rdf:type |
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lifeskim:mentions |
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pubmed:issue |
1
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pubmed:dateCreated |
1989-5-10
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pubmed:abstractText |
Protease activity present in aerobically grown cells of Pseudomonas perfectomarina, protease apparently copurified with cytochrome c-552, and trypsin achieved a limited proteolysis of the diheme cytochrome c-552. That partial lysis conferred cytochrome c peroxidase activity upon cytochrome c-552. The removal of a 4000-Da peptide explains the structural changes in the cytochrome c-552 molecule that resulted in the appearance of both cytochrome c peroxidase activity (with optimum activity at pH 8.6) and a high-spin heme iron. The oxidized form of the modified cytochrome c-552 bound cyanide to the high-spin ferric heme with a rate constant of (2.1 +/- 0.1) X 10(3) M-1 s-1. The dissociation constant was 11.2 microM. Whereas the intact cytochrome c-552 molecule can be half-reduced by ascorbate, the cytochrome c peroxidase was not reducible by ascorbate, NADH, ferrocyanide, or reduced azurin. Dithionite reduced the intact protein completely but only half-reduced the modified form. The apparent second-order rate constant for dithionite reduction was (7.1 +/- 0.1) X 10(2) M-1 s-1 for the intact protein and (2.2 +/- 0.1) X 10(3) M-1 s-1 for the modified form. In contrast with other diheme cytochrome c peroxidases, reduction of the low-spin heme was not necessary to permit ligand binding by the high-spin heme iron.
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pubmed:language |
eng
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pubmed:journal |
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pubmed:citationSubset |
IM
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pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Ascorbic Acid,
http://linkedlifedata.com/resource/pubmed/chemical/Cytochrome c Group,
http://linkedlifedata.com/resource/pubmed/chemical/Cytochrome-c Peroxidase,
http://linkedlifedata.com/resource/pubmed/chemical/Dithionite,
http://linkedlifedata.com/resource/pubmed/chemical/Heme,
http://linkedlifedata.com/resource/pubmed/chemical/Peptide Fragments,
http://linkedlifedata.com/resource/pubmed/chemical/Peroxidases,
http://linkedlifedata.com/resource/pubmed/chemical/Potassium Cyanide,
http://linkedlifedata.com/resource/pubmed/chemical/Trypsin,
http://linkedlifedata.com/resource/pubmed/chemical/cytochrome C-552,
http://linkedlifedata.com/resource/pubmed/chemical/cytochrome c553,
http://linkedlifedata.com/resource/pubmed/chemical/hemochromogen
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pubmed:status |
MEDLINE
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pubmed:month |
Apr
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pubmed:issn |
0003-9861
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pubmed:author |
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pubmed:issnType |
Print
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pubmed:volume |
270
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
114-25
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pubmed:dateRevised |
2006-11-15
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pubmed:meshHeading |
pubmed-meshheading:2539041-Amino Acid Sequence,
pubmed-meshheading:2539041-Ascorbic Acid,
pubmed-meshheading:2539041-Binding Sites,
pubmed-meshheading:2539041-Cytochrome c Group,
pubmed-meshheading:2539041-Cytochrome-c Peroxidase,
pubmed-meshheading:2539041-Dithionite,
pubmed-meshheading:2539041-Electron Spin Resonance Spectroscopy,
pubmed-meshheading:2539041-Heme,
pubmed-meshheading:2539041-Hydrolysis,
pubmed-meshheading:2539041-Molecular Sequence Data,
pubmed-meshheading:2539041-Oxidation-Reduction,
pubmed-meshheading:2539041-Peptide Fragments,
pubmed-meshheading:2539041-Peroxidases,
pubmed-meshheading:2539041-Potassium Cyanide,
pubmed-meshheading:2539041-Pseudomonas,
pubmed-meshheading:2539041-Spectrophotometry,
pubmed-meshheading:2539041-Trypsin
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pubmed:year |
1989
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pubmed:articleTitle |
Cytochrome c peroxidase activity of a protease-modified form of cytochrome c-552 from the denitrifying bacterium Pseudomonas perfectomarina.
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pubmed:affiliation |
Department of Biochemistry, University of Georgia, Athens 30602.
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pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, Non-P.H.S.,
Research Support, Non-U.S. Gov't
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