The present work reports exopeptidase activity existing in cacao (Theobroma cacao L) during germination. Aminopeptidase (APE). carboxypeptidase (CP) and Xaa-Prolyl dipeptidyl aminopeptidase (Xaa-Pro-DAP) membrane-bound enzymes have been identified. The Xaa-Pro-DAP enzyme (E.C. 3.4.14.5) had not been previously detected in germinating cacao seeds. Xaa-Pro-DAP was partially purified and characterized, and the highest activity was found after 10 days of germination. Xaa-Pro-DAP was isolated by precipitation with 40% ammonium sulfate and partially purified with two chromatographic steps. The enzyme had a relative molecular weight of 80 kDa as determined by Native-PAGE and was, able to use Ala-Pro-4 mu beta NA as substrate. In the presence of SOS, this enzyme did not show activity because it must be in a trimer to be functional. Its activity was inhibited 44% by the chelating agent EDTA and 48% by the serine peptidase inhibitor PMSF at 0.1 mM, indicating that the partially purified Xaa-Pro-DAP is a serine metallopeptidase. The cations Cu2+ and Cd2+ caused 44% and 67% inhibition, respectively, while the other divalent cations tested had no significant effect on the activity of the partially purified enzyme. The enzyme showed a high specificity for Ala-Pro-pNA as a proteolytic substrate. (C) 2010 Elsevier Ltd. All rights reserved.