Publications

TitleAbstractYear
Filter
PMID(sorted ascending)
Filter
the cytochrome c oxidase of paracoccus denitrificans pumps protons in a reconstituted system.the purified two-subunit cytochrome c oxidase of paracoccus denitrificans was reconstituted into phospholipid vesicles having a high internal buffering capacity and exhibiting a respiratory control index greater than 6.6. with these proteoliposomes, ph changes of the suspending medium were monitored in response to reductant pulses in the presence of valinomycin and potassium. when reduced cytochrome c was added to allow for a limited number of turnovers (2-12), a net acidification of the extrave ...19826276393
changes in the cytochrome c content during the aerobic adaptation of paracoccus denitrificans.concentration of cytochrome c decreases when shaking anaerobically grown cells in a non-growth medium down to 50% of the original amount in the cell, depending on the degree of aeration. only 10-20% of this amount can be found in the adaptation medium. the main portion of cytochrome c is degraded during the adaptation. inhibitors of proteinases do not influence the degradation. addition of mammalian cytochrome c fully prevents the degradation of bacterial cytochrome c but not its release from ce ...19826277754
solubilized cytochrome c oxidase from paracoccus denitrificans is a monomer.cytochrome c oxidase purified from the bacterium paracoccus denitrificans was analyzed by analytical ultracentrifugation. in the detergent octyltetra/pentaoxyethylene (c8e45), the isolated enzyme exhibits a molecular weight of 79,000 to 84,000. the detergent-solubilized enzyme is thus a monomer which contains one copy of each of the two subunits.19826279605
isolation of paracoccus denitrificans cytochrome cd1: comparative kinetics with other nitrite reductases. 19826284044
purification and characterization of the cytochrome c oxidase from rhodopseudomonas sphaeroides.when grown aerobically in the dark, rhodopseudomonas sphaeroides develops a respiratory chain similar to that in mitochondria and the photosynthetic apparatus is suppressed. the aa3-type cytochrome c oxidase from rps. sphaeroides has been purified in triton x-100 by affinity chromatography with sepharose 4b coupled to yeast cytochrome c. the oxidase contains 14 nmol heme a/mg protein and is composed of three polypeptide subunits with relative molecular masses of 45000, 37000 and 35000. the enzym ...19826286309
microbial envelope proteins related to iron. 19826293371
turnover of cytochrome c oxidase from paracoccus denitrificans.the heme aa3 type cytochrome oxidase from paracoccus denitrificans incorporated into vesicles with phospholipid reacts during turnover much as the oxidase from mitochondria does. the spectrophotometric changes observed at various wavelengths are closely similar, and the rate is about one-half of that for beef heart oxidase under the same conditions. the rate of appearance of oxidized cytochrome c on initiation of the reaction is also similar and depends on the previous treatment of the oxidase a ...19836296100
the distribution of redox equivalents in the anaerobic respiratory chain of paracoccus denitrificans. 19836297904
electrochemically driven respiration in mitochondria and paracoccus denitrificans. the coupling of the electrochemistry of horse heart cytochrome c with respiration in mitochondria and a model thereof, paracoccus denitrificans.by exploiting the rapid, direct electrochemistry of horse heart cytochrome c at a modified gold electrode it has been possible to couple the electrode reaction with respiration in rat liver mitochondria and in protoplasts of paracoccus denitrificans, but not in protoplasts from e. coli. oxidation of endogenous and exogenous sources of reducing equivalents via cytochrome c is also observed.19836299804
characterisation of membrane vesicles from paracoccus denitrificans and measurements of the effect of partial uncoupling on their thermodynamics of oxidative phosphorylation.1. vesicles from paracoccus denitrificans were prepared by applying an osmotic shock to spheroplasts derived from cells that had been grown anaerobically with succinate as carbon source and nitrate as electron acceptor. in the presence of either phenazinemethosulphate or n,n,n' n',-tetramethyl-p-phenylenediamine, the oxidation of isoascorbate supported the uptake of both s14cn- and 86rb+ (in the presence of valinomycin), whereas nadh and succinate oxidation resulted only in s14cn- uptake. these ...19836301833
the effects of partial uncoupling upon the kinetics of atp synthesis by vesicles from paracoccus denitrificans and by bovine heart submitochondrial particles. implications for the mechanism of the proton-translocating atp synthase.1. reduction in the magnitude of the respiration-dependent protonmotive force (proton electrochemical gradient in mv) of vesicles from paracoccus denitrificans, and of submitochondrial particles, has been found to be paralleled small increases in s50% values for both adp and pi. for example, reduction of the protonmotive force of p. denitrificans vesicles from 145 mv to 110 mv was accompanied by an increase of s50% (adp) from 8 microm to 18 microm, and an increase of s50% (pi) from 0.33 mm to 1. ...19836301834
dicyclohexylcarbodiimide does not inhibit proton pumping by cytochrome c oxidase of paracoccus denitrificans.the effect of dicyclohexylcarbodiimide (dccd) on the proton pumping two-subunit cytochrome c oxidase from paracoccus denitrificans was investigated. purified paracoccus oxidase was reconstituted into phospholipid vesicles by cholate dialysis. following incubation with increasing amounts of dccd, proton ejection was recorded in response to reductant pulses with reduced cytochrome c. concentrations of dccd which greatly reduced proton pumping by bovine cytochrome c oxidase used as a control were f ...19836305656
receptor sites involved in posttranslational transport of apocytochrome c into mitochondria: specificity, affinity, and number of sites.assembly of cytochrome c involves a series of steps: synthesis of apocytochrome c on free ribosomes, specific binding of apocytochrome c to the mitochondrial surface, transfer across the outer membrane, covalent addition of protoheme, refolding of the polypeptide chain, and association of holocytochrome c with its functional sites at the inner membrane. the binding step of apocytochrome c to neurospora crassa mitochondria was studied by inhibiting the subsequent transfer steps with the heme anal ...19836308663
