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Elucidation of the primary structures of the cockroach hyperglycaemic hormones I and II using enzymatic techniques and gas‐phase sequencing
Author(s) -
SIEGERT KARL J.,
MORDUE WILLIAM
Publication year - 1986
Publication title -
physiological entomology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.693
H-Index - 57
eISSN - 1365-3032
pISSN - 0307-6962
DOI - 10.1111/j.1365-3032.1986.tb00407.x
Subject(s) - periplaneta , biology , cockroach , biochemistry , american cockroach , peptide , glycogen phosphorylase , protein primary structure , edman degradation , carboxypeptidase , aminopeptidase , enzyme , hormone , residue (chemistry) , peptide sequence , amino acid , ecology , leucine , gene
. Two peptides, HGHI and HGHII, both inducing hyperglycaemia and activation of fat body glycogen phosphorylase can be isolated from the corpora cardiaca of the American cockroach, Periplaneta americana , using high‐performance liquid chromatography. Both peptides are N‐terminally blocked by a pyroglutamate residue and are thus not available for sequencing methods using the Edman degradation as this technique requires a free N‐terminus. The blocked peptides were treated with pyroglutamate aminopeptidase to cleave the pyroglutamate residue, and the C‐terminus of each peptide is also blocked and neither molecule can be cleaved by carboxypeptidase A. The following sequences for hyperglycaemic hormones HGHI and HGHII have been revealed using gas‐phase sequencing. HGHI pGlu‐Val‐Asn‐Phe‐Ser‐Pro‐Asn‐Trp‐NH 2 HGHII pGlu‐Leu‐Thr‐Phe‐Thr‐Pro‐Asn‐Trp‐NH 2 Both peptides show remarkable similarities to locust adipokinetic hormones I and II and prawn red‐pigment concentrating hormone, and are identical to two myotropic peptides MI and MII (O'Shea et al. , 1984; Witten et al. , 1984) and two cardioactive and hyperglycaemic peptides CC‐1 and CC‐2 (Scarborough et al. , 1984), respectively, also isolated from the corpora cardiaca of P. americana.