1
|
Dodda SR, Hossain M, Mondal S, Das S, Khator (Jain) S, Aikat K, Mukhopadhyay SS. The S-S bridge mutation between the A2 and A4 loops (T416C-I432C) of Cel7A of Aspergillus fumigatus enhances catalytic activity and thermostability. Appl Environ Microbiol 2024; 90:e0232923. [PMID: 38440989 PMCID: PMC11022540 DOI: 10.1128/aem.02329-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Accepted: 01/28/2024] [Indexed: 03/06/2024] Open
Abstract
Disulfide bonds are important for maintaining the structural conformation and stability of the protein. The introduction of the disulfide bond is a promising strategy to increase the thermostability of the protein. In this report, cysteine residues are introduced to form disulfide bonds in the Glycoside Hydrolase family GH 7 cellobiohydrolase (GH7 CBHs) or Cel7A of Aspergillus fumigatus. Disulfide by Design 2.0 (DbD2), an online tool is used for the detection of the mutation sites. Mutations are created (D276C-G279C; DSB1, D322C-G327C; DSB2, T416C-I432C; DSB3, G460C-S465C; DSB4) inside and outside of the peripheral loops but, not in the catalytic region. The introduction of cysteine in the A2 and A4 loop of DSB3 mutant showed higher thermostability (70% activity at 70°C), higher substrate affinity (Km = 0.081 mM) and higher catalytic activity (Kcat = 9.75 min-1; Kcat/Km = 120.37 mM min-1) compared to wild-type AfCel7A (50% activity at 70°C; Km = 0.128 mM; Kcat = 4.833 min-1; Kcat/Km = 37.75 mM min-1). The other three mutants with high B factor showed loss of thermostability and catalytic activity. Molecular dynamic simulations revealed that the mutation T416C-I432C makes the tunnel wider (DSB3: 13.6 Å; Wt: 5.3 Å) at the product exit site, giving flexibility in the entrance region or mobility of the substrate in the exit region. It may facilitate substrate entry into the catalytic tunnel and release the product faster than the wild type, whereas in other mutants, the tunnel is not prominent (DSB4), the exit is lost (DSB1), and the ligand binding site is absent (DSB2). This is the first report of the gain of function of both thermostability and enzyme activity of cellobiohydrolase Cel7A by disulfide bond engineering in the loop.IMPORTANCEBioethanol is one of the cleanest renewable energy and alternatives to fossil fuels. Cost efficient bioethanol production can be achieved through simultaneous saccharification and co-fermentation that needs active polysaccharide degrading enzymes. Cellulase enzyme complex is a crucial enzyme for second-generation bioethanol production from lignocellulosic biomass. Cellobiohydrolase (Cel7A) is an important member of this complex. In this work, we engineered (disulfide bond engineering) the Cel7A to increase its thermostability and catalytic activity which is required for its industrial application.
Collapse
Affiliation(s)
- Subba Reddy Dodda
- Department of Biotechnology, National Institute of Technology Durgapur, Durgapur, West Bengal, India
| | - Musaddique Hossain
- Department of Biotechnology, National Institute of Technology Durgapur, Durgapur, West Bengal, India
| | - Sudipa Mondal
- Department of Biotechnology, National Institute of Technology Durgapur, Durgapur, West Bengal, India
| | - Shalini Das
- Department of Biotechnology, National Institute of Technology Durgapur, Durgapur, West Bengal, India
| | - Sneha Khator (Jain)
- Department of Biotechnology, National Institute of Technology Durgapur, Durgapur, West Bengal, India
| | - Kaustav Aikat
- Department of Biotechnology, National Institute of Technology Durgapur, Durgapur, West Bengal, India
| | - Sudit S. Mukhopadhyay
- Department of Biotechnology, National Institute of Technology Durgapur, Durgapur, West Bengal, India
| |
Collapse
|
2
|
Hu C, Wang Y, Wang W, Cui W, Jia X, Mayo KH, Zhou Y, Su J, Yuan Y. A trapped covalent intermediate as a key catalytic element in the hydrolysis of a GH3 β-glucosidase: An X-ray crystallographic and biochemical study. Int J Biol Macromol 2024; 265:131131. [PMID: 38527679 DOI: 10.1016/j.ijbiomac.2024.131131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Revised: 03/21/2024] [Accepted: 03/22/2024] [Indexed: 03/27/2024]
Abstract
Glycoside hydrolases (GHs) are industrially important enzymes that hydrolyze glycosidic bonds in glycoconjugates. In this study, we found a GH3 β-glucosidase (CcBgl3B) from Cellulosimicrobium cellulans sp. 21 was able to selectively hydrolyze the β-1,6-glucosidic bond linked glucose of ginsenosides. X-ray crystallographic studies of the ligand complex ginsenoside-specific β-glucosidase provided a novel finding that support the catalytic mechanism of GH3. The substrate was clearly identified within the catalytic center of wild-type CcBgl3B, revealing that the C1 atom of the glucose was covalently bound to the Oδ1 group of the conserved catalytic nucleophile Asp264 as an enzyme-glycosyl intermediate. The glycosylated Asp264 could be identified by mass spectrometry. Through site-directed mutagenesis studies with Asp264, it was found that the covalent intermediate state formed by Asp264 and the substrate was critical for catalysis. In addition, Glu525 variants (E525A, E525Q and E525D) showed no or marginal activity against pNPβGlc; thus, this residue could supply a proton for the reaction. Overall, our study provides an insight into the catalytic mechanism of the GH3 enzyme CcBgl3B.
