Purification and Characterization of Broccoli (Brassica oleracea var. italica) Myrosinase (beta-Thioglucosidase Glucohydrolase)

MAHN, A; Angulo, A; Cabanas F.

Keywords: Brassica oleracea var. italica; kinetics; myrosinase; purification process

Abstract

Myrosinase (beta-thioglucosidase glucohydrolase, EC 3.2.1.147) from broccoli (Brassica oleracea var. italica) was purified by ammonium sulfate precipitation followed by concanavalin A affinity chromatography, with an intermediate dialysis step, resulting in 88% recovery and 1318-fold purification. These are the highest values reported for the purification of any myrosinase. The subunits of broccoli myrosinase have a molecular mass of 50-55 kDa. The native molecular mass of myrosinase was 157 kDa, and accordingly, it is composed of three subunits. The maximum activity was observed at 40 degrees C and at pH below 5.0. Kinetic assays demonstrated that broccoli myrosinase is subjected to substrate (sinigrin) inhibition. The Michaelis-Menten model, considering substrate inhibition, gave V-max equal to 0.246 mu mol min(-1), K-m equal to 0.086 mM, and K-I equal to 0.368 mM. This is the first study about purification and characterization of broccoli myrosinase.

Más información

Título según WOS: Purification and Characterization of Broccoli (Brassica oleracea var. italica) Myrosinase (beta-Thioglucosidase Glucohydrolase)
Título según SCOPUS: Purification and characterization of broccoli (Brassica oleracea var. italica) myrosinase (?-thioglucosidase glucohydrolase)
Título de la Revista: JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
Volumen: 62
Número: 48
Editorial: AMER CHEMICAL SOC
Fecha de publicación: 2014
Página de inicio: 11666
Página final: 11671
Idioma: English
DOI:

10.1021/jf504957c

Notas: ISI, SCOPUS