Peptides, Vol. 11, pp, 849-856. e Pergamon Press plc, 1990, Printed in the U.S.A. 0196-9781/90 $3.00 + .00 A New Peptide in the FMRFamide Family Isolated From the CNS of the Hawkmoth, Manduca sexta TIMOTHY G. KINGAN, *t DAVID B. TEPLOW,t JESSICA M. PHILLIPS,$ JOHN P. RIEHM,$ K. RANGA RAO,:~ JOHN G. HILDEBRAND,* UWE HOMBERG,* ANN E. KAMMER,§ IAN JARDINE,¶ PATRICK R. GRIFFIN# AND DONALD F. HUNT# *ARL, Division of Neurobiology, University of Arizona, Tucson, AZ 85721 "~Division of Biology, California Institute of Technology, Pasadena, CA 91125 ¢Department of Biology, University of West Florida, Pensacola, FL 32514 #Department of Zoology, Arizona State University, Tempe, AZ 85287 ¶Finnigan-Mat, 355 River Oaks Parkway, San Jose, CA 95134 #Department of Chemistry, University of Virginia, Charlottesville, VA 22901 Received 5 March 1990 KINGAN, T. G., D. B. TEPLOW, J. M. PHILLIPS, J. P. RIEHM, K. R. RAO, J. G. HILDEBRAND, U. HOMBERG, A. E. KAMMER, I. JARDINE, P. R. GRIFFIN AND D. F. HUNT. A newpeptidein the FMRFamide family isolated from the CNSof the hawkmoth, Manduca sexta. PEPTIDES 11(4) 849-856, 1990.--We have purified a FMRFamide-like peptide from extracts of brain-subesophageal ganglion of the moth, Manduca sexta. The purification was monitored with a new, competitive ELISA, and accomplished with ion exchange and reverse-phase HPLC. The peptide structure was determined by a combination of tandem mass spectrometry and automated Edman degradation. The amino acid sequence of the peptide is <Glu-Asp-Val-Val-His-Ser-Phe- Leu-Arg-Phe-amide (pEDVVHSFLRF-NH2). In a separate purification, an identical peptide was isolated from extracts of brain-associated neurohemal structures. We have named this peptide ManducaFLRFamide, to indicate its homology with other members of the "FMRFamide" family. In bioassays, chemically synthesized peptide increased the force of neurally evoked contractions in the major power-producing flight muscles, the dorsal longitudinal muscles. This observation suggests that hormonally released ManducaFLRFamide may play a role in sustaining or promoting the flight behavior necessary for mate-seeking (in males) or oviposition (in females) in sphingid moths. FMRFamide family Hawkmoth Ion exchange HPLC Peptide purification THE neuropeptide FMRFamide was first isolated from extracts of molluscan ganglia based on its ability to induce tonic contractions of a skeletal muscle in a whelk and cardioexcitation in a clam (28). FMRFamide and a number of structural homologs, 5-18 amino acids in length ending with Arg-Phe-amide, have since been isolated and sequenced (7, 10-12, 23, 26, 29, 32, 37, 41) or identified chromatographically (21) from several phyla. To date, all but one (23) of the peptides identified in protostomous invertebrates end in Phe-X-Arg-Phe-amide, where "X" is methio- nine, leucine, or isoleucine, while the apparent vertebrate repre- sentatives of this peptide family (2 bovine, 1 avian) end in Pro-Leu(or Gln)-Arg-Phe-amide. Targets for FMRFamide and other, structurally related peptides (FMRFamide-related peptiedes, FaRPs) in the central nervous system (CNS) and in innervated peripheral tissues mediate diverse biological activities in vertebrates (31, 34, 41) and invertebrates (1, 7, 9, 12, 20, 21, 24, 28, 29, 32, 39, 40). Studies in pulmonate molluscs have shown that peptides of this family variously elicit contraction or modulate spontaneous activity in visceral and somatic musculature as well as in the heart (20). Other investiga- tions in the opisthobranch molluscs have documented a role for FaRPs in the central modulation of a sensory-motor synapse (1,24). Most studies in arthropods have focused on the action of FaRPs at peripheral targets, particularly skeletal and visceral muscles (9, 12, 32, 39, 40). Vertebrate studies have shown that FaRPs decrease tail-flick latency and the antinociceptive action of morphine (41) and exhibit pressor activity (34) in rats. The tissue distribution of FaRPs has been studied in diverse vertebrate and invertebrate species, through the application of various antisera, which invariably have been selective for the C-terminal Arg-Phe-amide. Our work in the CNS of a moth has revealed peptide-like immunoreactivity in sensory neuropils and 1Requests for reprints should be addressed to Timothy G. Kingan at his present address: USDA, ARS, Insect Chemical Ecology Laboratory, BARC-East, Bldg. 402, Beltsville, MD 20705. 849