protease

(proteinase) Any *hydrolase enzyme that catalyses the hydrolysis of protein chains. Specific proteases act only on certain peptide (CO-NH) linkages. For example, the bacterial protein thermolysin hydrolyses only those peptide bonds in which the amino group is donated by leucine, isoleucine, or valine. The best known plant protease is papain, from the latex of the papaw or papaya tree, Carica papaya, which is used commercially as a meat tenderizer. See also peptidase.