Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1996-10-25
pubmed:abstractText
Variants of tissue-type plasminogen activator (t-PA) were constructed with selected cysteines replaced by alanine to evaluate the role of an unpaired cysteine, which has been presumed to be in the growth factor module. C75A, C83A, C84A and CC83-84AA variants of t-PA were expressed transiently in human embryonic kidney cells. The biochemical properties of these variants provided experimental evidence to identify the unpaired cysteine in t-PA. Assays of amidolytic activity, plasminogen activation (in the presence or absence of fibrinogen or fibrin), plasma clot lysis, fibrin binding, clearance in mice, and interaction with a panel of monoclonal antibodies were performed as the basis for comparing these variants with wild-type t-PA. In all assays, C83A t-PA was biochemically equivalent to wild-type t-PA. C75A t-PA, C84A t-PA and CC83-84AA t-PA variants exhibited reduced activities in a variety of functional assays. These variants displayed two-to threefold lower activity in fibrinogen or fibrin stimulated plasminogen activation, and fivefold reduced plasma clot lysis activity compared with that of wild-type t-PA. The affinity of C75A t-PA and C84A t-PA for fibrin was decreased more than two orders of magnitude compared with C83A t-PA or wild-type t-PA. Plasma clearance of C75A t-PA and C84A t-PA was reduced 2-fold in mice. The C75A, C84A and CC83-84AA variants displayed significantly decreased reactivity with anti-tPA monoclonal antibodies specific for finger/growth factor domain epitopes. These data are consistent with a disulfide linkage of Cys75 with Cys84 and that Cys83 exists as an unpaired sulfhydryl. The significance of the unpaired cysteine is as yet undetermined since C83A t-PA and wild-type t-PA are functionally equivalent.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0269-2139
pubmed:author
pubmed:issnType
Print
pubmed:volume
9
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
283-90
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed-meshheading:8736495-Amino Acid Sequence, pubmed-meshheading:8736495-Animals, pubmed-meshheading:8736495-Antibodies, Monoclonal, pubmed-meshheading:8736495-Binding Sites, pubmed-meshheading:8736495-Cell Line, pubmed-meshheading:8736495-Computer Graphics, pubmed-meshheading:8736495-Cricetinae, pubmed-meshheading:8736495-Cysteine, pubmed-meshheading:8736495-Embryo, Mammalian, pubmed-meshheading:8736495-Epidermal Growth Factor, pubmed-meshheading:8736495-Fibrin, pubmed-meshheading:8736495-Genetic Variation, pubmed-meshheading:8736495-Humans, pubmed-meshheading:8736495-Kidney, pubmed-meshheading:8736495-Mice, pubmed-meshheading:8736495-Mice, Inbred ICR, pubmed-meshheading:8736495-Models, Molecular, pubmed-meshheading:8736495-Molecular Sequence Data, pubmed-meshheading:8736495-Mutagenesis, Site-Directed, pubmed-meshheading:8736495-Point Mutation, pubmed-meshheading:8736495-Protein Structure, Secondary, pubmed-meshheading:8736495-Recombinant Proteins, pubmed-meshheading:8736495-Sequence Homology, Amino Acid, pubmed-meshheading:8736495-Tissue Plasminogen Activator, pubmed-meshheading:8736495-Transfection
pubmed:year
1996
pubmed:articleTitle
Locating the unpaired cysteine of tissue-type plasminogen activator.
pubmed:affiliation
Department of Cardiovascular Research, Genentech, Inc., South San Francisco, CA 94080, USA.
pubmed:publicationType
Journal Article