proton translocation during denitrification by a nitrifying--denitrifying alcaligenes sp.a heterotrophic nitrifying alcaligenes sp. from soil was grown as a denitrifier on nitrate and subjected to oxidant pulse experiments to ascertain the apparent efficiencies of proton translocations during o2 and nitrogen-oxide respirations. with endogenous substrate as the reducing agent the leads to h+/2e- ratios, extrapolated to zero amount of oxidant per pulse, were 9.4, 3.7, 4.3 and 3.5 for o2, nitrate, nitrite and n2o, respectively. the value for o2 and those for the n-oxides are, respectiv ...19836311094
production, isolation and characterization of monoclonal antibodies to cytochromes c of beef heart and paracoccus denitrificans.hybridoma cell lines secreting monoclonal antibodies which bind beef heart cytochrome c or paracoccus denitrificans cytochrome c have been produced using spleen cells from balb/c mice immunized with cytochrome c. immunization was performed with either the native cytochrome c, succinylated hemocyanin-conjugated cytochrome c, or beef heart cytochrome c polymerized with glutaraldehyde. of 10 such fusions, the hybridization frequency ranged from 0 to 42%. the cell fusion efficiency, the possible fac ...19836312296
sequence homology of bacterial and mitochondrial cytochrome c oxidases. partial sequence data of cytochrome c oxidase from paracoccus denitrificans.the aerobic electron transport chain of paracoccus denitrificans is very similar to that of mitochondria. it has therefore been suggested that this bacterium might be evolutionarily related to mitochondria. the two subunits (mr 45.000 and 28.000) of the paracoccus cytochrome c oxidase were isolated and partially sequenced. the sequences were found to be surprisingly homologous to sequences of the subunits i and ii of mitochondrial cytochrome c oxidases. the data provide a molecular basis for the ...19836315007
reaction of cytochrome c in the electron-transport chain of paracoccus denitrificans.the reaction of the cytochrome c oxidase (ferrocytochrome c:oxygen oxidoreductase, ec 1.9.3.1) of paracoccus denitrificans cytoplasmic membranes with the endogenous cytochrome c of the membranes was studied, as well as its interaction with added exogenous cytochrome c from p. denitrificans or bovine heart. the polarographic method was employed, using n,n,n',n'-tetramethyl-p-phenylenediamine plus ascorbate to reduce the cytochrome c. we found that overall electron transport can proceed maximally ...19836315059
atp-amp phosphotransferase from paracoccus denitrificans.adenylate kinase has been extracted from paracoccus denitrificans by toluene treatment and purified 370-fold (overall yield of 44%, 554 u/mg, mr 22 000, pi 4.7; ph optimum 7.5-8.0) by using successive column chromatography on deae-cellulose de-52, matrex-blue a and sephadex g-75. the enzyme was homogeneous by dodecylsulfate gel electrophoresis and constancy of specific activity across the single peak found in sephadex g-75 chromatography. crystals in the form of heavy needles have been obtained ...19836315432
cytochrome c1 from paracoccus denitrificans.cytochrome c1 was purified from the bacterium paracoccus denitrificans. it is an acidic, hydrophobic polypeptide with an apparent molecular weight of around 65000 and a single, covalently attached heme; it cross-reacts immunologically with cytochrome c1 from yeast mitochondria. the amino acid sequence of the tryptic heme peptide of the bacterial cytochrome c1 shows extensive homology to the corresponding region of beef heart cytochrome c1 [wakabayashi, s. et al. (1982) j. biol. chem. 257, 9335-9 ...19836319128
denitrification and nitrite reduction: pseudomonas aeruginosa nitrite-reductase.present knowledge of the different enzymatic steps of the denitrification chains in various bacteria, particularly paracoccus denitrificans and pseudomonas aeruginosa has been briefly reviewed. the question whether nitric oxide (no), nitrous oxide (n2o) and other nitrogen derivatives are obligatory intermediates has been discussed. the second part is an extensive review of the structure and the function of a key enzyme in denitrification, cytochrome c551-nitrite-oxidoreductase from p. aeruginosa ...19846331530
comparison of denitrification by pseudomonas stutzeri, pseudomonas aeruginosa, and paracoccus denitrificans.a comparison was made of denitrification by pseudomonas stutzeri, pseudomonas aeruginosa, and paracoccus denitrificans. although all three organisms reduced nitrate to dinitrogen gas, they did so at different rates and accumulated different kinds and amounts of intermediates. their rates of anaerobic growth on nitrate varied about 1.5-fold; concomitant gas production varied more than 8-fold. cell yields from nitrate varied threefold. rates of gas production by resting cells incubated with nitrat ...19836407395
proposed structure for the noncovalently associated heme prosthetic group of dissimilatory nitrite reductases. identification of substituents.the substituents of the noncovalently associated heme prosthetic group of the bacterial nitrite reductase-cytochrome oxidase (ec 1.9.6.1 or ec 1.9.3.2.) from pseudomonas aeruginosa (atcc 19429) and paracoccus denitrificans (atcc 13456) have been identified. this was accomplished by 1h nmr, infrared, visible, and mass spectroscopic techniques applied to semi-purified heme and purified methyl ester derivatives of the iron-free porphyrin. the main structural features are as follows. 1) the macrocyc ...19846420411
immunochemical identification of a two-subunit nadh-ubiquinone oxidoreductase from paracoccus denitrificans.analysis by crossed-immunoelectrophoresis of paracoccus denitrificans membrane vesicles has shown that only one antigen stains for nadh dehydrogenase activity. this activity could be partially purified by a combination of gel filtration and ion-exchange chromatography of membrane vesicles that had been solubilised in the non-ionic detergent nonidet p-40. from the limited number of precipitates observed after crossed immunoelectrophoresis of this partially purified preparation of nadh dehydrogena ...19846434308
the intracellular na+ and k+ composition of the moderately halophilic bacterium, paracoccus halodenitrificans.the intracellular concentrations of na+ and k+ in exponentially growing paracoccus halodenitrificans were independent of the nacl concentration of the growth medium. the observed values were approximately 100 and 300 mm for na+ and k+, respectively. in stationary phase cells, the ultimate values for na+ depended on the nacl concentration of the growth medium. with cells grown in the presence of 1 m nacl, the value was about 500 mm; for cells grown in the presence of 3 m nacl, the value was about ...19806445774
