52705-93-8Relevant articles and documents
A novel ginsenoside-hydrolyzing enzyme from Penicillium oxalicum and its application in ginsenoside Rd production
Gao, Juan,Hu, Yanbo,Ji, Li,Wang, Nan,Wang, Jiao,Tai, Guihua,Zhou, Yifa
, p. 305 - 312 (2013)
The fungus Penicillum oxalicum can selectively metabolize the major 20(S)-protopanaxadiol ginsenosides Rb1, Rb2, and Rc using extracellular glycosidases yielding a series of bioactive metabolites. A β-glucosidase GH1 was purified from the culture of P. oxalicum with a yield of 9.5% and a specific activity of 3.9 × 103 U/mg. GH1 was a tetramer with a native molecular weight of 484 kDa and its pI value was pH 4.2. GH1 specifically cleaved the β-(1-6)-glucosidic linkage at C-20 site of ginsenoside Rb1 to give the sole product Rd. The optimum conditions were established to be pH 4.5, 55°C, and 0.25 U/ml purified enzyme at 2 mg/ml ginsenoside Rb1. GH1 could be used in the pharmaceutical industry.
Overexpression and characterization of a glucose-tolerant β-glucosidase from Thermotoga thermarum DSM 5069T with high catalytic efficiency of ginsenoside Rb1 to Rd
Zhao, Linguo,Xie, Jingcong,Zhang, Xuesong,Cao, Fuliang,Pei, Jianjun
, p. 62 - 69 (2013)
The β-glucosidase gene Tt-bgl from Thermotoga thermarum DSM 5069T was cloned and overexpressed in Escherichia coli. A simple strategy, induction at 37 °C with no IPTG, was explored to reduce the inclusion bodies, by which the activity of Tt-BGL was 13 U/mL in LB medium. Recombinant Tt-BGL was purified by heat treatment followed by Ni.NTA affinity. The optimal activity was at pH 4.8 and 90 °C. The activity of Tt-BGL was significantly enhanced by methanol and Al3+. The enzyme was stable over pH range of 4.4.8.0, and had a 2-h half life at 90 °C. The Vmax for p-nitrophenyl-β-d- glucopyranoside and ginsenoside Rb1 was 142 U/mg and 107 U/mg, while the K m was 0.59 mM and 0.15 mM, respectively. The activity of the enzyme was not inhibited by ginsenoside Rb1 (36 g/L). It was activated by glucose at concentrations lower that 400 mM. With glucose further increasing, the activity of Tt-BGL was gradually inhibited, but remained 50% of the original value in even as high as 1500 mM glucose. Under the optimal conditions, Tt-BGL transformed ginsenoside Rb1 (36 g/L) to Rd by 95% in 1 h.
Biotransformation of the principal ginsenosides of Panax ginseng into minor glycosides through the action of bacterium Paenibacillus sp. BG134
Ten,Chae,Yoo
, (2014)
The bacterium Paenibacillus sp. BG134 was capable of biotransforming the principal 20(S)-protopanaxadiol ginsenosides Rc, Rb2, Rd, and Rb1 into the corresponding minor glycosides C-Mc1, C-O, and F-2. The specificity of Paenibacillus
Two key amino acids variant of α-l-arabinofuranosidase from bacillus subtilis str. 168 with altered activity for selective conversion ginsenoside rc to rd
Guo, Zi Yu,Luo, Zhi Yong,Tan, Shi Quan,Tian, Liang Yu,Weng, Pei,Zhang, Bian Ling,Zhang, Ru
, (2021/06/16)
α-L-arabinofuranosidase is a subfamily of glycosidases involved in the hydrolysis of L-arabinofuranosidic bonds, especially in those of the terminal non-reducing arabinofuranosyl residues of glycosides, from which efficient glycoside hydrolases can be screened for the transformation of ginsenosides. In this study, the ginsenoside Rc-hydrolyzing α-L-arabinofuranosidase gene, BsAbfA, was cloned from Bacilus subtilis, and its codons were optimized for efficient expression in E. coli BL21 (DE3). The recombinant protein BsAbfA fused with an N-terminal His-tag was overexpressed and purified, and then subjected to enzymatic characterization. Site-directed mutagenesis of BsAbfA was performed to verify the catalytic site, and the molecular mechanism of BsAbfA catalyzing ginsenoside Rc was analyzed by molecular docking, using the homology model of sequence alignment with other β-glycosidases. The results show that the purified BsAbfA had a specific activity of 32.6 U/mg. Under optimal conditions (pH 5, 40?C), the kinetic parameters Km of BsAbfA for pNP-α-Araf and gin-senoside Rc were 0.6 mM and 0.4 mM, while the Kcat /Km were 181.5 s?1 mM?1 and 197.8 s?1 mM?1, respectively. More than 90% of ginsenoside Rc could be transformed by 12 U/mL purified BsAbfA at 40?C and pH 5 in 24 h. The results of molecular docking and site-directed mutagenesis suggested that the E173 and E292 variants for BsAbfA are important in recognizing ginsenoside Rc effectively, and to make it enter the active pocket to hydrolyze the outer arabinofuranosyl moieties at C20 position. These remarkable properties and the catalytic mechanism of BsAbfA provide a good alternative for the effective biotransformation of the major ginsenoside Rc into Rd.
Rational design of a β-glycosidase with high regiospecificity for triterpenoid tailoring
Park, Sang Jin,Choi, Jung Min,Kyeong, Hyun-Ho,Kim, Song-Gun,Kim, Hak-Sung
, p. 854 - 860 (2015/03/30)
Triterpenoids with desired glycosylation patterns have attracted considerable attention as potential therapeutics for inflammatory diseases and various types of cancer. Sugar-hydrolyzing enzymes with high substrate specificity would be far more efficient than other methods for the synthesis of such specialty triterpenoids, but they are yet to be developed. Here we present a strategy to rationally design a β-glycosidase with high regiospecificity for triterpenoids. A β-glycosidase with broad substrate specificity was isolated, and its crystal structure was determined at 2.0 ? resolution. Based on the product profiles and substrate docking simulations, we modeled the substrate binding modes of the enzyme. From the model, the substrate binding cleft of the enzyme was redesigned in a manner that preferentially hydrolyzes glycans at specific glycosylation sites of triterpenoids. The designed mutants were shown to produce a variety of specialty triterpenoids with high purity.
