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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
20
pubmed:dateCreated
2008-10-20
pubmed:abstractText
Nociceptin is an endogenous ligand that activates a G protein-coupled receptor ORL1 and contains two indispensable Arg-Lys (RK) dipeptide units at positions 8-9 and 12-13. By replacing an additional RK unit at positions 6-7, 10-11, 14-15, or 16-17, of the peptide we have identified the analog, [RK(14-15)]nociceptin as a superagonist. In fact, this peptide exhibits 3-fold higher binding affinity and 17-fold greater potency in a functional GTPgammaS-binding assay compared to wild-type nociceptin. Here, we have further investigated the role of basic residues in position 14-15. The replacement of three other possible basic dipeptides, KR, RR, and KK, into nociceptin at positions 14-15 resulted in similar enhancements of binding affinity (3-5-fold) and biological potency (10-12-fold in the GTPgammaS assay). However, when only a single basic residue (Arg or Lys) was replaced in either position 14 or 15, all the resulting analogs showed moderate enhancements of binding and biological activity (2-4-fold in both). These results indicate that the addition of basic charges in positions 14 and 15 enhance in a synergistic fashion the interaction of nociceptin with the receptor and only the simultaneous presence of two adjacent basic residues yields an optimal effect. This suggests that specific electrostatic interactions between both amino acids present in 14-15 and corresponding residues in the receptor are responsible for the enhancement of nociceptin activity.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
1464-3391
pubmed:author
pubmed:issnType
Electronic
pubmed:day
15
pubmed:volume
16
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
9261-7
pubmed:meshHeading
pubmed:year
2008
pubmed:articleTitle
Synergistic effect of basic residues at positions 14-15 of nociceptin on binding affinity and receptor activation.
pubmed:affiliation
Laboratory of Structure-Function Biochemistry, Department of Chemistry, Faculty of Sciences, Kyushu University, Fukuoka 812-8581, Japan.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't