Comparison of Deamidation Activity of Transglutaminases

Abstract

ABSTRACT: A comparison was made of the deamidation activity of transglutaminases fro m guinea pig liver (GTGase), fish red sea bream liver (FTGase) and microorganisms (MTGase). Against the Z‐Gln‐Gly, kinetic constants of the deamidation and incorporation of primary amine were measured. GTGase and FTGase showed similar deamidation activity, however, that of MTGase was less than 1/7 of the other two TGases. Against the proteins, N, N‐dimethylated casein and native gliadin, FTGase was the most active and deamidated respectively 45.5% and 38.2% of Gln residues. The deamidation rate of these proteins by GTGase was less than 1/2 and these results were expected to be caused by the difference of substrate specificity of the TGases.