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Nam KH. The Conformational Change of the L3 Loop Affects the Structural Changes in the Substrate Binding Pocket Entrance of β-Glucosidase. Molecules 2023; 28:7807. [PMID: 38067537 PMCID: PMC10707726 DOI: 10.3390/molecules28237807] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 11/20/2023] [Accepted: 11/25/2023] [Indexed: 12/18/2023] Open
Abstract
β-glucosidase (Bgl) hydrolyzes cellobiose to glucose, thereby releasing non-reducing terminal glucosyl residues. Bgl is an essential enzyme belonging to the biomass-degrading enzyme family, which plays a vital role in enzymatic saccharification during biofuel production. The four loops above the Bgl substrate-binding pocket undergo a conformational change upon substrate recognition. However, the structural dynamism of this loop and how it is conserved among Bgl family members remain unknown. Herein, to better understand the four loops above the substrate-binding pocket of Bgl, four Bgl crystal structures in Thermoanaerobacterium saccharolyticum (TsaBgl) were determined at 1.5-2.1 Å. The L1, L2, and L4 loops of TsaBgl showed a rigid conformation stabilized by their neighboring residues via hydrogen bonds and hydrophobic interactions. The TsaBgl L3 loop showed relatively high flexibility and two different N-terminal region conformations. The conformational change in the TsaBgl L3 loop induced a change in charge and shaped at the substrate-binding pocket entrance. The amino acid sequences and structures of the TsaBgl L1-4 loops were compared with other 45 Bgl proteins, and a diversity of the L2 and L3 loops was observed. Differences in amino acids and lengths of Bgls L2-L3 loop induced differences in the conformation and structure of the Bgls substrate-binding pocket entrance. These findings expand our knowledge on the molecular function of the loops in the Bgl enzyme family.
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Affiliation(s)
- Ki Hyun Nam
- College of General Education, Kookmin University, Seoul 02707, Republic of Korea
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2
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Biochemical and Structural Analysis of a Glucose-Tolerant β-Glucosidase from the Hemicellulose-Degrading Thermoanaerobacterium saccharolyticum. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27010290. [PMID: 35011521 PMCID: PMC8746653 DOI: 10.3390/molecules27010290] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Revised: 11/30/2021] [Accepted: 12/08/2021] [Indexed: 01/09/2023]
Abstract
β-Glucosidases (Bgls) convert cellobiose and other soluble cello-oligomers into glucose and play important roles in fundamental biological processes, providing energy sources in living organisms. Bgls are essential terminal enzymes of cellulose degradation systems and attractive targets for lignocellulose-based biotechnological applications. Characterization of novel Bgls is important for broadening our knowledge of this enzyme class and can provide insights into its further applications. In this study, we report the biochemical and structural analysis of a Bgl from the hemicellulose-degrading thermophilic anaerobe Thermoanaerobacterium saccharolyticum (TsaBgl). TsaBgl exhibited its maximum hydrolase activity on p-nitrophenyl-β-d-glucopyranoside at pH 6.0 and 55 °C. The crystal structure of TsaBgl showed a single (β/α)8 TIM-barrel fold, and a β8-α14 loop, which is located around the substrate-binding pocket entrance, showing a unique conformation compared with other structurally known Bgls. A Tris molecule inhibited enzyme activity and was bound to the active site of TsaBgl coordinated by the catalytic residues Glu163 (proton donor) and Glu351 (nucleophile). Titration experiments showed that TsaBgl belongs to the glucose-tolerant Bgl family. The gatekeeper site of TsaBgl is similar to those of other glucose-tolerant Bgls, whereas Trp323 and Leu170, which are involved in glucose tolerance, show a unique configuration. Our results therefore improve our knowledge about the Tris-mediated inhibition and glucose tolerance of Bgl family members, which is essential for their industrial application.
