scholarly journals Dissection of Catalytic Site in Crucial Gut Microbiome Enzyme: Bile Salt Hydrolase

2019 ◽  
Author(s):  
Yashpal Yadav ◽  
Mrityunjay K. Tiwari ◽  
Deepak Chand ◽  
Debjoyati Boral ◽  
Archana Pundle ◽  
...  
Keyword(s):  
Bile Salt ◽  
Bile Acids ◽  
Active Sites ◽  
Electrostatic Force ◽  
Enteric Bacteria ◽  
Significant Loss ◽  
Bile Salt Hydrolase ◽  
Hydrolysis Of ◽  
Determining Factor ◽  
Bsh Activity

AbstractBile Salt Hydrolases (BSHs) are enzymes from enteric bacteria that catalyze the hydrolysis of Bile Acids and consequently promote the reduction of cholesterol level in the mammalian body. Out of several reported BSHs, the Enterococcus faecalis BSH (EfBSH) has been reported to have the highest enzymatic activity. Herein, we have investigated the mechanistic details of the EfBSH activity. The study was carried out employing two mutants of EfBSH: E269A and R207A, which shows differential catalytic activity. The mutant E269A exhibits significant loss in the BSH activity with an increased affinity towards the substrate as compared to R207A mutant. Further, R207A was found to be involved in allostery with an increased EfBSH activity towards tauro-conjugated bile acids. The structural and electrostatic force analyses of the active sites of the E269A mutant and the wild type EfBSH (wt EfBSH) revealed that the interaction between Glu21 and Arg207 is the determining factor in maintaining the dynamic allostery and high activity of EfBSH.

scholarly journals Development of a Covalent Inhibitor of Gut Bacterial Bile Salt Hydrolases

2019 ◽  
Author(s):  
Arijit A. Adhikari ◽  
Tom C. Seegar ◽  
Scott B. Ficarro ◽  
Megan D. McCurry ◽  
Deepti Ramachandran ◽  
...  
Keyword(s):  
Bile Acid ◽  
Bile Salt ◽  
Bile Acids ◽  
Unmet Need ◽  
Cysteine Residue ◽  
Gut Bacteria ◽  
Bile Salt Hydrolase ◽  
Secondary Bile Acid ◽  
Bsh Activity

AbstractBile salt hydrolase (BSH) enzymes are widely expressed by human gut bacteria and catalyze the gateway reaction leading to secondary bile acid formation. Bile acids regulate key metabolic and immune processes by binding to host receptors. There is an unmet need for a potent tool to inhibit BSHs across all gut bacteria in order to study the effects of bile acids on host physiology. Here, we report the development of a covalent pan-inhibitor of gut bacterial BSH. From a rationally designed candidate library, we identified a lead compound bearing an alpha-fluoromethyl ketone warhead that modifies BSH at the catalytic cysteine residue. Strikingly, this inhibitor abolished BSH activity in conventional mouse feces. Mice gavaged with a single dose of this compound displayed decreased BSH activity and decreased deconjugated bile acid levels in feces. Our studies demonstrate the potential of a covalent BSH inhibitor to modulate bile acid composition in vivo.

scholarly journals A gut-restricted lithocholic acid analog as an inhibitor of gut bacterial bile salt hydrolases

2021 ◽  
Author(s):  
Arijit A. Adhikari ◽  
Deepti Ramachandran ◽  
Snehal N. Chaudhari ◽  
Chelsea E. Powell ◽  
Megan D. McCurry ◽  
...  
Keyword(s):  
Bile Acid ◽  
Bile Salt ◽  
Bile Acids ◽  
Mammalian Cells ◽  
Lithocholic Acid ◽  
Bile Salt Hydrolase ◽  
Host Physiology ◽  
Secondary Bile Acids ◽  
Bsh Activity

