A novel ginsenosidase from an Aspergillus strain hydrolyzing 6-O-multi-glycosides of protopanaxatriol-type ginsenosides, named ginsenosidase type IV.
Herein, a novel ginsenosidase, named ginsenosidase type IV, hydrolyzing 6-O-multi-glycosides of protopanaxatrioltype ginsenosides (PPT), such as Re, R1, Rf, and Rg2, was isolated from the Aspergillus sp. 39g strain, purified, and characterized. Ginsenosidase type IV was able to hydrolyze the 6-O-alpha-L-(1-->2)-rhamnoside of Re and the 6-O-beta-D- (1-->2)-xyloside of R1 into ginsenoside Rg1. Subsequently, it could hydrolyze the 6-O-beta-D-glucoside of Rg1 into F1. Similarly, it was able to hydrolyze the 6-O-alpha-L-(1-->2)- rhamnoside of Rg2 and the 6-O-beta-D-(1-->2)-glucoside of Rf into Rh1, and then further hydrolyze Rh1 into its aglycone. However, ginsenosidase type IV could not hydrolyze the 3-O- or 20-O-glycosides of protopanaxadioltype ginsenosides (PPD), such as Rb1, Rb2, Rb3, Rc, and Rd. These exhibited properties are significantly different from those of glycosidases described in Enzyme Nomenclature by the NC-IUBMB. The optimal temperature and pH for ginsenosidase type IV were 40°C and 6.0, respectively. The activity of ginsenosidase type IV was slightly improved by the Mg(2+) ion, and inhibited by Cu(2+) and Fe(2+) ions. The molecular mass of the enzyme, based on SDS-PAGE, was noted as being approximately 56 kDa.
College of Science, Yanbian University, Yanji City 133002, China.
Dong-Ming
DM
Wang
Hong-Shan
HS
Yu
Jian-Guo
JG
Song
Yu-Feng
YF
Xu
Chun-Ying
CY
Liu
Feng-Xie
FX
Jin
D001230:Aspergillus / Q000737:chemistry / Q000201:enzymology* / Q000235:genetics; D004795:Enzyme Stability; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D036145:Ginsenosides / Q000737:chemistry / Q000378:metabolism*; D006026:Glycoside Hydrolases / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D006868:Hydrolysis; D013379:Substrate Specificity
D005656:Fungal Proteins; D036145:Ginsenosides; D006026:Glycoside Hydrolases