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Sharma K, Thakur A, Kumar R, Goyal A. Structure and biochemical characterization of glucose tolerant β-1,4 glucosidase (HtBgl) of family 1 glycoside hydrolase from Hungateiclostridium thermocellum. Carbohydr Res 2019; 483:107750. [PMID: 31357130 DOI: 10.1016/j.carres.2019.107750] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2019] [Revised: 06/14/2019] [Accepted: 07/16/2019] [Indexed: 12/15/2022]
Abstract
β-1,4-glucosidase (HtBgl) of family 1 glycoside hydrolase from Hungateiclostridium thermocellum was cloned in pET28a(+) vector, expressed, biochemically and structurally characterized. HtBgl displayed 67 U/mg activity against 4-nitrophenyl-β-d-glucopyranoside, followed by 180 U/mg against cellobiose and 42 U/mg activity against 4-nitrophenyl-β-d-galactopyranoside. HtBgl displayed an optimum temperature of 65 °C and an optimum pH of 6.0. HtBgl was stable in the pH range, 4.0-8.0 and displayed the thermostability up to 60 °C for 1 h. HtBgl displayed the glucose tolerance up to 750 mM and retained ~70% activity after 20 h. HtBgl crystal structure submitted (PDB id 5OGZ) by others exhibited a classical Triosephosphate Isomerase, (β/α)8-barrel fold. Protein melting analysis of HtBgl exhibited a single peak at 78 °C and the addition of 5 mM Mg2+ shifted the peak to 82 °C. Molecular dynamics studies showed that the amino acid residues from 351 to 375 exhibit the flexibility due to the presence of the catalytic acid residue. The structure comparison of HtBgl with homologous proteins and its docking analysis with probable ligands revealed that the residues, E166 and E355 are involved in the catalysis. The SAXS analysis of HtBgl showed that the protein is monomeric and present in a fully folded state. The radius of gyration (Rg) found was 2.15-2.26 nm. The bell-shaped curve obtained by Kratky plot analysis displayed the globular shape and fully folded state with flexibility in the N-terminal region. The HtBgl crystal structure superposed well with the SAXS derived dummy atom model.
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Affiliation(s)
- Kedar Sharma
- DBT PAN-IIT Centre of Bioenergy, Carbohydrate Enzyme Biotechnology Laboratory, Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, 781039, Assam, India
| | - Abhijeet Thakur
- DBT PAN-IIT Centre of Bioenergy, Carbohydrate Enzyme Biotechnology Laboratory, Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, 781039, Assam, India
| | - Rajeev Kumar
- DBT PAN-IIT Centre of Bioenergy, Carbohydrate Enzyme Biotechnology Laboratory, Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, 781039, Assam, India
| | - Arun Goyal
- DBT PAN-IIT Centre of Bioenergy, Carbohydrate Enzyme Biotechnology Laboratory, Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, 781039, Assam, India.
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4
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Singhania RR, Patel AK, Pandey A, Ganansounou E. Genetic modification: A tool for enhancing beta-glucosidase production for biofuel application. BIORESOURCE TECHNOLOGY 2017; 245:1352-1361. [PMID: 28596076 DOI: 10.1016/j.biortech.2017.05.126] [Citation(s) in RCA: 81] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Revised: 05/17/2017] [Accepted: 05/19/2017] [Indexed: 05/25/2023]
Abstract
Beta-glucosidase (BGL) is a rate-limiting enzyme for cellulose hydrolysis as it acts in the final step of lignocellulosic biomass conversion to convert cellobiose into glucose, the final end product. Most of the fungal strains used for cellulase production are deficient in BGL hence BGL is supplemented into cellulases to have an efficient biomass conversion. Genetic engineering has enabled strain modification to produce BGL optimally with desired properties to be employed for biofuel applications. It has been cloned either directly into the host strains lacking BGL or into another expression system, to be overexpressed so as to be blended into BGL deficient cellulases. In this article, role of genetic engineering to overcome BGL limitations in the cellulase cocktail and its significance for biofuel applications has been critically reviewed.
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Affiliation(s)
- Reeta Rani Singhania
- DBT-IOC Advanced Bio-Energy Research Centre, Indian Oil Corporation; R&D Centre, Sector-13, Faridabad 121007, India
| | - Anil Kumar Patel
- Department of Molecular Biosciences and Bioengineering, University of Hawaii at Manoa, Honolulu 96822, HI, United States.
