Transglutaminase (TG)

Transglutaminases are a family of enzymes that catalyze the formation of covalent isopeptide bonds between the γ-carboxamide group of glutamine residues and the ε-amino group of lysine residues in proteins, leading to the formation of stable, proteolysis-resistant crosslinks important in biological processes such as blood coagulation, skin formation, and extracellular matrix stabilization. Several isoforms exist (including tissue transglutaminase/TG2, TG1, TG3), which differ in tissue distribution and function. Transglutaminases play key roles in cell differentiation, barrier formation, and wound healing, and aberrant activity has been implicated in diseases such as celiac disease (TG2 is the autoantigen), neurodegeneration, and cancer. Their enzymatic action is typically Ca²⁺-dependent in mammals, but some microbial forms are Ca²⁺-independent. Commercially, transglutaminase (often bacterial) is used as a food additive to improve food texture by crosslinking proteins, known colloquially as "meat glue".

Other names

tissue transglutaminaseTG2protein-glutamine gamma-glutamyltransferasefibrinoligaseglutaminyl-peptide gamma-glutamyltransferaseprotein-glutamine:amine gamma-glutamyltransferaseR-glutaminyl-peptide:amine gamma-glutamyl transferasetransglutaminase 1transglutaminase 3

Inhibition of enzymatic cross-linking/transamidation activity; Modulation of enzyme's cofactor dependencies (such as Ca²⁺-dependence); Antibody-mediated inhibition in the case of autoimmunity (ex: celiac disease anti-TG2 antibodies).