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  • 1
    Electronic Resource
    Electronic Resource
    Development of amine oxidase-containing peroxisomes in yeasts during growth on glucose in the presence of methylamine as the sole source of nitrogen (1980)
    Springer
    Archives of microbiology 126 (1980), S. 117-126 
    Details
    ISSN: 1432-072X
    Keywords: Candida utilis ; Hansenula polymorpha ; Amine oxidase ; Methylamine ; Nitrogen metabolism ; Peroxisome
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The metabolism of methylamine as the nitrogen source for growth of the non-methylotrophic yeast Candida utilis and the methylotrophic yeast Hansenula polymorpha was investigated. Grwoth of both organisms in media with glucose and methylamine was associated with the presence of an amine oxidase in these cells. The enzyme catalyses the oxidation of methylamine by molecular oxygen into ammonia, formaldehyde and hydrogen peroxide and it is considered to be the key enzyme in methylamine metabolism in the organisms studied. In addition to synthesis of amine oxidase, derepression of catalase, formaldehyde and formate dehydrogenase was also observed upon transfer of cells of the two organisms from media containing ammonium ions into media containing methylamine as the nitrogen source. The synthesis of enzymes was paralleled by the development of a number of large microbodies in the cells. Cytochemical staining experiments indicated that the amine oxidase activity was located in the microbodies in both organisms. Catalase-activity was also demonstrated in these organelles, which can therefore be considered as peroxisomes. The present contribution is the first description of a peroxisomal amine oxidase.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00511216
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  • 2
    Electronic Resource
    Electronic Resource
    Physiological role of microbodies in the yeast Trichosporon cutaneum during growth on ethylamine as the source of energy, carbon and nitrogen (1986)
    Springer
    Archives of microbiology 145 (1986), S. 39-50 
    Details
    ISSN: 1432-072X
    Keywords: Amine metabolism ; Microbodies ; Amine oxidase ; Cytochemistry ; Cell fractionation ; Trichosporon cutaneum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Compartmentation of the metabolism of ethylamine in Trichosporon cutaneum X4 was studied in cells, grown on this compound as the sole source of energy, carbon, and nitrogen. Transfer experiments indicated that an amine oxidase is involved in the early metabolism of ethylamine. The synthesis of this enzyme was induced by primary amines and was subject to partial carbon catabolite repression. Repression by ammonium ions was not observed. Adaptation of glucose-grown cells to growth on ethylamine was associated with the development of many microbodies, which developed from already existing organelles present in the inoculum cells and multiplied by division. Cytochemical experiments indicated that the organelles contained amine oxidase and catalase. Therefore, they were considered to play a key role in the metabolism of ethylamine. The physiological significance of the microbodies was investigated by fractionation studies of homogenized protoplasts from ethylamine-grown cells by differential- and sucrose-gradient centrifugation of subcellular organelles. Intact microbodies were only obtained when the isolation procedure was performed at pH 5.8 in the absence of Mg2+-ions. Analysis of the different fractions indicated that the key enzymes of the glyoxylate cycle, namely isocitrate lyase and malate synthase, cosedimented together with catalase and amine oxidase. In addition, activities of malate dehydrogenase, glutamate:oxaloacetate aminotransferase (GOT) and (NAD-dependent) glutamate dehydrogenase were detected in these fractions. Electron microscopy revealed that they mainly contained microbodies. Cytochemical experiments indicated that the above enzymes were all present in the same organelle. These findings suggest that microbodies of ethylamine-grown T. cutaneum X4 produce aspartate, so allowing NADH generated in the oxidation of malate by malate dehydrogenase to be quantitatively reoxidized inside the organelles in a series of reactions involving GOT and glutamate dehydrogenase. Aspartase and fumarase were not detected in the microbodies; activities of these two enzymes were present in the cytoplasm.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00413025
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  • 3
    Electronic Resource
    Electronic Resource
    Proliferation and metabolic significance of peroxisomes in Candida boidinii during growth on d-alanine or oleic acid as the sole carbon source (1990)
    Springer
    Archives of microbiology 153 (1990), S. 485-489 
    Details
    ISSN: 1432-072X
    Keywords: Candida boidinii ; Yeast ; Peroxisomes ; β-Oxidation ; d-Amino acid oxidase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We have studied the induction of peroxisomes in the methylotrophic yeast Candida boidinii by d-alanine and oleic acid. The organism was able to utilize each of these compounds as the sole carbon source and grew with growth rates of μ=0.20 h-1 (on d-alanine) or μ=0.43 h-1 (on oleic acid). Growth was associated with the development of many peroxisomes in the cells. On d-alanine a cluster of tightly interwoven organelles was observed which made up 6.3% of the cytoplasmic volume and were characterized by the presence of d-amino acid oxidase and catalase. On oleic acid rounded to elongated peroxisomes were dominant which were scattered throughout the cytoplasm. These organelles contained increased levels of β-oxidation enzymes; their relative volume fraction amounted 12.8% of the cytoplasmic volume.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00248431
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  • 4
    Electronic Resource
    Electronic Resource
