Transglutaminase(300711-04-0)

Transglutaminase is an enzyme with the systematic name protein - glutamine γ - glutamyltransferase (EC 2.3.2.13). **1. Chemical and Physical Properties** - It usually appears as a white - to - yellowish or brown powder, or as a clear - to - brown liquid. It has a relatively high activity and can efficiently catalyze relevant reactions under certain conditions. It shows excellent thermal stability, with an optimal temperature around 50°C and remains highly active in the range of 45 - 55°C. Notably, its thermal stability is significantly enhanced in a protein - food system. In terms of pH stability, it is also quite good, with an optimal pH of 6.0 for its function, and it maintains a high level of activity within the pH range of 5.0 - 8.0. **2. Mechanism of Action** - Transglutaminase can catalyze cross - linking reactions either between or within protein molecules. Specifically, it catalyzes an amide - transfer reaction between the γ - amide group of glutamine residues and the ε - amino group of lysine in proteins. This reaction leads to the formation of ε-(γ - glutamyl)-lysine isopeptide bonds, thereby changing the functional properties of proteins. **3. Physiological Functions** - **In Organisms**: It is involved in many crucial physiological processes such as cell proliferation, differentiation, migration, metabolism, and immune defense. It plays a role in protein biosynthesis, cell - signal transduction, cell adhesion, and cell differentiation. - **In the Food Field**: - **Texture Improvement**: It can bind fragmented meat together and cross - link various non - meat proteins to meat proteins, significantly enhancing the taste, flavor, texture, and nutrition of meat products. For example, it is used in the production of restructured meat, steaks, sausages, hamburgers, and meatballs. - **Nutritional Value Enhancement**: It can covalently cross - link some essential amino acids for human beings to proteins, preventing the destruction of amino acids by the Maillard reaction. It can also introduce lacking amino acids into proteins with an imperfect amino acid composition. - **Edible Film Formation**: Casein cross - linked by this enzyme can be dehydrated to obtain a water - insoluble film, which can be used as food - packaging material. - **Lipid or Liposoluble Substance Encapsulation**: It can be used to encapsulate lipids or liposoluble substances, improving the elasticity and water - holding capacity of food. **4. Sources** - Transglutaminase is widely distributed in various tissues of animals, plants, and microorganisms. However, due to the high cost and scarcity of natural sources, microbial fermentation is currently the main method to produce it to meet industrial demands. **5. Application Areas** - **Food Industry**: As a new - type food additive, it is applied in the processing and production of a wide variety of foods such as meat products, fish products, dairy products, bean products, and flour products to improve their quality and performance. - **Biomedicine**: It also has potential application value in fields such as tissue engineering and drug research and development. For example, it is used for preparing medical materials with good biocompatibility and developing new - type drug carriers. - **Cosmetics Industry**: It can be used to improve the texture and stability of cosmetics and enhance their moisturizing performance and anti - wrinkling effects.