1. Introduction
Plant proteases, enzymes that catalyse the hydrolysis of peptide
bonds, participate in several biological processes, including mobilisation
of storage proteins, degradation of light-damaged chloroplast
proteins, defense against phytopathogen attack, tissue
differentiation, and floral senescence (Estelle, 2001). Different
industrial processes utilise proteases such as papain, bromelain,
and ficin, and new enzymes with appealing physicochemical properties
have been investigated for that purpose (Feijoo-Siota & Villa,
2001).