The purification, specificity, and role of dipeptidyl peptidase III in Dictyostelium discoideum
Dipeptidyl peptidase III was purified from culminating cells of Dictyostelium discoideum to apparent homogeneity by salt fractionation, isoelectric focusing, hydrophobic interaction, gel filtration, and ion-exchange chromatography. The enzyme was also found in and purified from cells growing on bact...
Gespeichert in:
Veröffentlicht in: | Experimental mycology 1992-01, Vol.16 (2), p.102-109 |
---|---|
Hauptverfasser: | , , , |
Format: | Artikel |
Sprache: | eng |
Schlagworte: | |
Online-Zugang: | Volltext |
Tags: |
Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
|
Zusammenfassung: | Dipeptidyl peptidase III was purified from culminating cells of
Dictyostelium discoideum to apparent homogeneity by salt fractionation, isoelectric focusing, hydrophobic interaction, gel filtration, and ion-exchange chromatography. The enzyme was also found in and purified from cells growing on bacteria or in axenic media. The enzyme from the growth phase was indistinguishable from the culmination enzyme during all purification procedures. Thus dipeptidyl peptidase III is not a developmentally associated enzyme and probably is involved in peptide breakdown throughout the life cycle. The enzyme cleaved arginyl-arginyl-2-naphthylamide most effectively and showed no action on leucyl-glycyl-naphthylamide, thus resembling the mammalian enzyme and differing from the yeast enzyme. Aspartyl-arginyl-naphthylamide was cleaved at 6% of the rate observed with arginyl-arginyl-naphthylamide and the enzyme
in vivo might therefore be capable of removing the N-terminal peptide (aspartyl-arginine) from peptides such as angiotensins I and II. It showed no aminopeptidase or endopeptidase activity. Angiotensin III was an effective inhibitor of the enzyme; peptides with the N-terminal sequences Gly-Gly, Gly-Arg, Arg-Val, and Gly-His inhibited the enzyme weakly. |
---|---|
ISSN: | 0147-5975 1878-4399 |
DOI: | 10.1016/0147-5975(92)90016-K |