Linked Life Data

15708807

Source:http://linkedlifedata.com/resource/pubmed/id/15708807

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2005-2-14
pubmed:abstractText
Three microperoxidases--hemin-6(7)-gly-gly-his methyl ester (HGGH), mesohemin-6(7)-gly-gly-his methyl ester (MGGH) and deuterohemin-6(7)-gly-gly-his methyl ester (DGGH)--have been prepared as models for heme-containing peroxidases by condensation of glycyl-glycyl-L-histidine methyl ester with the propionic side chains of hemin, mesohemin and deuterohemin, respectively. The three microperoxidases differ in two substituents, R, of the protoporphyrin IX framework (HGGH: R=vinyl, MGGH: R=ethyl, DGGH: R=H). X-band and high field EPR spectra show that the microperoxidases exhibit spectroscopic properties similar to those of metmyoglobin, i.e. a high spin ferric S=5/2 signal at g(perpendicular)=6 and g parallel)=2 and an estimated D value of 7.5+/-1cm(-1). The catalytic activities of the microperoxidases towards K4[Fe(CN)6], L-tyrosine methyl ester and 2,2'-azino(bis(3-ethylbenzothiazoline-6-sulfonic acid)) (ABTS) have been investigated. It was found that all three microperoxidases exhibit peroxidase activity and that the reactions follow the generally accepted peroxidase reaction scheme [Biochem. J. 145 (1975) 93-103] with the exception that the initial formation of a Compound I analogue is the rate-limiting step for the whole process. The general activity trend was found to be MGGH approximately DGGH>HGGH. For each microperoxidase, DFT calculations (B3LYP) were made on the reactions of compounds 0, I and II with H+, e- and H+ + e-, respectively, in order to probe the possible relationship between the nature of the 2- and 4-substituents of the hemin and the observed reactivity. The computational modeling indicates that the relative energy differences are very small; solvation and electrostatic effects may be factors that decide the relative activities of the microperoxidases.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/2,2'-azino-di-(3-ethylbenzothiazolin..., http://linkedlifedata.com/resource/pubmed/chemical/Benzothiazoles, http://linkedlifedata.com/resource/pubmed/chemical/Dipeptides, http://linkedlifedata.com/resource/pubmed/chemical/Heme, http://linkedlifedata.com/resource/pubmed/chemical/Hemin, http://linkedlifedata.com/resource/pubmed/chemical/Hydrogen Peroxide, http://linkedlifedata.com/resource/pubmed/chemical/Mesoporphyrins, http://linkedlifedata.com/resource/pubmed/chemical/Oligopeptides, http://linkedlifedata.com/resource/pubmed/chemical/Peroxidases, http://linkedlifedata.com/resource/pubmed/chemical/Sulfonic Acids, http://linkedlifedata.com/resource/pubmed/chemical/Tyrosine, http://linkedlifedata.com/resource/pubmed/chemical/deuterohemin, http://linkedlifedata.com/resource/pubmed/chemical/glycylhistidine, http://linkedlifedata.com/resource/pubmed/chemical/mesoporphyrin IX, http://linkedlifedata.com/resource/pubmed/chemical/microperoxidase, http://linkedlifedata.com/resource/pubmed/chemical/tyrosine methyl ester
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0162-0134
pubmed:author
pubmed:issnType
Print
pubmed:volume
99
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
852-63
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2005
pubmed:articleTitle
A comparative reactivity study of microperoxidases based on hemin, mesohemin and deuterohemin.
pubmed:affiliation
Inorganic Chemistry, Center for Chemistry and Chemical Engineering, Lund University, Box 124, SE-221 00 Lund, Sweden.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't