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Purification and characterization of a ginsenoside Rb(1)-hydrolyzing β-glucosidase from Aspergillus niger KCCM 11239.

Chang KH, Jo MN, Kim KT, Paik HD - Int J Mol Sci (2012)

Bottom Line: In the specificity tests, the enzyme was found to be active against ginsenoside Rb(1), but showed very low levels of activity against Rb(2), Rc, Rd, Re, and Rg(1).The enzyme hydrolyzed the 20-C,β-(1→6)-glucoside of ginsenoside Rb(1) to generate ginsenoside Rd and Rg(3), and hydrolyzed 3-C,β-(1→2)-glucoside to generate F(2).The properties of the enzyme indicate that it could be a useful tool in biotransformation applications in the ginseng industry, as well as in the development of novel drug compounds.

View Article: PubMed Central - PubMed

Affiliation: Division of Animal Life Science, Konkuk University, Seoul 143-701, Korea; E-Mails: khchang80@cj.net (K.H.C); ulul55@naver.com (M.N.J.).

ABSTRACT
Rb(1)-hydrolyzing β-glucosidase from Aspergillus niger KCCM 11239 was studied to develop a bioconversion process for minor ginsenosides. The specific activity of the purified enzyme was 46.5 times greater than that of the crude enzyme. The molecular weight of the native enzyme was estimated to be approximately 123 kDa. The optimal pH of the purified enzyme was pH 4.0, and the enzyme proved highly stable over a pH range of 5.0-10.0. The optimal temperature was 70 °C, and the enzyme became unstable at temperatures above 60 °C. The enzyme was inhibited by Cu(2+), Mg(2+), Co(2+), and acetic acid (10 mM). In the specificity tests, the enzyme was found to be active against ginsenoside Rb(1), but showed very low levels of activity against Rb(2), Rc, Rd, Re, and Rg(1). The enzyme hydrolyzed the 20-C,β-(1→6)-glucoside of ginsenoside Rb(1) to generate ginsenoside Rd and Rg(3), and hydrolyzed 3-C,β-(1→2)-glucoside to generate F(2). The properties of the enzyme indicate that it could be a useful tool in biotransformation applications in the ginseng industry, as well as in the development of novel drug compounds.

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Bioconversion pathway of ginsenoside Rb1 by β-glucosidase.
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f6-ijms-13-12140: Bioconversion pathway of ginsenoside Rb1 by β-glucosidase.

Mentions: When ginsenoside Rb1 was incubated, it was converted completely into Rd after 1 h. After 2 h, the ginsenoside Rd content decreased gradually, and the F2 content increased gradually. After 12 h, both S-Rg3 and R-Rg3 began to be detected, and the content of total Rg3 increased over time. This result indicated that the hydrolysis pathway of ginsenoside Rb1 by β-glucosidase was Rb1→Rd→F2 and Rb1→Rd→Rg3, purified enzyme hydrolyzed a β-(1→6)-glucosidic linkage at C-20, as well as a β-(1→2)-glucosidic linkage at C-3 (Figure 6). These results are similar to those of the pathway by which ginsenoside Rb1 is converted to Rg3 by Microbacterium sp. GS514 [9]. Ginsenoside Rd has been shown to protect neurons against neurotoxic chemicals [21] and to prevent the contraction of blood vessels [22]. F2 is a potent inhibitor of acetylcholine-evoked secretion [23]. Rg3 induces a variety of pharmacological activities, such as tumor suppression [24], and hepatoprotective [25] and immune-enhancing effects [26]. Therefore, the β-glucosidase obtained from A. niger KCCM 11239 is considered a good candidate for use in biotransformation applications for the ginseng industry, and for the development of new drugs.


Purification and characterization of a ginsenoside Rb(1)-hydrolyzing β-glucosidase from Aspergillus niger KCCM 11239.

Chang KH, Jo MN, Kim KT, Paik HD - Int J Mol Sci (2012)

Bioconversion pathway of ginsenoside Rb1 by β-glucosidase.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC3472798&req=5

f6-ijms-13-12140: Bioconversion pathway of ginsenoside Rb1 by β-glucosidase.
Mentions: When ginsenoside Rb1 was incubated, it was converted completely into Rd after 1 h. After 2 h, the ginsenoside Rd content decreased gradually, and the F2 content increased gradually. After 12 h, both S-Rg3 and R-Rg3 began to be detected, and the content of total Rg3 increased over time. This result indicated that the hydrolysis pathway of ginsenoside Rb1 by β-glucosidase was Rb1→Rd→F2 and Rb1→Rd→Rg3, purified enzyme hydrolyzed a β-(1→6)-glucosidic linkage at C-20, as well as a β-(1→2)-glucosidic linkage at C-3 (Figure 6). These results are similar to those of the pathway by which ginsenoside Rb1 is converted to Rg3 by Microbacterium sp. GS514 [9]. Ginsenoside Rd has been shown to protect neurons against neurotoxic chemicals [21] and to prevent the contraction of blood vessels [22]. F2 is a potent inhibitor of acetylcholine-evoked secretion [23]. Rg3 induces a variety of pharmacological activities, such as tumor suppression [24], and hepatoprotective [25] and immune-enhancing effects [26]. Therefore, the β-glucosidase obtained from A. niger KCCM 11239 is considered a good candidate for use in biotransformation applications for the ginseng industry, and for the development of new drugs.

Bottom Line: In the specificity tests, the enzyme was found to be active against ginsenoside Rb(1), but showed very low levels of activity against Rb(2), Rc, Rd, Re, and Rg(1).The enzyme hydrolyzed the 20-C,β-(1→6)-glucoside of ginsenoside Rb(1) to generate ginsenoside Rd and Rg(3), and hydrolyzed 3-C,β-(1→2)-glucoside to generate F(2).The properties of the enzyme indicate that it could be a useful tool in biotransformation applications in the ginseng industry, as well as in the development of novel drug compounds.

View Article: PubMed Central - PubMed

Affiliation: Division of Animal Life Science, Konkuk University, Seoul 143-701, Korea; E-Mails: khchang80@cj.net (K.H.C); ulul55@naver.com (M.N.J.).

ABSTRACT
Rb(1)-hydrolyzing β-glucosidase from Aspergillus niger KCCM 11239 was studied to develop a bioconversion process for minor ginsenosides. The specific activity of the purified enzyme was 46.5 times greater than that of the crude enzyme. The molecular weight of the native enzyme was estimated to be approximately 123 kDa. The optimal pH of the purified enzyme was pH 4.0, and the enzyme proved highly stable over a pH range of 5.0-10.0. The optimal temperature was 70 °C, and the enzyme became unstable at temperatures above 60 °C. The enzyme was inhibited by Cu(2+), Mg(2+), Co(2+), and acetic acid (10 mM). In the specificity tests, the enzyme was found to be active against ginsenoside Rb(1), but showed very low levels of activity against Rb(2), Rc, Rd, Re, and Rg(1). The enzyme hydrolyzed the 20-C,β-(1→6)-glucoside of ginsenoside Rb(1) to generate ginsenoside Rd and Rg(3), and hydrolyzed 3-C,β-(1→2)-glucoside to generate F(2). The properties of the enzyme indicate that it could be a useful tool in biotransformation applications in the ginseng industry, as well as in the development of novel drug compounds.

Show MeSH
Related in: MedlinePlus