Linked Life Data

6375257

Source:http://linkedlifedata.com/resource/pubmed/id/6375257

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:dateCreated
1984-7-23
pubmed:abstractText
The formation of EAC 4b2a is a two step reaction: first, the temperature- and time-independent binding of C2 to EAC4b2a resulting in EAC4b2 , secondly, the enzymatically triggered conversion of EAC4b2 to EAC4b2a . In the classical cascade of complement activation, the generation of C3 convertase activity is triggered by the C1 esterase, C1-s, which is part of C-1. Evidence is presented that the enzymes trypsin, chymotrypsin, plasmin, and pronase are also able to activate EAC4b2 to EAC4b2a . Kinetic studies showed that the formation of C3 convertase by these enzymes was dependent on concentration, temperature, and time. The optimal conditions were found as follows: trypsin, 2 micrograms/ml (final conc.) for 8 min at 23 degrees C; chymotrypsin 165 micrograms/ml for 18 min at 23 degrees C; plasmin 0.8 units/ml for 15 min at 23 degrees C; pronase 1.25 microgram/ml for 15 min at 23 degrees C. Even under optimal (tmax) conditions the number of generated EAC4b2a differed from enzyme to enzyme: trypsin (= 100%), pronase (58.3%), chymotrypsin (47.9%), and plasmin (12.9%). The enzymes were also able to generate C3 convertase activity from C2 which was adsorbed to EAC1i4b , a C1 inactivator treated and therefore hemolytically inactive intermediate ( EAC1i4b2 ). These findings underline the biological importance of C1 esterase replacing enzymes.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0108-0172
pubmed:author
pubmed:issnType
Print
pubmed:volume
284
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
67-74
pubmed:dateRevised
2008-2-12
pubmed:meshHeading
pubmed:year
1984
pubmed:articleTitle
Generation of the classical pathway C3 convertase (EAC4b2a) by proteolytic enzymes.
pubmed:publicationType
Journal Article, Comparative Study, In Vitro, Research Support, Non-U.S. Gov't