Amino Acid Composition of Cockroach Hypertrehalosaemic Hormones

Abstract

Hypertrehalosaemic hormones I and II from the corpus cardiacum of the American cockroach (Periplaneta americana) were separated by reversed-phase high-performance liquid chromato­graphy using a Nucleosil C18 column with a trifluoroacetic acid/acetonitrile gradient. The eluent was monitored at 206 nm and the hypertrehalosaemic activity detected by bioassay. The amino acid compositions of hypertrehalosaemic hormone I and II were determined after acid hydrolysis with HCl or methanesulfonic acid. Both neurohormones are octapeptides. Hypertrehalosaemic hormone I contained the amino acids Asp(2), Ser, Glu, Pro, Val, Phe and Trp, whereas hyper­trehalosaemic hormone II contained the amino acid residues Asp, Thr(2), Glu, Pro, Leu, Phe and Trp.