ABSTRACT
Cysteine proteases are everywhere in nature. In the plants, they perform multiple functions associated with growth and development. This chapter addresses the essential aspects associated with the main botanical families studied by the presence of these enzymes, their classification in clans, fami-lies and subfamilies, and other subgroups; fundamental structural features associated with each group and their relationship with the mechanism of action; the main functions that they perform in plants and applications they have today in social life, as well as other potentialities that systematic study can provide. In general remarks, the principal applications and potentiali-ties of these enzymes are shown, especially of those more studied: papain and bromelain. The chapter also identified the major sources of information about cysteine proteases in web databases; also a general bibliography about 222the theme supports these comments, useful for those academics interested in deeper knowledge about these interesting enzymes.
