title: Amino acid sequences of both isoforms of crustacean hyperglycemic hormone (CHH) and corresponding precursor-related peptide in Cancer pagurus.
abstract: Both isoforms of the crustacean hyperglycemic hormone (CHH) and corresponding crustacean hyperglycemic hormone precursor-related peptide (CPRP) derived from HPLC-purified sinus gland extracts from the edible crab Cancer pagurus were fully characterised by microsequencing and mass spectrometry. The amino acid sequences of the CHH isoforms were almost identical except that the N-terminus of the minor isoform (CHH-I), was glutamine rather than pyroglutamate in the major isoform (CHH-II). Both CHH isoforms were of similar biological activity, as tested by in vivo hyperglycemia bioassays and in vitro repression of ecdysteroid synthesis. Comparison with other published CHH and CPRP sequences show that for crabs, these peptides form a distinct group, that the presence of CHH isoforms with free and blocked N-termini seems unique to crabs. It is argued that this phenomenon reflects a slow post-translational modification in sinus gland neurosecretory terminals. This study appears to complete the entire sinus gland inventory of functionally and structurally characterised CHH-related peptides in a crab.
authors.affiliation: School of Biological Sciences, University of Wales Bangor, Gwynedd, UK.
authors.forename: J S
authors.initials: JS
authors.lastname: Chung
authors.forename: M C
authors.initials: MC
authors.lastname: Wilkinson
authors.forename: S G
authors.initials: SG
authors.lastname: Webster
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D060829:Arthropod Proteins; D001786:Blood Glucose / Q000187:drug effects; D003386:Brachyura; D002851:Chromatography, High Pressure Liquid; D026461:Ecdysteroids; D006458:Hemolymph / Q000378:metabolism; D007447:Invertebrate Hormones; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000737:chemistry*; D011498:Protein Precursors / Q000737:chemistry*; D011863:Radioimmunoassay / Q000379:methods; D016415:Sequence Alignment; D017421:Sequence Analysis; D013256:Steroids / Q000378:metabolism; D014357:Trypsin / Q000378:metabolism
chemical_list: D060829:Arthropod Proteins; D001786:Blood Glucose; D026461:Ecdysteroids; D007447:Invertebrate Hormones; D009419:Nerve Tissue Proteins; D011498:Protein Precursors; D013256:Steroids; C015947:hyperglycemic hormone, crustacean; C061766:hyperglycemic hormone precursor, crustacean; D014357:Trypsin