Linked Life Data

6910423

Source:http://linkedlifedata.com/resource/pubmed/id/6910423

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
10
pubmed:dateCreated
1981-9-25
pubmed:abstractText
High Mr kininogen increases the activation rate of prekallikrein by activated factor XII on a surface. The resulting serine protease, plasma kallikrein, Mr 88 000, is inhibited in plasma by C1 inhibitor, Mr 105 000. Since prekallikrein circulates in plasma with high Mr kininogen as a complex and a kallikrein-high Mr kininogen complex can be formed in purified systems, we studied whether the inhibition of kallikrein by C1 inhibitor was influenced by high Mr kininogen. With C1 inhibitor in excess, the inactivation of kallikrein followed pseudo-first-order kinetics. The second-order rate constant for the reaction was 1.7 X 10(4) M-1 s-1, and a kallikrein-C1 inhibitor complex, Mr 190 000 was identified on polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. Kallikrein and C1 inhibitor formed an irreversible complex without measurable prior equilibrium. The rate of this reaction was decreased by 50% in the presence of high Mr kininogen (1 unit/mL or 0.73 muM). Kinetic analysis indicated that this protection was the result of the formation of a reversible complex between kallikrein and high Mr kininogen, which had a dissociation constant of 0.75 muM. However, low Mr kininogen did not protect kallikrein from inactivation by C1 inhibitor. High Mr kininogen also protected kallikrein from inactivation by diisopropyl fluorophosphate. These findings suggest that the kallikrein-high Mr kininogen complex was formed by noncovalent interactions between the light chains of both kallikrein and high Mr kininogen.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
12
pubmed:volume
20
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2738-43
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1981
pubmed:articleTitle
Protection of human plasma kallikrein from inactivation by C1 inhibitor and other protease inhibitors. The role of high molecular weight kininogen.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.