Cholecystokinin (CCK) is a peptide hormone endowed with several important biological activities, both in the central and peripheral nervous system. Previous conformational studies have dealt mainly with its C-terminal octapeptide fragment (CCK8), which represents the shortest fully circulating form of this hormone. We have undertaken a detailed NMR conformational study in a DMSOd6/H2O cryomixture at 278 K of the CCK analog H-Arg-Asp-Tyr(SO3H)-Thr-Gly-Trp-Nle-Asp-PheNH2 (CCK9) which retains all the bioactivities of CCK8, but was found to he remarkably more stable in acidic media and unaffected by air oxidation due to Met replacements. The predominant conformation contains a γ-turn centered on Thr4, separated by Gly5 from a helical segment that comprises the C-terminal residues. © 1993 Academic Press, Inc.
Solution Conformation of CCK9, a Cholecystokinin Analog
D'Ursi A.;Picone D.;
1993-01-01
Abstract
Cholecystokinin (CCK) is a peptide hormone endowed with several important biological activities, both in the central and peripheral nervous system. Previous conformational studies have dealt mainly with its C-terminal octapeptide fragment (CCK8), which represents the shortest fully circulating form of this hormone. We have undertaken a detailed NMR conformational study in a DMSOd6/H2O cryomixture at 278 K of the CCK analog H-Arg-Asp-Tyr(SO3H)-Thr-Gly-Trp-Nle-Asp-PheNH2 (CCK9) which retains all the bioactivities of CCK8, but was found to he remarkably more stable in acidic media and unaffected by air oxidation due to Met replacements. The predominant conformation contains a γ-turn centered on Thr4, separated by Gly5 from a helical segment that comprises the C-terminal residues. © 1993 Academic Press, Inc.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.