reduction of dl-selenocystine and isolation of l-seleoncysteine.cystine, selenocytsine, and several analogs were reduced by dithiothreitol (dtt), beta-mercaptoethanol (me) and sodium borohydride (nabh4). dtt was the most effective; dtt to cystine ratios from 10 to 80 were equally effective. with selenocysteine, however, absorption was considerably reduced at all ratios. selenocysteine was identified as the reduction product by reaction with gaitonde's reagent, comparison of absorption spectra, paper chromatograhy, utilization by cysteinyl-trna synthetase fro ...19806447770
microbial growth associated with granular activated carbon in a pilot water treatment facility.the microbial dynamics associated with granular activated carbon (gac) in a pilot water treatment plant were investigated over a period of 16 months. microbial populations were monitored in the influent and effluent waters and on the gac particles by means of total plate counts and atp assays. microbial populations between the influent and effluent waters of the gac columns generally increased, indicating microbial growth. the dominant genera of microorganisms isolated from interstitial waters a ...19836625567
presence of a new cytochrome b - like pigment with a peak at 567 nm in various aerobic bacteria.several physiological groups of bacteria were examined for the presence of a cytochrome b - like pigment which is demonstrable in dithionite-reduced minus substrate-reduced difference spectra. this pigment is characterized by an unusually high alpha band at 567 nm, a low concentration relative to conventional cytochromes, and an inability to be fully reduced by endogenous substrates or nadh. previous studies with one denitrifying and nondenitrifying species of the genus pseudomonas, in paracoccu ...19836652580
the effect of uncoupler on the distribution of the electron flow between the terminal acceptors oxygen and nitrite in the cells of paracoccus denitrificans.the preferential utilization of oxygen, the terminal acceptor, in anaerobically grown cells of paracoccus denitrificans was abolished in the presence of uncoupler (3 microm carbonyl cyanide m-chlorophenylhydrazone) which brought about a switch to the reduction of nitrite. it has been proved by measuring the redox state of cytochromes that this effect is due to the inhibition of the electron flow to oxygen caused by nitrite, which attains the site of its inhibitory action when the membrane potent ...19836661222
the function of cytoplasmic membrane of paracoccus denitrificans in controlling the rate of reduction of terminal acceptors.the rate of reduction of terminal acceptors (nitrate, nitrite, and oxygen) in anaerobically grown cells of paracoccus denitrificans increased on permeabilization of cytoplasmic membrane. it was proved that under aerobic conditions the increase of the rate of nitrate reduction was caused by: (i) the abolishment of the permeability barrier for nitrate, (ii) the enhancement of the influx of redox equivalents to the respiratory chain due to the stimulation of succinate dehydrogenase reaction, and (i ...19836684550
the effect of oxygen on denitrification during steady-state growth of paracoccus halodenitrificans.steady-state cultures of paracoccus halodenitrificans were grown anaerobically prior to establishing steady states at different concentrations of oxygen. in the absence of oxygen, nitrate-limited cultures produced dinitrogen, and as the oxygen supply increased, these cultures produced nitrous oxide, then nitrite. these changes reflected two phenomena: the inactivation of nitrous oxide reductase by oxygen and the diversion of electrons from nitrite to oxygen.19846712418
a dissimilatory nitrite reductase in paracoccus halodenitrificans.paracoccus halodenitrificans produced a membrane-associated nitrite reductase. spectrophotometric analysis showed it to be associated with a cd-cytochrome and located on the inner side of the cytoplasmic membrane. when supplied with nitrite, membrane preparations produced nitrous oxide and nitric oxide in different ratios depending on the electron donor employed. the nitrite reductase was maximally active at relatively low concentrations of sodium chloride and remained attached to the membranes ...19846712419
nitrous oxide reductase and the 120,000 mw copper protein of n2-producing denitrifying bacteria are different entities.zumft and matsubara [1982) febs lett. 148, 107-112) isolated a 120,000 mw copper protein from certain denitrifying bacteria which were capable of producing n2. the presence of this protein correlated with a nutritional requirement of copper for growth on and reduction of n2o by the bacteria. the copper protein was alleged by these workers to be nitrous oxide reductase. however, it is shown that the copper protein and nitrous oxide reductase have different molecular weights and exhibit different ...19846712645
heterotrophic nitrification among denitrifiers.twelve denitrifying bacteria representing six genera were tested for an ability to nitrify pyruvic oxime heterotrophically. six of these bacteria exhibited appreciable nitrification activity, yielding as much as 5.8 mm nitrite and little or no nitrate when grown in a mineral salts medium containing 7 mm pyruvic oxime and 0.05% yeast extract. of the six active bacteria, four (pseudomonas denitrificans, pseudomonas aeruginosa, and two strains of pseudomonas fluorescens) could grow on yeast extract ...19846721486
on the effects of thiocyanate and venturicidin on respiration-driven proton translocation in paracoccus denitrificans.a fast-responding o2 electrode has been used to confirm and extend observations of a significant kinetic discrepancy between o2 reduction and consequent proton translocation in 'o2-pulse' experiments in intact cells of p. denitrificans. the permeant, chaotropic scn- ion abolishes this discrepancy, and greatly increases the observable----h+/o ratio, to a value approaching its accepted, true, limiting stoichiometry. the observable h+ decay rates are very slow, particularly in the absence of scn-. ...19846743650
the bioenergetics of denitrification.in anaerobically grown paracoccus denitrificans the dissimilatory nitrate reductase is linked to the respiratory chain at the level of cytochromes b. electron transport to nitrite and nitrous oxide involves c-type cytochromes. during electron transport from nadh to nitrate one phosphorylation site is passed, whereas two sites are passed during electron transport from nadh to oxygen, nitrite and nitrous oxide. the presentation of a respiratory chain as a linear array of electron carriers gives a ...19826762847