Collapse
Affiliation(s)
- Chenxing Hu
- Engineering Research Center of Glycoconjugates Ministry of Education, Jilin Provincial Key Laboratory of Chemistry and Biology of Changbai Mountain Natural Drugs, School of Life Sciences, Northeast Normal University, Changchun 130024, China
| | - Yibing Wang
- Engineering Research Center of Glycoconjugates Ministry of Education, Jilin Provincial Key Laboratory of Chemistry and Biology of Changbai Mountain Natural Drugs, School of Life Sciences, Northeast Normal University, Changchun 130024, China
| | - Weiyang Wang
- College of Life Science and Technology, Changchun University of Science & Technology, Changchun, Jilin 130022, China
| | - Wanli Cui
- Engineering Research Center of Glycoconjugates Ministry of Education, Jilin Provincial Key Laboratory of Chemistry and Biology of Changbai Mountain Natural Drugs, School of Life Sciences, Northeast Normal University, Changchun 130024, China
| | - Xinyue Jia
- Engineering Research Center of Glycoconjugates Ministry of Education, Jilin Provincial Key Laboratory of Chemistry and Biology of Changbai Mountain Natural Drugs, School of Life Sciences, Northeast Normal University, Changchun 130024, China
| | - Kevin H Mayo
- Department of Biochemistry, Molecular Biology & Biophysics, 6-155 Jackson Hall, University of Minnesota, Minneapolis, MN 55455, USA
| | - Yifa Zhou
- Engineering Research Center of Glycoconjugates Ministry of Education, Jilin Provincial Key Laboratory of Chemistry and Biology of Changbai Mountain Natural Drugs, School of Life Sciences, Northeast Normal University, Changchun 130024, China
| | - Jiyong Su
- Engineering Research Center of Glycoconjugates Ministry of Education, Jilin Provincial Key Laboratory of Chemistry and Biology of Changbai Mountain Natural Drugs, School of Life Sciences, Northeast Normal University, Changchun 130024, China.
| | - Ye Yuan
- Engineering Research Center of Glycoconjugates Ministry of Education, Jilin Provincial Key Laboratory of Chemistry and Biology of Changbai Mountain Natural Drugs, School of Life Sciences, Northeast Normal University, Changchun 130024, China.
| |
Collapse
|
3
|
Lu X, Li X, Zhao J. Improving enzymatic efficiency of β-glucosidases in cellulase system by altering its binding behavior to the insoluble substrate during bioconversion of lignocellulose. BIORESOURCE TECHNOLOGY 2024; 391:129974. [PMID: 37939741 DOI: 10.1016/j.biortech.2023.129974] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Revised: 10/31/2023] [Accepted: 11/01/2023] [Indexed: 11/10/2023]
Abstract
The enzymatic efficiency of β-glucosidases is influenced by their binding behavior onto insoluble substrates (cellulose and lignin) during bioconversion of lignocellulose. This study suggested that the Bgl3 protein (Aspergillus fumigatus) showed strong adsorption affinity to lignin and the Bgl1 protein (Penicillium oxalicum) tended to adsorb to cellulose. It indicated that the various surface properties of the fibronectin type Ш-like domain (FnIII) led to different binding properties of β-glucosidases by investigating their binding mechanism. By engineering β-glucosidases' FnIII domain, Bgl3-1 and Bgl1-3 were constructed, which both showed lower binding capacities to insoluble substrates. As well as for Bgl1-3, its sensitivity to the phenolic component was also eased. Based on that, the reconstructed protein showed high catalytic efficiency during the enzymatic hydrolysis of corn stover by effectively transforming cellobiose to glucose. Thus, this study provided a new strategy to engineer β-glucosidases to enhance their performance in the cellulase system.
