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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
10
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pubmed:dateCreated |
1990-5-3
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pubmed:abstractText |
Recombinant variants of tissue plasminogen activator (t-PA) containing either substitutions or deletions of amino acids within the fibronectin finger-like domain (residues 6-50) were found to exhibit widely varying in vivo clearance profiles in rats and fibrinolytic activity in 125I-fibrin clot lysis assays. Clearance was not significantly affected by changes in the densely charged region of amino acid residues 7-10. Deletions or substitutions of amino acids in the region 14-32 decreased both fibrinolytic activity and the clearance of the enzyme. Modifications within the predicted omega loop of residues 37-41 affected clearance only to a small degree, whereas amino acid alterations in the region of residues 42-49 resulted in as much as a 6-fold decrease in the rate of clearance with only relatively minor decreases in the fibrinolytic activity of the variants. The cumulative results distinguish discrete sections of the NH2-terminal region of the enzyme as determinants of in vivo clearance and fibrinolytic activity of t-PA. In addition, the fibrinolytic activity of a variant containing the substitutions Gln42----Asn, His44----Glu, and Asn117----Gln, when compared with wild-type t-PA in an in vivo rabbit venous clot lysis model, was found to have similar lytic efficacy at approximately one-fourth the dose. We conclude that decreases in the in vivo clearance of t-PA can result in more potent thrombolytic agents in vivo, even though the in vitro fibrinolytic activity of the enzyme may be somewhat impaired.
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pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical | |
pubmed:status |
MEDLINE
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pubmed:month |
Apr
|
pubmed:issn |
0021-9258
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:day |
5
|
pubmed:volume |
265
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pubmed:owner |
NLM
|
pubmed:authorsComplete |
Y
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pubmed:pagination |
5540-5
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pubmed:dateRevised |
2006-11-15
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pubmed:meshHeading |
pubmed-meshheading:2108143-Amino Acid Sequence,
pubmed-meshheading:2108143-Animals,
pubmed-meshheading:2108143-Cell Line,
pubmed-meshheading:2108143-Cricetinae,
pubmed-meshheading:2108143-Fibrinolysis,
pubmed-meshheading:2108143-Humans,
pubmed-meshheading:2108143-Male,
pubmed-meshheading:2108143-Metabolic Clearance Rate,
pubmed-meshheading:2108143-Molecular Sequence Data,
pubmed-meshheading:2108143-Mutation,
pubmed-meshheading:2108143-Plasminogen,
pubmed-meshheading:2108143-Protein Conformation,
pubmed-meshheading:2108143-Rats,
pubmed-meshheading:2108143-Rats, Inbred Strains,
pubmed-meshheading:2108143-Recombinant Proteins,
pubmed-meshheading:2108143-Structure-Activity Relationship,
pubmed-meshheading:2108143-Tissue Plasminogen Activator
|
pubmed:year |
1990
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pubmed:articleTitle |
Site-directed mutagenesis in human tissue-plasminogen activator. Distinguishing sites in the amino-terminal region required for full fibrinolytic activity and rapid clearance from the circulation.
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pubmed:affiliation |
Genetics Institute Inc., Cambridge, Massachusetts 02140.
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pubmed:publicationType |
Journal Article,
Comparative Study
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