evolution of bacterial denitrification and denitrifier diversity.little is known about the role of nitrate in evolution of bacterial energy-generating mechanisms. denitrifying bacteria are commonly regarded to have evolved from nitrate-respiring bacteria. some researchers regard denitrification to be the precursor of aerobic respiration; others feel the opposite is true. currently recognized denitrifying bacteria such as hyphomicrobium, paracoccus, pseudomonas and thiobacillus form a very diverse group. however, inadequate testing procedures and uncertain tax ...19826762849
semimicro extraction of ubiquinone and menaquinone from bacteria. 19806767895
inhibition, but not uncoupling, of respiratory energy coupling of three bacterial species by nitrite.the effect of nitrite on respiratory energy coupling of three bacteria was studied in light of a recent report that nitrite acted as an uncoupling agent with paracoccus denitrificans grown under denitrifying conditions. our determinations of proton translocation stoichiometry of pseudomonas putida (aerobically grown), pseudomonas aeruginosa, and p. denitrificans (grown both aerobically and under denitrifying conditions) showed nitrite inhibition of proton-to-oxidant stoichiometry, but not uncoup ...19806777373
mode of action of copper complexes of some 2,2'-bipyridyl analogs on paracoccus denitrificans.copper complexes of 2,2'-bipyridyl and related compounds and cuso4 inhibited the growth of paracoccus denitrificans. the copper(i) complex of 2,9-dimethyl-1,10-phenanthroline [cu(dmp)2no3] showed the highest activity, whereas the copper(ii) complex of 1,10-phenanthroline and cuso4 inhibited the growth to a lesser extent. the uncomplexed ligands (1,10-phenanthroline and 2,9-dimethyl-1,10-phenanthroline) showed little activity, but in the presence of noninhibitory amounts of cuso4 this activity in ...19806778379
15n,18o tracer studies on the activation of nitrite by denitrifying bacteria. nitrite/water-oxygen exchange and nitrosation reactions as indicators of electrophilic catalysis. 19826806292
patterns of nucleotide utilisation in bacterial succinate thiokinases. 19826811321
the pathway of nitrogen and reductive enzymes of denitrification.some recent studies on the pathway of nitrogen and the reductases of denitrification are reviewed. the available evidence suggests that while the intermediates of denitrification can remain enzyme-bound (presumably to nitrite reductase) prior to formation of n2o, no and nitroxyl (hno) can be released in part by certain bacteria. release of no is recognized by a nitrite/no-15n exchange reaction and isotopic scrambling in product n2o; release of nitroxyl by pseudomonas stutzeri is recognized by is ...19826820251
15n-tracer and nmr studies on the pathway of denitrification. evidence against trioxodinitrate but for nitroxyl as an intermediate.the effects of four species of denitrifying bacteria on the conversion of [15n]nitrite to trioxodinitrate (hn2o3-) and n2o and of trioxodinitrate to n2o were studied. for all species, the n2o produced in the presence of [15n]nitrite and trioxodinitrate was isotopically randomized throughout the period of incubation and was not composed at the outset predominantly of 14n2o or 14n2o plus 15n2o. the n2o produced was also heavily enriched in 15n at times when the trioxodinitrate pool was only weakly ...19836833215
consensus structure and evolution of 5s rrna.a consensus structure model of 5s rrna presenting all conserved nucleotides in fixed positions has been deduced from the primary and secondary structure of 71 eubacterial, archaebacterial, eukaryotic cytosolic and organellar molecules. phylogenetically related groups of molecules are characterized by nucleotide deletions in helices iii, iv and v, and by potential base pair interactions in helix iv. the group-specific deletions are correlated with the early branching pattern of a dendrogram calcu ...19836835839
phosphate transport system in paracoccus denitrificans.pi uptake in cells or spheroplasts of paracoccus denitrificans is biphasic; only the first rapid phase represents net pi transport. the second phase is limited by the rate of pi utilization inside the cell, i.e., mainly by its esterification, and as such it was inhibited by dccd. the pi/dicarboxylate antiporter does not seem to be operative, and its inhibitor n-butylmalonate did not exert specific inhibition. pi transport is inhibited by sh reagents; the most potent inhibitor is pcmb, and mersal ...19836853472
saturation behavior of the manganese-containing superoxide dismutase from paracoccus denitrificans.a pulse radiolysis study of the mn-superoxide dismutase from paracoccus denitrificans has shown that, at concentration of 0(2)-. below 0.8 x 10(-4)m, the catalyzed dismutation of 0(2)-. is a first order reaction with regard to 0(2)-.. at concentration of 0(2)-. above 0.8 x 10(-4)m, the mn-superoxide dismutase is shown to catalyze superoxide dismutation with a mechanism which exhibits saturation kinetics. this behavior was previously found in the bovine cu/zn-superoxide dismutase and in the fe-su ...19836860328
aspects of the control and organization of bacterial electron transport. 19826890481
alterations in the phospholipid composition of rhodopseudomonas sphaeroides and other bacteria induced by tris.alterations in the phospholipid head group composition of most strains of rhodopseudomonas sphaeroides, as well as rhodopseudomonas capsulata and paracoccus denitrificans, occurred when cells were grown in medium supplemented with tris. growth of r. sphaeroides m29-5 in tris-supplemented medium resulted in the accumulation of n-acylphosphatidylserine (naps) to as much as 40% of the total whole-cell phospholipid, whereas naps represented approximately 28 an 33% of the total phospholipid when r. c ...19826982264
orientation of hydrogenase in the plasma membrane of paracoccus denitrificans. 19806993232
the regulation of hydrogenase formation as a differentiating character of strains of paracoccus denitrificans.paracoccus denitrificans strains stanier 381 (dsm 65), morris (dsm 413), and vogt 11 (dsm 415) and eleven newly isolated strains were compared with respect to the localization of hydrogenase and its regulation. in all strains hydrogenase was found to be membrane-bound and not able to reduce pyridine nucleotides. the enzyme was inducible in strain 381 and was found only in cells grown with hydrogen as the sole hydrogen donor; in cells grown under mixotrophic or heterotrophic conditions the hydrog ...19807002036
the implication of the topography of dissimilatory nitrite reductase and methanol dehydrogenase in paracoccus denitrificans. 19817011869