Collapse
Affiliation(s)
- Xianqin Lu
- State Key Laboratory of Microbial Technology, Shandong University, No.72, Binhai Road, Qingdao 266237, China
| | - Xuezhi Li
- State Key Laboratory of Microbial Technology, Shandong University, No.72, Binhai Road, Qingdao 266237, China
| | - Jian Zhao
- State Key Laboratory of Microbial Technology, Shandong University, No.72, Binhai Road, Qingdao 266237, China.
| |
Collapse
|
4
|
Li N, Zhang R, Zhou J, Huang Z. Structures, Biochemical Characteristics, and Functions of β-Xylosidases. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2023; 71:7961-7976. [PMID: 37192316 DOI: 10.1021/acs.jafc.3c01425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
The complete degradation of abundant xylan derived from plants requires the participation of β-xylosidases to produce the xylose which can be converted to xylitol, ethanol, and other valuable chemicals. Some phytochemicals can also be hydrolyzed by β-xylosidases into bioactive substances, such as ginsenosides, 10-deacetyltaxol, cycloastragenol, and anthocyanidins. On the contrary, some hydroxyl-containing substances such as alcohols, sugars, and phenols can be xylosylated by β-xylosidases into new chemicals such as alkyl xylosides, oligosaccharides, and xylosylated phenols. Thus, β-xylosidases shows great application prospects in food, brewing, and pharmaceutical industries. This review focuses on the molecular structures, biochemical properties, and bioactive substance transformation function of β-xylosidases derived from bacteria, fungi, actinomycetes, and metagenomes. The molecular mechanisms of β-xylosidases related to the properties and functions are also discussed. This review will serve as a reference for the engineering and application of β-xylosidases in food, brewing, and pharmaceutical industries.
Collapse
Affiliation(s)
- Na Li
- Engineering Research Center of Sustainable Development and Utilization of Biomass Energy, Ministry of Education, Yunnan Normal University, Kunming 650500, People's Republic of China
- College of Life Sciences, Yunnan Normal University, Kunming 650500, People's Republic of China
- Key Laboratory of Yunnan for Biomass Energy and Biotechnology of Environment, Kunming 650500, People's Republic of China
- Key Laboratory of Yunnan Provincial Education Department for Plateau Characteristic Food Enzymes, Kunming 650500, People's Republic of China
| | - Rui Zhang
- Engineering Research Center of Sustainable Development and Utilization of Biomass Energy, Ministry of Education, Yunnan Normal University, Kunming 650500, People's Republic of China
- College of Life Sciences, Yunnan Normal University, Kunming 650500, People's Republic of China
- Key Laboratory of Yunnan for Biomass Energy and Biotechnology of Environment, Kunming 650500, People's Republic of China
- Key Laboratory of Yunnan Provincial Education Department for Plateau Characteristic Food Enzymes, Kunming 650500, People's Republic of China
| | - Junpei Zhou
- Engineering Research Center of Sustainable Development and Utilization of Biomass Energy, Ministry of Education, Yunnan Normal University, Kunming 650500, People's Republic of China
- College of Life Sciences, Yunnan Normal University, Kunming 650500, People's Republic of China
- Key Laboratory of Yunnan for Biomass Energy and Biotechnology of Environment, Kunming 650500, People's Republic of China
- Key Laboratory of Yunnan Provincial Education Department for Plateau Characteristic Food Enzymes, Kunming 650500, People's Republic of China
| | - Zunxi Huang
- Engineering Research Center of Sustainable Development and Utilization of Biomass Energy, Ministry of Education, Yunnan Normal University, Kunming 650500, People's Republic of China
- College of Life Sciences, Yunnan Normal University, Kunming 650500, People's Republic of China
