| physiological role of oxygenated cytochrome o: observations on whole-cell suspensions of vitreoscilla. | the form of cytochrome o that predominates in vitreoscilla cells having various levels of respiratory activity was studied by using untreated, frozen-thawed, and starved cells, which had respiratory rates decreasing in the order given. direct spectral observation revealed that the oxygenated form of cytochrome o predominated during the aerobic steady-state oxidation of endogenous substrate or exogenous glutamate in untreated and frozen-thawed cells and was replaced by the reduced form when the c ... | 1978 | 97275 |
| amino acid sequence of yeast hemoglobin. a two-domain structure. | the complete amino acid sequence of a hemoglobin from yeast (candida norvegensis) has been determined by peptide and cdna sequence analyses. the protein is composed of 387 amino acid residues and its amino terminus was blocked by an acetyl group. a computer search showed that the sequence of 155 n-terminal residues has 39% homology with that of vitreoscilla hemoglobin. on the other hand, the sequence of 230 c-terminal residues showed a small, but notable, degree of similarity with that of a meth ... | 1992 | 1404399 |
| purification and aqueous two-phase partitioning properties of recombinant vitreoscilla hemoglobin. | soluble recombinant vitreoscilla hemoglobin was purified from e. coli lysate by sequential two-phase extraction techniques. extraction of lysate containing vhb in peg/dextran gave a 3.6-fold increase in vhb purity in the peg-rich phase via a size exclusion mechanism. further extraction of the recovered peg phase in peg/sodium sulfate gave an additional 2.0-fold increase in purity in the peg-rich phase due to an electrostatic mechanism. final extraction of the peg phase in peg/magnesium sulfate g ... | 1991 | 1367636 |
| expression of recombinant proteins in escherichia coli using an oxygen-responsive promoter. | the oxygen-dependent promoter of the vitreoscilla hemoglobin (vhb) gene has been shown to be functional in e. coli. earlier studies established that the promoter is maximally induced under microaerobic conditions and that its activity is also influenced by the camp-cap complex. we demonstrate here that the promoter can be used for regulated, high-level expression of recombinant proteins in two-stage fed-batch fermentations. the promoter is maximally induced at dissolved oxygen levels lower than ... | 1990 | 1367436 |
| expression of intracellular hemoglobin improves protein synthesis in oxygen-limited escherichia coli. | we have previously cloned the vitreoscilla hemoglobin gene (vhb) and expressed the protein in escherichia coli in its active form. under oxygen-limited conditions the presence of vhb improves protein synthesis as indicated by both total protein content and the activity of an enzyme expressed from a cloned gene present on a multicopy plasmid. measurements of nitrogen utilization rates corroborate the observation of enhanced protein synthesis; however, the rates of carbon consumption and acid synt ... | 1990 | 1366796 |
| electron-accepting properties of cytochrome o purified from vitreoscilla. | the reduction of cytochrome o which contains two hemes/molecule required two electrons/molecule when titrated with dithionite under anaerobic conditions. two types of spectral transitions occurred during this reduction, first a decrease in absorption bands for the oxidized protein at 540 and 405 nm and then a shift in the absorption maxima to 555 and 425 nm, respectively. each of these two transitions required approximately one electron, evidence that the two hemes reduced separately. preliminar ... | 1978 | 701279 |
| sodium-coupled atp synthesis in the bacterium vitreoscilla. | the bacterium vitreoscilla generates an electrical potential gradient due to sodium ion (delta psi na+) across its membrane via respiratory-driven primary na+ pump(s). the role of the delta psi na+ as a driving force for atp synthesis was, therefore, investigated. in respiring starved cells pulsed with 100 mm external na+ [( na+]o) there was a 167% net increase in cellular atp concentration over basal levels compared with 0, 56, 78, and 78% for no addition, choline, li+, and k+ controls, respect ... | 1992 | 1309288 |
| oxygenated cytochrome o. an active intermediate observed in whole cells of vitreoscilla. | the oxygenerated form of cytochrome o can be readily observed in whole cell suspensions of vitreoscilla because it is the predominant steady state form of the cytochrome in respiring cells. when oxygen is introduced to an anaerobic suspension of cells, the steady state is established immediately and absorption maxima are observed at 578, 545, and 425 nm in difference spectra using ammonium persulfate-oxidized cells as reference. the oxygenerated form of cytochrome o is identified as the predomin ... | 1977 | 845146 |
| intermediates in the reaction of reduced cytochrome o (vitreoscilla) with oxygen. | | 1979 | 758318 |
| nadh-dependent methemoglobin reductase from the obligate aerobe vitreoscilla: improved method of purification and reexamination of prosthetic groups. | the nadh-dependent methemoglobin reductase from the bacterium vitreoscilla was purified using hydrophobic chromatography on a phenyl-sepharose column. the new procedure resulted in a purer protein and increased the overall yield of the enzyme by a factor of approximately three. the active site of the enzyme was investigated by ultraviolet/visible, fluorescence, mössbauer, and electron paramagnetic resonance spectroscopy (epr) at 9.4 ghz. prosthetic group analysis revealed the presence of one fad ... | 1992 | 1309298 |
| the formation of hydrogen peroxide during the oxidation of reduced nicotinamide adenine dinucleotide by cytochrome o from vitreoscilla. | the formation of hydrogen peroxide during the oxidation of nadh by purified preparations of cytochrome o has been demonstrated by employing three independent methods: polarographic, colorimetric, and fluorometric. the first two methods were used to assay for the accumulation of hydrogen peroxide and showed that hydrogen peroxide did accumulate as a product, but only about 30% of the oxygen consumed or 15 to 20% of the nadh oxidized was recoverable as hydrogen peroxide. this lack of 1:1 stoichiom ... | 1975 | 238973 |
| the bacterial hemoglobin from vitreoscilla can support the aerobic growth of escherichia coli lacking terminal oxidases. | two escherichia coli mutants that lack both cytochrome o and d terminal oxidases are able to grow with glucose as the carbon source but not with the aerobic substrates succinate or lactate. one of these, gv101, is a deletion mutant of cytochrome o and a point mutation of cytochrome d. the other, gk100, is a total deletion mutant of all the genes for both cytochromes. when these mutants were transformed with a plasmid containing the gene for the bacterial hemoglobin from vitreoscilla, they were c ... | 1992 | 1311160 |
| the binding of cyanide and carbon monoxide to cytochrome o purified from vitreoscilla. evidence for subunit interaction in the reduced protein. | | 1978 | 690137 |
