Linked Life Data

3122757

Source:http://linkedlifedata.com/resource/pubmed/id/3122757

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1988-2-20
pubmed:abstractText
It has recently been reported that the fluorogenic serine proteolytic active site titrant, 4-methyl-umbelliferyl-p-guanidinobenzoate (MUGB), cannot be employed in this capacity for tissue-type plasminogen activator (TPA) [Geiger, M., and Binder, B.R. (1987) Biochim. Biophys. Acta 912, 34-40]. Since this observation has such important ramifications in this area of research, we have studied the reaction of MUGB with recombinant (rec)TPA under a variety of experimental conditions and find that MUGB is indeed an effective titrant of rec-two chain TPA (recTCTPA) at 4 degrees, a condition under which the deacylation rate constant is diminished to the point that acylation can be readily observed. The KS for the interaction of MUGB with recTCTPA is 43 microM-46 microM, the acylation rate constant, k2, is approximately 3.6 min-1-4.2 min-1, and the rate constant for deacylation of p-guanidinobenzoyl-recTCTPA is 0.084 min-1-0.110 min-1. This same recTCTPA, after treatment with diisopropylfluorophosphate, does not react with MUGB. Single-chain TPA (recSCTPA) has been found to acylate more slowly than its two-chain counterpart and to exhibit a higher degree of turnover of the acyl-enzyme with this reagent. These results demonstrate that the active site concentration of TCTPA can be accurately determined by titration with MUGB, a consideration which is essential to the proper kinetic evaluation of this agent and its genetic variants. On the other hand, the presteady state kinetic characteristics for MUGB toward SCTPA are not favorable for its use as a titrant with this form of the enzyme.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0006-291X
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
150
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
45-51
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1988
pubmed:articleTitle
Reaction of tissue-type plasminogen activator with 4-methylumbelliferyl-p-guanidinobenzoate hydrochloride.
pubmed:affiliation
Department of Chemistry, University of Notre Dame, Indiana 46556.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.