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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
26
pubmed:dateCreated
2003-12-11
pubmed:abstractText
The three-dimensional NMR structures of eight cyclic octapeptide analogues of somatostatin (SRIF) are described. These analogues, with the basic sequence H-c[Cys(3)-Phe(6)-Xxx(7)-Yyy(8)-Lys(9)-Thr(10)-Zzz(11)-Cys(14)]-OH (the numbering refers to the position in native SRIF), with Xxx(7) being Phe/Ala/Tyr, Yyy(8) being Trp/DTrp/D-threo-beta-Me2Nal/L-threo-beta-Me2Nal, and Zzz(11) being Phe/Ala, exhibit potent and highly selective binding to human SRIF type 4 (sst(4)) receptors. The conformations reveal that the backbones of these analogues do not have the usual type-II' beta-turn reported in the literature for sst(2)-subtype-selective analogues. Instead, the structures contain a unique arrangement of side chains of Yyy(8), Lys(9), and Phe(6) or Phe(11). The conformational preferences and results from biological analyses of these analogues (parts 1-3 of this series, Rivier et al., Erchegyi et al., and Erchegyi et al., J. Med. Chem. 2003, preceding papers in this issue) allow a detailed study of the structure-activity relationship of SRIF. The proposed consensus structural motif at the binding pocket for the sst(4)-selective analogues requires a unique set of distances between an indole/2-naphthyl ring, a lysine side chain, and another aromatic ring. This motif is necessary and sufficient to explain the binding affinities of all of the analogues studied and is distinct from the existing model suggested for sst(2)/sst(5) selectivity.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0022-2623
pubmed:author
pubmed:issnType
Print
pubmed:day
18
pubmed:volume
46
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
5606-18
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2003
pubmed:articleTitle
Novel sst(4)-selective somatostatin (SRIF) agonists. 4. Three-dimensional consensus structure by NMR.
pubmed:affiliation
Structural Biology Laboratory and The Clayton Foundation Laboratories for Peptide Biology, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't