Table 1.
Enzymatic hydrolysis of ginsenoside Rc to PPD-type ginsenosides.
Fig 1.
Construction of ligand docked pose and sequence alignment on S. solfataricus β-glycosidase.
(A) Docking of C-Mc to S. solfataricus β-glycosidase in the homology model. The C-Mc ligand was docked to the active site of β-glycosidase from S. solfataricus (2CEQ), and amino acid residues within 4 Å distance of the substrate in the ligand docked model were selected. The selected non-catalytic residues, catalytic residues, and C-Mc are colored with red, blue, and green, respectively. (B) Amino acid sequence alignment of S. solfataricus β-glycosidase with P. furiosus β-glycosidase. The catalytic residues (Glu206 and Glu387) and non-catalytic residues (Leu213, Glu217, Lys219, and His342) of S. solfataricus β-glycosidase are colored with red and blue boxes, respectively.
Table 2.
Produced concentrations of ginsenoside Rd and C-K from ginsenoside Rc and C-Mc, respectively, by the wild-type and variant β-glycosidases of S. solfataricus.
Numerical values in round brackets present the experimental data under optimum conditions (95°C, pH 4.5, and 4% DMSO).
Table 3.
Substrate specificity of the wild-type and L213A variant β- glycosidase from S. solfataricus for the PPD-type ginsenosides.
Fig 2.
Biotransformation pathways from ginsenosides Rb1, Rb2, and Rc to C-K by the wild-type and L213A variant β-glycosidases from S. solfataricus.
The black arrow indicates newly formed hydrolytic activity by the L213A variant.
Fig 3.
C-K production from ginsenoside Rc via C-Mc with Rd and C-Mc as intermediates by (A) the wild-type and (B) L213A variant β-glycosidases from S. solfataricus, respectively. Ginsenoside Rc (filled circle), Rd (open circle), C-Mc (filled triangle), and C-K (filled square).
Fig 4.
HPLC profiles of the reaction solutions obtained after 4 h and 10 h for the production of C-K from ginsenoside Rc by (A) the wild-type and (B) L213A variant β-glycosidases from S. solfataricus.
Fig 5.
C-K production from ginsenoside Mc by (A) the wild-type and (B) L213A variant β-glycosidases from S. solfataricus. Ginsenoside C-Mc (filled triangle), and C-K (filled square).
Fig 6.
HPLC profiles of the reaction solutions obtained after 14 h for the production of C-K from ginsenoside Mc by (A) the wild-type and (B) L213A variant enzymes from S. solfataricus.