Linked Life Data

6553050

Source:http://linkedlifedata.com/resource/pubmed/id/6553050

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
12
pubmed:dateCreated
1983-8-11
pubmed:abstractText
The purposes of this study were to demonstrate the C3 convertase complex, C3b, Bb (EC 3.4.21.47), of the alternative pathway of complement by ultracentrifugation and to determine whether the metal ion required for enzyme formation is present in the active enzyme complex. It has been shown previously that C3b,Bb formed with Ni2+ rather than Mg2+ exhibits enhanced stability. Using sucrose density gradient ultracentrifugation, an enzymatically active C3b,Bb(Ni) complex could be demonstrated which has a sedimentation coefficient of 10.7 S and which is stable in 10 mM EDTA. Upon formation of the enzyme with the radioisotope 63Ni2+, the ultracentrifugal distribution of the metal correlated with that of the enzyme complex. The molar ratio of Ni to C3b,Bb was 1:1. Displacement of Ni by Mg during formation of the enzyme indicated that both metals may bind to the same site in the enzyme. Binding of 63Ni to the catalytic site bearing fragment Bb was significantly stronger than its binding to C3b or to the zymogen, Factor B. It is proposed that there is one metal-binding site in the C3b,Bb enzyme which is not susceptible to chelation by EDTA and which is located in the Bb subunit.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
25
pubmed:volume
258
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
7411-5
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1983
pubmed:articleTitle
C3 convertase of the alternative complement pathway. Demonstration of an active, stable C3b, Bb (Ni) complex.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't