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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
11
|
| pubmed:dateCreated |
1983-2-25
|
| pubmed:abstractText |
Human alpha 1-proteinase inhibitor (alpha 1-PI) can form very stable complexes with chymotrypsinogen A or chymotrypsin if limited proteolysis by a contaminant proteinase is prevented with diisopropyl fluorophosphate. The contaminant proteinase cleaves the alpha 1-PI component in the alpha 1-PI-chymotrypsinogen A complex close to its N-terminus, between threonine-11 and aspartate-12 and the chymotrypsinogen A part between tyrosine-146 and threonine-147. By this modification the complex becomes unstable and dissociates into modified alpha 1-PI and neo-chymotrypsinogen A. A tritium labelling experiment shows that the contaminant proteinase is present in a 0.5-1.0% (w/w) ratio in the inhibitor preparation. These experiments indicate that alpha 1-PI is not a temporary inhibitor for these enzymes, as assumed by other authors. Isolated modified alpha 1-PI can be crystallized as tetragonal bipyramides from 2.6M sodium potassium phosphate pH 8.0. The crystals are suitable for three dimensional X-ray structure analysis. In spite of the cleavage of the susceptible peptide bond by chymotrypsinogen A, the C-terminal 3.6 kDa cleavage peptide remains tightly bound to the inhibitor by means of non-covalent interactions. In accordance with the result of the known complete amino-acid sequence of the inhibitor this finding offers an alternative explanation to the suggestion of alpha 1-PI being a double headed inhibitor. Isolated neo-chymotrypsinogen A can be activated to active chymotrypsin and can form a very labile 1 : 1 complex with alpha 1-PI, which dissociates rapidly into inactive inhibitor and neo-chymotrypsinogen.
|
| pubmed:language |
eng
|
| pubmed:journal | |
| pubmed:citationSubset |
IM
|
| pubmed:chemical | |
| pubmed:status |
MEDLINE
|
| pubmed:month |
Nov
|
| pubmed:issn |
0018-4888
|
| pubmed:author | |
| pubmed:issnType |
Print
|
| pubmed:volume |
363
|
| pubmed:owner |
NLM
|
| pubmed:authorsComplete |
Y
|
| pubmed:pagination |
1377-88
|
| pubmed:dateRevised |
2004-11-17
|
| pubmed:meshHeading |
pubmed-meshheading:6983488-Amino Acid Sequence,
pubmed-meshheading:6983488-Binding Sites,
pubmed-meshheading:6983488-Blood Proteins,
pubmed-meshheading:6983488-Chymotrypsinogen,
pubmed-meshheading:6983488-Crystallization,
pubmed-meshheading:6983488-Humans,
pubmed-meshheading:6983488-Protease Inhibitors,
pubmed-meshheading:6983488-Protein Binding,
pubmed-meshheading:6983488-X-Ray Diffraction,
pubmed-meshheading:6983488-alpha 1-Antitrypsin
|
| pubmed:year |
1982
|
| pubmed:articleTitle |
Interaction of human alpha 1-proteinase inhibitor with chymotrypsinogen A and crystallization of a proteolytically modified alpha 1-proteinase inhibitor.
|
| pubmed:publicationType |
Journal Article
|