Primary structure of the hypertrehalosaemic factor II from the corpus cardiacum of the Indian stick insect, Carausius morosus, determined by fast atom bombardment mass spectrometry.

The primary structure of hypertrehalosaemic factor II, isolated from the corpus cardiacum of the Indian Stick Insect Carausius morosus, has been assigned as Glu-Leu-Thr-Phe-Thr-Pro-Asn-Trp-Gly-Thr-NH2 from its fast atom bombardment (FAB) mass spectrum and metastable scans of its FAB spectrum. The structure assigned shows close homology to other insect neuropeptides. A synthetic sample of this peptide gave the same FAB spectra, reversed-phase high-performance liquid chromatographic behavior, and biological behavior as the natural material. Mass spectrometric fragmentation of the synthetic peptide was examined by B/E linked scan and MIKES techniques in a two-sector mass spectrometer and by the MS/MS technique in a four-sector (tandem) spectrometer.