| nutrition of vitreoscilla stercoraria. | the present study has shown that the glutamate or aspartate families, plus the aromatic amino acid family are required for growth of vitreoscilla stercoraria. furthermore, glutamine can substitute for the glutamate family, asparagine and methionine can replace the aspartate family, and tyrosine can substitute for the aromatic family. amino acids which are easily oxidized by this organism, particularly serine and cysteine, stimulated growth. from these data, a defined medium was devised, which co ... | 1975 | 1220862 |
| respiratory mechanisms in the flexibacteriaceae: terminal oxidase systems of saprospira grandis and vitreoscilla species. | particles from both saprospira grandis and vitreoscilla species, obtained by high-pressure extrusion and sonic treatment, respectively, actively catalyze the oxidation of reduced nicotinamide adenine dinucleotide (nadh) and succinate with o(2). these activities are inhibited by cyanide but not by antimycin; saprospira is also amytal- and rotenone-insensitive. vitreoscilla preparations were unable to oxidize mammalian ferrocytochrome c and reduced tetramethyl-p-phenylenediamine, whereas the sapro ... | 1971 | 4323292 |
| effect of aldehyde fixatives on the adenosine phosphatases and ultrastructure of vitreoscilla. | | 1973 | 4356831 |
| oxygen inhibition of globin gene transcription and bacterial haemoglobin synthesis in vitreoscilla. | a soluble dimeric haemoprotein, structurally and functionally similar to plant and animal haemoglobins, is found in the gram-negative aerobic bacterium vitreoscilla sp., strain c1. vitreoscilla haemoglobin (vthb) increases in concentration when the cells are exposed to hypoxic conditions. the globin part of vthb is encoded by a single gene (vgb). an rna transcript, approximately 500 bases long, specific for vgb was detected after northern hybridization. the relative amount of this mrna increased ... | 1989 | 2483729 |
| characterization of the oxygen-dependent promoter of the vitreoscilla hemoglobin gene in escherichia coli. | the gene coding for the vitreoscilla hemoglobin (vhb) molecule has been cloned and functionally expressed in escherichia coli. by using a plasmid-encoded gene as well as single-copy integrants, the oxygen-dependent vhb gene (vhb) promoter was shown to be functional in e. coli. the promoter was maximally induced under microaerobic conditions (dissolved oxygen levels of less than 2% air saturation). direct analysis of mrna levels as well as the use of gene fusions with lacz showed that oxygen-depe ... | 1989 | 2681149 |
| a tree reconstruction method that is economical in the number of pairwise comparisons used. | a fast method for reconstructing phylogenies from distance data is presented. the method is economical in the number of pairwise comparisons needed. it can be combined with a new phylogenetic alignment procedure to yield an algorithm that gives a complete history of a set of homologous sequences. the method is applicable to very large distance matrices. an auxiliary program was developed that simplifies large phylogenies without ignoring biologically essential features. a set of 213 globins from ... | 1989 | 2488478 |
| reduced nicotinamide adenine dinucleotide cytochrome o reductase associated with cytochrome o purified from vitreoscilla. evidence for an intermediate oxygenated form of cytochrome o. | | 1974 | 4369125 |
| physiological studies on vitreoscilla stercoraria. | vitreoscilla stercoraria atcc 15218 was studied to elucidate some of its physiological characteristics. the initial optimal ph for the organism was found to be 7.5 to 7.7. the characteristics of the growth curve of the organism showed that its growth in shake cultures is by increasing trichome number up to approximately 15 hr and by increasing trichome length after 15 hr. nutritional studies indicated that it is auxotrophic for biotin, thiamine, and l-arginine, and it appears to be an obligate a ... | 1972 | 4565526 |
| respiratory-driven na+ electrical potential in the bacterium vitreoscilla. | vitreoscilla is a gram-negative bacterium with unique respiratory physiology in which na+ was implicated as a coupling cation for the generation of a transmembrane electrical gradient (delta psi). thus, cells respiring in the presence of 110 mm na+ generated a delta psi of -142 mv compared to only -42 and -56 mv for li+ and choline, respectively, and even the -42 and -56 mv were insensitive to the protonophore 3,5-di-tert-butyl-4-hydroxybenzaldehyde (dthb). the kinetics of delta psi formation an ... | 1990 | 2372555 |
| study of vitreoscilla globin (vgb) gene expression and promoter activity in e. coli through transcriptional fusion. | bacterial hemoglobin (vthb) is produced by the gram-negative bacterium, vitreoscilla, in large quantity in response to hypoxic environmental conditions. the vgb gene coding for vthb has been cloned in e. coli where it is expressed strongly by its natural promoter. the expression of the vgb gene in vitreoscilla is transcriptionally regulated by oxygen. when e. coli cells were shifted from 20% to 5% oxygen, vgb specific transcript increased. in e. coli cells with plasmids carrying transcriptional ... | 1990 | 2198533 |
| protein composition of vitreoscilla hemoglobin inclusion bodies produced in escherichia coli. | the protein composition of inclusion bodies produced in recombinant escherichia coli overproducing vitreoscilla hemoglobin (vhb) was analyzed by one-dimensional and two-dimensional electrophoresis techniques. results indicate the presence of two types of cytoplasmic aggregates of differing morphology in single bacterial cells. these aggregates also differ in their relative content of vhb and pre-beta-lactamase and are separable by differential centrifugation. results further suggest that the cyt ... | 1990 | 2197280 |
| presence of the bacterial hemoglobin gene improves alpha-amylase production of a recombinant escherichia coli strain. | a recombinant plasmid (pmk57) was constructed by cloning the bacillus stearothermophilus alpha-amylase gene into puc8; plasmid pmk79 was then derived from pmk57 by inserting the bacterial (vitreoscilla) hemoglobin gene into the latter plasmid. both pmk57 and pmk79 were transformed into escherichia coli strain jm 103 to make strains mk57 and mk79, respectively. both mk57 and mk79 produced alpha-amylase and mk79 produced hemoglobin. mk79 outgrew mk57 in shake flasks in lb medium, the advantage of ... | 1990 | 2136531 |
| the purification and properties of cytochrome o from vitreoscilla. | | 1966 | 5913119 |
| purification, partial characterization, and possible role of catalase in the bacterium vitreoscilla. | vitreoscilla is a gram-negative bacterium that contains a unique bacterial hemoglobin that is relatively autoxidizable. it also contains a catalase whose primary function may be to remove hydrogen peroxide produced by this autoxidation. this enzyme was purified and partially characterized. it is a protein of 272,000 da with a probable a2b2 subunit structure, in which the estimated molecular size of a is 68,000 da and that of b, 64,000 da, and an average of 1.6 molecules of protoheme ix per tetra ... | 1990 | 2337355 |