| | - Ashok Pandey
- Center of Innovative and Applied Bioprocessing, Sector 81, Knowledge City PO Manauli, SAS Nagar, Mohali 140306, Punjab, India
| | - Edgard Ganansounou
- Bioenergy and Energy Planning Research Group, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
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Brognaro H, Almeida VM, de Araujo EA, Piyadov V, Santos MAM, Marana SR, Polikarpov I. Biochemical Characterization and Low-Resolution SAXS Molecular Envelope of GH1 β-Glycosidase from Saccharophagus degradans. Mol Biotechnol 2017; 58:777-788. [PMID: 27670285 DOI: 10.1007/s12033-016-9977-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The marine bacteria Saccharophagus degradans (also known as Microbulbifer degradans), are rod-shaped and gram-negative motile γ-proteobacteria, capable of both degrading a variety of complex polysaccharides and fermenting monosaccharides into ethanol. In order to obtain insights into structure-function relationships of the enzymes, involved in these biochemical processes, we characterized a S. degradans β-glycosidase from glycoside hydrolase family 1 (SdBgl1B). SdBgl1B has the optimum pH of 6.0 and a melting temperature T m of approximately 50 °C. The enzyme has high specificity toward short D-glucose saccharides with β-linkages with the following preferences β-1,3 > β-1,4 ≫ β-1,6. The enzyme kinetic parameters, obtained using artificial substrates p-β-NPGlu and p-β-NPFuc and also the disaccharides cellobiose, gentiobiose and laminaribiose, revealed SdBgl1B preference for p-β-NPGlu and laminaribiose, which indicates its affinity for glucose and also preference for β-1,3 linkages. To better understand structural basis of the enzyme activity its 3D model was built and analysed. The 3D model fits well into the experimentally retrieved low-resolution SAXS-based envelope of the enzyme, confirming monomeric state of SdBgl1B in solution.
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Affiliation(s)
- Hevila Brognaro
- Instituto de Física de São Carlos, Universidade de São Paulo, Avenida Trabalhador São Carlense 400, São Carlos, SP, 13566-590, Brazil
| | - Vitor Medeiros Almeida
- Instituto de Química, Universidade de São Paulo, Avenida Prof. Lineu Prestes, 748, Bloco 10, Sala 1054, São Paulo, SP, 05508-900, Brazil
| | - Evandro Ares de Araujo
- Instituto de Física de São Carlos, Universidade de São Paulo, Avenida Trabalhador São Carlense 400, São Carlos, SP, 13566-590, Brazil
| | - Vasily Piyadov
- Instituto de Física de São Carlos, Universidade de São Paulo, Avenida Trabalhador São Carlense 400, São Carlos, SP, 13566-590, Brazil
| | - Maria Auxiliadora Morim Santos
- Instituto de Física de São Carlos, Universidade de São Paulo, Avenida Trabalhador São Carlense 400, São Carlos, SP, 13566-590, Brazil
| | - Sandro Roberto Marana
- Instituto de Química, Universidade de São Paulo, Avenida Prof. Lineu Prestes, 748, Bloco 10, Sala 1054, São Paulo, SP, 05508-900, Brazil
| | - Igor Polikarpov
- Instituto de Física de São Carlos, Universidade de São Paulo, Avenida Trabalhador São Carlense 400, São Carlos, SP, 13566-590, Brazil.
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6
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Matsuzawa T, Yaoi K. Screening, identification, and characterization of a novel saccharide-stimulated β-glycosidase from a soil metagenomic library. Appl Microbiol Biotechnol 2016; 101:633-646. [DOI: 10.1007/s00253-016-7803-2] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2016] [Revised: 07/20/2016] [Accepted: 08/09/2016] [Indexed: 01/27/2023]
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7
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Matsuzawa T, Jo T, Uchiyama T, Manninen JA, Arakawa T, Miyazaki K, Fushinobu S, Yaoi K. Crystal structure and identification of a key amino acid for glucose tolerance, substrate specificity, and transglycosylation activity of metagenomic β-glucosidase Td2F2. FEBS J 2016; 283:2340-53. [DOI: 10.1111/febs.13743] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2015] [Revised: 03/11/2016] [Accepted: 04/18/2016] [Indexed: 11/27/2022]
Affiliation(s)
- Tomohiko Matsuzawa
- Bioproduction Research Institute; National Institute of Advanced Industrial Science and Technology (AIST); Tsukuba Ibaraki Japan
| | - Toshinori Jo
- Department of Biotechnology; The University of Tokyo; Japan
| | - Taku Uchiyama
- Department of Biomaterial Sciences; Graduate School of Agricultural and Life Sciences; The University of Tokyo; Japan
| | | | | | - Kentaro Miyazaki
- Bioproduction Research Institute; National Institute of Advanced Industrial Science and Technology (AIST); Tsukuba Ibaraki Japan
