Details

Autor(en) / Beteiligte

• Nachman, R.J. (Veterinary Toxicology and Entomology Research Laboratory, ARS, USDA, College Station, TX)
• Roberts, V.A
• Dyson, H.J
• Holman, G.M
• Tainer, J.A

Titel

Active conformation of an insect neuropeptide family

Ist Teil von

• Proceedings of the National Academy of Sciences - PNAS, 1991-05, Vol.88 (10), p.4518-4522

Ort / Verlag

Washington, DC: National Academy of Sciences of the United States of America

Erscheinungsjahr

1991

Quelle

Electronic Journals Library

Beschreibungen/Notizen

• To understand the structural and chemical basis for insect neuropeptide activity, we have designed, synthesized, and determined the conformation of a biologically active cyclic analog of the pyrokinins, an insect neuropeptide family that mediates myotropic (visceral muscle contractile) activity. Members of this insect neuropeptide family share the common C-terminal pentapeptide sequence Phe-Xaa-Pro-Arg-Leu-NH2 (Xaa = Ser, Thr, or Val). Circular dichroic, nuclear magnetic resonance, and molecular dynamics analyses of the conformationally restricted cyclic pyrokinin analog cyclo (-Asn-Thr-Ser-Phe-Thr-Pro-Arg-Leu-) indicated the presence of a beta-turn in the active core region encompassing residues Thr-Pro-Arg-Leu. The rigid cyclic analog retains biological activity, suggesting that its C-terminal beta-turn is the active pyrokinin conformation recognized by the myotropic receptor. As individual pyrokinins and pyrokinin-like neuropeptides demonstrate both oviduct-contractile and pheromone-biosynthesis activities in various insects, the biologically active beta-turn structure reported here holds broad significance for many biological processes