Linked Life Data

11884127

Source:http://linkedlifedata.com/resource/pubmed/id/11884127

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2002-3-8
pubmed:abstractText
Bivalent peptidic thrombin inhibitors consisting of an N-terminal d-cyclohexylalanine-Pro-N(alpha)(Me)Arg active-site fragment, a flexible polyglycine linker, and a C-terminal hirugen-like segment directed towards the fibrinogen recognition exosite inhibit thrombin with K(i) values in the picomolar range, remaining stable in buffered solution at pH 7.8 for at least 15 hours. In order to investigate the structural basis of this increased stability, the most potent of these inhibitors, I-11 (K(i)=37pM), containing an N(alpha)(Me)Arg-Thr bond, was crystallized in complex with human alpha-thrombin. X-ray data were collected to 1.8A resolution and the crystal structure of this complex was determined. The Fourier map displays clear electron density for the N-terminal fragment and for the exosite binding segment. It indicates, however, that in agreement with Edman sequencing, the peptide had been cleaved in the crystal, presumably due to the long incubation time of 14 days needed for crystallization and data collection. The N(alpha)(Me) group is directed toward the carbonyl oxygen atom of Ser214, pushing the Ser195 O(gamma) atom out of its normal site. This structure suggests that upon thrombin binding, the scissile peptide bond of the intact peptide and the Ser195 O(gamma) are separated from each other, impairing the nucleophilic attack of the Ser195 O(gamma) toward the N(alpha)(Me)Arg carbonyl group. In the time-scale of two weeks, however, cleavage geometries favoured by the crystal allow catalysis at a slow rate.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0022-2836
pubmed:author
pubmed:copyrightInfo
Copyright 2002 Elsevier Science Ltd.
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
316
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
869-74
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
The methyl group of N(alpha)(Me)Arg-containing peptides disturbs the active-site geometry of thrombin, impairing efficient cleavage.
pubmed:affiliation
Max-Planck-Institut für Biochemie, Abteilung Strukturforschung, Martinsried, Germany. rfried@biochem.mpg.de
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't