Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
18
pubmed:dateCreated
1989-7-18
pubmed:abstractText
To define determinants of interactions of tissue-type plasminogen activator (t-PA) with plasminogen activator inhibitor type-1 (PAI-1), we utilized site-directed mutagenesis to substitute either threonine or glycine for the active-site serine of tissue-type plasminogen activator. Assays of conditioned media of transfected cells demonstrated that the threonine substitution markedly decreased but did not entirely abolish plasminogen activating activity. In contrast, the glycine substitution yielded a mutant with absolutely no detectable plasminogen activating activity. Wild-type t-PA formed stable complexes with PAI-1. However, even when exogenous inhibitor was present in the medium or purified mutant was added to plasma that had been rendered PAI-1-rich in vivo, the mutants were present in the free form exclusively judging from results of fibrin autography and Western blot analysis. Thus, despite maintenance of some residual plasminogen-activating activity associated with preservation of the hydroxyl group at the active site, the threonine mutant did not form stable complexes with inhibitor. The glycine mutant, developed so that steric hindrance or other unfavorable interactions at the modified active site would be minimal, was similarly incapable of forming complexes with PAI-1. These results show that the presence of an active site serine residue is necessary for formation of stable complexes between t-PA and PAI-1.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
25
pubmed:volume
264
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
10922-5
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1989
pubmed:articleTitle
Characterization of interaction of active-site serine mutants of tissue-type plasminogen activator with plasminogen activator inhibitor-1.
pubmed:affiliation
Department of Medicine, Washington University School of Medicine, St. Louis, Missouri 63110.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't