[Conformational properties of the CalliFMRF-amide series neuropeptides].
Conformational properties of five neuropeptides belonging to the calliFMRF-amide series with the Xaa-Pro-Yaa-Gln-Asp-Phe-Met-Arg-Phe-NH2 homologous sequences were studied by the method of theoretical conformational analysis. Three members of these group (1) (Xaa = Thr, Yaa = Gln), (2) (Xaa = Thr, Yaa = Ser), and (3) (Xaa = Yaa = Ser) can stimulate the saliva secretion from the separated salivary gland of the Calliphora vomitoria fly, whereas two other calliFMRF-amides (4) (Xaa = Lys, Yaa = Asn) and (5) (Xaa = Ala, Yaa = Gly) are inactive in this biological test. Low-energy spatial structures of the studied compounds were determined by a conformational analysis. A comparison of the stable structures of the biologically active and inactive neuropeptides revealed a similarity in their conformational properties and allowed determination of the role of separate residues in the peptide folding. The calculations demonstrated that the C-terminal hexapeptide fragment identical in all the five peptides tends to form alpha-helical structure, whereas the variable N-terminal tripeptide regions of CalliFMRF-amides (1)-(5) form more conformationally flexible structures.
Agaeva
G A
GA
Baku State University, ul. Khallilova 23, Baku, 370148 Azerbaijan. gulshen@mail.ru
Godzhaev
N M
NM
D000577:Amides / Q000737:chemistry; D000818:Animals; D004175:Diptera / Q000737:chemistry; D008958:Models, Molecular; D009479:Neuropeptides / Q000737:chemistry* / Q000494:pharmacology; D010446:Peptide Fragments / Q000737:chemistry; D011487:Protein Conformation; D017510:Protein Folding
D000577:Amides; D009479:Neuropeptides; D010446:Peptide Fragments
Konformatsionnye svoĭstva neĭropeptidov calliFMRF-amidov.