- Department of Computational Biology and Medical Sciences; Graduate School of Frontier Sciences; The University of Tokyo; Chiba Japan
| | | | - Katsuro Yaoi
- Bioproduction Research Institute; National Institute of Advanced Industrial Science and Technology (AIST); Tsukuba Ibaraki Japan
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Two New Native β-Glucosidases from Clavispora NRRL Y-50464 Confer Its Dual Function as Cellobiose Fermenting Ethanologenic Yeast. PLoS One 2016; 11:e0151293. [PMID: 27011316 PMCID: PMC4806929 DOI: 10.1371/journal.pone.0151293] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Accepted: 02/25/2016] [Indexed: 11/19/2022] Open
Abstract
Yeast strain Clavispora NRRL Y-50464 is able to produce cellulosic ethanol from lignocellulosic materials without addition of external β-glucosidase by simultaneous saccharification and fermentation. A β-glucosidase BGL1 protein from this strain was recently reported supporting its cellobiose utilization capability. Here, we report two additional new β-glucosidase genes encoding enzymes designated as BGL2 and BGL3 from strain NRRL Y-50464. Quantitative gene expression was analyzed and the gene function of BGL2 and BGL3 was confirmed by heterologous expression using cellobiose as a sole carbon source. Each gene was cloned and partially purified protein obtained separately for direct enzyme assay using varied substrates. Both proteins showed the highest specific activity at pH 5 and relatively strong affinity with a Km of 0.08 and 0.18 mM for BGL2 and BGL3, respectively. The optimum temperature was found to be 50°C for BGL2 and 55°C for BGL3. Both proteins were able to hydrolyze 1,4 oligosaccharides evaluated in this study. They also showed a strong resistance to glucose product inhibition with a Ki of 61.97 and 38.33 mM for BGL2 and BGL3, respectively. While BGL3 was sensitive showing a significantly reduced activity to 4% ethanol, BGL2 demonstrated tolerance to ethanol. Its activity was enhanced in the presence of ethanol but reduced at concentrations greater than 16%. The presence of the fermentation inhibitors furfural and HMF did not affect the enzyme activity. Our results suggest that a β-glucosidase gene family exists in Clavispora NRRL Y-50464 with at least three members in this group that validate its cellobiose hydrolysis functions for lower-cost cellulosic ethanol production. Results of this study confirmed the cellobiose hydrolysis function of strain NRRL Y-50464, and further supported this dual functional yeast as a candidate for lower-cost cellulosic ethanol production and next-generation biocatalyst development in potential industrial applications.
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9
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Park SJ, Choi JM, Kyeong HH, Kim SG, Kim HS. Rational Design of a β-Glycosidase with High Regiospecificity for Triterpenoid Tailoring. Chembiochem 2015; 16:854-60. [DOI: 10.1002/cbic.201500004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Indexed: 11/11/2022]
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10
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Singhania RR, Patel AK, Sukumaran RK, Larroche C, Pandey A. Role and significance of beta-glucosidases in the hydrolysis of cellulose for bioethanol production. BIORESOURCE TECHNOLOGY 2013; 127:500-7. [PMID: 23069613 DOI: 10.1016/j.biortech.2012.09.012] [Citation(s) in RCA: 321] [Impact Index Per Article: 29.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2012] [Revised: 09/05/2012] [Accepted: 09/05/2012] [Indexed: 05/02/2023]
Abstract
One of the major challenges in the bioconversion of lignocellulosic biomass into liquid biofuels includes the search for a glucose tolerant beta-gulucosidase. Beta-glucosidase is the key enzyme component present in cellulase and completes the final step during cellulose hydrolysis by converting the cellobiose to glucose. This reaction is always under control as it gets inhibited by its product glucose. It is a major bottleneck in the efficient biomass conversion by cellulase. To circumvent this problem several strategies have been adopted which we have discussed in the article along with its production strategies and general properties. It plays a very significant role in bioethanol production from biomass through enzymatic route. Hence several amendments took place in the commercial preparation of cellulase for biomass hydrolysis, which contains higher and improved beta-glucosidase for efficient biomass conversion. This article presents beta-glucosidase as the key component for bioethanol from biomass through enzymatic route.
