Papain is a low specificity proteolytic enzyme. It is widely found in the roots, stems, leaves and fruits of papaya, and has the highest content in immature latex. Papain is a sulfhydryl protease, and its active site contains cysteine, which has the characteristics of high enzymatic activity, high thermal stability and high safety. Therefore, it is widely used in the food, medicine, feed, chemical, cosmetic, leather and textile industries.

The role of papain
The immature papaya fruit contains a variety of proteolytic enzymes such as papain, chymotrypsin A, chymotrypsin B, and papain B. It is known that the primary structures of the four cysteine proteases have a high degree of homology. Among them, papain is a sulfhydryl protease, which can hydrolyze the carboxyl end of arginine and lysine in proteins and polypeptides. And can preferentially hydrolyze those amino acids with two carboxyl groups or aromatic L-amino acids at the N-terminus of the peptide bond.

Papain is a proteolytic enzyme with a molecular weight of 23.4 kDa, composed of a single peptide chain, containing 212 amino acid residues. There are at least three amino acid residues in the active center of the enzyme. They are Cys25, His159 and Asp158. When Cys25 is oxidized by oxidants or combined with metal ions, the activity of the enzyme is inhibited, while the reducing agent cysteine (or sulfite) or EDTA can restore the activity of the enzyme. The other six cysteine residues form three pairs of disulfide bonds, and none of them are in the active site. Pure papain products can contain: (1) papain, with a molecular weight of 21 kDa, accounting for about 10% of soluble protein. (2) Papaya chymotrypsin has a molecular weight of 26 kDa and accounts for about 45% of soluble protein. (3) Lysozyme, with a molecular weight of 25 kDa, accounts for about 20% of soluble protein, and different enzymes such as cellulase.

Application areas of papain

1. Pharmaceutical industry: drugs containing papain can treat tumors, lymphatic leukemia, protobacteria and parasites, tuberculosis, etc., and can also help reduce inflammation, promote choleretics, relieve pain, and aid digestion. It can also help treat gynecological diseases, glaucoma, bone hyperplasia, gun knife wound healing, blood type identification, insect bites, etc.

2. Food industry: Enzymatic reactions can be used to hydrolyze large food molecules into small peptides or amino acids. It is used to hydrolyze animal and plant proteins, make meat tenderizer, hydrolyzed sheep placenta, hydrolyzed soybeans, biscuit loosening agent, noodle stabilizer, beer beverage clarifier, advanced oral liquid, health food, soy sauce brewing and wine starter, etc. It can effectively transform the utilization of protein, greatly improve the nutritional value of food and reduce costs.

3. Cosmetics: papain is added to cosmetics containing protein and oil, which has unique whitening and rejuvenation, beauty and health care, freckle removal and dirt removal, promoting blood circulation, improving skin, etc., and improving product quality. It can be made into slimming tea, beauty and skin care products.

4. Daily chemical industry: papain is used in the production of soaps, soaps, detergents, washing powders, and hand sanitizers, with strong detergency.

5. Feed industry: Papain is used as a feed additive to develop protein sources, which is good for absorption, improves feed utilization, and saves costs. Such as adding to the feed of pigs, cattle, sheep, chickens, ducks, geese, fish, shrimps, etc. It can also be used as an additive for high-grade compound fertilizers for vegetables and fruits.

The use of papain is very extensive, and the methods of use are also diversified. Creative Enzymes provides high-quality papain that can meet your different needs.

Author's Bio: 

Creative Enzymes is a remarkable supplier and manufacturer in the Enzymology field. Equipped with advanced technique platform, Creative Enzymes is able to offer high-quality and professional services for customers. Its products and services are widely used in the academic and pharmaceutical industries.