Linked Life Data

1693856

Source:http://linkedlifedata.com/resource/pubmed/id/1693856

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
16
pubmed:dateCreated
1990-7-20
pubmed:abstractText
Substrate specificities, as reflected in kc/Km, were determined for the peptidyl prolyl cis-trans isomerase activities of cyclophilin and the FK-506 binding protein (FKBP). The substrates investigated were peptides of the general structure Suc-Ala-Xaa-Pro-Phe-p-nitroanilide, where Xaa = Gly, Ala, Val, Leu, Phe, His, Lys, on Glu. While kc/Km for cyclophilin-catalyzed isomerization shows little dependence on Xaa, kc/Km values for FKBP-catalyzed isomerization display a marked dependence on Xaa and vary over 3 orders of magnitude. An important outcome of this work is the discovery that Suc-Ala-Leu-Pro-Phe-pNA is a reactive substrate for FKBP (kc/Km = 640,000 M-1 s-1). This substrate can be used with FKBP concentrations that are low enough to allow, for the first time, accurate determinations of Ki values for tight-binding inhibitors of FKBP. Using this new assay, we found that FK-506 inhibits FKBP with Ki = 1.7 +/- 0.6 nM. The results of this work support the hypothesis that cyclophilin and FKBP are members of a family of peptidyl prolyl cis-trans isomerases and that the members of this family possess distinct substrate specificities that allow them to play diverse physiologic roles.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
24
pubmed:volume
29
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3813-6
pubmed:dateRevised
2003-11-14
pubmed:meshHeading
pubmed:year
1990
pubmed:articleTitle
Substrate specificities of the peptidyl prolyl cis-trans isomerase activities of cyclophilin and FK-506 binding protein: evidence for the existence of a family of distinct enzymes.
pubmed:affiliation
Department of Enzymology, Merck Research Laboratories, Rahway, New Jersey 07065.
pubmed:publicationType
Journal Article