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Affiliation(s)
- Reeta Rani Singhania
- Laboratoire de Génie Chimique et Biochimique, Université Blaise Pascal, Polytech Clermont-Ferrand, Aubiere cedex, France.
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11
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Jiang C, Li SX, Luo FF, Jin K, Wang Q, Hao ZY, Wu LL, Zhao GC, Ma GF, Shen PH, Tang XL, Wu B. Biochemical characterization of two novel β-glucosidase genes by metagenome expression cloning. BIORESOURCE TECHNOLOGY 2011; 102:3272-3278. [PMID: 20971635 DOI: 10.1016/j.biortech.2010.09.114] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2010] [Revised: 09/28/2010] [Accepted: 09/28/2010] [Indexed: 05/30/2023]
Abstract
Two novel β-glucosidase genes designated as bgl1D and bgl1E, which encode 172- and 151-aa peptides, respectively, were cloned by function-based screening of a metagenomic library from uncultured soil microorganisms. Sequence analyses indicated that Bgl1D and Bgl1E exhibited lower similarities with some putative β-glucosidases. Functional characterization through high-performance liquid chromatography demonstrated that purified recombinant Bgl1D and Bgl1E proteins hydrolyzed D-glucosyl-β-(1-4)-D-glucose to glucose. Using p-nitrophenyl-β-D-glucoside as substrate, K(m) was 0.54 and 2.11 mM, and k(cat)/K(m) was 1489 and 787 mM(-1) min(-1) for Bgl1D and Bgl1E, respectively. The optimum pH and temperature for Bgl1D was pH 10.0 and 30°C, while the optimum values for Bgl1E were pH 10.0 and 25°C. Bgl1D exhibited habitat-specific characteristics, including higher activity in lower temperature and at high concentrations of AlCl(3) and LiCl. Bgl1D also displayed remarkable activity across a broad pH range (5.5-10.5), making it a potential candidate for industrial applications.
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Affiliation(s)
- Chengjian Jiang
- Guangxi Key Laboratory of Subtropical Bioresources Conservation and Utilization, College of Life Science and Technology, Guangxi University, Nanning, Guangxi, People's Republic of China
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Ketudat Cairns JR, Esen A. β-Glucosidases. Cell Mol Life Sci 2010; 67:3389-405. [PMID: 20490603 PMCID: PMC11115901 DOI: 10.1007/s00018-010-0399-2] [Citation(s) in RCA: 359] [Impact Index Per Article: 25.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2010] [Revised: 04/13/2010] [Accepted: 04/30/2010] [Indexed: 10/19/2022]
Abstract
β-Glucosidases (3.2.1.21) are found in all domains of living organisms, where they play essential roles in the removal of nonreducing terminal glucosyl residues from saccharides and glycosides. β-Glucosidases function in glycolipid and exogenous glycoside metabolism in animals, defense, cell wall lignification, cell wall β-glucan turnover, phytohormone activation, and release of aromatic compounds in plants, and biomass conversion in microorganisms. These functions lead to many agricultural and industrial applications. β-Glucosidases have been classified into glycoside hydrolase (GH) families GH1, GH3, GH5, GH9, and GH30, based on their amino acid sequences, while other β-glucosidases remain to be classified. The GH1, GH5, and GH30 β-glucosidases fall in GH Clan A, which consists of proteins with (β/α)(8)-barrel structures. In contrast, the active site of GH3 enzymes comprises two domains, while GH9 enzymes have (α/α)(6) barrel structures. The mechanism by which GH1 enzymes recognize and hydrolyze substrates with different specificities remains an area of intense study.
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Affiliation(s)
- James R Ketudat Cairns
- Schools of Biochemistry and Chemistry, Institute of Science, Suranaree University of Technology, 111 University Avenue, Muang District, Nakhon Ratchasima, Thailand.
