Monitoring of transglutaminase crosslinking reaction by H-1 NMR spectroscopy on model substrates

A new method based on H-1 NMR spectroscopy was developed for monitoring transglutamina se cros slinking reaction with model molecules (CBZ-Gln-Gly and N-alpha-acetyl-lysine). The transglutaminase reaction led to the appearance of newresonances on NMR spectrum as well as significant decrease in others. The new observed resonances, originated from newly formed alpha-(gamma-glutamyl)lysine isopeptide bonds, evidence the enzymatic reaction and allow to quantify the epsilon-(gamma-glutamyl)lysine fragment. Moreover, the decrease in resonance intensity, originated from lysine, permit to determine the crosslinking degree. These results obtained by H-1 NMR spectroscopy can be used as an alternative method to LC-MS, reducing drastically the analysis time from 7 days to 2 h. (C) 2015 Elsevier B.V. All rights reserved.