Data for the synthesis of oligo-γ-glutamylglutamines as model compounds for γ-glutamyltransferases (GGTs) and for normalization of activities of different GGTs.

γ-Glutamyltransferases (GGTs) are widespread, conserved enzymes that catalyze the transfer of the γ-glutamyl moiety from a donor substrate to water (hydrolysis) or to an acceptor amino acid (transpeptidation) through the formation of a γ-glutamyl enzyme intermediate. Although the vast majority of the known GGTs has a short sequence called lid-loop covering the glutamate binding site, GGT and some other enzymes from spp. lack the lid loop. In order to assess the possible role of the lid loop of GGTs in substrate selection, synthetic oligo-γ-glutamylglutamines containing up to three γ-glutamyl residues were used as model substrates. The activities of the enzymes under investigation were standardized with respect to a common reaction to ensure comparable results. The activity of an engineered mutant enzyme containing the amino acid sequence of the lid loop from GGT inserted into the backbone of GGT was compared to that of the lid loop-deficient GGT and the lid loop-carrier GGT (Calvio et al., 2018) [1]. Here we report the experimental procedures for the synthesis of model substrates γ-glutamylglutamines through the method of the -phtaloyl-L-glutamic acid anhydride and the spectral data of the synthetized compounds. The data obtained in the normalization procedure of the activities of the three enzymes are also reported.