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Jeng WY, Wang NC, Lin MH, Lin CT, Liaw YC, Chang WJ, Liu CI, Liang PH, Wang AHJ. Structural and functional analysis of three β-glucosidases from bacterium Clostridium cellulovorans, fungus Trichoderma reesei and termite Neotermes koshunensis. J Struct Biol 2010; 173:46-56. [PMID: 20682343 DOI: 10.1016/j.jsb.2010.07.008] [Citation(s) in RCA: 132] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2010] [Revised: 07/17/2010] [Accepted: 07/29/2010] [Indexed: 11/18/2022]
Abstract
β-glucosidases (EC 3.2.1.21) cleave β-glucosidic linkages in disaccharide or glucose-substituted molecules and play important roles in fundamental biological processes. β-Glucosidases have been widely used in agricultural, biotechnological, industrial and medical applications. In this study, a high yield expression (70-250 mg/l) in Escherichia coli of the three functional β-glucosidase genes was obtained from the bacterium Clostridium cellulovorans (CcBglA), the fungus Trichoderma reesei (TrBgl2), and the termite Neotermes koshunensis (NkBgl) with the crystal structures of CcBglA, TrBgl2 and NkBgl, determined at 1.9Å, 1.63Å and 1.34Å resolution, respectively. The overall structures of these enzymes are similar to those belonging to the β-retaining glycosyl hydrolase family 1, which have a classical (α/β)(8)-TIM barrel fold. Each contains a slot-like active site cleft and a more variable outer opening, related to its function in processing different lengths of β-1,4-linked glucose derivatives. The two essential glutamate residues for hydrolysis are spatially conserved in the active site. In both TrBgl2 and NkBgl structures, a Tris molecule was found to bind at the active site, explaining the slight inhibition of hydrolase activity observed in Tris buffer. Manganese ions at 10mM exerted an approximate 2-fold enzyme activity enhancement of all three β-glucosidases, with CcBglA catalyzing the most efficiently in hydrolysis reaction and tolerating Tris as well as some metal inhibition. In summary, our results for the structural and functional properties of these three β-glucosidases from various biological sources open important avenues of exploration for further practical applications.
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Affiliation(s)
- Wen-Yih Jeng
- Institute of Biological Chemistry, Academia Sinica, Taipei 115, Taiwan
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14
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Nam KH, Sung MW, Hwang KY. Structural insights into the substrate recognition properties of beta-glucosidase. Biochem Biophys Res Commun 2009; 391:1131-5. [PMID: 20005197 DOI: 10.1016/j.bbrc.2009.12.038] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2009] [Accepted: 12/08/2009] [Indexed: 11/17/2022]
Abstract
Beta-glucosidase enzymes (EC 3.2.1-3.2.3) hydrolyze sugars and are implicated in a wide spectrum of biological processes. Recently, we reported that beta-glucosidase has varied kinetic parameters for the natural and synthetic substrates [K.H Nam, S.J. Kim, M.Y. Kim, J.H. Kim, T.S. Yeo, C.M. Lee, H.K Jun, K.Y. Hwang. Crystal structure of engineered beta-glucosidase from a soil metagenome, Proteins 73 (2008) 788-793]. However, an understanding of the kinetic values of beta-glucosidase has not yet enabled the elucidation of its molecular function. Here, we report the X-ray crystal structure of beta-glucosidase with a glucose and cellobiose fragment from uncultured soil metagenome. From the various crystals, we obtained the pre-reaction (native), intermediate (disaccharide cleavage) and post-reaction (glucose binding) states of the active site pocket. These structures provide snapshots of the catalytic processing of beta-glucosidase. In addition, the intermediate state of the crystal structure provides insight into the substrate specificity of beta-glucosidase. These structural studies will facilitate elucidation of the architectural mechanism responsible for the substrate recognition of beta-glucosidase.
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Affiliation(s)
- Ki Hyun Nam
- Division of Biotechnology, College of Life Sciences & Biotechnology, Korea University, Seoul 136-701, South Korea
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15
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Acebrón I, Curiel JA, de las Rivas B, Muñoz R, Mancheño JM. Cloning, production, purification and preliminary crystallographic analysis of a glycosidase from the food lactic acid bacterium Lactobacillus plantarum CECT 748T. Protein Expr Purif 2009; 68:177-82. [DOI: 10.1016/j.pep.2009.07.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2009] [Revised: 07/08/2009] [Accepted: 07/09/2009] [Indexed: 01/22/2023]
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16
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Jiang C, Ma G, Li S, Hu T, Che Z, Shen P, Yan B, Wu B. Characterization of a novel β-glucosidase-like activity from a soil metagenome. J Microbiol 2009; 47:542-8. [DOI: 10.1007/s12275-009-0024-y] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2009] [Accepted: 05/26/2009] [Indexed: 11/27/2022]
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