AbstractBile acids play crucial roles in host physiology by acting as both detergents that aid in digestion and as signaling molecules that bind to host receptors. Gut bacterial bile salt hydrolase (BSH) enzymes perform the gateway reaction leading to the conversion of host-produced primary bile acids into bacterially modified secondary bile acids. Small molecule probes that target BSHs will help elucidate the causal roles of these metabolites in host physiology. We previously reported the development of a covalent BSH inhibitor with low gut permeability. Here, we build on our previous findings and describe the development of a second-generation gut-restricted BSH inhibitor with enhanced potency, reduced off-target effects, and durable in vivo efficacy. SAR studies focused on the bile acid core identified a compound, AAA-10, containing a C3-sulfonated lithocholic acid scaffold and an alpha-fluoromethyl ketone warhead as a potent pan-BSH inhibitor. This compound inhibits BSH activity in conventional mouse fecal slurries, bacterial cultures, and purified BSH proteins and displays reduced toxicity against mammalian cells compared to first generation compounds. Oral administration of AAA-10 to wild-type mice for 5 days resulted in a decrease in the abundance of the secondary bile acids deoxycholic acid (DCA) and lithocholic acid (LCA) in the mouse GI tract with low systemic exposure of AAA-10, demonstrating that AAA-10 is an effective tool for inhibiting BSH activity and modulating bile acid pool composition in vivo.

scholarly journals The influence of probiotics on individual fecal secondary bile acid levels: a two-case study of schizophrenic patients receiving an atypical antipsychotic drug

2017 ◽  
Vol 7 (11) ◽  
pp. 849
Author(s):  
Yosuke Saito ◽  
Hiroyuki Nishimiya ◽  
Yasue Kondo ◽  
Toyoaki Sagae
Keyword(s):  
Bile Acid ◽  
Bile Salt ◽  
Bile Acids ◽  
Acid Metabolism ◽  
Bile Acid Metabolism ◽  
Bile Salt Hydrolase ◽  
Atypical Antipsychotic Drug ◽  
Secondary Bile Acid ◽  
Secondary Bile Acids ◽  
Bsh Activity

Background: Probiotics is used as a promising approach in the prevention and treatment of hypercholesterolemia. Modification of bile acid metabolism through the deconjugation of bile salts by microbial bile salt hydrolase (BSH) is considered to be the core mechanism of the hypocholesterolemic effects of probiotics. Nevertheless, BSH activity is reported to be detrimental to the human host due to the generation of toxic secondary bile acids. Thus, the influence of probiotic intake on bile acid metabolism needs to be elucidated. We analyzed the bile acid levels and microbiota in human fecal samples after probiotic supplementation to assess the influence of probiotic intake on fecal bile acid levels. Two patients hospitalized for schizophrenia and dyslipidemia, receiving an atypical antipsychotic drug, were enrolled in this study (Subjects A and B). Both subjects received Lactobacillus rhamnosus GG (LGG) for 4 weeks, and no probiotics for the following 4 weeks. Fecal samples were collected at baseline and after 4 and 8 weeks.Results: Conjugated bile acids may be modified by indigenous intestinal bacteria into unconjugated bile acids and secondary bile acids through deconjugation reactions by BSH activity and the subsequent 7a-dehydroxylation pathway, respectively. In the fecal microbiota from Subject A, the relative abundance of Bifidobacterium increased after LGG supplementation (30%–49%). Most Bifidobacterium and Lactobacillus strains that colonize mammalian intestines may report BSH activity, and in general bifidobacteria reveals a higher BSH activity than lactobacilli. The fecal unconjugated bile acid and secondary bile acid levels in Subject A increased after the LGG supplementation (0.36–1.79 and 1.82–16.19 mmol/g respectively). Although the LGG supplementation appears to promote bile acid deconjugation, most of the unconjugated bile acids in Subject A appear to have been modified into secondary bile acids. Alternatively, in Subject B there were no significant changes throughout the study.Conclusion: We observed a significant increase in the fecal secondary bile acid levels after probiotic administration in one of our cases. Further studies are needed to elucidate the factors affecting 7a-dehydroxylation of bile acids to confirm the safety of using probiotics.Keywords: bile salt hydrolase; BSH; dihydroxylation; Bifidobacterium

scholarly journals In Vitro Bile Salt Hydrolase (BSH) Activity Screening of Different Probiotic Microorganisms

