Linked Life Data

16341900

Source:http://linkedlifedata.com/resource/pubmed/id/16341900

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2006-2-10
pubmed:abstractText
The pH dependence of redox properties, spectroscopic features and CO binding kinetics for the chelated protohemin-6(7)-L-histidine methyl ester (heme-H) and the chelated protohemin-6(7)-glycyl-L-histidine methyl ester (heme-GH) systems has been investigated between pH 2.0 and 12.0. The two heme systems appear to be modulated by four protonating groups, tentatively identified as coordinated H(2)O, one of heme's propionates, N(epsilon) of the coordinating imidazole, and the carboxylate of the histidine residue upon hydrolysis of the methyl ester group (in acid medium). The pK (a) values are different for the two hemes, thus reflecting structural differences. In particular, the different strain at the Fe-N(epsilon) bond, related to the different length of the coordinating arm, results in a dramatic alteration of the bond strength, which is much smaller in heme-H than in heme-GH. It leads to a variation in the variation of the pKa for the protonation of the N(epsilon) of the axial imidazole as well as in the proton-linked behavior of the other protonating groups, envisaging a cross-talk communication mechanism among different groups of the heme, which can be operative and relevant also in the presence of the protein matrix.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0949-8257
pubmed:author
pubmed:issnType
Print
pubmed:volume
11
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
153-67
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2006
pubmed:articleTitle
pH-dependent redox and CO binding properties of chelated protoheme-L-histidine and protoheme-glycyl-L-histidine complexes.
pubmed:affiliation
Department of Molecular, Cellular and Animal Biology, University of Camerino, Via F. Camerini 2, 62032 Camerino, Italy.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't