| yeast flavohemoglobin is an ancient protein related to globins and a reductase family. | the hemoglobin of yeast is a two-domain protein with both heme and flavin prosthetic groups. the nucleotide sequences of the cdna and genomic dna encoding the protein from saccharomyces cerevisiae show that introns are absent and that both domains are homologous with a flavoheme protein from escherichia coli. the heme domains are also homologous with those of o2-binding heme proteins from several other distantly related bacteria, plants, and animals; all appear to be members of the same globin s ... | 1992 | 1594608 |
| a cytochrome that can pump sodium ion. | previous studies have shown that the bacterium, vitreoscilla, generates a respiratory-driven delta psi na+. two major respiratory electron transport proteins, nadh dehydrogenase (nadh:quinone oxidoreductase), and cytochrome o terminal oxidase are candidates for the electrogenic na+ pumping that mediates the delta psi na+ formation. the nadh oxidase activity of the membranes was enhanced more by na+ than by li+. the nadh:quinone oxidoreductase activity in the respiratory chain was enhanced by na+ ... | 1990 | 2256929 |
| selection and characterization of alpha-amylase-overproducing recombinant escherichia coli containing the bacterial hemoglobin gene. | we previously reported that the presence of the bacterial (vitreoscilla) hemoglobin gene enhances alpha-amylase production in recombinant escherichia coli strain mk79. using the growth of mk79 on starch as a selective method we have produced a mutant strain (bsc9) that produces up to four times as much alpha-amylase as mk79. both mk79 and bsc9 produce the most alpha-amylase (per cell and per milliliter) in the stationary phase; almost all of the enzyme is intracellular in both strains. modificat ... | 1992 | 1369145 |
| evidence for partial export of vitreoscilla hemoglobin into the periplasmic space in escherichia coli. implications for protein function. | the vitreoscilla hemoglobin protein has been implicated in earlier studies to serve a globin-like function under oxygen-limited growth conditions. evidence is presented using fractionation as well as proteinase k accessibility techniques to prove that a considerable amount of this protein is localized in the periplasmic space of the cell. genetic evidence points towards the existence of information within the n-terminal domain of the protein that plays a role in the process of protein export. ho ... | 1989 | 2685332 |
| protozoan myoglobin from paramecium caudatum. its unusual amino acid sequence. | a protozoan myoglobin (or monomeric hemoglobin) was isolated from paramecium caudatum, and its complete amino acid sequence determined. it consists of 116 amino acid residues with a molecular mass of 12,565 daltons, this being much smaller than sperm whale myoglobin by 37 residues and even smaller than a bacterial hemoglobin from vitreoscilla by 30 residues in terms of the monomer unit. a computer search showed no notable sequence homology with other hemoproteins. it contains two histidine resid ... | 1989 | 2769763 |
| isolation and nucleotide sequence of the hmp gene that encodes a haemoglobin-like protein in escherichia coli k-12. | in the course of an attempt to identify genes that encode escherichia coli dihydropteridine reductase (dhpr) activities, a chromosomal dna fragment that directs synthesis of two soluble polypeptides of mr 44000 and 46000 was isolated. these proteins were partially purified and were identified by determination of their n-terminal amino acid sequences. the larger was serine hydroxymethyltransferase, encoded by the glya gene, while the smaller was the previously described product of an unnamed gene ... | 1991 | 2034230 |
| cloning, characterization and expression of the bacterial globin gene from vitreoscilla in escherichia coli. | the genomic locus responsible for production of the globin portion of vitreoscilla hemoglobin (vthb), the only well-characterized bacterial hemoglobin (hb), has been cloned and expressed in escherichia coli. a 17-mer oligodeoxynucleotide, corresponding to a region of the vthb amino acid sequence was used as a hybridization probe to screen a vitreoscilla genomic library constructed in broad-host-range cosmid vector pvk102. e. coli, carrying recombinant pvk102:h5 which contained a 16.5-kb insert o ... | 1988 | 2850971 |
| effect of biosynthetic manipulation of heme on insolubility of vitreoscilla hemoglobin in escherichia coli. | vitreoscilla hemoglobin (vhb) is accumulated at high levels in both soluble and insoluble forms when expressed from its native promoter on a puc19-derived plasmid in escherichia coli. examination by atomic absorption spectroscopy and electron paramagnetic resonance spectroscopy revealed that the insoluble form uniformly lacks the heme prosthetic group (apovhb). the purified soluble form contains heme (holovhb) and is spectroscopically indistinguishable from holovhb produced by vitreoscilla cells ... | 1994 | 8074522 |
| cyanide- and carbon monoxide-resistant mutants of vitreoscilla: altered cytochromes and respiratory properties. | two respiratory mutants of the aerobic bacterium, vitreoscilla, have been studied: a co-resistant mutant that can grow in 50% co-50% oxygen, and a cyanide-resistant mutant that can grow in 1 mm kcn. wild-type cells are unable to grow under either condition. this report presents evidence that the resistance of the co mutant is due to an altered membrane-bound cytochrome o [cytochrome o(m)], and that of the cyanide mutant is due to the presence of an increased amount of cytochrome d, which has a l ... | 1986 | 3004339 |
| the vitreoscilla hemoglobin gene: molecular cloning, nucleotide sequence and genetic expression in escherichia coli. | vitreoscilla hemoglobin is involved in oxygen metabolism of this bacterium, possibly in an unusual role for a microbe. we have isolated the vitreoscilla hemoglobin structural gene from a puc19 genomic library using mixed oligodeoxy-nucleotide probes based on the reported amino acid sequence of the protein. the gene is expressed in escherichia coli from its natural promoter as a major cellular protein. the nucleotide sequence, which is in complete agreement with the known amino acid sequence of t ... | 1988 | 3067078 |
| identification of b, c, and d cytochromes in the membrane of vitreoscilla. | cytochromes b, c, d, and o were identified by spectroscopic analysis of respiratory membrane fragments from vitreoscilla sp., strain c1. carbon monoxide difference spectra of the reduced membranes had absorption maxima at 416, 534, and 571 nm (ascribed to cytochrome o) and 632 nm (cytochrome d). derivative spectra of the pyridine hemochromogen spectra of the membranes identified the presence of b- and c-type cytochromes in vitreoscilla. the cyanide binding curve of the membranes was biphasic wit ... | 1987 | 2825616 |
| relationships between membrane-bound cytochrome o from vitreoscilla and that of escherichia coli. | the cytochrome o terminal oxidases from the bacteria vitreoscilla and escherichia coli are structurally and functionally related. they have similar optical spectra, both exhibit ubiquinol-1 oxidase activity and are inhibited similarly. both enzymes contain four subunits by sds-polyacrylamide gel electrophoresis analysis and contain protoheme ix and cu2+ prosthetic groups. antibodies raised against the oxidase purified from e. coli crossreact with the vitreoscilla oxidase. | 1988 | 3280028 |
