Linked Life Data

12939144

Source:http://linkedlifedata.com/resource/pubmed/id/12939144

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
34
pubmed:dateCreated
2003-8-26
pubmed:abstractText
The shutter region of serpins consists of a number of highly conserved residues that are critical for both stability and function. Several variants of antithrombin with substitutions in this region are unstable and predispose the carrier to thrombosis. Although most mutations in the shutter region investigated to date are deleterious with respect to serpin stability and function, the substitution of Phe51 by Leu in alpha(1)-antitrypsin results in enhanced stability. Here, we have investigated the effects of introducing an analogous mutation into antithrombin (Phe 77 to Leu). The mutation did not affect the kinetics of interaction with proteases. Strikingly, however, the thermostability of the protein was markedly decreased, with the serpin displaying a 13 degrees C decrease in melting temperature as compared to wild-type recombinant antithrombin. Further studies revealed that in contrast to wild-type antithrombin, the mutant adopted the latent (inactive) conformation upon mild heating. Previous studies on shutter region mutations that destabilize antithrombin revealed that such variants possess enhanced affinity for both heparin pentasaccharide and full-length heparin. The N135A/F77L mutant had unchanged affinity for heparin pentasaccharide, but the affinity for full-length heparin was increased. We suggest that the Phe77Leu mutation causes conformational changes around the top of the D-helix in antithrombin, in particular, to the arginine 132 and 133 residues that may mediate additional antithrombin/heparin interactions. This paper also demonstrates that there are major differences between the shutter regions of antithrombin and alpha(1)-antitrypsin since a stabilizing mutation in antitrypsin has the converse effect in antithrombin.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
2
pubmed:volume
42
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
10169-73
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
2003
pubmed:articleTitle
Introduction of a mutation in the shutter region of antithrombin (Phe77 --> Leu) increases affinity for heparin and decreases thermal stability.
pubmed:affiliation
Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria 3800, Australia.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't