Effects of transglutaminase on SDS-PAGE patterns of wheat, soy, and barley proteins and their blends

Transglutaminase (TG) catalyzes the formation of nondisulfide covalent crosslinks between peptide-bound glutaminyl residues and ε-amino groups of lysine residues in proteins. TG can be used for polymerizing proteins from 1 or more sources through formation of intermolecular crosslinks. This study investigated, by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, polymers created by the action of TG on proteins of wheat, soy, barley, wheat-soy, and wheat-barley blends. Electrophoretic results showed that with increasing incubation time, the crosslinking reaction is substantially increased, with progressive decrease or disappearance of some protein monomers. Densitometric results showed that soy proteins were the best substrates of TG while barley and wheat proteins were similar in reactivity.