the gradostat: a bidirectional compound chemostat and its application in microbiological research.a multistage continuous culture system is described in which solutes are transferred between vessels in opposite directions simultaneously. the system, called a gradostat, produces opposing solute gradients and is a good laboratory model of many natural microbial ecosystems in which solute gradients are important. theoretical predictions concerning solute transfer were confirmed under steady-state and non steady-state conditions, using a coloured dye. paracoccus denitrificans grew anaerobically ...19817045277
oxygen tolerance of strictly aerobic hydrogen-oxidizing bacteria.growth of various bacteria, especially aerobic hydrogen-oxidizing bacteria, in the presence of 2 to 100% (v/v) oxygen in the gas atmosphere was evaluated. the bacterial strains included alcaligenes eutrophus, a. paradoxus, aquaspirillum autotrophicum, arthrobacter spec. strain 11 x, escherichia coli, arthrobacter globiformis, nocardia opaca, n. autotrophica, paracoccus denitrificans, pseudomonas facilis, p. putida, and xanthobacter autotrophicus. under heterotrophic conditions with fructose or g ...19827049081
isolation and characterization of a protein with cyanide-sensitive superoxide dismutase activity from the prokaryote, paracoccus denitrificans.1. a protein with cyanide-sensitive superoxide dismutase activity was isolated from the prokaryote paracoccus denitrificans. 2. this enzyme, present in low amount in the cell, represented not more than 10% of the total cellular superoxide dismutase activity. it was obtained in a form which was 20-40-times less active than the main superoxide dismutase of p. denitrificans which is a manganese-containing enzyme. 3. it was a soluble monomeric enzyme, highly negatively charged (pi = 4.8), with an ap ...19827066332
electron transport-linked nitrous oxide synthesis and reduction by paracoccus denitrificans monitored with an electrode. 19827073731
a novel inhibitor of nadh dehydrogenase in paracoccus denitrificans. 19827084467
the 5s ribosomal rnas of paracoccus denitrificans and prochloron.the nucleotide sequences of the 5s rrnas of paracoccus denitrificans and prochloron sp. are (formula: see text), respectively. specific phylogenetic relationships of p. denitrificans with purple non-sulphur bacteria, and of prochloron with cyanobacteria are demonstrated, and unique features of potential secondary structure are described.19827099971
proton translocation and proline uptake associated with reduction of nitric oxide by denitrifying paracoccus denitrificans. 19827138549
tetraphenylborate-sensitive electrode for measuring membrane potential.the paper describes the construction of a new type of ion-selective electrode sensitive to tetraphenylborate (tpb-) and its electric characteristics. the electrode responds to increasing concentrations of the tpb- anion in accordance with the nernst equation and can be used down to 0.1 microm concentration. the applicability of the electrode for measuring the membrane potential (positive inside) was proved in inside-out oriented membrane vesicles derived from paracoccus denitrificans. the calcul ...19827173748
benzyl viologen cation radical: first example of a perfectly selective anion ionophore of the carrier type. 19827181886
proton-coupled energy transduction by biological membranes. principles, pathways and praxis. 19827183456
induction of nitrate reductase and membrane cytochromes in wild type and chlorate-resistant paracoccus denitrificans.an experimental system has been devised for induction of nitrate reductase in suspensions of wild type paracoccus denitrificans incubated with limited aeration in the presence of azide, nitrate or nitrite. azide promoted maximum synthesis of enzyme, accompanied by formation of excess b-type cytochrome; the level of enzyme attained with nitrate was less and c-type cytochrome predominated in the membrane. the nitrate reductase was solubilized with deoxycholate from membranes of azide-induced cells ...19807192081
effects of molybdenum and tungsten on induction of nitrate reductase and formate dehydrogenase in wild type and mutant paracoccus denitrificans.molybdenum is required for induction of nitrate reductase and of nad-linked formate dehydrogenase activities in suspensions of wild type paracoccus denitrificans; tungsten prevents the development of these enzyme activities. the wild type forms a membrane protein mr150,000 when incubated with tungsten and inducers of nitrate reductase and this is presumed to represent an inactive form of the enzyme. suspensions of mutuant m-1 did not develop nitrate reductase or formate dehydrogenase activities ...19807192082
the location of dissimilatory nitrite reductase and the control of dissimilatory nitrate reductase by oxygen in paracoccus denitrificans.1. a method is described for preparing spheroplasts from paracoccus denitrificans that are substantially depleted of dissimilatory nitrate reductase (cytochrome cd) activity. treatment of cells with lysozyme + edta together with a mild osmotic shock, followed by centrifugation, yielded a pellet of spheroplasts and a supernatant that contained d-type cytochrome. the spheroplasts were judged to have retained an intact plasma membrane on the basis that less than 1% of the activity of a cytoplasmic ...19807197918
a manganese-containing superoxide dismutase from paracoccus denitrificans.a cyanide-insensitive superoxide dismutase (superoxide: superoxide dismutase ec 1.15.1.1) has been isolated from paracoccus denitrificans, purified to homogeneity and characterized. it is a soluble, manganese-containing protein with an apparent molecular weight of 41 500 +/- 1000. it is composed of two identical subunits (mr 23 500) not bound by disulfide linkage. it's isoelectric point is 4.5. the amino acid composition shows strong similarities with other dimeric procaryotic and with tetrameri ...19817213754
15n tracer studies on the role of no in denitrification. 19817240149
occurrence of proteins immunoreactive with anti-coupling factor b in phosphorylating membrane preparations.coupling factor b has been isolated from beef heart mitochondria, apparently in multiple forms which differ in molecular weight and specific activity. since it has no known intrinsic catalytic activity, detection and quantitation have been based upon the factor b-dependent stimulation of atp-linked activities in factor b-deficient sub-mitochondrial particles. this communication reports the development of a reliable and more universally applicable enzyme-linked immunosorbent assay (elisa) for det ...19817284357
