Abstract
Transglutaminase, catalyzing the formation of polymers through ε-(y-glutamyl) lysyl crosslinks between the glutaminyl residues and the lysyl residues, was usefully used in order to give evidence for polymerization of acidic subunit as a thermal gelation initiator. Electrophoresis of transglutaminase-treated glycinin indicated that acidic subunit was selectively polymerized in the native glycinin molecule, but not the counterpart basic subunit. When the transglutaminase-treated glycinin was heated at various protein concentrations, it became gelled even at 2 % protein concentration. This result implies that artificial polymerization of acidic subunit inhibits releasing of acidic subunit from soluble aggregate and precipitation of basic subunit monomer, oligomer and polymer, and so that polymerization of acidic subunit initiates or accelerates thermal gelation of glycinin.
