In vitro effect on the proteolytic activity of papain with proteins of the skin as substrate

Objective This work aims to evaluate the effects of enzyme concentration, pH, temperature and time course degree of hydrolysis (DH) of papain regarding further development of pharmaceutical and cosmetic formulations. Methods The hydrolysis of casein, collagen, keratin and porcine skin at pH and temperature ranges of the human skin was evaluated. Also, low contact times of enzyme-substrate were studied. The incorporation of 3mM of cysteine improved the caseinolytic (PU), collagenolytic (CU) and keratinolytic (KU) activities of papain. Results: In general, the increase from 0.1 to 1.0 or 2.0 mgmL(-1) of papain improved PU, CU and KU. When 2.0 mgmL(-1) of papain was used, the highest DH of casein, collagen and keratin was obtained at 240min (14%, 35% and 6% respectively). The decrease in pH and temperature reduced all proteolytic activities, but papain maintained at least 50% and 40% of its activity at 26 degrees C and pH 4.5 respectively. Scanning electron micrographs of the surface of the skin showed that papain application had exfoliating activity. Conclusion This preformulation study demonstrated that papain concentration, time of application and pH of the product should be evaluated when developing a product to promote the hydrolysis of the proteins of the skin.