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rdf:type |
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lifeskim:mentions |
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pubmed:issue |
6
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pubmed:dateCreated |
1989-1-20
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pubmed:abstractText |
Two plasmin-resistant mutant forms of pro-urokinase (pro-UK) constructed by site-directed mutagenesis of Lys158 to Val158 and Met158 were used to evaluate the intrinsic enzymatic and fibrinolytic properties of pro-UK as distinct from those of its two-chain UK (TC-UK) derivative. Both mutants, while resistant to plasmin activation, were as sensitive as pro-UK to degradation by thrombin. Since thrombin cleaves a peptide bond only two residues from the activation site, the integrity of this loop was maintained in the two mutants. The amidolytic and plasminogen-activating activities of the mutants averaged 0.14 and 0.12% that of TC-UK, respectively. The fibrin plate activities were 2,400 IU/ml and 700 IU/mg for the Met158 and Val158 mutants or about 1.5% that of TC-UK. These findings attest to a discrete but low intrinsic activity for pro-UK and suggest that the higher values reported in the literature may be related to UK contaminants or plasmin-induced TC-UK generation during the assay. Clot lysis by the mutants required doses greater than 100-fold higher than those of pro-UK to induce a comparable effect. From this it appears that pro-UK activation is a major determinant of the rate of clot lysis occurring with pro-UK. Clot lysis by the mutants was potentiated by plasmin pretreatment of the fibrin and by the addition of small amounts of TC-UK or tissue plasminogen activator (t-PA). Combinations of t-PA and the mutants were synergistic in their fibrinolytic effects. These findings mirror those previously obtained with pro-UK. We concluded that the previously described potentiation of pro-UK-induced clot lysis by UK or t-PA is mediated primarily by pro-UK itself rather than by a promotion of its activation.
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pubmed:commentsCorrections |
http://linkedlifedata.com/resource/pubmed/commentcorrection/2974047-14895792,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2974047-14907713,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2974047-271968,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2974047-2935529,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2974047-2949785,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2974047-2963831,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2974047-3081506,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2974047-3083889,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2974047-3095946,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2974047-3097872,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2974047-3106341,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2974047-3156857,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2974047-322279,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2974047-324671,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2974047-3667621,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2974047-3790724,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2974047-4504350,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2974047-4705382,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2974047-6154876,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2974047-6183168,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2974047-6210827,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2974047-6246368,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2974047-6292436,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2974047-6305508,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2974047-6338833,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2974047-6373753,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2974047-6460318,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2974047-6725557,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2974047-6806270,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2974047-6835212,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2974047-6891264,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2974047-7017722,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2974047-7037592,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2974047-7037781,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2974047-9279398
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pubmed:language |
eng
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pubmed:journal |
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pubmed:citationSubset |
AIM
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pubmed:chemical |
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pubmed:status |
MEDLINE
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pubmed:month |
Dec
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pubmed:issn |
0021-9738
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pubmed:author |
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pubmed:issnType |
Print
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pubmed:volume |
82
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
1956-62
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pubmed:dateRevised |
2009-11-19
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pubmed:meshHeading |
pubmed-meshheading:2974047-Amino Acid Sequence,
pubmed-meshheading:2974047-Animals,
pubmed-meshheading:2974047-Base Sequence,
pubmed-meshheading:2974047-Binding Sites,
pubmed-meshheading:2974047-Cell Line,
pubmed-meshheading:2974047-Drug Resistance,
pubmed-meshheading:2974047-Fibrinolysin,
pubmed-meshheading:2974047-Fibrinolysis,
pubmed-meshheading:2974047-Humans,
pubmed-meshheading:2974047-Lysine,
pubmed-meshheading:2974047-Methionine,
pubmed-meshheading:2974047-Molecular Sequence Data,
pubmed-meshheading:2974047-Mutation,
pubmed-meshheading:2974047-Plasminogen Activators,
pubmed-meshheading:2974047-Recombinant Proteins,
pubmed-meshheading:2974047-Structure-Activity Relationship,
pubmed-meshheading:2974047-Tissue Plasminogen Activator,
pubmed-meshheading:2974047-Urokinase-Type Plasminogen Activator,
pubmed-meshheading:2974047-Valine
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pubmed:year |
1988
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pubmed:articleTitle |
Characterization of the intrinsic fibrinolytic properties of pro-urokinase through a study of plasmin-resistant mutant forms produced by site-specific mutagenesis of lysine(158).
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pubmed:affiliation |
Department of Vascular Medicine, St. Elizabeth's Hospital, Boston, MA 02135.
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pubmed:publicationType |
Journal Article
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