Transglutaminases (TGs) are Ca²⁺and thiol-dependent enzymes that catalyze posttranslational modifications ofproteins. These covalent reactions include formation of isopeptide linkagesbetween the carboxamide groups of protein-bound glutamine residues and ε-aminogroups of protein-bound lysine and polyamine residues, hydrolysis andesterification of glutamine residues. Family of TGs includes at least nine members: TG 1-7, coagulation factor XIIIa,and the keratinocyte membrane bound TG form. TG has attracted considerable interest as apotential drug target. Its activity isthought to contribute to Alzheimer disease, Parkinson disease, Huntingtondisease, and supranuclear palsy.

SensoLyte^®Transglutaminase Activity Assay Kit provides a convenient assay for the highthroughput screening of TG modulators and inhibitors. TG catalyzes covalentbond formation between a free amine group of poly-D-lysine, which is coated onthe plate surface, and γ-carboxamide group of glutamine in biotin-TVQQELpeptide substrate. The reaction immobilizes biotin-conjugated peptide to theplate surface. The amount of immobilized biotin is determined usingstreptavidin-horseradishperoxidase (HRP) andTMB substrate. Colorimetric signal generated by HRP and TMBsubstrate is proportional to the activity of TG in a sample. Assay is performedin a convenient 96-well microplate format.