estimation with an ion-selective electrode of the membrane potential in cells of paracoccus denitrificans from the uptake of the butyltriphenylphosphonium cation during aerobic and anaerobic respiration.1. aerobic respiration by cells of paracoccus dentrificans drives the uptake of the lipophilic cation butyltriphenylphosphonium. anaerobiosis or addition of an uncoupler of oxidative phosphorylation (carbonyl cyanide p-trifluoromethoxyphenylhydrazone) results in efflux of the cation. changes in the concentration of butyltriphenylphosphonium in the suspension medium were measured by using an ion-selective electrode, the construction of which is described. 2. if the uptake of butyltriphenylphospho ...19817306073
respiration-driven proton translocation with nitrite and nitrous oxide in paracoccus denitrificans.(1)h+ leads to/electron acceptor ratios have been determined with the oxidant pulse method for cells of denitrifying paracoccus denitrificans oxidizing endogenous substrates during reduction of o2, no2- or n2o. under optimal h+-translocation conditions, the ratios leads to h+/o, h+ leads to/n2o, h+ leads to/no2- for reduction to n2 and h+ leads to/no2- for reduction to n2o were 6.0-6.3, 4.02, 5.79 and 3.37, respectively. (2) with ascorbate/n,n,n,'n'-tetramethyl-p-phenylene-diamine as exogenous s ...19817317386
removal of paracoccus denitrificans outer membrane material by sodium chloride.the effects of water washing and nacl treatment on the cell surface of p. denitrificans were studied. both treatments caused a release of material from cells. chemical studies showed that nacl treatment released material containing components characteristic of outer membrane. this treatment also increased the susceptibility of the organism to lysozyme. scanning electron microscopy was used to monitor the effects of water washing and nacl treatment on the cell surface. both treatments were shown ...19817332408
first practical assay for soluble nitrous oxide reductase of denitrifying bacteria and a partial kinetic characterization.lysis of spheroplasts made from denitrification-adapted paracoccus denitrificans released a soluble nitrous oxide reductase which was assayed spectrophotometrically under anaerobic conditions by following the oxidation of methyl or benzyl viologen cation radical upon reduction of n2o to n2. other classes of reductants so far tested, including dithionite, could not substitute for viologen dyes. viologen dyes, therefore, afford the first practical assay for this previously elusive enzyme of denitr ...19807356639
purification and properties of paracoccus denitrificans azurin. 19807362239
13n,15n isotope and kinetic evidence against hyponitrite as an intermediate in dentrification.13n- and 15n-labeling experiments were carried out with paracoccus denitrificans, grown anaerobically on nitrate, to determine whether hyponitrite might be an obligatory intermediate in denitrification and a precursor of nitrous oxide. from experiments designed to trap [13n]- or [15n,15n]hyponitrite by dilution into authentic hyponitrite it was calculated that the intracellular concentration of a presumptive hyponitrite pool must be less than 0.4 mm. in order for a pool of this size to turn over ...19807372623
growth and physiology of potassium-limited chemostat cultures of paracoccus denitrificans. 19807377905
isolation and characterization of an ornithine-containing lipid from paracoccus denitrificans.the isolation and characterization of an ornithine-containing lipid from various strains of paracoccus denitrificans (grown heteretrophically and autotrophically) is reported. the structure of this aminolipid was found to be h2n--ch2--(ch2)2--ch[nh--co--ch2--ch(o--co--r1)--r2]--co2h, where r1 predominantly represents the residue of octadec-11-enoic acid, r2 the residue of a 3-hydroxyeicos-13-enoic acid. in addition, the major phospholipids (phosphatidylcholine, phosphatidylethanolamine, phosphat ...19807379785
[inhibition of the autotrophic growth of hydrogen bacteria by the autoregulation factor].the purpose of this work was to study the action of the autoregulation factor isolated from the organotrophous culture of pseudomonas carboxydoflava z-1107 on autotrophous growth of this organism and some other cultures of hydrogen bacteria. if a sufficient dose of this metabolite was added to the culture growing lithoautotrophously, the growth of ps. carboxydoflava z-1107 stopped completely after 24 hours. a curve of false diauxia was observed if an increase in the concentration of the autoregu ...19807402116
kinetics of oxidation and reduction of high-potential iron-sulfur proteins with nonphysiological reactants.we have investigated the kinetic and equilibrium oxidation-reduction properties of hipip's from four sources: chromatium vinosum, thiocapsa pfennigii, rhodopseudomonas gelatinosa, and a paracoccus sp. these studies focused on the interaction of the various hipip's and the iron hexacyanides as a function of ionic strength, ph, and temperature. on the basis of the kinetic and equilibrium data obtained and the known structrual properties of the various hipip's a number of conclusions concerning the ...19807426625
energy coupling to k+ transport in paracoccus denitrificans.paracoccus denitrificans requires potassium for normal growth and transports this cation by at least two systems, one with low (km approximately 1 to 2 mm) and another with high (km approximately 0.1 microm) affinity. neither of the two systems seems to be dependent on periplasmic components since each retains full activity in cells subjected to an osmotic shock. p. denitrificans accumulates potassium at high velocity (270 nmol of k+/min/mg dry weight of cells) and against a large concentration ...19817451438
midpoint potentials of cytochromes in vesicles of anaerobically-grown paracoccus denitrificans determined by the indirect coulometric titration method.1. multiplicity of redox components with spectral properties similar to b-type cytochromes was established in vesicles derived fro anaerobically-grown paracoccus denitrificans. 2. multiplicity of c-type cytochromes was not apparent either from low temperature spectroscopy or potentiometric titrations. 3. cytochromes a + a3 and a component, only observable at liquid nitrogen temperature, with a spectral maximum at 582.5 nm were detected. 4. redox cycling of electron transport components using the ...19817470501
isolation and characterization of a novel insertion sequence element, is1248, in paracoccus denitrificans.a new suicide vector, prvs3, was constructed to facilitate gene replacements in the genome of paracoccus denitrificans. in control experiments, incorporation of this suicide vector into the genome did not depend on the presence of homologous dna. using appropriate restriction enzymes, the suicide vector and flanking dna were recovered from the genomic dna. sequence analysis demonstrated that both up- and downstream of the ex-integrant vector there was an element that showed high homology with ba ...19957480167