| biphasic recombination of photodissociated co compound of cytochrome o(s) from vitreoscilla. | the soluble cytochrome o from vitreoscilla contains two identical subunits and two hemes. the reduced form binds 2 mol of co in a cooperative manner with a hill coefficient near 2 (tyree, b., and webster, d. a. (1978) j. biol. chem. 253, 6988-6991). this carbonyl compound was photolysed with a dye laser and recombination followed at 437 or 420 nm where maximal absorbance changes were registered. recombination kinetics were biphasic, and the fast phase was approximately 10 times the rate of the s ... | 1985 | 4066683 |
| studies on the bacterial hemoglobin from vitreoscilla. redox properties and spectroscopic characterization of the different forms of the hemoprotein. | vitreoscilla contained a homodimeric bacterial hemoglobin (vthb). the purification of this protein yielded vtmethb which exhibited electronic and electron paramagnetic resonance (epr) spectra, showing that it existed predominantly in a high-spin ferric form, both axial and rhombic components being present. the preparations also contained variable amounts of low-spin components. there was no evidence that these high-spin and low-spin forms were in equilibrium. the former were reducible by nadh ca ... | 1991 | 1652267 |
| organization of non-vertebrate globin genes. | the organization of non-vertebrate globin genes exhibits substantially more variability than the three-exon, two-intron structure of the vertebrate globin genes. (1) the structures of genes of the single-domain globin chains of the annelid lumbricus and the mollusc anadara, and the globin gene coding for the two-domain chains of the clam barbatia, are similar to the vertebrate plan. (2) genes for single-domain chains exist in bacteria and protozoa. although the globin gene is highly expressed in ... | 1992 | 1478060 |
| adenosine phosphate hydrolases in cell fractions of vitreoscilla. | bound, soluble, and whole-cell fractions of two strains of the gliding bacterium vitreoscilla were found to contain two enzymes capable of hydrolyzing adenosine phosphates: a mg(++)-activated adenosine triphosphatase with a temperature optimum of 37 c, and a mg(++)-activated adenosine diphosphatase with a temperature optimum of 55 c. both enzymes had an optimal ph response between 8.5 and 9.5. maximal activation was achieved at an ionic strength of 0.2 for the adenosine triphosphatase and at 0.3 ... | 1967 | 4289806 |
| heterologous expression of a bacterial haemoglobin improves the growth properties of recombinant escherichia coli. | rational design of novel as well as improved cellular biocatalysts by genetic manipulation of cellular metabolism has recently attracted considerable interest. a wide range of bacteria have been genetically modified by integrating new enzymatic functions into their metabolic network. a central problem in the aerobic growth of any cell culture is the maintenance of dissolved oxygen (do) concentrations above growth-limiting levels especially in high cell-density fermentations which are usually of ... | 1988 | 3277067 |
| unusual sulfonolipids are characteristic of the cytophaga-flexibacter group. | capnocytophaga spp. contain a group of unusual sulfonolipids, called capnoids (w. godchaux iii and e. r. leadbetter, j. bacteriol. 144:592-602, 1980). one of these lipids, capnine, is 2-amino-3-hydroxy-15-methylhexadecane-1-sulfonic acid; the others are, apparently, n-acylated versions of capnine. the lipids were found, in amounts ranging from 2.5 to 16 mumol of capnoid sulfur per g of cells (wet weight), in two cytophaga spp. and also in several closely related organisms: several capnocytophaga ... | 1983 | 6298180 |
| dependence of the cell morphology of vitreoscilla on the temperature of incubation. | | 1966 | 5973215 |
| oxygenated intermediate and carbonyl species of cytochrome o (vitreoscilla). characterization by infrared spectroscopy. | | 1982 | 6798033 |
| [a new species of vitreoscilla (vitreoscilla proteolytica) in lake constance]. | | 1970 | 4922160 |
| effect of growth conditions on yield and heme content of vitreoscilla. | vitreoscilla, a gliding bacterium in the beggiatoaceae, is an obligate aerobe in which cytochrome o functions as the terminal oxidase. protoheme ix is the only heme type present in this organism. the yield and heme content of vitreoscilla cells grown in yeast extract, peptone, and acetate were dependent on growth conditions. cells harvested in early stationary phase contained roughly three times as much heme as cells in early log phase. there was an optimal shaking rate for maximum heme content ... | 1980 | 7372568 |
| bacterial flavohaemoglobins: a consensus sequence and identification of a discrete enterobacterial group and of further bacterial globins. | the amino acid sequences of haemoglobin-like proteins from the bacteria alcaligenes eutrophus, bacillus subtilis, erwinia chrysanthemi, escherichia coli, vibrio parahaemolyticus, vitreoscilla sp. and the yeast saccharomyces cerevisiae were studied. phylogenies based on distance and parsimony analysis showed that the eubacterial group can be easily distinguished from the other haemoglobin-like proteins. the construction of a consensus bacterial flavohaemoglobin based on the alignment of six bacte ... | 1997 | 9351199 |
| respiratory chain of colorless algae. ii. cyanophyta. | whole cell difference spectra of the blue-green algae, saprospira grandis, leucothrix mucor, and vitreoscilla sp. have one, or at the most 2, broad alpha-bands near 560 mmu. at -190 degrees these bands split to give 4 peaks in the alpha-region for b and c-type cytochromes, but no alpha-band for a-type cytochromes is visible. the nadh oxidase activity of these organisms was shown to be associated with particulate fractions of cell homogenates. the response of this activity to inhibitors differed ... | 1966 | 5932404 |
| purification and properties of nadh-cytochrome o reductase from vitreoscilla. | | 1980 | 7354040 |
| spectral evidence for the existence of a second cytochrome o in whole cells of vitreoscilla. | cytochrome o, a protoheme ix pigment, has been proposed as the terminal oxidase of the filamentous bacterium, vitreoscilla. aerobic and anaerobic photolysis of co-liganded whole cells demonstrated the presence of a second co-reactive pigment, cytochrome o'. at temperatures lower than -100 degrees c, anaerobic photolysis dissociated only about 25% of the total co-liganded components to reveal the unliganded cytochrome o'. at these temperatures, the photolysis of cytochrome o could not be demonstr ... | 1983 | 6643452 |
| improved erythromycin production in a genetically engineered industrial strain of saccharopolyspora erythraea. | an industrial erythromycin production strain of saccharopolyspora erythraea spp. was used to demonstrate that careful genetic engineering can significantly improve productivity. the chromosomally integrated vitreoscilla hemoglobin gene (vhb) was shown to enhance the final titer of erythromycin by some 70% compared to the original s. erythraea spp. overall, specific erythromycin yields were about 2.5 g of erythromycin/g of total protein for s. erythraea::vhb but <1 for the s. erythraea spp. the m ... | 1998 | 9694676 |