- Key Laboratory of Yunnan for Biomass Energy and Biotechnology of Environment, Kunming 650500, People's Republic of China
- Key Laboratory of Yunnan Provincial Education Department for Plateau Characteristic Food Enzymes, Kunming 650500, People's Republic of China
| |
Collapse
|
5
|
The evolutionary advantage of an aromatic clamp in plant family 3 glycoside exo-hydrolases. Nat Commun 2022; 13:5577. [PMID: 36151080 PMCID: PMC9508125 DOI: 10.1038/s41467-022-33180-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Accepted: 09/03/2022] [Indexed: 11/08/2022] Open
Abstract
In the barley β-D-glucan glucohydrolase, a glycoside hydrolase family 3 (GH3) enzyme, the Trp286/Trp434 clamp ensures β-D-glucosides binding, which is fundamental for substrate hydrolysis during plant growth and development. We employ mutagenesis, high-resolution X-ray crystallography, and multi-scale molecular modelling methods to examine the binding and conformational behaviour of isomeric β-D-glucosides during substrate-product assisted processive catalysis that operates in GH3 hydrolases. Enzyme kinetics reveals that the W434H mutant retains broad specificity, while W434A behaves as a strict (1,3)-β-D-glucosidase. Investigations of reactant movements on the nanoscale reveal that processivity is sensitive to mutation-specific alterations of the tryptophan clamp. While wild-type and W434H utilise a lateral cavity for glucose displacement and sliding of (1,3)-linked hydrolytic products through the catalytic site without dissociation, consistent with their high hydrolytic rates, W434A does not adopt processive catalysis. Phylogenomic analyses of GH3 hydrolases disclose the evolutionary advantage of the tryptophan clamp that confers broad specificity, high catalytic efficiency, and processivity.
Collapse
|
6
|
Liu Y, Ding C, Su D, Wang T, Wang T. Solar park promoted microbial nitrogen and phosphorus cycle potentials but reduced soil prokaryotic diversity and network stability in alpine desert ecosystem. Front Microbiol 2022; 13:976335. [PMID: 36160250 PMCID: PMC9493309 DOI: 10.3389/fmicb.2022.976335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Accepted: 08/08/2022] [Indexed: 11/18/2022] Open
Abstract
Solar park (SP) is rapidly growing throughout the planet due to the increasing demand for low-carbon energy, which represents a remarkable global land-use change with implications for the hosting ecosystems. Despite dozens of studies estimating the environmental impacts of SP based on local microclimate and vegetation, responses of soil microbial interactions and nutrient cycle potentials remain poorly understood. To bridge this gap, we investigated the diversity, community structure, complexity, and stability of co-occurrence network and soil enzyme activities of soil prokaryotes and fungi in habitats of ambient, the first, and sixth year since solar park establishment. Results revealed different response patterns of prokaryotes and fungi. SP led to significant differences in both prokaryotic and fungal community structures but only reduced prokaryotic alpha diversity significantly. Co-occurrence network analysis revealed a unimodal pattern of prokaryotic network features and more resistance of fungal networks to environmental variations. Microbial nitrogen and phosphorus cycle potentials were higher in SP and their variances were more explained by network features than by diversity and environmental characteristics. Our findings revealed for the first time the significant impacts of SP on soil prokaryotic and fungal stability and functional potentials, which provides a microbial insight for impact evaluation and evidence for the optimization of solar park management to maximize the delivery of ecosystem services from this growing land use.
