Transglutaminases are a family of enzymes (EC 2.3. 2.13) that catalyze the formation of a covalent bond between a free amine group of protein- or peptide-bound lysine (acyl acceptors) and the gamma-carboxamide group of protein- or peptide-bound glutamine (acyl donors).
What is the function of transglutaminase?
Transglutaminases (TGs) are multifunctional proteins having enzymatic and scaffolding functions that participate in regulation of cell fate in a wide range of cellular systems and are implicated to have roles in development of disease.
How is transglutaminase produced?
Examples of foods made using transglutaminase include imitation crabmeat, and fish balls. It is produced by Streptoverticillium mobaraense fermentation in commercial quantities (P81453) or extracted from animal blood, and is used in a variety of processes, including the production of processed meat and fish products.
Which amino acid residues are the substrates of transglutaminase?
Transglutaminases (TGs) constitute a family of Ca2+-dependent enzymes catalyzing the cross-link formation between protein-bound glutamine residues (Q-donor) and the ɛ-amino group of protein-bound lysine residues (K-donor).
What is transglutaminase enzyme?
Transglutaminase is an enzyme that catalyses the formation of isopeptide bonds between proteins. Its cross-linking property is widely used in various processes: to manufacture cheese and other dairy products, in meat processing, to produce edible films and to manufacture bakery products.
What foods contain microbial transglutaminase?
Foods that contain “TG enzyme,” “enzyme” or “TGP enzyme” Fast food. Manufactured poultry pieces, sausages, bacon crumbles and hot dogs. Imitation seafood.
Is transglutaminase healthy?
However, there is no scientific research directly linking transglutaminase to an increased risk of disease, although research in this area is ongoing. The FDA classifies transglutaminase as GRAS (generally recognized as safe), and the USDA deems the ingredient safe to use in meat and poultry products (7).
What is a tTG?
A tissue transglutaminase IgA (tTg-IgA) test is used to help doctors diagnose celiac disease. In this autoimmune disorder, the immune system mistakenly thinks that gluten — a protein in wheat, barley, rye, and oats — is a foreign invader.
Is transglutaminase an emulsifier?
Stabilizes food mixtures. Transglutaminase can also act as an emulsifier. Emulsifiers blend ingredients that might not mix well otherwise, like oil and water.
Is transglutaminase safe to eat?
The FDA recognizes transglutaminase as safe to eat. It has several characteristics that make it nontoxic. Transglutaminase breaks down at a cooking temperature. Most meat is safe to eat only after it’s thoroughly cooked.
What is the catalytic mechanism of transglutaminase 2?
The catalytic mechanism of transglutaminase 2 shares some similarities with cysteine proteases (Figure 1), where a thiol residue (Cys277 in human TG2) in the active site attacks the glutamine carboxamide, releasing ammonia.
How does transglutaminase crosslink proteins?
Like other transglutaminases, it crosslinks proteins between an ε- amino group of a lysine residue and a γ- carboxamide group of glutamine residue, creating an inter- or intramolecular bond that is highly resistant to proteolysis (protein degradation).
What is the catalytic mechanism for crosslinking in human tTG?
The catalytic mechanism for crosslinking in human tTG involves the thiol group from a Cys residue in the active site of tTG. The thiol group attacks the carboxamide of a glutamine residue on the surface of a protein or peptide substrate, releasing ammonia, and producing a thioester intermediate.
How does a transaminase catalyse a transamidation reaction?
The upper reaction shows how a transaminase combines with a glutamine residue, releasing ammonia, and then the combination reacts with the amine group of a lysine residue of another protein, setting the enzyme free again. Nine transglutaminases have been characterised in humans, eight of which catalyse transamidation reactions.
