Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
29
pubmed:dateCreated
1994-8-25
pubmed:abstractText
Site-directed mutants of cytochrome c peroxidase (CcP) were created to modify the interaction domain between CcP and yeast iso-1-cytochrome c (yCC) seen in the crystal structure of the CcP-yCC complex [Pelletier & Kraut (1992) Science 258, 1748-1755]. In the crystalline CcP-yCC complex, two acidic regions of CcP contact lysine residues on yCC. Mutants E32Q, D34N, E35Q, E290N, and E291Q were used to examine the effect of converting individual carboxylate side chains in the acidic regions to amides. The A193F mutant was used to test the effect of introducing a phenyl moiety at the point of closest contact between CcP and yCC in the crystal structure. Stopped-flow experiments carried out in 310 mM ionic strength buffer at pH 7 revealed that yCC initially reduced the indole radical on Trp-191 of the parent CcP compound I with a bimolecular rate constant ka = 2.5 x 10(8) M-1 s-1. A second molecule of yCC subsequently reduced the oxyferryl heme of compound II with a rate constant kb = 5 x 10(7) M-1 s-1. The bimolecular rate constants ka and kb were affected in parallel by each mutation examined. CcP mutants D34N and E290N that are closest to a complementary yCC lysine residue in the crystalline CcP-yCC complex gave the lowest values for ka and kb, which were 25-50% of the values of the CcP parent. Mutants E32Q and E291Q that are removed from the interaction domain gave the same ka and kb values as the CcP parent.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
26
pubmed:volume
33
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
8686-93
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1994
pubmed:articleTitle
Interaction domain for the reaction of cytochrome c with the radical and the oxyferryl heme in cytochrome c peroxidase compound I.
pubmed:affiliation
Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville 72701.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.