Isolation and molecular characterization of a hyperglycemic neuropeptide from the sinus gland of the terrestrial isopod Armadillidium vulgare (Crustacea)

Abstract

The major peptide from the sinus gland of the terrestrial isopod Armadillidium vulgare (Crustacea) has been extracted and purified by reverse-phase HPLC. This neuropeptide exhibited a high hyperglycemic activity and was therefore named A. vulgare crustacean hyperglycemic hormone (Arv-CHH). Its average molecular mass measured by mass spectrometry was 8729.3 Da. Its complete amino acid sequence was determined by a combination of Edman degradation and mass spectrometry. The N-terminal amino acid was found to be unblocked, the C-terminal residue was found amidated and none of the other 72 residues was affected by any post-translational modification. Disulfide bond assignment was made unambigously by mass spectromety and Edman degradation was performed on peptides produced by enzymatic cleavage. Relationships with other, similar neuropeptides from decapod sinus glands are discussed.

Abbreviations

CHH

crustacean hyperglycemic hormone: Arv-CHH, Armadillidium vulgare crustacean hyperglycemic hormone

MIH

molt-inhibiting hormone

VIH

vitellogenesis-inhibiting hormone

AIH

androgenic-inhibiting hormone

LSIMS

liquid secondary-ion mass spectrometry

ESMS

electrospray mass spectrometry

MIKES

mass-analysed ion-kinetic-energy spectrum

RP

reversephase