Amino Acid Composition of Cockroach Hypertrehalosaemic Hormones

Hypertrehalosaem ic horm ones I and II from the corpus card iacum o f the A m erican cockroach (Periplaneta americana) were separated by reversed-phase h igh-perform ance liquid chrom ato­ graphy using a N ucleosil C 18 colum n with a trifluoroacetic acid /aceton itrile gradient. T he eluent was monitored at 206 nm and the hypertrehalosaem ic activity detected by bioassay. T he am ino acid compositions o f hypertrehalosaem ic horm one I and II were d e term ined a fte r acid hydrolysis with HC1 or m ethanesulfonic acid. Both neurohorm ones are octapep tides. H ypertreha losaem ic hormone I contained the am ino acids Asp(2), Ser, G lu , Pro, Val, Phe and T rp , w hereas h yper­ trehalosaem ic horm one II contained the am ino acid residues Asp, T h r(2), G lu , Pro, Leu, Phe and Trp.