ANALOGS OF MANDUCA ADIPOKINETIC HORMONE TESTED IN A BIOASSAY AND IN ARECEPTOR-BINDING ASSAY

Single amino acid replacement analogs of Manduca adipokinetic hormone (M-AKH) pGlu-Leu-Thr-Phe-Thr-Ser-Ser-Trp-GlyNH(2) were tested for acti vity in bioassays as well as receptor binding assays. Amino acids were replaced by Ala and by D-analogs. In addition an extended M-AKH and a nalogs containing photo affinity labels were tested. All analogs had r educed activity. All the peptides which had enough activity to allow a full dose response curve reached the same maximal activity as native M-AKH. The use of analogs, in which L-Phe(4) was replaced by Ala or by D-Phe and of L-Thr(3) replaced by D-Thr, as competitors led to improv ed binding of M-AKH in our competitive receptor binding assay. In the bioassay an inactive concentration of Ala(4) M-AKH increased the activ ity of a half optimal concentration of native M-AKH. (C) 1998 Elsevier Science Inc.