Extraction, identification and activity of Papain from Iran

Background and Papain, a proteolytic enzyme, is found in the dried and purified latex from the fruits of Carica papaya L. (Caricaceae). Papain is used in medicine as a digestive and in the debridement of necrotic tissues. It is used in pharmaceutics as a spreading agent for drugs, supplied as an ointment (10%) with urea which denatures nonviable protein matter present in lesions. Large amounts of papain are used industrially to tenderize meat. In this research, crude latex was collected from Sarbaz region of Sistan-o-Baluchestan province. The full-grown but unriped fruit was subjected to shallow incisions on several sides (depth of incision was important). After collection, the coagulated lumps were shredded and dried by the use of heat (30°C). Extraction and sedimentation procedures were used for extraction of papain. In this method, cystein hydrochloride at adjusted pH was used for extraction and sodium chloride for sedimentation. The extracted papain was identified by the use of electrophoresis method and also by comparing its IR spectrum with the standard papain. The activity of extracted papain was determined by USP procedure. In this research, 1.2 g papain was obtained from 100g latex. Electrophoresis pattern and IR spectrum of extracted papain were identical with the satndard papain. The extracted papain from Iranian Carica papaya (c = 1mg/ml) showed 5800 U/ml activity.