Isolation and primary structure of two peptides with cardioacceleratory and hyperglycemic activity from the corpora cardiaca of Periplaneta americana.

Two cardioacceleratory peptides from the corpora cardiaca of Periplaneta americana have been purified by gel filtration and reversed-phase liquid chromatography, Based on analysis of the intact factors and their chymotryptic fragments, we have assigned the primary structure of these octapeptides as pGlu-Val-Asn-Phe-Ser-Pro-Asn-Trp-NH2, designated periplanetin CC-1, and pGlu-Leu-Thr-Phe-Thr-Pro-Asn-Trp-NH2, designated periplanetin CC-2. They represent new members of a family of invertebrate peptides that includes locust adipokinetic hormone and crustacean red-pigment concentrating hormone. Both peptides show adipokinetic activity in grasshoppers and hyperglycemic activity in cockroaches. One of these peptides (CC-2) has provocative sequence homology with the NH2-terminal portion of glucagon.