Wilson, Claire L. and Shirras, Alan D. and Isaac, R. Elwyn (2002) Extracellular peptidases of imaginal discs of Drosophila melanogaster. Peptides, 23 (11). pp. 2007-2014. ISSN 0196-9781Full text not available from this repository.
The imaginal discs of Drosophila melanogaster give rise to the adult epidermis during metamorphosis. During this developmental period several peptidase genes are expressed in disc cells, but there is a paucity of biochemical information regarding substrate specificity. We have used peptides and peptidyl 7-amino-4-methylcoumarin (AMC) substrates to detect several peptidases either positioned on the surface of wing discs or secreted by the imaginal cells. Using [Leu5]enkephalin as a substrate, a captopril sensitive dipeptidyl carboxypeptidase (angiotensin I-converting enzyme) and an amastatin-sensitive aminopeptidase were detected as prominent activities associated with intact discs. The formation of [Leu5]enkephalin-derived Phe was attributed to the concerted action of the D. melanogaster angiotensin I-converting enzyme (Ance) and a dipeptidase. The disc Ance also showed endopeptidic activity towards locust tachykinin-1 (LomTK-I) by cleaving the Gly–Val peptide bond, but this enzyme was not the sole endopeptidase activity associated with discs. Complete inhibition of the endopeptidic hydrolysis of the LomTK-1 by a disc homogenate required a combination of captopril and the neprilysin inhibitor, phosphoramidon, providing biochemical evidence for a neprilysin-like peptidase, in addition to Ance, in imaginal discs of D. melanogaster. Peptidyl AMC substrates for furin, prohormone convertase and tryptase provided evidence for trypsin-like serine endopeptidases in addition to the metalloendopeptidases. We conclude that imaginal discs are endowed with a variety of peptidases from different families that together are capable of hydrolyzing a broad range of peptides and proteins. Some of these peptidases might be responsible for the metabolic activation/inactivation of signaling peptides, as well as being involved in the production of dipeptides and free amino acids required for protein synthesis and osmotic balance during adult morphogenesis.
|Journal or Publication Title:||Peptides|
|Uncontrolled Keywords:||Peptide metabolism ; Angiotensin I-converting enzyme ; Aminopeptidase ; Dipeptidase ; Dipeptidyl peptidase IV ; Neprilysin|
|Subjects:||Q Science > QH Natural history > QH301 Biology|
|Departments:||Faculty of Health and Medicine > Biomedical & Life Sciences|
Faculty of Science and Technology > Lancaster Environment Centre
|Deposited By:||Dr Alan Shirras|
|Deposited On:||05 Jun 2008 16:54|
|Last Modified:||26 Jul 2012 18:36|
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