title: Dipeptidyl-aminopeptidases and aminopeptidases in Dictyostelium discoideum.
abstract: Extracts prepared from culminating cells of Dictyostelium discoideum have been found to contain dipeptidyl-aminopeptidases I (EC 3.4.14.1), II (EC 3.4.14.2), III (EC 3.4.14.4), arginine aminopeptidase (EC 3.4.11.6) and valine aminopeptidase. Dipeptidyl-aminopeptidase III was the most active of the dipeptidyl-aminopeptidases; its molecular weight was 158,000, with a pH optimum of 10.2 and gave a single peak of activity on gel-filtration or when fractionated by chromatofocusing. The specific activities of dipeptidyl-aminopeptidases I and III increased during development being highest during the culmination stage before decreasing during sorocarp formation; dipeptidyl-aminopeptidase II and arginine aminopeptidase decreased progressively throughout development. The presence of these dipeptidyl-aminopeptidases suggests the possibility that processing of peptides may be necessary during the development of Dictyostelium.
mesh_terms: D000626:Aminopeptidases / Q000302:isolation & purification / Q000378:metabolism*; D020789:Cathepsin C; D004023:Dictyostelium / Q000201:enzymology* / Q000254:growth & development; D004152:Dipeptidyl-Peptidases and Tripeptidyl-Peptidases / Q000302:isolation & purification / Q000378:metabolism*; D010450:Endopeptidases / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D008970:Molecular Weight
chemical_list: D010450:Endopeptidases; D000626:Aminopeptidases; C044775:valine aminopeptidase; C019721:aminopeptidase B; D004152:Dipeptidyl-Peptidases and Tripeptidyl-Peptidases; D020789:Cathepsin C; C100151:dipeptidyl peptidase II; C100152:dipeptidyl peptidase III