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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1989-9-7
pubmed:abstractText
Both isomers of (E)-2,3-methanophenylalanine (delta EPhe), a sterically restricted amino acid, were incorporated into peptides in order to examine their possible enzyme inhibitory activity. Both (2R,3S)- and (2S,3R)- delta EPhe-Phe(or Leu)-OMe were found to inhibit effectively the hydrolysis of Ac-Tyr-OEt by chymotrypsin in a competitive manner. The ester groups of these dipeptides were quite resistant to chymotrypsin hydrolysis, and the delta EPhe-Phe peptide bond was also entirely stable. The inhibition constant (Ki) of the most potent dipeptide of H-(2R,3S)-delta EPhe-Phe-OMe was 0.16 mM at 25 degrees C. The inhibitory action of delta Phe-containing peptides was found to depend on the configuration of the delta Phe residue. The electrophilic nature of the cyclopropane ring which is conjugated with both the phenyl ring and the ester carbonyl group appears to be relevant to the inhibitory activity. Fully irreversible inactivation of chymotrypsin was achieved by its incubation with H-(2R,3S)- delta EPhe-Leu-OMe. An enzyme carboxylate group is thought to be responsible for nucleophilic attack on the cyclopropane ring leading to irreversible inactivation.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0014-5793
pubmed:author
pubmed:issnType
Print
pubmed:day
3
pubmed:volume
250
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
227-30
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1989
pubmed:articleTitle
Enzyme inhibition by dipeptides containing 2,3-methanophenylalanine, a sterically constrained amino acid.
pubmed:affiliation
Laboratory of Biochemistry, Faculty of Science, Kyushu University, Fukuoka, Japan.
pubmed:publicationType
Journal Article