UDP-glucose:protein transglucosylase in developing maize endosperm

UDP-Glc:protein transglucosylase (UPTG) (EC 2.4.1.112), involved in the first step of a two-step mechanism proposed in potato tuber for protein-bound α-glucan synthesis, was found in developing maize endosperm. The enzyme transfers glucosyl residues from UDP-[14C]glucose to an endogenous protein acc...

Descripción completa

Guardado en:
Detalles Bibliográficos
Autores principales: Rothschild, A., Tandecarz, J.S.
Formato: JOUR
Materias:
Acceso en línea:http://hdl.handle.net/20.500.12110/paper_01689452_v97_n2_p119_Rothschild
Aporte de:
Descripción
Sumario:UDP-Glc:protein transglucosylase (UPTG) (EC 2.4.1.112), involved in the first step of a two-step mechanism proposed in potato tuber for protein-bound α-glucan synthesis, was found in developing maize endosperm. The enzyme transfers glucosyl residues from UDP-[14C]glucose to an endogenous protein acceptor in a Mn2+-dependent reaction in the absence of added primer. After SDS-polycrylamide gel electrophrresis of the reaction product, radioactivity co-migrated with a 38-kDa protein band. A two-step experiment shows that the developing endosperm of maize contains phosphorylase and starch synthase, capable of utilizing the UPTG reaction product formed during the first step as a primer for the synthesis of protein-bound glucan in the presence of the respective glucosyl donors during the second incubation step. © 1994.