Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0026918 (Mycobacterium)
 52,428 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Formate dehydrogenase activity (EC 1.2.1.2) has been demonstrated in cell-free preparations of Mycobacterium phlei by following the reduction of 2,6 dichlorophenolindophenol. thiazolyl blue tetrazolium, or equine cytochrome c. The reduction of equine cytochrome c was inhibited by 2-heptyl-4-hydroxyquinoline-N-oxide. Neither nicotinamide adenine dinucleotide nor nicotinamide adenine dinucleotide phosphate were reduced by this formate dehydrogenase. The enzyme was constitutive and associated with the particular fraction. The greatest level of activity was observed at pH 9.0, with 8 mM formate, and with extracts of cells taken from the log phase of growth. Formaldehyde, hypophosphite, nitrate, and bicarbonate all inhibited the oxidation of formate.
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PMID:Nicotinamide adenine dinucleotide -- independent formate dehydrogenase in Mycobacterium phlei. 1 20

The present study tested the hypothesis that BCG-activated macrophages become injured when they phagocytose certain particulates. The data indicate that alveolar macrophages obtained from Mycobacterium bovis BCG-sensitized animals were more susceptible to cell death after in vitro incubation with BCG or zymosan than were macrophages from normal animals. Increased susceptibility was dependent on phagocytosis, since incubation with cytochalasin B, a phagocytosis inhibitor, abrogated the effect. Catalase, cytochrome c, and ascorbic acid offered partial protection to the macrophage, suggesting the involvement of free radicals in the generation of cytotoxicity. Not all of the cells from the alveolar populations were equally susceptible to cell death, thus suggesting either heterogeneity in the cell population or a requirement of more than one cell type in the induction of necrosis or both.
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PMID:Phagocytosis-induced injury of normal and activated alveolar macrophages. 23 Oct 11

Irradiation with ultraviolet light (360 nm) of cell-free extracts, electron-transport particles, and soluble components from Mycobacterium phlei resulted in the loss of malate oxidation by the flavine adenine dinucleotide pathway both in cell-free extracts and reconstituted systems. Addition of vitamin K1 restored the loss to the extent of 14% and 11% in cell-free extracts and reconstituted systems respectively. Electron-transport particles from M. phlei upon reduction with malate exhibited electron-paramagnetic resonance signals at g = 2.002 and 1.94, characteristic of napthosemiquinone and nonheme iron protein, respectively. Upon irradiating the particles with ultraviolet light (360 nm) these signals were not observed. Particulate flavine-adenine-dinucleotide-dependent malate dehydrogenase (EC 1.1.1.37) of M. phlei assayed by the 3-(4,5-dimethylthiazolyl-2)-2,5-diphenyl tetrazolium bromide and phenazine methosulfate - 2,6-dichlorophenolindophenol systems, which trap electrons at cytochrome c and at the flavine level respectively, was inhibited by o-phenanthroline. These observations suggest that nonheme iron protein is sensitive to ultraviolet light (360 nm) and participates before or in combination with flavine in the malate (flavine adenine dinucleotide) pathway of M. phlei.
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PMID:Site of action of nonheme iron in the malate (flavine adenine dinucleotide) pathway of Mycobacterium phlei. 96 13

Mycobacterium lepraemurium was cultivated on Ogawa egg-yolk medium and its energy coupling mechanisms were investigated. Cell-free extracts prepared from in vitro-grown cells catalyzed phosphorylation coupled to the oxidation of generated NADH, added NADH, and succinate-yielding ratios of phosphorus moles incorporated into high-energy bonds to oxygen atoms utilized (P/O ratios) of 0.75, 0.52, and 0.36, respectively. Ascorbate oxidation alone or in the presence of tetramethyl-p-phenyline-diamine (TMPD) did not yield any adenosine triphosphate (ATP). However, ascorbate in the presence of added cytochrome c was coupled to ATP synthesis and yielded a P/O ratio of 0.12. The oxidative phosphorylation was uncoupled by all of the uncouplers used without any inhibition of oxygen consumption. ATP generation coupled to NADH oxidation was completely inhibited by the flavoprotein inhibitors, such as rotenone and amytal; these inhibitors had no effect, however, on ATP synthesis associated with succinate oxidation. Antimycin A or 2-n-heptyl-4-hydroxy-quinoline-N-oxide (HQNO) and cyanide inhibited markedly the oxidations of NADH and succinate as well as the coupled ATP generation. The phosphorylation coupled to ascorbate plus cytochrome c was not affected by either of the flavoprotein inhibitors or by antimycin A or HQNO, but was completely inhibited by cyanide. The thiol-bearing agents p-chloromercuribenzoate (PCMB) and N-ethylmaleimide were the potent inhibitors of the phosphorylation associated with the oxidation of NADH and succinate. The results indicate that the three energy-coupling sites are functional in the respiratory chain of in vitro-grown M. lepraemurium.
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PMID:Energy generation mechanisms in the in vitro-grown Mycobacterium lepraemurium. 131 45

