Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2000-6-30
pubmed:abstractText
Two spectrophotometric assays have been developed for methionine aminopeptidases (MetAPs). The first method employs a thioester substrate which, upon enzymatic removal of the N-terminal methionine, generates a free thiol group. The released thiol is quantitated using Ellman's reagent. The MetAP reaction is conveniently monitored on a UV-VIS spectrophotometer in a continuous fashion, with the addition of an excess of Ellman's reagent into the assay reaction. Two tripeptide analogues were synthesized and found to be excellent substrates of both Escherichia coli MetAP and human MetAP2 (k(cat)/K(M) = 2.8 x 10(5) M(-1) s(-1) for the most reactive substrate). In the second assay method, the MetAP reaction is coupled to a prolyl aminopeptidase reaction using Met-Pro-p-nitroanilide as substrate. MetAP-catalyzed cleavage of the N-terminal methionine produces prolyl-p-nitroanilide, which is rapidly hydrolyzed by the prolyl aminopeptidase from Bacillus coagulans to release a chromogenic product, p-nitroaniline. This allows the MetAP reaction to be continuously monitored at 405 nm on a UV-VIS spectrophotometer. The assays have been applied to determine the pH optima and kinetic constants for the E. coli and human MetAPs as well as to screen MetAP inhibitors. These results demonstrate that the current assays are convenient, rapid, and sensitive methods for kinetic studies of MetAPs and effective tools for screening MetAP inhibitors.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0003-2697
pubmed:author
pubmed:issnType
Print
pubmed:day
10
pubmed:volume
280
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
159-65
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2000
pubmed:articleTitle
Two continuous spectrophotometric assays for methionine aminopeptidase.
pubmed:affiliation
Department of Chemistry, The Ohio State University, Columbus 43210, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't