Foods ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 674
Author(s):  
Jimmy G. Hernández-Gómez ◽  
Argelia López-Bonilla ◽  
Gabriela Trejo-Tapia ◽  
Sandra V. Ávila-Reyes ◽  
Antonio R. Jiménez-Aparicio ◽  
...  
Keyword(s):  
Bile Salt ◽  
High Performance ◽  
Probiotic Strain ◽  
Saccharomyces Boulardii ◽  
Bile Salt Hydrolase ◽  
Sodium Glycocholate ◽  
Probiotic Yeast ◽  
Probiotic Strains ◽  
Bsh Activity

Bile salt hydrolase (BSH) activity in probiotic strains is usually correlated with the ability to lower serum cholesterol levels in hypercholesterolemic patients. The objective of this study was the evaluation of BSH in five probiotic strains of lactic acid bacteria (LAB) and a probiotic yeast. The activity was assessed using a qualitative direct plate test and a quantitative high-performance thin- layer chromatography assay. The six strains differed in their BSH substrate preference and activity. Lactobacillus plantarum DGIA1, a potentially probiotic strain isolated from a double cream cheese from Chiapas, Mexico, showed excellent deconjugation activities in the four tested bile acids (69, 100, 81, and 92% for sodium glycocholate, glycodeoxycholate, taurocholate, and taurodeoxycholate, respectively). In the case of the commercial probiotic yeast Saccharomyces boulardii, the deconjugation activities were good against sodium glycodeoxycholate, taurocholate, and taurodeoxycholate (100, 57, and 63%, respectively). These last two results are part of the novelty of the work. A weak deconjugative activity (5%) was observed in the case of sodium glycocholate. This is the first time that the BSH activity has been detected in this yeast.

scholarly journals Compact Miniaturized Bioluminescence Sensor Based on Continuous Air-Segmented Flow for Real-Time Monitoring: Application to Bile Salt Hydrolase (BSH) Activity and ATP Detection in Biological Fluids

Chemosensors ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 122
Author(s):  
Aldo Roda ◽  
Pierpaolo Greco ◽  
Patrizia Simoni ◽  
Valentina Marassi ◽  
Giada Moroni ◽  
...  
Keyword(s):  
Bile Salt ◽  
Light Emission ◽  
Ex Vivo ◽  
Biological Fluids ◽  
Low Cost ◽  
Bile Salt Hydrolase ◽  
Segmented Flow ◽  
Active Substrate ◽  
Flat Spiral ◽  
Bsh Activity

A simple and versatile continuous air-segmented flow sensor using immobilized luciferase was designed as a general miniaturized platform based on sensitive biochemiluminescence detection. The device uses miniaturized microperistaltic pumps to deliver flows and compact sensitive light imaging detectors based on BI-CMOS (smartphone camera) or CCD technology. The low-cost components and power supply make it suitable as out-lab device at point of need to monitor kinetic-related processes or ex vivo dynamic events. A nylon6 flat spiral carrying immobilized luciferase was placed in front of the detector in lensless mode using a fiber optic tapered faceplate. ATP was measured in samples collected by microdialysis from rat brain with detecting levels as low as 0.4 fmoles. The same immobilized luciferase was also used for the evaluation of bile salt hydrolase (BSH) activity in intestinal microbiota. An aminoluciferin was conjugatated with chenodeoxycholic acid forming the amide derivative aLuc-CDCA. The hydrolysis of the aLuc-CDCA probe by BSH releases free uncaged aminoluciferin which is the active substrate for luciferase leading to light emission. This method can detect as low as 0.5 mM of aLuc-CDCA, so it can be used on real faecal human samples to study BSH activity and its modulation by diseases and drugs.

Relationship between bile salt hydrolase activity, changes in the internal pH and tolerance to bile acids in lactic acid bacteria

2012 ◽  
Vol 34 (8) ◽  
pp. 1511-1518 ◽  
Author(s):  
Ana Yanina Bustos ◽  
Lucila Saavedra ◽  
Graciela Font de Valdez ◽  
Raúl Ricardo Raya ◽  
María Pía Taranto
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Bile Salt ◽  
Bile Acids ◽  
Hydrolase Activity ◽  
Bile Salt Hydrolase ◽  
Internal Ph ◽  
Bile Salt Hydrolase Activity

scholarly journals Cloning and Characterization of the Bile Salt Hydrolase Genes (bsh) from Bifidobacterium bifidum Strains

