Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
9
pubmed:dateCreated
1988-10-4
pubmed:abstractText
Cyclosporine A (CsA, 1), an immunosuppressive cyclic undecapeptide, in apolar solvents adopts a II' beta-turn at the Sar3-MeLeu4 residues. [D-Proline3]Cs has been reported to be a nonimmunosuppressive analogue in which the II' beta-turn is retained. In order to determine if this loss of activity is caused by steric hindrance between the Cs analogue and its receptor or is caused by a change in the peptide conformation, an analogue that stabilizes a II' beta-turn has been synthesized, [lactam3,4]Cs. We also have studied the solution conformation of two other analogues, [D-MeAla3]Cs and [L-MeAla3]Cs. The conformations have been established by 1D difference NOE and 2D (NOESY or ROESY) NMR. The conformations of [lactam3,4]Cs and [D-MeAla3]Cs are indistinguishable from that of CsA in solution. [L-MeAla3]Cs was found to adopt a conformation with a cis amide bond between Sar3 and MeLeu4. The inhibition of concanavalin A stimulated thymocytes by CsA, [D-MeAla3]Cs, [L-MeAla3]Cs, and [lactam3,4]Cs gave IC50 values (nM) of 5, 6, 100, and 100, respectively. The weak immunosuppressive activity of [lactam3,4]Cs possessing the II' beta-turn suggests that the loss of activity for 4 is due to steric hindrance with the Cs receptor.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0022-2623
pubmed:author
pubmed:issnType
Print
pubmed:volume
31
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1805-15
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1988
pubmed:articleTitle
Synthesis, conformation, and immunosuppressive activity of a conformationally restricted cyclosporine lactam analogue.
pubmed:affiliation
University of Wisconsin, School of Pharmacy, Madison 53706.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't