title: Short communication: Improving the activity of bile salt hydrolases in Lactobacillus casei based on in silico molecular docking and heterologous expression.
abstract: Bile salt hydrolase (BSH) plays an essential role in the cholesterol-removing effect of lactic acid bacteria, which hydrolyze conjugated bile salts to amino acid and deconjugated bile salts. However, Lactobacillus casei lacks the bsh gene, which may make it highly sensitive to bile salt stress. We wanted to improve the BSH activity of L. casei for various food-industry applications (e.g., milk fermentation). Plate assay testing indicated that Lactobacillus plantarum AR113 has the highest BSH activity. We cloned and sequenced 4 bsh genes from the genome of L. plantarum AR113. Structure modeling and molecular docking of BSH indicated that BSH1 and BSH3 could react efficiently with bile salts, so we selected BSH1 and BSH3 for heterologous expression in L. casei. Compared with single expression of BSH1 or BSH3, co-expression of both protein sequences showed the highest hydrolysis activity by HPLC analysis. Our results suggested that heterologous expression of BSH in L. casei can significantly improve host activity against bile salts, and in silico molecular docking could be an efficient method of rapid screening for BSH with high activity.
authors.affiliation: Shanghai Engineering Research Center of Food Microbiology, School of Medical Instruments and Food Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China.
authors.forename: Zhi-Qiang
authors.initials: ZQ
authors.lastname: Xiong
authors.affiliation: Shanghai Engineering Research Center of Food Microbiology, School of Medical Instruments and Food Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China.
authors.forename: Qiao-Hui
authors.initials: QH
authors.lastname: Wang
authors.affiliation: Shanghai Engineering Research Center of Food Microbiology, School of Medical Instruments and Food Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China.
authors.forename: Ling-Hui
authors.initials: LH
authors.lastname: Kong
authors.affiliation: Shanghai Engineering Research Center of Food Microbiology, School of Medical Instruments and Food Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Song
authors.affiliation: Shanghai Engineering Research Center of Food Microbiology, School of Medical Instruments and Food Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China.
authors.forename: Guang-Qiang
authors.initials: GQ
authors.lastname: Wang
authors.affiliation: Shanghai Engineering Research Center of Food Microbiology, School of Medical Instruments and Food Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China.
authors.forename: Yong-Jun
authors.initials: YJ
authors.lastname: Xia
authors.affiliation: Shanghai Engineering Research Center of Food Microbiology, School of Medical Instruments and Food Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Yangzhou Sanhesimei Pickles Co. Ltd., Yangzhou 225000, China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Sun
authors.affiliation: Shanghai Engineering Research Center of Food Microbiology, School of Medical Instruments and Food Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China. Electronic address: ailianzhong@hotmail.com.
authors.forename: Lian-Zhong
authors.initials: LZ
authors.lastname: Ai
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001647:Bile Acids and Salts; D003001:Cloning, Molecular; D007778:Lactobacillus / Q000235:genetics; D007780:Lacticaseibacillus casei / Q000235:genetics*; D048191:Lactiplantibacillus plantarum / Q000235:genetics; D062105:Molecular Docking Simulation
chemical_list: D001647:Bile Acids and Salts
keywords: Lactobacillus casei; bile salt hydrolase; heterologous expression; molecular docking