2004 ◽  
Vol 70 (9) ◽  
pp. 5603-5612 ◽  
Author(s):  
Geun-Bae Kim ◽  
Carol M. Miyamoto ◽  
Edward A. Meighen ◽  
Byong H. Lee
Keyword(s):  
Bile Salt ◽  
Active Sites ◽  
Biochemical Characterization ◽  
Bifidobacterium Longum ◽  
Pcr Amplification ◽  
Bacillus Sphaericus ◽  
Bifidobacterium Bifidum ◽  
Bile Salt Hydrolase ◽  
Cloned Gene

ABSTRACT Biochemical characterization of the purified bile salt hydrolase (BSH) from Bifidobacterium bifidum ATCC 11863 revealed some distinct characteristics not observed in other species of Bifidobacterium. The bsh gene was cloned from B. bifidum, and the DNA flanking the bsh gene was sequenced. Comparison of the deduced amino acid sequence of the cloned gene with previously known sequences revealed high homology with BSH enzymes from several microorganisms and penicillin V amidase (PVA) of Bacillus sphaericus. The proposed active sites of PVA were highly conserved, including that of the Cys-1 residue. The importance of the SH group in the N-terminal cysteine was confirmed by substitution of Cys with chemically and structurally similar residues, Ser or Thr, both of which resulted in an inactive enzyme. The transcriptional start point of the bsh gene has been determined by primer extension analysis. Unlike Bifidobacterium longum bsh, B. bifidum bsh was transcribed as a monocistronic unit, which was confirmed by Northern blot analysis. PCR amplification with the type-specific primer set revealed the high level of sequence homology in their bsh genes within the species of B. bifidum.

scholarly journals Functional Analysis of Four Bile Salt Hydrolase and Penicillin Acylase Family Members in Lactobacillus plantarum WCFS1

2008 ◽  
Vol 74 (15) ◽  
pp. 4719-4726 ◽  
Author(s):  
Jolanda M. Lambert ◽  
Roger S. Bongers ◽  
Willem M. de Vos ◽  
Michiel Kleerebezem
Keyword(s):  
Bile Salt ◽  
Lactobacillus Plantarum ◽  
Bile Salts ◽  
Natural Habitat ◽  
Penicillin Acylase ◽  
Exponential Growth Phase ◽  
Bile Salt Hydrolase ◽  
Intestinal Microbes ◽  
Bsh Activity

ABSTRACT Bile salts play an important role in the digestion of lipids in vertebrates and are synthesized and conjugated to either glycine or taurine in the liver. Following secretion of bile salts into the small intestine, intestinal microbes are capable of deconjugating the glycine or taurine from the bile salts, using an enzyme called bile salt hydrolase (Bsh). Intestinal lactobacilli are regarded as major contributors to bile salt hydrolysis in vivo. Since the bile salt-hydrolyzing strain Lactobacillus plantarum WCFS1 was predicted to carry four bsh genes (bsh1, bsh2, bsh3, and bsh4), the functionality of these bsh genes was explored using Lactococcus lactis heterologous overexpression and multiple bsh deletion strains. Thus, Bsh1 was shown to be responsible for the majority of Bsh activity in L. plantarum WCFS1. In addition, bsh1 of L. plantarum WCFS1 was shown to be involved in conferring tolerance to specific bile salts (i.e., glycocholic acid). Northern blot analysis established that bsh1, bsh2, bsh3, and bsh4 are all expressed in L. plantarum WCFS1 during the exponential growth phase. Following biodiversity analysis, bsh1 appeared to be the only bsh homologue that was variable among L. plantarum strains; furthermore, the presence of bsh1 correlated with the presence of Bsh activity, suggesting that Bsh1 is commonly responsible for Bsh activity in L. plantarum strains. The fact that bsh2, bsh3, and bsh4 genes appeared to be conserved among L. plantarum strains suggests an important role of these genes in the physiology and lifestyle of the species L. plantarum. Analysis of these additional bsh-like genes in L. plantarum WCFS1 suggests that they might encode penicillin acylase rather than Bsh activity, indicating their implication in the conversion of substrates other than bile acids in the natural habitat.

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