| intracellular expression of vitreoscilla hemoglobin alters the aerobic metabolism of saccharomyces cerevisiae. | vitreoscilla hemoglobin (vhb) has been expressed in saccharomyces cerevisiae, and its influence on yeast aerobic metabolism has been investigated. new expression vectors were constructed to express vhb constitutively under the control of the adh-1 promoter. the presence of vhb was shown by western blot analysis. vhb has been shown to localize predominantly in the cytoplasm. batch fermentation results indicated that the wild-type strain expressing vhb exhibited a shift in the carbon flux toward e ... | 1994 | 7764938 |
| sequence of the region downstream of the vitreoscilla hemoglobin gene: vgb is not part of a multigene operon. | the 1668 base pairs (bp) downstream of the vitreoscilla hemoglobin gene were sequenced in the hope of finding related genes that might be part of an operon. instead, a sequence was found that constituted an open reading frame (orf) of 569 amino acids (apparently the carboxy-terminal part of a larger orf), in the direction opposite to the hemoglobin gene. this sequence was found to have 64% similarity with the 1685 bp at the 3' end of the escherichia coli uvra gene. the inferred amino acid sequen ... | 1994 | 7765771 |
| fnr, a global transcriptional regulator of escherichia coli, activates the vitreoscilla hemoglobin (vhb) promoter and intracellular vhb expression increases cytochrome d promoter activity. | the oxygen-regulated promoter (pvhb) of the vitreoscilla hemoglobin gene has been applied to direct high-level expression of several cloned proteins, including vitreoscilla hemoglobin (vhb), which improves productivity of many aerobic processes. in an effort to gain a better understanding of the regulation of pvhb, and to guide further optimization of this technology, we investigated whether the escherichia coli global regulatory molecules fnr and the arc system (arca and arcb), which control th ... | 1995 | 7619398 |
| the production of cephalosporin c by acremonium chrysogenum is improved by the intracellular expression of a bacterial hemoglobin. | a dna vector for expressing an oxygen-binding heme protein (vitreoscilla hemoglobin, or vhb) in filamentous fungi was constructed and introduced into a cephalosporin c-producing strain of acremonium chrysogenum. expression of vhb in transformants was demonstrated by western immunoblot analysis and by increased carbon monoxide binding activity of cell extracts. several vhb-expressing transformants produced significantly higher yields of cephalosporin c than control strains in batch culture experi ... | 1993 | 7763915 |
| oxygen dependent regulation of vitreoscilla globin gene: evidence for positive regulation by fnr. | vitreoscilla globin (vgb) gene, encoding for vitreoscilla haemoglobin (vthb) has been cloned and functionally expressed in heterologous bacterial hosts. analysis of vgb gene expression and the study on vgb-xyle transcriptional fusion revealed that vgb promoter is preferentially activated in response to oxygen limitation in vitreoscilla and other heterologous bacterial hosts. microaerobic mode of induction in various hosts, provided evidence for a common regulatory factor involved in activation o ... | 1994 | 8037759 |
| intracellular expression of vitreoscilla hemoglobin alters escherichia coli energy metabolism under oxygen-limited conditions. | an earlier stoichiometric analysis of oxygen-limited metabolism of escherichia coli expressing cloned vitreoscilla hemoglobin (vhb) suggested improved efficiency of atp production relative to wild-type controls [khosla, c., curtis, j. e., demodena, j., rinas, j. & bailey, j. e. (1990) biotechnol. 8, 849-853]. this hypothesis has been further examined by determining several energetic parameters of different vhb-expressing e. coli (vhb+) strains relative to controls not expressing vhb (vhb-). the ... | 1994 | 8306987 |
| the metabolic effects of native and transgenic hemoglobins on plants. | the strictly aerobic bacterium vitreoscilla expresses a hemoglobin-like protein, vhb, when subjected to oxygen stress. when expressed in plants, this has several intriguing physiological effects, such as improving the overall growth rate, speeding germination and flowering, and increasing the productivity of certain oxygen-requiring metabolic pathways. although the mechanisms behind the effects of vhb in heterologous hosts are not yet fully characterized, it has been suggested that vhb facilitat ... | 1999 | 10098274 |
| adventitious variability? the amino acid sequences of nonvertebrate globins. | 1. the more than 140 amino acid sequences of non-vertebrate hemoglobins (hbs) and myoglobins (mbs) that are known at present, can be divided into several distinct groups: (1) single-chain globins, containing one heme-binding domain; (2) truncated, single-chain, one-domain globins; (3) chimeric, one-domain globins; (4) chimeric, two-domain globins; and (5) chimeric multi-domain globins. 2. the crystal structures of eight nonvertebrate hbs and mbs are known, all of them monomeric, one-domain globi ... | 1993 | 8403841 |
| distribution of the flavohaemoglobin, hmp, between periplasm and cytoplasm in escherichia coli. | the subcellular distribution of the soluble flavohaemoglobin (hmp) of escherichia coli has been determined. cells over-expressing hmp from the cloned hmp gene on a multicopy plasmid were fractionated by osmotic shock and lysozyme treatment. spectral analysis of subcellular fractions showed the co-binding haemoprotein to be cytoplasmic. however, western blotting using antibody raised to purified hmp revealed approximately 30% of the protein to be periplasmic in the over-expressing strain. western ... | 1995 | 7875569 |
| regulation of saccharomyces cerevisiae flavohemoglobin gene expression. | the saccharomyces cerevisiae hemoglobin is a flavoprotein of unknown function. it shares extensive sequence homology with the globin of candida as well as those of several bacterial species. we have studied its gene regulation in order to better understand its purpose in the cell. transcriptional analyses indicate that, in sharp contrast to the bacterial globins of vitreoscilla and alcaligenes eutrophus, the s. cerevisiae globin message is induced during logarithmic growth and under oxygen-reple ... | 1995 | 7896850 |
| purification and partial characterization of the membrane-bound cytochrome o(561,564) from vitreoscilla. | cytochrome o(561,564) terminal oxidase was solubilized from the membrane fraction of the bacterium vitreoscilla sp., strain c1, and purified by differential ph dialysis, gel filtration chromatography, and ion-exchange chromatography. subunit molecular weights, determined on sodium dodecyl sulfate-polyacrylamide gels by the ferguson plot method, were 49,500 and 23,500. there were two protohemes ix, two coppers, and 45 mol of phosphorus per mole of protomer (73,000). the molecular weight of the cy ... | 1987 | 3427021 |
| primary sequence of a dimeric bacterial haemoglobin from vitreoscilla. | vitreoscilla, a filamentous bacterium in the beggiatoa family, synthesizes a soluble haem-protein which has two identical subunits of relative molecular mass 15,775 and two b haems per molecule. it is synthesized in relatively large quantities when the organism, a strict aerobe, is grown under hypoxic conditions. it forms a relatively stable oxygenated form which is spectrally similar to oxymyoglobin (oxyhb) and oxyhaemoglobin (oxyhb). the amino acid sequence of this protein has been determined ... | 1986 | 3736670 |
