Papain, Chymo - Manual

In 1941, Jansen and Balls first described chymopapain, after obtaining it in crystalline form from papaya latex (Guha et al. 2006). It was termed chymopapain to distinguish it as the proteolytic activity remaining after the removal of papain (Taylor et al. 1999).

In 1967, Kunimitsu and Yasunobo first demonstrated chymopapain’s charge heterogeneity through cation-exchange chromatography, creating the notion that two forms of the enzyme existed: chymopapain A and chymopapain B. It has since been determined the separation observed during cation-exchange chromatography was instead due to the charge heterogeneity of chymopapain, and contamination with glycyl endopeptidase (Buttle 2004).

The amino acid sequences for chymopapain were published by Jacquet et al. in 1989 (Jacquet et al. 1989b) and Watson et al. in 1990. In 1996, Maes et al. elucidated the structure of chymopapain to a 1.7 Å resolution, and in 1999 Taylor et al.’s molecular cloning studies revealed five isoforms of the enzyme, putting an end to the chymopapain A and chymopapain B terminologies.

Recent research continues to investigate the wound-induced expression of chymopapain, as well as other papaya endopeptidases (Azarkan 2006). Chymopapain is also being used as a control to study human invertebral disc degeneration, as it mimics the natural process of degradation (Chen et al. 2009). Chymopapain has also found use in research in rheumatoid arthritis as it mimics the increased activity of proteases found in the joints of patients with rheumatoid arthritis (Sabaratnam et al. 2007).