Papain, also known as papaya proteinase I, is a cysteine protease (EC 3.4.22.2) enzyme present in papaya (Carica papaya) and mountain papaya (Vasconcellea cundinamarcensis).
A papaína, tamén chamada papaia proteinase I, é unha cisteina protease (EC 3.4.22.2), un encima presente na papaia (Carica papaya) e na papaia de montaña (Vasconcellea cundinamarcensis).