| overexpression of bacterial hemoglobin causes incorporation of pre-beta-lactamase into cytoplasmic inclusion bodies. | the expression of vitreoscilla hemoglobin (vhb) in escherichia coli jm101 (pred2) causes the incorporation of the tem beta-lactamase precursor into cytoplasmic inclusion bodies (ibs). less pre-beta-lactamase is translocated and processed to its mature, periplasmic form in the strain coexpressing vhb than in the control strain e. coli jm101(puc19) not expressing vhb. when cells are grown in a special fed-batch procedure, the formation of cytoplasmic ibs consisting of pre-beta-lactamase is also in ... | 1993 | 8382023 |
| photodissociation of oxygenated cytochrome o(s) (vitreoscilla) and kinetic studies of reassociation. | oxygenated cytochrome o(s) from vitreoscilla was photodissociated by a laser flash but the quantum yield was low. the rebinding of oxygen to the ferrous cytochrome proceeded monophasically, and the second order rate constant was 7.8 x 10(7) m-1 s-1, the off rate constant 5.6 x 10(3) s-1, and the calculated dissociation constant for the oxygenated compound 7.2 x 10(-5) m at ph 7.3 and 25 degrees c. rapid scanning spectroscopy revealed the formation of chytochrome o-o2 directly from ferrous chytoc ... | 1986 | 3949777 |
| na(+)-translocating cytochrome bo terminal oxidase from vitreoscilla: some parameters of its na+ pumping and orientation in synthetic vesicles. | vitreoscilla cytochrome bo ubiquinol oxidase is similar in some properties to the escherichia coli enzyme, but unlike the latter, the vitreoscilla oxidase functions as a primary na+ pump. when purified vitreoscilla cytochrome bo is incorporated into liposomes made from vitreoscilla phospholipids and energized with a quinol substrate, it translocates na+, not h+, across the vesicle membrane. since protonophores cccp (carbonyl cyanide m-chlorophenylhydrazone) and dthb (3,5-di-tert-butyl-4-hydroxyb ... | 1996 | 8794772 |
| a new system for expressing heterologous gene in escherichia coli regulated by oxygen consistence in the environment. | the expression of vitreosilla hemoglobin gene (vgb) is regulated by oxygen consistence in e. coli. the gene transcription is activated under the condition of limited oxygen. a new system for expressing heterologous gene in e. coli regulated by dissolved oxygen consistence was constructed. it includes a host bacteria gj100, which contained t7 rna polymerase gene controlled by vgb promoter, and an expression vector on which the heterologous gene was under the control of a t7 promoter. the results ... | 1999 | 10935165 |
| intracellular expression of vitreoscilla hemoglobin (vhb) enhances total protein secretion and improves the production of alpha-amylase and neutral protease in bacillus subtilis. | in an attempt to alleviate oxygen limitation during batch cultivations, a heterologous bacterial hemoglobin gene (vhb) of vitreoscilla was introduced into bacillus subtilis. biochemically active vhb, as demonstrated by immunoblot analysis and carbon monoxide binding assay, was intracellularly expressed in b. subtilis from an inducible promoter-repressor (spac-laci). expression of vhb in oxygen-limited b. subtilis batch bioreactor cultivations enhanced cell growth, decreased accumulation of aceta ... | 1996 | 8845107 |
| recombinant acremonium chrysogenum strains for the industrial production of cephalosporin. | conventional strain improvement programs based on random mutagenesis and rational screening have meant valuable results to the antibiotic producing companies. the development of recombinant dna techniques and their applications to the industrially-used cephalosporin-producing fungus acremonium chrysogenum has provided a new tool, complementary to classical mutation, promoting the design of alternative biosynthetic pathways making it possible to obtain new antibiotics and to improve cephalosporin ... | 1996 | 8897416 |
| transgenic tobacco expressing vitreoscilla hemoglobin exhibits enhanced growth and altered metabolite production. | the gene for vitreoscilla hemoglobin (vhb) has been introduced and expressed in nicotiana tabaccum (tobacco). transgenic tobacco plants expressing vhb exhibited enhanced growth, on average 80-100% more dry weight after 35 days of growth compared to wild-type controls. furthermore, germination time is reduced from 6-8 days for wild-type tobacco to 3-4 days and the growth phase from germination to flowering was 3-5 days shorter for the vhb-expressing transgenes. transgenic plants contained, on ave ... | 1997 | 9062923 |
| genetic transformation of vitreoscilla sp. | of all the methods customarily used to transform e. coli we found only electroporation to be effective for transformation of the gram-negative bacterium vitreoscilla, yielding 5.10(5) transformants/microgram of plasmid dna. the conditions used were close to those described for e. coli e. coli plasmids are stably maintained in vitreoscilla. this is the first report of exogenous dna transfer in vitreoscilla which opens the way for the application of recombinant-dna techniques to study this unique ... | 1996 | 8921878 |
| expression of vitreoscilla hemoglobin is superior to horse heart myoglobin or yeast flavohemoglobin expression for enhancing escherichia coli growth in a microaerobic bioreactor. | expression of a gene encoding hemoglobin (vhb) from the aerobic bacterium vitreoscilla sp. in several organisms, including escherichia coli, has been shown to improve microaerobic cell growth and enhance oxygen-dependent product formation. the suitability of vhb to enhance microaerobic metabolism has been suggested to depend on its unusual oxygen binding characteristics. to examine whether hemoproteins of other origins can also elicit the positive effects vhb exerts in microaerobic e. coli cells ... | 1996 | 8983204 |
| expression, purification, crystallization, and preliminary x-ray diffraction analysis of the homodimeric bacterial hemoglobin from vitreoscilla stercoraria. | the recombinant homodimeric hemoglobin from the strictly aerobe gram-negative bacterium vitreoscilla stercoraria has been expressed in escherichia coli, purified to homogeneity, and crystallized by vapor diffusion techniques, using ammonium sulfate as precipitant. the crystals belong to the monoclinic space group p2(1) and diffract to high resolution. the unit cell parameters are alpha = 62.9, b = 42.5, c = 63.2 a, beta = 106.6 degrees; the asymmetric unit contains the homodimeric hemoglobin, wi ... | 1997 | 9037720 |
| novel hemoglobins to enhance microaerobic growth and substrate utilization in escherichia coli. | limited oxygen availability is a prevalent problem in microbial biotechnology. recombinant escherichia coli expressing the hemoglobin from vitreoscilla (vhb) or the flavohemoglobin from ralstonia eutropha (formerly alcaligenes eutrophus) (fhp) demonstrate significantly increased cell growth and productivity under microaerobic conditions. we identify novel bacterial hemoglobin-like proteins and examine if these novel bacterial hemoglobins can elicit positive effects similar to vhb and fhp and if ... | 2001 | 11587567 |
