THE MOLECULAR-CONFORMATIONS OF REPRESENTATIVE ARTHROPOD ADIPOKINETIC PEPTIDES DETERMINED BY CIRCULAR-DICHROISM SPECTROSCOPY

The secondary structure of six members of the AKH/RPCH family of arthr opod neuropeptides has been studied by circular dichroism spectroscopy , None of the peptides examined shows a clear ordered conformation in aqueous solution, pH 7.5 at room temperature. At low temperatures in e thanediol/aqueous buffer (2:1, pH 7.5), however, a P-II extended confo rmation becomes apparent in all of the peptides tested. For the peptid es that are most active in the lipid mobilization assay, interaction w ith SDS micelles induces the formation of a beta-structure. (C) 1998 E lsevier Science Ltd. All rights reserved.