Papain is a natural enzyme, a kind of endopeptidese containing hydrosulfide group (-SH), extracted from the milky juice of the unripe papaya by biotechnology. It has strong ability of hydrolyzing protein and can be used for improving the nutritional value or function of the plants and the animal protein. The strict concentration limit of microbe and heavy metal by using the biotechnology and the membrane separation technique, can achieve the pharma and food grade.

Functions

• Papain is commonly used in cell isolation procedures where it has proven more efficient and less destructive than other proteases on certain tissues.
• Papain is used in red cell serology to modify the red cell surface to enhance or destroy the reactivity of many red cell antigens as an adjunct to grouping, antibody screening, or antibody identification procedures. Papain has also been shown to be useful in platelet serology
• Papain has also been used in the enzymatic synthesis of amino acids, peptides, and other molecules.
• Papain is used routinely for the preparation of Fab fragments from IgG. IgM may also be digested with papain resulting in high yields of homogeneous Fab preparations.
• Papain cleaves antibodies into two Fab fragments, which recognize the antigen specifically with their variable region, and one Fc fragment. It cleaves above the hinge region containing the disulfide bonds that join the heavy chains, but below the site of the disulfide bond between the light chain and heavy chain. This generates two separate monovalent (containing a single antibody binding site) Fab fragments and an intact Fc fragment. The fragments can be purified by gel filtration, ion exchange, or affinity chromatography.
• In tissues such as lymph nodes or spleen, or in peripheral blood preparations, cells with Fc receptors (macrophages, monocytes, B lymphocytes, and natural killer cells) are present which can bind the Fc region of intact antibodies, causing background staining in areas that do not contain the target antigen. Use of Fab fragments ensures that the antibodies are binding to the antigen and not to Fc receptors. These fragments may also be desirable for staining cell preparations in the presence of plasma, because they are not able to bind complement, which could lyse the cells. Fab fragments allow more exact localization of the target antigen, i.e. in staining tissue for electron microscopy.

Applications:

1. Clinical practice
   • Home remedy treatment: for jellyfish, bee, yellow jacket (wasps) stings, mosiquito bites, and possibly stingray wounds, breaking down the proteintoxins in the venom.
   • main ingredient in Stop Itch and Stop Itch Plus.
   • Medicines contained papain can be used for anti-cancer, tumor, lymphocytic leukemia, bacteria and parasites, and TB.
   • Treatment of gynecological diseases, glaucoma, bone hyperplasia, chronic wound healing, blood type identification, and insect biting.
2. Cosmetics industry
   • Papain can be added to the protein and fat containing cosmetics to improve product level with its unique whitening rejuvenation, beauty care, freckle removing, promoting blood circulation, changing skin;
   • It can be made into weight loss tea.
3. Food industry
   • Hydrolyzed animal and plant protein, Placenta, and soy;
   • Biscuits pine agent, stabilizer noodles, beer & beverage clarifying agent, advanced oral liquid, health food, soy sauce and alcoholic fermentation agent et
   • meat tenderizer powde
4. Daily-use chemical industry  Used for soap, soap, detergent, washing powder, hand sanitizer with strong effects on sterilization disinfection, safety.
5. Other industries