characterisation and amino acid sequence of cytochrome c-550 from thiosphaera pantotropha.a cytochrome c-550, with mid-point potential +265 mv, has been purified from thiosphaera pantotropha. the cytochrome was recognised by antibodies to paracoccus denitrificans cytochrome c-550, but the two proteins were not immunologically identical. amino acid sequencing of the cytochrome c-550 showed 85.9% and 95.5% identities, respectively, with the cytochromes c-550 of p. denitrificans and thiobacillus versutus; these are amongst the highest values reported for similarities between class i c-t ...19947508392
[microbial purine decomposition].27 microorganisms were tested for their ability to degrade extracellular purines as sole sources of carbon, nitrogen, and energy. beside adenine, guanine, xanthine, hypoxanthine, and urate as free purine bases, this test included 5'-amp, 5'-gmp, 5'-xmp, and 5'-imp, as well as dna and rna as purine compounds. generally, only a limited number of microbial species was capable of metabolizing the substances named above. compared to the other species, paracoccus denitrificans showed the greatest subs ...19947521548
paracoccus thiocyanatus sp. nov., a new species of thiocyanate-utilizing facultative chemolithotroph, and transfer of thiobacillus versutus to the genus paracoccus as paracoccus versutus comb. nov. with emendation of the genus.a facultatively chemolithotrophic thiocyanate-degrading bacterium, strain thi 011t, which was previously isolated from activated sludge and tentatively named thiobacillus sp., was studied taxonomically and phylogenetically. this bacterium utilizes thiocyanate as sole energy source and the specific growth rate for chemolithoautotrophic growth with thiocyanate was 0.059 h-1. molecular phylogenetic relationships of strain thi 011t to thiobacillus versutus and members of the genus paracoccus were el ...19957545513
phylogenetic inferences and taxonomic consequences of 16s ribosomal dna sequence comparison of chromohalobacter marismortui, volcaniella eurihalina, and deleya salina and reclassification of v. eurihalina as halomonas eurihalina comb. nov.the phylogenetic positions of the moderately halophilic bacteria chromohalobacter marismortui, volcaniella eurihalina, and deleya salina were determined by pcr amplification of rrna genes and direct sequencing. the resulting data were compared with data for other bacteria obtained from 16s rrna sequence databases. c. marismortui, v. eurihalina, and d. salina clustered phylogenetically within the gamma subclass of the proteobacteria and are closely related to other species on the halomonas-deleya ...19957547290
intermolecular electron transfer from substrate-reduced methylamine dehydrogenase to amicyanin is linked to proton transfer.within the methylamine dehydrogenase-amicyanin complex, intermolecular electron transfer (et) occurs between tryptophan tryptophylquinone (ttq) and copper. the et reactions from two chemically distinct reduced forms of ttq were studied. the quinol form of ttq was generated by reduction by dithionite. an aminoquinol form of ttq, in which an amino group displaces the carbonyl oxygen, was generated by reduction by the substrate methylamine. thermodynamic analysis of the et reactions suggested that ...19957547947
fv fragment-mediated crystallization of the membrane protein bacterial cytochrome c oxidase.crystallization of membrane proteins, a prerequisite for their x-ray crystallographic analysis, remains difficult. here, we demonstrate that the crystallization of the cytochrome c oxidase from paracoccus denitrificans can be mediated by co-crystallization with an antibody fv fragment. the crystals obtained contain all four subunits of this membrane protein complex and the fv fragment. the approach of co-crystallizing membrane proteins with antibody fragments should be useful in obtaining well-o ...19957552705
spectroscopic and mutagenesis studies on the cua centre from the cytochrome-c oxidase complex of paracoccus denitrificans.cytochrome-c oxidase contains an unusual copper centre (cua) located in subunit ii. this centre mediates one-electron transfer from cytochrome c to low-spin heme a. recent spectroscopic and biochemical studies have shown that this centre is a valence delocalised dinuclear [cu(+1.5)-cu(+1.5)] centre. we have measured the absorption, epr and variable-temperature magnetic circular dichroism spectra of the cua-binding domain isolated from paracoccus denitrificans cytochrome aa3. the epr spectrum sho ...19957556164
reversed electron transfer through the bc1 complex enables a cytochrome c oxidase mutant (delta aa3/cbb3) of paracoccus denitrificans to grow on methylamine.in paracoccus denitrificans four classes of redox proteins are involved in the electron transfer from methylamine to oxygen:methylamine dehydrogenase (madh), amicyanin, cytochrome c and cytochrome c oxidase. madh and its electron acceptor amicyanin are indispensable for growth on methylamine. at least three different cytochromes c and two types of cytochrome c oxidase, cytochromes aa3 and cbb3, have previously been proposed to participate in the electron transfer pathways from methylamine to oxy ...19957556607
subunit iii of cytochrome c oxidase influences the conformation of subunits i and ii: an infrared study.the secondary structure of wild-type paracoccus denitrificans cytochrome c oxidase obtained by decomposition of the infrared amide i band contains 44% alpha-helix, 18% beta-sheet, 14% beta-turns, 18% loops, and 6% nonordered segments. the mutant lacking subunit iii presents a small but significant increase (from 18% to 24%) in the percentage of loops and slight differences in the other components. using band/area ratios and tyrosine side chain absorption as an inner standard, it is shown that in ...19957577945
nucleotide sequence of the mxcq and mxce genes, required for methanol dehydrogenase synthesis in methylobacterium organophilum xx: a two-component regulatory system.nucleotide sequence analysis of the mxcq and mxce loci, required for the synthesis of methanol dehydrogenase in methylobacterium organophilum xx, has revealed two open reading frames that show significant similarity to sequences of prokaryotic two-component systems, especially mxay and mxax proteins of another methylotrophic bacterium, paracoccus denitrificans. cell-free extracts and dna-column-fractionated proteins from wild-type m. organophilum xx cells grown on methanol or succinate contained ...19957582014