| hemoglobin biosynthesis in vitreoscilla stercoraria dw: cloning, expression, and characterization of a new homolog of a bacterial globin gene. | in the strictly aerobic, gram-negative bacterium vitreoscilla strain c1, oxygen-limited growth conditions create a more than 50-fold increase in the expression of a homodimeric heme protein which was recognized as the first bacterial hemoglobin (hb). the recently determined crystal structure of vitreoscilla hb has indicated that the heme pocket of microbial globins differs from that of eukaryotic hbs. in an attempt to understand the diverse functions of hb-like proteins in prokaryotes, we have c ... | 1998 | 9603838 |
| unusual structure of the oxygen-binding site in the dimeric bacterial hemoglobin from vitreoscilla sp. | the first hemoglobin identified in bacteria was isolated from vitreoscilla stercoraria (vthb) as a homodimeric species. the wild-type protein has been reported to display medium oxygen affinity and cooperative ligand-binding properties. moreover, vthb can support aerobic growth in escherichia coli with impaired terminal oxidase function. this ability of vthb to improve the growth properties of e. coli has important applications in fermentation technology, assisting the overexpression of recombin ... | 1997 | 9115439 |
| genetic engineering of serratia marcescens with bacterial hemoglobin gene: effects on growth, oxygen utilization, and cell size. | the bacterial hemoglobin from vitreoscilla has been shown to increase growth yield and yield of genetically engineered product in escherichia coli. to test the generality of this phenomenon, the approximately 560-bp bacterial (vitreoscilla) hemoglobin gene (vgb) (including the native promoter), cloned into the vector puc8 in two constructs containing about 1650 and 850 bp, respectively, of vitreoscilla dna downstream of vgb, was transformed into serratia marcescens. after several transfers of th ... | 1998 | 10099225 |
| role of the hema gene product and delta-aminolevulinic acid in regulation of escherichia coli heme synthesis. | we initiated these studies to help clarify the roles of heme, delta-aminolevulinic acid (ala), hema, and hemm in escherichia coli heme synthesis. using recombinant human hemoglobin (rhb1.1) as a tool for increasing e. coli's heme requirements, we demonstrated that heme is a feedback inhibitor of heme synthesis. cooverexpression of rhb1.1 and the hema-encoded glutamyl-trna (gtr) reductase increased intracellular levels of ala and heme and increased the rate of rhb1.1 formation. these results supp ... | 1997 | 9226269 |
| metabolic engineering of serratia marcescens with the bacterial hemoglobin gene: alterations in fermentation pathways. | serratia marcescens was transformed with plasmid vector puc8 or puc8 containing the bacterial (vitreoscilla) hemoglobin gene (vgb) on either a 2.3-kb fragment (puc8:15) or 1.4-kb fragment (puc8:16) of vitreoscilla dna. the vgb-bearing strains were compared with the puc8 transformant and untransformed s. marcescens with respect to growth in luria-bertani (lb) broth supplemented with glucose or casein acid hydrolysate. growth (on a viable cell basis) was similar to that in unsupplemented lb. total ... | 1998 | 10099382 |
| site-directed mutagenesis of bacterial hemoglobin: the role of glutamine (e7) in oxygen-binding in the distal heme pocket. | the bacterial and yeast hemoglobins have a glutamine instead of histidine in the e7 position of the distal heme pocket. the recently determined crystal structure of vitreoscilla hemoglobin (vhb) indicates that this residue is oriented out of the heme pocket and may not ligand the bound oxygen. this is in contrast to elephant myoglobin which also has a gln(e7) but which does ligand the bound oxygen. this residue was changed in vhb using site-directed mutagenesis to leucine (vhbl) or to histidine ... | 1998 | 9439594 |
| photoinhibition of respiration in bacteria and the cyanophycea vitreoscilla stercoraria. | | 1972 | 11946834 |
| genetic engineering of an industrial strain of saccharopolyspora erythraea for stable expression of the vitreoscilla haemoglobin gene (vhb). | several actinomycetes/streptomycetes expression vectors are described for expression of the vitreoscilla haemoglobin gene (vhb) in an industrial erythromycin-producing strain of saccharopolyspora erythraea. cloning of vhb under the control of either the thiostrepton-inducible ptipa promoter or the constitutive perme* promoter led to the production of chemically active haemoglobin (vhb) in streptomyces lividans tk24 transformed with these constructs. however, theplasmids could not be transformed ... | 1998 | 9782491 |
| anticooperative ligand binding properties of recombinant ferric vitreoscilla homodimeric hemoglobin: a thermodynamic, kinetic and x-ray crystallographic study. | thermodynamics and kinetics for cyanide, azide, thiocyanate and imidazole binding to recombinant ferric vitreoscilla sp. homodimeric hemoglobin (vitreoscilla hb) have been determined at ph 6.4 and 7.0, and 20.0 degrees c, in solution and in the crystalline state. moreover, the three-dimensional structures of the diligated thiocyanate and imidazole derivatives of recombinant ferric vitreoscilla hb have been determined by x-ray crystallography at 1.8 a (rfactor=19.9%) and 2.1 a (rfactor=23.8%) res ... | 1999 | 10448042 |
| expression of vitreoscilla hemoglobin in escherichia coli enhances ribosome and trna levels: a flow field-flow fractionation study. | asymmetrical flow field-flow fractionation (fff) was used to separate and quantitate 70s ribosomes, the 30s and 50s subunits, and trna in one single analytical procedure. the method was applied to an investigation of the effect of vitreoscilla hemoglobin (vhb) on the translational machinery of the recombinant escherichia coli cells. the number of active 70s ribosomes per cell increased dramatically, more than 2-fold, as did also the trna levels for the vhb-expressing strain relative to vhb-negat ... | 1999 | 10194389 |
| purification, crystallization and preliminary x-ray analysis of the soluble domain of the na+-pumping cytochrome bo quinol oxidase from vitreoscilla. | the 24 kda cyoa soluble domain of vitreoscilla cytochrome bo quinol oxidase, which pumps out na(+) during respiration, has been crystallized from a solution of 2 m ammonium sulfate and 5% 2-propanol. the crystal belongs to cubic space group p4(3)32, with unit-cell parameters a = b = c = 122.2 a, alpha = beta = gamma = 90 degrees and one subunit in the asymmetric unit. a 99.8% complete data set to 3.3 a has been collected at the 17-id beamline of the advanced photon source. the structure was dete ... | 2002 | 12136145 |
| cloning and expression of vitreoscilla hemoglobin gene in burkholderia sp. strain dnt for enhancement of 2,4-dinitrotoluene degradation. | the gene (vgb) encoding the hemoglobin (vhb) of vitreoscilla sp. was cloned into a broad host range vector and stably transformed into burkholderia (formerly pseudomonas) sp. strain dnt, which is able to degrade and metabolize 2,4-dinitrotoluene (dnt). vgb was stably maintained and expressed in functional form in this recombinant strain (yv1). when growth of yv1, in both tryptic soy broth and minimal salts broth containing dnt and yeast extract, was compared with that of the untransformed strain ... | 2000 | 10662485 |
