Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
34
pubmed:dateCreated
1995-9-28
pubmed:abstractText
Urokinase (u-PA) is synthesized and secreted as a single-chain polypeptide (single-chain u-PA, scu-PA), which has such little enzymatic activity in solution that it has been considered essentially enzymatically inert. We found that plasminogen activator inhibitor type 1 (PAI-1), the major PAI in plasma, demonstrated concentration-dependent inhibition of this solution-phase scu-PA enzymatic activity. 125I-scu-PA formed complexes with PAI-1 in a concentration- and time-dependent manner, as detected by SDS-polyacrylamide gel electrophoresis under reducing conditions. Among a given population of scu-PA molecules, all measurable enzymatic activity was inhibited by a 10-fold molar excess of PAI-1. However, at this stoichiometry, only a minority of 125I-scu-PA molecules formed SDS-stable complexes with PAI-1 (i.e. complexes that formed a covalent bond upon denaturation), even though the uncomplexed PAI-1 molecules remained competent to inhibit u-PA enzymatic activity. Neither the extent nor the time course of complex formation was altered by using PAI-1 that had been pre-incubated with native human vitronectin, compared with native PAI-1 alone. 125I-scu-PA.PAI-1 complexes that would form a covalent bond if denatured were reversible and existed in equilibrium with either non-complexed or loosely complexed reactants. These data suggest that scu-PA has more enzyme-like properties than previously appreciated and raises the possibility that it resembles single-chain tissue type-plasminogen activator in lacking a complete zymogen conformation.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
25
pubmed:volume
270
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
20032-5
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
Interaction of single-chain urokinase and plasminogen activator inhibitor type 1.
pubmed:affiliation
Department of Medicine, University of Wisconsin, Madison, USA.
pubmed:publicationType
Journal Article, In Vitro, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.