mössbauer characterization of paracoccus denitrificans cytochrome c peroxidase. further evidence for redox and calcium binding-induced heme-heme interaction.mössbauer and electron paramagnetic resonance (epr) spectroscopies were used to characterize the diheme cytochrome c peroxidase from paracoccus denitrificans (l.m.d. 52.44). the spectra of the oxidized enzyme show two distinct spectral components characteristic of low spin ferric hemes (s = 1/2), revealing different heme environments for the two heme groups. the paracoccus peroxidase can be non-physiologically reduced by ascorbate. mössbauer investigation of the ascorbate-reduced peroxidase show ...19957592634
immunoelectron microscopy and epitope mapping with monoclonal antibodies suggest the existence of an additional n-terminal transmembrane helix in the cytochrome b subunit of bacterial ubiquinol:cytochrome-c oxidoreductases.the topology of the ubiquinol:cytochrome-c oxidoreductase (cytochrome bc1 complex) from paracoccus denitrificans was investigated by immunoelectron microscopy with sequence-specific murine monoclonal antibodies. epitope mapping with synthetic peptides and enzymic proteolytic cleavage of the cytochrome bc1 complex were employed to localize precisely the respective antibody epitopes on the subunits of this membrane protein complex. localization of defined epitopes on the cytochrome bc1 complex by ...19957601123
mutational analysis of mau genes involved in methylamine metabolism in paracoccus denitrificans.a chromosomal fragment containing dna downstream from mauc was isolated from paracoccus denitrificans. sequence analysis of this fragment revealed the presence of four open reading frames, all transcribed in the same direction. the products of the putative genes were found to be highly similar to mauj, maug, maum and maun of methylobacterium extorquens am1. using these four mau genes, 11 mau genes have been cloned from p. denitrificans to date. the gene order is maurfbedacjgmn, which is similar ...19957601147
amperometric detection of histamine at a quinoprotein dehydrogenase enzyme electrode.methylamine dehydrogenase, a tryptophan tryptophyl quinone (ttq) containing quinoprotein, catalyzes the oxidation of a variety of primary aliphatic monomaines and diamines to their respective aldehydes and ammonia. this paper reports the construction and characterization of an enzyme electrode capable of detecting histamine and methylamine at +200 mv versus a saturated calomel reference electrode. the methylamine dehydrogenase isolated from paracoccus denitrificans was used in conjunction with t ...19957612208
site-directed mutagenesis of cytochrome c oxidase reveals two acidic residues involved in the binding of cytochrome c.site-directed mutagenesis in subunit ii of the cytochrome c oxidase (haem aa3) from paracoccus denitrificans reveals that two carboxylic residues, glu-246 and asp-206 (corresponding to 198 and 158 in the bovine subunit ii), are involved in the binding of cytochrome c. spectrophotometric and polarographic measurements with the isolated enzymes of both mutant strains show a strongly reduced activity compared to wild-type oxidase, with the overall catalytic capacity (kcat/km) of both mutants decrea ...19957612644
purification of paracoccus denitrificans cytochrome c552 and sequence analysis of the gene.unlike mitochondria, many bacteria use a large repertoire of c-type cytochromes in different branches of their electron transport system. among the many cytochromes c present in the soil bacterium paracoccus denitrificans, a membrane-bound cytochrome (c552) has been suggested to mediate the electron transport between the cytochrome bc1 complex and cytochrome-c oxidase [berry, e. a. & trumpower, b. l. (1985) j. biol. chem. 260, 2458-2467]. we have purified this cytochrome from cytoplasmic membran ...19957628479
expression and characterization of the 66-kilodalton (nqo3) iron-sulfur subunit of the proton-translocating nadh-quinone oxidoreductase of paracoccus denitrificans.the proton-translocating nadh-quinone oxidoreductase (ndh-1) of paracoccus denitrificans is composed of at least 14 dissimilar subunits which are designated nqo1-14 and contains one noncovalently bound fmn and at least five epr-visible iron-sulfur clusters (n1a, n1b, n2, n3, and n4) as prosthetic groups. comparison of the deduced primary structures of the subunits with consensus sequences for the cofactor binding sites has predicted that nqo1, nqo2, nqo3, nqo9, and probably nqo6 subunits are cof ...19957629145
the napedabc gene cluster encoding the periplasmic nitrate reductase system of thiosphaera pantotropha.the napedabc locus coding for the periplasmic nitrate reductase of thiosphaera pantotropha has been cloned and sequenced. the large and small subunits of the enzyme are coded by napa and napb. the sequence of napa indicates that this protein binds the gmp-conjugated form of the molybdopterin cofactor. cysteine-181 is proposed to ligate the molybdenum atom. it is inferred that the active site of the periplasmic nitrate reductase is structurally related to those of the molybdenum-dependent formate ...19957639719
integration of heterologous dna into the genome of paracoccus denitrificans is mediated by a family of is1248-related elements and a second type of integrative recombination event.all members of the is1248 family residing in the genome of paracoccus denitrificans have been isolated by using a set of insertion sequence entrapment vectors. the family consists of five closely related members that integrate the entrapment vectors at distinct sites. one of these, is1248b, was sequenced and, except for a single base change, shown to be identical to the previously isolated is1248a. southern analysis of genomic dna with labeled is1248 revealed different hybridization patterns for ...19957642505
dictyostelium discoideum mitochondrial dna encodes a nadh:ubiquinone oxidoreductase subunit which is nuclear encoded in other eukaryotes.complex i, a key component of the mitochondrial electron transport system, is thought to have evolved from at least two separate enzyme systems prior to the evolution of mitochondria from a bacterial endosymbiont, but the genes for one of the enzyme systems are thought to have subsequently been transferred to the nuclear dna. we demonstrated that the cellular slime mold dictyostelium discoideum retains the ancestral characteristic of having mitochondria encoding at least one gene (80-kda subunit ...19957643412
Refresh
firstprev
12345678910...
nextlast
Displaying items 401 - 500 of 1577