Ficin

Ficin is classified as a thiol protease. It contains a reactive cysteine in its active part. People take ficin to solve digestive problems and get rid of intestinal worms. In medical procedures, ficin is used to produce suture materials (sutures) and animal arteries to be implanted. In the manufacturing process, ficin is used to make cheese and sausage casings and anti-freeze beer. Mucin is sometimes included in meat tenderizers, usually in combination with papain and bromelain.

Introductions

Ficin is an enzyme derived from fig latex and belongs to the class of cysteine endopeptidases. It also includes papain derived from papaya latex, bromelain extracted from pineapple stem, calpain, caspases Cathepsin B and chymotrypsin. It is one of the most commonly used to distinguish many blood group antigens: for example, it will destroy M, N, S, Tamiflu a and Tamiflu b, and enhance some other antigens, including Rh, Kidd, Lewis, I, and P1 systems. This is a common situation when eating skin or white flesh directly inside fig skin to produce a burning or itching sensation. This is due to the mucin in the fruit latex (juice), especially when it is immature. Ficin was found in alcoholic beverages. Beer, meat tenderizer, dough conditioner, antifreeze for rennet substitutes, processing aids for pre-cooked grains. Ficin (or serine) by GRAS (Generally Recognized as Safe) is a fig-derived latex-derived enzyme. It belongs to the family of proteases, called cysteine endopeptidases, and also includes papain derived from papaya latex, bromelain (pineapple protease) extracted from pineapple stems, calpain, cysteine protease, cathepsin B And chymotrypsin. It is one of the most commonly used methods to differentiate many blood group antigens: for example, to destroy M, N, S, Duffy a and Duffy b and enhance some other antigens.

Chemical properties

The stability is extremely great. For example, if it is kept in a sealed room at room temperature for 1 to 3 years, its effectiveness only drops by 10% to 20%. The aqueous solution is inactivated below 100 ° C, while the powder takes several hours to inactivate at 100 ° C. The aqueous solution has a stable activity at a pH value of 4 to 8.5. Its activity can be inhibited by iron, copper and lead. The aqueous solution can hydrolyze gelatin, coagulated protein, cheese casein, meat, liver, etc., coagulate the emulsion, and has the function of digesting parasite eggs such as roundworms, whipworms and the like. Has certain hygroscopicity. It can be completely dissolved in water, showing light brown to dark brown. Insoluble in general organic solvents. If it is a concentrated preparation of fig pectin emulsion, it is light brown to dark brown. The main principle of action is to hydrolyze peptides into low molecular peptides. The optimal pH = 5.7; the optimal temperature 65 ℃.

Catalytic mechanism

Ficin reacts with the substrate in three steps: the rapid formation of a loose enzyme substrate complex; the -SH group in the active center of the enzyme is acylated by the carbonyl group of the substrate; the decomposition of the acylating enzyme produces enzymes and products.

Functions

Ficin can inhibit the browning of fruits, so it can be used as a preservative for natural foods such as vegetables, fruits, shrimps and so on. In addition, Ficin has strong proteolytic capacity, curd, lipolysis and bacteriolytic activity, and it is a pure natural substance that can act on various proteins. It has the characteristics of high temperature resistance, strong activity and high stability. It is insensitive to changes in pH and metal ions and detergents. It has a wide range of applications in medicine, food, light industry, cosmetics, feed and life science research. Ficin mainly used for beer cold resistance (hydrolysis of protein in beer to avoid turbidity caused by refrigeration); meat softening (hydrolysis of muscle protein and collagen to soften meat); dough regulator during baking; cheese manufacturing Emulsion coagulant (replaces rennet). Separating the shell of the shrimp from the meat to achieve mechanized shelling, and also separating the clam meat from its internal organs. It can also be used as an additive for pesticides and cosmetics.

Reference:

1. Liener IE, et al. Ficin. Methods Enzymol. 1970,19: 261-273.