576580 |
| a two [4fe-4s]-cluster-containing ferredoxin as an alternative electron donor for 2-hydroxyglutaryl-coa dehydratase from acidaminococcus fermentans. | the key step in the fermentation of glutamate by acidaminococcus fermentans is a reversible syn-elimination of water from ( r)-2-hydroxyglutaryl-coa to ( e)-glutaconyl-coa catalyzed by 2-hydroxyglutaryl-coa dehydratase, a two-component enzyme system. the actual dehydration is mediated by component d, which contains 1.0 [4fe-4s](2+) cluster, 1.0 reduced riboflavin-5'-phosphate and about 0.1 molybdenum (vi) per heterodimer. the enzyme has to be activated by the extremely oxygen-sensitive [4fe-4s]( ... | 2003 | 12610725 |
| crystal structure of the carboxyltransferase subunit of the bacterial sodium ion pump glutaconyl-coenzyme a decarboxylase. | glutaconyl-coa decarboxylase is a biotin-dependent ion pump whereby the free energy of the glutaconyl-coa decarboxylation to crotonyl-coa drives the electrogenic transport of sodium ions from the cytoplasm into the periplasm. here we present the crystal structure of the decarboxylase subunit (gcdalpha) from acidaminococcus fermentans and its complex with glutaconyl-coa. the active sites of the dimeric gcdalpha lie at the two interfaces between the mono mers, whereas the n-terminal domain provide ... | 2003 | 12853465 |
| a 49 kda microtubule cross-linking protein from artemia franciscana is a coenzyme a-transferase. | embryos and larvae of the brine shrimp, artemia franciscana, were shown previously to possess a protein, now termed p49, which cross-links microtubules in vitro. molecular characteristics of p49 were described, but the protein's identity and its role in the cell were not determined. degenerate oligonucleotide primers designed on the basis of peptide sequence obtained by edman degradation during this study were used to generate p49 cdnas by rt-pcr and these were cloned and sequenced. comparison w ... | 2003 | 14653822 |
| dehydration of (r)-2-hydroxyacyl-coa to enoyl-coa in the fermentation of alpha-amino acids by anaerobic bacteria. | several clostridia and fusobacteria ferment alpha-amino acids via (r)-2-hydroxyacyl-coa, which is dehydrated to enoyl-coa by syn-elimination. this reaction is of great mechanistic interest, since the beta-hydrogen, to be eliminated as proton, is not activated (pk 40-50). a mechanism has been proposed, in which one high-energy electron acts as cofactor and transiently reduces the electrophilic thiol ester carbonyl to a nucleophilic ketyl radical anion. the 2-hydroxyacyl-coa dehydratases are two-c ... | 2004 | 15374661 |
| structural basis for stereo-specific catalysis in nad(+)-dependent (r)-2-hydroxyglutarate dehydrogenase from acidaminococcus fermentans. | nad(+)-dependent (r)-2-hydroxyglutarate dehydrogenase (hgdh) catalyses the reduction of 2-oxoglutarate to (r)-2-hydroxyglutarate and belongs to the d-2-hydroxyacid nad(+)-dependent dehydrogenase (d-2-hydroxyacid dehydrogenase) protein family. its crystal structure was determined by phase combination to 1.98 a resolution. structure-function relationships obtained by the comparison of hgdh with other members of the d-2-hydroxyacid dehydrogenase family give a chemically satisfying view of the subst ... | 2005 | 15634349 |
| dual mechanisms of tricarboxylate transport and catabolism by acidaminococcus fermentans. | acidaminococcus fermentans utilized citrate or the citrate analog aconitate as an energy source for growth, and these tricarboxylates were used simultaneously. citrate utilization and uptake showed biphasic kinetics. high-affinity citrate uptake had a k(t) of 40 mum, but the v(max) was only 25 nmol/mg of protein per min. low-affinity citrate utilization had a 10-fold higher v(max), but the k(s) was greater than 1.0 mm. aconitate was a competitive inhibitor (k(i) = 34mum) of high-affinity citrate ... | 1994 | 16349331 |
| sodium ion pumps and hydrogen production in glutamate fermenting anaerobic bacteria. | anaerobic bacteria ferment glutamate via two different pathways to ammonia, carbon dioxide, acetate, butyrate and molecular hydrogen. the coenzyme b12-dependent pathway in clostridium tetanomorphum via 3-methylaspartate involves pyruvate:ferredoxin oxidoreductase and a novel enzyme, a membrane-bound nadh:ferredoxin oxidoreductase. the flavin- and iron-sulfur-containing enzyme probably uses the energy difference between reduced ferredoxin and nadh to generate an electrochemical na+ gradient, whic ... | 2005 | 16645308 |
| acidaminococcus intestini sp. nov., isolated from human clinical samples. | eleven strains of a hitherto unknown, gram-negative, anaerobic coccus were recovered from various human clinical samples of patients hospitalized in two geographically distant french hospitals. these strains displayed the morphology and growth characteristics of those related to the genus acidaminococcus. the clinical isolates shared at least 99.9 and 99.7 % of their nucleotide positions in the 16s and 23s rrna gene sequences, respectively. they displayed 95.6 and 88.9 % 16s and 23s rrna gene se ... | 2007 | 17911303 |