Figure 1.

PX-12 inhibits recombinant and cellular TG2 more effectively than ERW1041. (A) TG2-mediated cross-linking of PTG was quantified by fluorometry. Normalization was performed against a condition, where the plate was coated with TG2 and no inhibitors were used. Background subtraction was performed against conditions where neither PTG nor TG2 were applied. n = 4 with three technical replicates per experiment. (B) TG2 activity in Caco-2 cell lysates was determined by cross-linking of 5BP (1 h). Reduction of protein lysate by DTT or treatment of Caco-2 cells with IFN-γ for 48 h significantly increased TG2 activity. Background subtraction was performed against conditions where no protein lysate was applied. n = 3 with three technical replicates per experiment. (C) Cell lysates were incubated overnight in the presence of inhibitors. Inhibition of cellular TG2 by PX-12 is more effective than competitive inhibition by ERW1041. Background subtraction was performed against conditions where no protein lysate was applied. n = 3 with three technical replicates per experiment. All data are shown as mean ± SD. Statistical significance was tested with Student’s t-test (with Welch correction where appropriate). * p < 0.05, ** p < 0.01, *** p < 0.001, **** p < 0.0001.