Quantitation and localisation of (in vitro) transglutaminase-catalysed glutamine hydroxylation using mass spectrometry

A mass spectrometric approach was chosen to quantify and localise in vitro enzymatically modified glutamine (Gln) residues in a glutamine-rich protein. This protein (named dB1), a cloned domain of the high molecular weight wheat glutenin subunit Dx5, was modified by microbial transglutaminase (TGase) using hydroxylamine as the amine donor. Using...