Release of a C-terminal amino acid with broad specificity. Inhibited by mercuric ions. Monomer. Secreted into the endosperm. Expressed mainly in the aleurone and, to a lesser extent in the embryo, throughout the 5-days germination period exclusively, with a maximal level at 3 days. Also found in the roots and shoots of the growing seedling. Belongs to the peptidase S10 family.