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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
1
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pubmed:dateCreated |
1982-4-22
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pubmed:abstractText |
1. Proenzymic C1r was purified from human plasma in a two-step technique involving indirect affinity chromatography on Sepharose Ig anti-C1s. The capacity of C1r to monomerize at pH 5.0 and to redimerize at neutral pH was used for selective elution of C1r. The yield in purified C1r was 39% from plasma; no trace of contaminating serine proteases was detected from [3H]diisopropyl phosphorofluoridate labelling of C1r. 2. C14 was able to undergo a two-way autoactivation: an intramolecular catalytic process catalysed by proenzymic C1r itself and an intermolecular reaction catalysed by activated C1r formed in the process of the reaction. DFP (5mM) and C1 Inh at a C1 Inh/C1r ratio of 1:1 were effective on the solely intermolecular activation, leading to partial inhibition of the autoactivation from proenzymic C1r: C1r formed during the activation was titrated by the inhibitors. Calcium, high ionic strength or acid pH decreased C1r activation. The pH effect was characterized by a slowed-down reaction below pH 6.0 and no net influence at values as high as 10.5. The two types of activation developed similarly as a function of pH. 3. Peripheral iodination of C1r revealed differences in label distribution between proenzymic (A chain moiety 48%, B chain moiety 52%) and activated C1r (A chain 20%, B chain 80%). Two different conformational states of C1r were also suggested by 125I-labelling at different temperatures.
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pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical | |
pubmed:status |
MEDLINE
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pubmed:month |
Jan
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pubmed:issn |
0006-3002
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:day |
4
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pubmed:volume |
700
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
118-26
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pubmed:dateRevised |
2006-11-15
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pubmed:meshHeading |
pubmed-meshheading:6275893-Calcium,
pubmed-meshheading:6275893-Chromatography, Affinity,
pubmed-meshheading:6275893-Complement Activating Enzymes,
pubmed-meshheading:6275893-Complement C1r,
pubmed-meshheading:6275893-Enzyme Activation,
pubmed-meshheading:6275893-Enzyme Precursors,
pubmed-meshheading:6275893-Humans,
pubmed-meshheading:6275893-Hydrogen-Ion Concentration,
pubmed-meshheading:6275893-Kinetics,
pubmed-meshheading:6275893-Osmolar Concentration
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pubmed:year |
1982
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pubmed:articleTitle |
Fluid phase activation of proenzymic C1r purified by affinity chromatography.
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pubmed:publicationType |
Journal Article,
Research Support, Non-U.S. Gov't
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