Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1989-5-10
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.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0003-9861
pubmed:author
pubmed:issnType
Print
pubmed:volume
270
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
114-25
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1989
pubmed:articleTitle
Cytochrome c peroxidase activity of a protease-modified form of cytochrome c-552 from the denitrifying bacterium Pseudomonas perfectomarina.
pubmed:affiliation
Department of Biochemistry, University of Georgia, Athens 30602.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't