    Arthrobacter P 1, a fast growing versatile methylotroph with amine oxidase as a key enzyme in the metabolism of methylated amines (1981)
    Springer
    Archives of microbiology 129 (1981), S. 72-80 
    Details
    ISSN: 1432-072X
    Keywords: Arthrobacter ; Facultative methylotroph ; Amine oxidase ; Catalase ; RuMP cycle of formaldehyde fixation ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A facultative methylotrophic bacterium was isolated from enrichment cultures containing methylamine as the sole carbon source. It was tentatively identified as an Arthrobacter species. Extracts of cells grown on methylamine or ethylamine contained high levels of amine oxidase (E.C. 1.4.3.) activity. Glucose- or choline-grown cells lacked this enzyme. Oxidation of primary amines by the enzyme resulted in the formation of H2O2; as a consequence high levels of catalase were present in methylamine-and ethylamine-grown cells. The significance of catalase in vivo was demonstrated by addition of 20 mM aminotriazole (a catalase inhibitor) to exponentially growing cells. This completely blocked growth on methylamine whereas growth on glucose was hardly affected. Cytochemical studies showed that methylamine-dependent H2O2 production mainly occurred on invaginations of the cytoplasmic membrane. Assimilation of formaldehyde which is generated during methylamine oxidation was by the FBP variant of the RuMP cycle of formaldehyde fixation. The absence of NAD-dependent formaldehyde and formate dehydrogenases indicated the operation of a non-linear oxidation sequence for formal-dehyde via hexulose phosphate synthase. Enzyme profiles of the organism grown on various substrates suggested that the synthesis of amine oxidase, catalase and the enzymes of the RuMP cycle is not under coordinate control.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00417184
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  • 5
    Electronic Resource
    Electronic Resource
    Permeability properties of peroxisomal membranes from yeasts (1990)
    Springer
    Archives of microbiology 153 (1990), S. 490-495 
    Details
    ISSN: 1432-072X
    Keywords: Hansenula polymorpha ; Candida boidinii ; Peroxisome ; Peroxisomal membrane ; Permeability ; Membrane fusion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We have studied the permeability properties of intact peroxisomes and purified peroxisomal membranes from two methylotrophic yeasts. After incorporation of sucrose and dextran in proteoliposomes composed of asolectin and peroxisomal membranes isolated from the yeasts Hansenula polymorpha and Candida boidinii a selective leakage of sucrose occurred indicating that the peroxisomal membranes were permeable to small molecules. Since the permeability of yeast peroxisomal membranes in vitro may be due to the isolation procedure employed, the osmotic stability of peroxisomes was tested during incubations of intact protoplasts in hypotonic media. Mild osmotic swelling of the protoplasts also resulted in swelling of the peroxisomes present in these cells but not in a release of their matrix proteins. The latter was only observed when the integrity of the cells was disturbed due to disruption of the cell membrane during further lowering of the concentration of the osmotic stabilizer. Stability tests with purified peroxisomes indicated that this leak of matrix proteins was not associated with the permeability to sucrose. Various attempts to mimic the in vivo situation and generate a proton motive force across the peroxisomal membranes in order to influence the permeability properties failed. Two different proton pumps were used for this purpose namely bacteriorhodopsin (BR) and reaction center-light-harvesting complex I (RCLHI complex). After introduction of BR into the membrane of intact peroxisomes generation of a pH-gradient was not or barely detectable. Since this pump readily generated a pH-gradient in pure liposomes, these results strengthened the initial observations on the leakiness of the peroxisomal membrane fragments. Generation of a membrane potential (Δψ) was also not observed when RCLHI complex was introduced into vesicles of purified peroxisomal membranes. The significance of the observed permeability of isolated yeast peroxisomal membranes to small molecules with respect to current and future in vitro import studies is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00248432
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  • 6
    Electronic Resource
    Electronic Resource
    Occurrence of peroxisomal membrane proteins in methylotrophic yeasts grown under different conditions (1990)
    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 6 (1990), S. 35-43 
    Details
    ISSN: 0749-503X
    Keywords: Hanseula polymorpha ; Candida boidinii ; peroxisomes ; peroxisomal membrane proteins ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: We have the substructure and polypeptide composition of the peroxisomal membranes in two methylotrophic yeasts in relation to different growth conditions. The results obtained that no significant ultrastructural differences existed between the membranes of variously grown cells.The presence of specific peroxisomal membrane proteins (PMPs) was studied biochemically. On sodium dodecyl sulphate-polyacrylamide gels of purified microbody membranes isolated from methanol-grown Hansenula polymorpha, prominent proteins bands were observed at 22, 31, 35, 42, 49 and 51 kD. These proteins were also present when the cells were grown in media containing ethanol and/or ethylamine. Apart from these, several other PMPs were specifically induced under these conditions, namely 24, 29, 37 and 62 kD proteins. The polypeptide composition of peroxisomal membranes from H. polymorpha was compared with that of another methylotroph. Candida biodinii. In the latter organism a specific PMP with a molecular weight of 23 kD was induced during growth on D-alanine instead of ammonium sulphate as the nitrogen source.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/yea.320060104
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