Hydrolases;
Glycosylases;
Glycosidases, i.e. enzymes that hydrolyse O- and S-glycosyl compounds
Sysname
ginsenoside glucohydrolase
Reaction(IUBMB)
(1) a protopanaxadiol-type ginsenoside with two glucosyl residues at position 3 + H2O = a protopanaxadiol-type ginsenoside with one glucosyl residue at position 3 + D-glucopyranose;
(2) a protopanaxadiol-type ginsenoside with one glucosyl residue at position 3 + H2O = a protopanaxadiol-type ginsenoside with no glycosidic modifications at position 3 + D-glucopyranose;
(3) a protopanaxadiol-type ginsenoside with two glycosyl residues at position 20 + H2O = a protopanaxadiol-type ginsenoside with a single glucosyl residue at position 20 + a monosaccharide
Substrate
protopanaxadiol-type ginsenoside with two glucosyl residues at position 3;
H2O [CPD:C00001];
protopanaxadiol-type ginsenoside with one glucosyl residue at position 3;
protopanaxadiol-type ginsenoside with two glycosyl residues at position 20
Product
protopanaxadiol-type ginsenoside with one glucosyl residue at position 3;
D-glucopyranose [CPD:C00031];
protopanaxadiol-type ginsenoside with no glycosidic modifications at position 3;
protopanaxadiol-type ginsenoside with a single glucosyl residue at position 20;
monosaccharide
Comment
Ginsenosidase type I is slightly activated by Mg2+ or Ca2+ [1]. The enzyme hydrolyses the 3-O-beta-D-(1->2)-glucosidic bond, the 3-O-beta-D-glucopyranosyl bond and the 20-O-beta-D-(1->6)-glycosidic bond of protopanaxadiol-type ginsenosides. It usually leaves a single glucosyl residue attached at position 20 and one or no glucosyl residues at position 3. Starting with a ginsenoside that is glycosylated at both positions (e.g. ginsenoside Rb1, Rb2, Rb3, Rc or Rd), the most common products are ginsenoside F2 and ginsenoside C-K, with low amounts of ginsenoside Rh2.
