Degradation profile of [His7]-corazonin in the hemolymph of the desert locust Schistocerca gregaria.
Degradation of the neuropeptide [His7]-corazonin, a key hormone in phase transition in locusts was studied using [3H][His7]-corazonin, RP-HPLC and mass spectrometry. After 4h incubation, 50 and 75% of [His7]-corazonin could still be found in hemolymph of gregarious and solitarious Schistocerca gregaria, respectively. Under in vivo conditions the half-life was 30 min. These results are in contrast to many other neuropeptides that usually have half lives of a few minutes. The peptide is cleaved first by an endopeptidase, either just before or after the Tyr residue at position 5. Next, the C-terminal degradation fragments are further degraded by a dipeptidyl-peptidase, whereas the N-terminal fragments are further broken down one amino acid at a time. In addition, [Dopa5][His7]-corazonin was detected. Upon synthesis, this unexpected molecular modification turned out to be biologically active in bringing about cuticular melanization.
Vandersmissen
Tim
T
Laboratory of Developmental Physiology, Genomics and Proteomics, Zoological Institute, K.U. Leuven, B-3000 Leuven, Belgium. Tim.Vandersmissen@bio.kuleuven.ac.be
Hoste
Bruno
B
Baggerman
Geert
G
Huybrechts
Jurgen
J
De Loof
Arnold
A
Chaltin
Patrick
P
Proost
Paul
P
Breuer
Michael
M
D000595:Amino Acid Sequence; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D004295:Dihydroxyphenylalanine / Q000031:analogs & derivatives / Q000494:pharmacology; D004152:Dipeptidyl-Peptidases and Tripeptidyl-Peptidases / Q000378:metabolism; D010450:Endopeptidases / Q000378:metabolism; D006110:Grasshoppers / Q000378:metabolism*; D006458:Hemolymph / Q000378:metabolism*; D019476:Insect Proteins / Q000378:metabolism* / Q000494:pharmacology; D009479:Neuropeptides / Q000378:metabolism* / Q000494:pharmacology; D009842:Oligopeptides / Q000378:metabolism / Q000494:pharmacology; D010446:Peptide Fragments / Q000378:metabolism; D010858:Pigmentation / Q000187:drug effects; D021241:Spectrometry, Mass, Electrospray Ionization
D019476:Insect Proteins; D009479:Neuropeptides; D009842:Oligopeptides; D010446:Peptide Fragments; C060602:corazonin protein, insect; D004295:Dihydroxyphenylalanine; D010450:Endopeptidases; D004152:Dipeptidyl-Peptidases and Tripeptidyl-Peptidases