Linked Life Data

8103046

Source:http://linkedlifedata.com/resource/pubmed/id/8103046

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
25
pubmed:dateCreated
1993-9-30
pubmed:abstractText
The activation of plasminogen at the surface of fibrin by single-chain urokinase-type plasminogen activator (scu-PA) was investigated using recombinant forms of a plasmin-resistant mutant of scu-PA, rscu-PA-Glu158, and an inactive catalytic site mutant of human plasminogen, rPg-Ala741. Conversion of cleavable 125I-labeled single-chain proteins to their two-chain forms, was quantitated by radioisotope counting of protein bands on reduced SDS-polyacrylamide gels. The efficiency of the activation (moles of plasmin generated per mol of plasminogen activator) of native Glu-plasminogen bound to degraded fibrin was comparable for scu-PA and its two-chain form (tcu-PA) and approximately 4-fold lower for rscu-PA-Glu158. The corresponding values with rPg-Ala741 were 4-fold or 9-fold lower for scu-PA or rscu-PA-Glu158, as compared to tcu-PA. In contrast, in solution in the absence of fibrin, the efficiency of scu-PA for activation of rPg-Ala741 was 100-fold lower than that of tcu-PA. Initial activation rates of rPg-Ala741 (32.7 fmol/well containing 50 microliters of solution) with 4 nM tcu-PA were comparable in solution and bound to degraded fibrin (v(o) = 1.01 and 1.16 fmol/min, respectively). In contrast, with 4 nM scu-PA the corresponding values when rPg-Ala741 was bound to degraded fibrin were 20-fold higher as compared to the soluble phase (v(o) = 0.23 and 0.012 fmol/min, respectively). Comparable results were obtained when using Glu- or Lys-forms of rPg-Ala741. Furthermore, in the presence of normal human plasma, activation of Glu-plasminogen bound to degraded fibrin was found to be about 2.5-fold more efficient with scu-PA than with tcu-PA. These findings indicate that the fibrin specificity of scu-PA does not require its conversion to tcu-PA, nor conversion of Glu- to Lys-plasminogen, but appears to be due to the additional binding of plasminogen to partially digested fibrin; scu-PA may thus represent a physiological functional form of u-PA in plasma.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
5
pubmed:volume
268
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
18554-9
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed-meshheading:8103046-Alanine, pubmed-meshheading:8103046-Binding Sites, pubmed-meshheading:8103046-Catalysis, pubmed-meshheading:8103046-Cell Line, pubmed-meshheading:8103046-Enzyme Activation, pubmed-meshheading:8103046-Fibrin, pubmed-meshheading:8103046-Fibrinolysis, pubmed-meshheading:8103046-Glutamates, pubmed-meshheading:8103046-Glutamic Acid, pubmed-meshheading:8103046-Humans, pubmed-meshheading:8103046-Kinetics, pubmed-meshheading:8103046-Lysine, pubmed-meshheading:8103046-Mutagenesis, Site-Directed, pubmed-meshheading:8103046-Plasminogen, pubmed-meshheading:8103046-Plasminogen Activator Inhibitor 1, pubmed-meshheading:8103046-Recombinant Proteins, pubmed-meshheading:8103046-Serine, pubmed-meshheading:8103046-Solutions, pubmed-meshheading:8103046-Urokinase-Type Plasminogen Activator
pubmed:year
1993
pubmed:articleTitle
Mechanism of the enhanced intrinsic activity of single-chain urokinase-type plasminogen activator during ongoing fibrinolysis.
pubmed:affiliation
Institut National de la Santé et de la Recherche Médicale U.143, Hôpital de Bicêtre, France.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't