Plant Proteolytic Enzymes: Their Role as Natural Pharmacophores

Proteases or proteinases are enzymes that catalyze cleavage of proteins at peptide bonds generating smaller peptides. Some of them are very specific in their choice of target site while others act rather nonspecifically and hydrolyze the protein substrate if conditions allow into short peptides. They must have appeared early in evolution along with proteins, to keep a balance between synthesis and protein degradation. Their early emergence is confirmed by their ubiquitous presence in most living forms including viruses, plants, and animals.