Growth of Mycobacterium phlei under low oxygen tension resulted in specific activities two to twenty times lower for formate dehydrogenase, malate dehydrogenase, beta-hydroxybutyrate dehydrogenase, lactate oxidase and NADH dehydrogenase than when cultures were grown under high aeration. An increase in fumarate reductase and succinate dehydrogenase occurred with M. phlei grown under low oxygen tension. Malate: vitamin K dehydrogenase and glucose-6-phosphate dehydrogenase activity were not significantly affected by the oxygen tension used to grow the bacteria, and neither culture contained a lactate dehydrogenase. With growth of M. phlei in conditions of low oxygen tension, cytochrome a was not detected, but cytochrome b was prominent in membranes and cytochrome c was present in the soluble fraction.
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PMID:Influence of oxygen tension on the respiratory activity of Mycobacterium phlei. 318 14

Ferric mycobactins were prepared from Mycobacterium phlei. Mycobacterium avium--intracellulare A and H, isolated respectively from armadillo and human leprosy specimens. Attempts were made to extract mycobactin from host grown M. leprae cells. The crude ferric mycobactin extracts were tested for growth supporting effect on the mycobactin dependent M. paratuberculosis strain ATCC 19698. Mycobactins prepared from M. phlei and the two M. avium--intracellulare strains had growth promoting effect on M. paratuberculosis. The same test organism did not grow in media supplemented with the extract prepared from M. leprae. Results indicate the absence of mycobactin from host grown M. leprae. Since M. leprae cells contain cytochrome c and since mycobactin is essential to growth of all mycobacteria, M. leprae might be considered as a microbe dependent microbe. It is proposed that secondary mycobacteria present in M. leprae infected humans and armadillos might provide mycobactin for in vivo multiplication of M. leprae.
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PMID:Absence of mycobactin in Mycobacterium leprae; probably a microbe dependent microorganism implications. 389 5

The toxicity for mice of the cord factor of Cornebacterium diphtheriae, trehalose-6,6'-dicorynomycolate, was studied. The diphtherial cord factor showed a delayed lethal toxicity for mice; the median lethal dose was 120 mug. Mouse liver mitochondria were disrupted in vivo under the toxic action of the diphtherial cord factor into fragments deficient in both respiration and phosphorylation. The site of metabolic defect in the mitochondrial electron transport system was located at the region prior to the level of cytochrome c in the livers of cord factor-intoxicated mice. These effects of the diphtherial cord factor on the host-cell mitochondria were essentially similar to those of the cord factor of Mycobacterium tuberculosis, trehalose-6,6'-dimycolate.
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PMID:Action of a toxic glycolipid of Corynebacterium diphtheriae on mitochondrial structure and function. 431 42

Chloramphenicol was found to have a direct effect on the respiratory chain of Mycobacterium phlei cells grown in the presence of this drug. Analysis of the respiratory chain components revealed that the presence of chloramphenicol during growth resulted in a partial inhibition in the synthesis of the cytochromes. However, a stimulation in oxidative phosphorylation was observed with the cell-free extract of cells grown in the presence of chloramphenicol. The oxidation of succinate was found to be stimulated 20 to 130%, depending on the particular extract, whereas the oxidation of reduced nicotinamide adenine dinucleotide (NADH) was found to be similar to that of extracts obtained from cells grown in the absence of the drug. Of particular interest was the finding that the cell-free extract of cells grown in the presence of the drug exhibited an increased level of phosphorylation (17 to 100%) when NADH was used as the electron donor. Chloramphenicol appears to affect a component of the respiratory chain between the flavoprotein and cytochrome c. Fractionation of the electron transport particles revealed an increased level of cytochrome b in the fractions which exhibited a stimulation in oxidative phosphorylation.
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PMID:Oxidative phosphorylation in fractionated bacterial systems: effect of chloramphenicol. 433 16

Recent improvements in the sensitivity of assay methods for superoxide dismutase (SOD) have enabled the detection of this enzyme in 18 cell-free extracts of purified Mycobacterium leprae. By converting back to units of SOD obtained in the cytochrome c-based method previously used in work on this enzyme in mycobacteria, it was shown that extracts of M. leprae had 0.15-3.84 U SOD/mg protein (this study). A mean value of 1.31 U/mg protein was calculated. It was not possible to find any factors which could explain the very high levels in some extracts, although correlation with the period of tissue storage at -80 degrees C suggested that M. leprae in freshly killed tissue would have 1.77 U SOD/mg protein. The possibility of contamination by SODs from host and other organisms was unlikely since on gel electrophoresis extracts of M. leprae with high levels of SOD showed only a single band of activity characteristic of manganese-dependent SOD previously demonstrated.
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PMID:Variation of superoxide dismutase levels in extracts of Mycobacterium leprae from armadillo liver. 636 28

The respiratory pigments of cell suspensions of Mycobacterium lepraemurium cultivated on Ogawa egg-yolk medium were investigated spectrophotometrically. The results obtained showed that whole cell suspensions of both Kumato and Hawaiian strains contained flavins, cytochromes of the a2 and b type, as well as a CO-binding pigment similar to cytochrome o. The whole cell suspensions of M. lepraemurium did not show detectable quantities of c type cytochrome. However, cytochrome c was present in small amounts, and its presence became evident in the dithionite-reduced minus oxidized difference spectra of pyridine haemochromogens prepared from in vitro grown cells of M. lepraemurium.
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PMID:Cytochrome system in cultivated Mycobacterium lepraemurium. 642 10


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