Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1991-2-14
pubmed:abstractText
Pro-Val pseudo dipeptides incorporating protio and halo enol lactones were tested for inhibitory activity against the serine proteases human leukocyte elastase (HLE), porcine pancreatic elastase, alpha-chymotrypsin, trypsin, thrombin, and urokinase. The protio enol lactones 1a-c were found to be HLE substrates but were poor alternate substrate inhibitors. The bromo enol lactone trans isomer 2a was found to be a very effective inhibitor of HLE and chymotrypsin, as shown by the binding constants (KI), acylation rates (ka), inactivation rates, and partition ratios determined for each enzyme. This inhibitor shows better specificity toward its target enzyme HLE than monosubstituted halo enol lactones; we attribute this to a pseudo dipeptide acyl enzyme whose structure is similar to that adopted by good peptide substrates of HLE. Inactivation of chymotrypsin by the bromo enol lactone 2a is permanent, but inactivation of HLE is partially recoverable upon treatment with the nucleophile hydrazine, indicating that lactone 2a produces two species of inactivated HLE. The more stable of these species could be the result of alkylation of His-57 by the electrophilic bromomethyl ketone revealed in the acyl enzyme, and the less stable, hydrazine-reactivatable species could be the result of alkylation of Asp-102 or the hydrolysis of the bromomethyl ketone group in the initially formed acyl enzyme to form a new, more stable acyl enzyme.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
5
pubmed:volume
266
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
13-21
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:1985887-Amino Acid Sequence, pubmed-meshheading:1985887-Animals, pubmed-meshheading:1985887-Binding Sites, pubmed-meshheading:1985887-Chymotrypsin, pubmed-meshheading:1985887-Dipeptides, pubmed-meshheading:1985887-Humans, pubmed-meshheading:1985887-Hydrazines, pubmed-meshheading:1985887-Kinetics, pubmed-meshheading:1985887-Lactones, pubmed-meshheading:1985887-Leukocyte Elastase, pubmed-meshheading:1985887-Models, Molecular, pubmed-meshheading:1985887-Molecular Sequence Data, pubmed-meshheading:1985887-Molecular Structure, pubmed-meshheading:1985887-Pancreatic Elastase, pubmed-meshheading:1985887-Protease Inhibitors, pubmed-meshheading:1985887-Protein Conformation, pubmed-meshheading:1985887-Substrate Specificity, pubmed-meshheading:1985887-Swine, pubmed-meshheading:1985887-Thrombin
pubmed:year
1991
pubmed:articleTitle
Proline-valine pseudo peptide enol lactones. Effective and selective inhibitors of chymotrypsin and human leukocyte elastase.
pubmed:affiliation
Department of Chemistry, University of Illinois, Urbana 61801.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.