Linked Life Data

14505074

Source:http://linkedlifedata.com/resource/pubmed/id/14505074

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
7
pubmed:dateCreated
2003-9-23
pubmed:abstractText
Cytochrome c peroxidase (C cP) variants with an engineered Mn(II) binding site, including MnC cP [C cP(MI, G41E, V45E, H181D)], MnC cP(W191F), and MnC cP(W191F, W51F), that mimic manganese peroxidase (MnP), have been characterized by resonance Raman (RR) spectroscopy. Analysis of the Raman bands in the 200-700 cm(-1) and 1300-1650 cm(-1) regions indicates that both the coordination and spin state of the heme iron in the variants differ from that of C cP(MI), the recombinant yeast C cP containing additional Met-Ile residues at the N-terminus. At neutral pH the frequencies of the nu(3) mode indicate that a pure five-coordinate heme iron exists in C cP(MI) whereas a six-coordinate low-spin iron is the dominant species in the C cP variants with the engineered Mn(II) binding site. The H181D mutation, which weakens the proximal linkage to the heme iron, may be responsible for these spectral and structural changes. Raman spectra of the variants C cP(MI, W191F) and C cP(MI, W191F, W51F) were also obtained to clarify the structural and functional roles of mutations at two tryptophan sites. The W51F mutation was found to disrupt H-bonding to the distal water molecules and the resulting variants tended to form transitional or mixed coordination states that possess spectral and structural features similar to that of MnP. Such structural features, with a loosened distal water, may facilitate the binding of H(2)O(2) and increase the rate constant for compound I formation. This effect, in addition to the elimination of an H-bond to ferryl oxygen by the same mutation, accounts for the increased MnP specific activity of MnC cP(W191F, W51F).
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0949-8257
pubmed:author
pubmed:issnType
Print
pubmed:volume
8
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
699-706
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2003
pubmed:articleTitle
Resonance Raman spectroscopy of cytochrome c peroxidase variants that mimic manganese peroxidase.
pubmed:affiliation
Department of Chemistry, Jackson State University, Box 17910, Jackson, MS 39217-0510, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.