| study of cytochrome bo function in vitreoscilla using a cyo(-) knockout mutant. | the bacterium, vitreoscilla, produces a delta mu(na+) across its membrane during respiration. a key enzyme for this function is the cytochrome bo terminal oxidase which, when incorporated into synthetic proteoliposomes, pumps na(+) across the membrane upon the addition of a substrate. a vitreoscilla cytochrome bo knock out (cyo(-)) mutant was isolated by transposon mutagenesis using put-mini-tn5cm. the membranes of this mutant lacked the characteristic 416 nm peak and 432 nm trough in co differe ... | 2000 | 10876157 |
| expression of double vitreoscilla hemoglobin enhances growth and alters ribosome and trna levels in escherichia coli. | in several organisms, expression of a gene encoding dimeric hemoglobin (vhb) from the obligate aerobic bacterium vitreoscilla stercoraria has been shown to increase microaerobic cell growth and enhance oxygen-dependent cell metabolism. in an attempt to further improve these effects of vhb, a gene encoding two vhb genes connected by a short linker of six base pairs was constructed and expressed in escherichia coli(double vhb). escherichia coli cells expressing double vhb reached a cell density 19 ... | 2002 | 12052087 |
| a pbrint family of plasmids for integration of cloned dna into the escherichia coli chromosome. | plasmid pbrint is an efficient vector for chromosomal integration of cloned dna into the lacz gene of escherichia coli [balbás et al., gene 136(1993) 211-213]. a family of related plasmids containing different antibiotic-resistance markers (cmr or gmr or kmr) and a larger multiple cloning site (mcs) has been constructed. this set of plasmids, whose integration efficiencies are as good as those obtained with the prototype plasmid pbrint, constitutes a collection of tools that allow rapid and easy ... | 1996 | 8654993 |
| bacterial hemoglobins and flavohemoglobins for alleviation of nitrosative stress in escherichia coli. | escherichia coli mg1655 cells expressing novel bacterial hemoglobin and flavohemoglobin genes from a medium-copy-number plasmid were grown in shake flask cultures under nitrosative and oxidative stress. e. coli cells expressing these proteins display enhanced resistance against the no(.) releaser sodium nitroprusside (snp) relative to that of the control strain bearing the parental plasmid. expression of bacterial hemoglobins originating from campylobacter jejuni (chb) and vitreoscilla sp. (vhb) ... | 2002 | 12324328 |
| production of alpha-amylase in fed-batch cultures of vgb+ and vgb- recombinant escherichia coli: some observations. | synthesis and excretion of bacillus stearothermophilus alpha-amylase is analyzed in fed-batch cultivations of escherichia coli jm103[pmk79] and e. coli jm103[pmk57], the former strain containing the plasmid-encoded vitreoscilla hemoglobin (vhb) gene (vgb) and the latter strain being devoid of this gene. fed-batch operation is observed to be substantially superior to batch operation as concerns the alpha-amylase production rate and the extent of excretion of the enzyme. faster feeding of a nutrie ... | 1999 | 10441355 |
| dissection of central carbon metabolism of hemoglobin-expressing escherichia coli by 13c nuclear magnetic resonance flux distribution analysis in microaerobic bioprocesses. | escherichia coli mg1655 cells expressing vitreoscilla hemoglobin (vhb), alcaligenes eutrophus flavohemoprotein (fhp), the n-terminal hemoglobin domain of fhp (fhpg), and a fusion protein which comprises vhb and the a. eutrophus c-terminal reductase domain (vhb-red) were grown in a microaerobic bioreactor to study the effects of low oxygen concentrations on the central carbon metabolism, using fractional (13)c-labeling of the proteinogenic amino acids and two-dimensional [(13)c, (1)h]-correlation ... | 2001 | 11157231 |
| cell growth and oxygen uptake of escherichia coli and pseudomonas aeruginosa are differently effected by the genetically engineered vitreoscilla hemoglobin gene. | vitreoscilla hemoglobin is a good oxygen trapping agent and its presence in genetically engineered escherichia coli helps this bacterium to grow better. here, the potential use of this hemoglobin, for improving the growth and the oxygen transfer properties of pseudomonas aeruginosa as well as escherichia coli, was investigated. to stably maintain it in both bacteria, a broad-host range cosmid vector (phg1), containing the entire coding sequence for vitreoscilla hemoglobin gene and its native pro ... | 2001 | 11164963 |
| expression of alcaligenes eutrophus flavohemoprotein and engineered vitreoscilla hemoglobin-reductase fusion protein for improved hypoxic growth of escherichia coli. | expression of the vhb gene encoding hemoglobin from vitreoscilla sp. (vhb) in several organisms has been shown to improve microaerobic cell growth and enhance oxygen-dependent product formation. the amino-terminal hemoglobin domain of the flavohemoprotein (fhp) of the gram-negative hydrogen-oxidizing bacterium alcaligenes eutrophus has 51% sequence homology with vhb. however, like other flavohemoglobins and unlike vhb, fhp possesses a second (carboxy-terminal) domain with nad(p)h and flavin aden ... | 2000 | 10618209 |
| [expression and roles of hemoglobin gene in bacillus subtilis]. | hemoglobin of the gram-negative bacterium vitreoscilla can bind oxygen strongly and reduce the oxygen requirement of the bacterium. a recombinant plasmid pav was constructed by inserting the hemoglobin gene (vgb) to the downstream of the promoter of beta-lactase gene of the b. subtilis plasmid pak4. the plasmid pav was transferred into strain db104, g331 (a subtilisin-producing b. subtilis) and b53 (a xylanase-producing b. subtilis). the subclones and transfer of the vgb gene into pak4 were dete ... | 2000 | 10887688 |
| globins in nonvertebrate species: dispersal by horizontal gene transfer and evolution of the structure-function relationships. | using a new template based on an alignment of 145 nonvertebrate globins we examined several recently determined sequences of putative globins and globin-like hemeproteins. we propose that all globins have evolved from a family of ancestral, approx. 17-kda hemeproteins, which displayed the globin fold and functioned as redox proteins. once atmospheric o2 became available the acquisition of oxygen-binding properties was initiated, culminating in the various highly specialized functions known as pr ... | 1996 | 8587498 |
| optimization of immunogold labeling tem. an elisa-based method for rapid and convenient simulation of processing conditions for quantitative detection of antigen. | we developed an elisa-based method for rapid optimization of various tissue processing parameters in immunogold labeling for electron microscopy. the effects of aldehyde fixation, tannic acid, postfixation, dehydration, temperature, and antigen retrieval on antibody binding activity of vitreoscilla hemoglobin (vhb) expressed in e. coli cells were assayed by elisa and the results confirmed by quantitative immunogold labeling transmission electron microscopy (tem). our results demonstrated that lo ... | 2001 | 11181739 |