β-D-Glucosidase from Seeds of Japanese Cycad, Cycas revoluta

Abstract

beta-D-Glucosidase was purified from seeds of Japanese cycad by dialysis, chromatography on CM-Sepharose CL-6B, gel filtration on Biogel P-200, and chromatofocusing. By chromatofocusing, beta-D-glucosidase was separated into four components whose isoelectric points were in a very narrow range (7.43-7.68). All these components were glycoproteins. The main component (pI = 7.59) was homogeneous on gel isoelectric focusing, and was crystallized from ammonium sulfate solution. The molecular weight of the crystalline preparation was determined to be 137,000 by gel filtration, and 67,000 by sodium dodecylsulfate polyacrylamide gel electrophoresis, indicating the main component was composed of two subunits with the same molecular weight. The amino acid composition and sugar content of the main component were also determined. All four components hydrolyzed not only o-nitrophenyl beta-D-glucopyranoside but also o-nitrophenyl beta-D-galactopyranoside, o-nitrophenyl beta-D-fucopyranoside, and o-nitrophenyl beta-D-xylopyranoside. Hydrolysis rates of each substrate by the four components were quite similar. Mixed substrate experiments using crystalline preparation proved that a single active site was responsible for the hydrolysis of these substrates.

Formation of Three New Trisaccharide-azoxyglycosides by Transglucosylation by Cycad β-Glucosidase

“…We are analyzing transglucosylation· of f3-D-glucosidase from cycad seeds, using a crystalline enz~me preparatjon. 9 ) In the course of the study, we have found the formation of three new trisaccharide-azoxyglycosides from some azoxyglycosides. This paper deals with the structures of these azoxyglycosides and the mechanism of their formation.…”

“…9 ) One unit of enzyme activity was defined as the amount of enzyme which hydrolyzed 1pmol of o-nitrophenyl j1-D-glucopyranoside in 0.1 M acetate buffer, pH 5.0, at 30°C.…”

Preventive Effect of Cycas Revoluta in 1,2-Dimethylhydrazine-Induced Colon Cancer in Wistar Rat Model

“…It is reported for the seeds to possess profound anticancer activity against colon cancer [11]. The plant contains several important chemicals including dihydroamentoflavone glucosides [12], peptides [11], chitinase [13], mannose-specific lectins [14], and beta-D-glucosidase [15]. C. revoluta has been reported to have many pharmacological effects such as antioxidant [16], anti-inflammatory, anticancer, antileishmaniasis [12], and antimicrobial [11].…”

A New Azoxyglycoside Containing Isomaltose: Neocycasin Bα

“…Glucoamylase of Rhizopus niveus hydrolyzed the compound to yield cycasin and glucose (I : I, molar ratio) but fJ-D-glucosidase from cycad seeds 10 ) did not. Furthermore, serial enzymatic hydrolysis of the compound with glucoamylase and cycad fJ-D-glucosidase gave MAM and glucose (1 : 2, molar ratio).…”