Collapse
Affiliation(s)
- Yu Liu
- College of Grassland, Beijing Forestry University, Beijing, China
| | - Chengxiang Ding
- Academy of Animal Husbandry and Veterinary Science, Qinghai University, Xining, China
- Chengxiang Ding,
| | - Derong Su
- College of Grassland, Beijing Forestry University, Beijing, China
- *Correspondence: Derong Su,
| | - Tiemei Wang
- College of Grassland, Beijing Forestry University, Beijing, China
| | - Tao Wang
- College of Grassland, Beijing Forestry University, Beijing, China
| |
Collapse
|
7
|
Kojima K, Sunagawa N, Mikkelsen NE, Hansson H, Karkehabadi S, Samejima M, Sandgren M, Igarashi K. Comparison of Glycoside Hydrolase family 3 β-xylosidases from basidiomycetes and ascomycetes reveals evolutionarily distinct xylan degradation systems. J Biol Chem 2022; 298:101670. [PMID: 35120929 PMCID: PMC8913315 DOI: 10.1016/j.jbc.2022.101670] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 01/27/2022] [Accepted: 01/28/2022] [Indexed: 11/28/2022] Open
Abstract
Xylan is the most common hemicellulose in plant cell walls, though the structure of xylan polymers differs between plant species. Here, to gain a better understanding of fungal xylan degradation systems, which can enhance enzymatic saccharification of plant cell walls in industrial processes, we conducted a comparative study of two glycoside hydrolase family 3 (GH3) β-xylosidases (Bxls), one from the basidiomycete Phanerochaete chrysosporium (PcBxl3), and the other from the ascomycete Trichoderma reesei (TrXyl3A). A comparison of the crystal structures of the two enzymes, both with saccharide bound at the catalytic center, provided insight into the basis of substrate binding at each subsite. PcBxl3 has a substrate-binding pocket at subsite -1, while TrXyl3A has an extra loop that contains additional binding subsites. Furthermore, kinetic experiments revealed that PcBxl3 degraded xylooligosaccharides faster than TrXyl3A, while the KM values of TrXyl3A were lower than those of PcBxl3. The relationship between substrate specificity and degree of polymerization of substrates suggested that PcBxl3 preferentially degrades xylobiose (X2), while TrXyl3A degrades longer xylooligosaccharides. Moreover, docking simulation supported the existence of extended positive subsites of TrXyl3A in the extra loop located at the N-terminus of the protein. Finally, phylogenetic analysis suggests that wood-decaying basidiomycetes use Bxls such as PcBxl3 that act efficiently on xylan structures from woody plants, whereas molds use instead Bxls that efficiently degrade xylan from grass. Our results provide added insights into fungal efficient xylan degradation systems.
Collapse
Affiliation(s)
- Keisuke Kojima
- Department of Biomaterial Sciences, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1, Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Naoki Sunagawa
- Department of Biomaterial Sciences, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1, Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Nils Egil Mikkelsen
- Department of Molecular Sciences, Swedish University of Agricultural Sciences, Uppsala SE-750 07, Sweden
| | - Henrik Hansson
- Department of Molecular Sciences, Swedish University of Agricultural Sciences, Uppsala SE-750 07, Sweden
| | - Saeid Karkehabadi
- Department of Molecular Sciences, Swedish University of Agricultural Sciences, Uppsala SE-750 07, Sweden
| | - Masahiro Samejima
- Department of Biomaterial Sciences, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1, Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan; Faculty of Engineering, Shinshu University, 4-17-1, Wakasato, Nagano 380-8533, Japan
| | - Mats Sandgren
- Department of Molecular Sciences, Swedish University of Agricultural Sciences, Uppsala SE-750 07, Sweden
| | - Kiyohiko Igarashi
- Department of Biomaterial Sciences, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1, Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan; VTT Technical Research Centre of Finland, PO Box 1000, Tietotie 2, Espoo FI-02044 VTT, Finland.
| |
Collapse
|
8
|
Sun N, Liu X, Wang X, Shi H, Zhang H, Li L, Na W, Guan Q. Optimization of fermentation conditions for the production of acidophilic β-glucosidase by Trichoderma reesei S12 from mangrove soil. BIOTECHNOL BIOTEC EQ 2022. [DOI: 10.1080/13102818.2021.1984989] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
Affiliation(s)
- Nan Sun
- Lab of Animal Nutrition, Reproduction & Breeding, College of Animal Science and Technology, Hainan University, Haikou, Hainan, P.R.China
| | - Xiaoxuan Liu
- Lab of Animal Nutrition, Reproduction & Breeding, College of Animal Science and Technology, Hainan University, Haikou, Hainan, P.R.China
| | - Xuemei Wang
- Lab of Animal Nutrition, Reproduction & Breeding, College of Animal Science and Technology, Hainan University, Haikou, Hainan, P.R.China
| | - Huiyu Shi
- Lab of Animal Nutrition, Reproduction & Breeding, College of Animal Science and Technology, Hainan University, Haikou, Hainan, P.R.China
| | - Haiwen Zhang
- Lab of Animal Nutrition, Reproduction & Breeding, College of Animal Science and Technology, Hainan University, Haikou, Hainan, P.R.China
| | - Lianbin Li
- Lab of Animal Nutrition, Reproduction & Breeding, College of Animal Science and Technology, Hainan University, Haikou, Hainan, P.R.China
| | - Wei Na
- Lab of Animal Genetics, Reproduction & Breeding, College of Animal Science and Technology, Hainan University, Haikou, Hainan, P.R.China
| | - Qingfeng Guan
- Lab of Microorganism Resource and Utilization Research, School of Life Sciences, Hainan University, Haikou, Hainan, P.R.China
| |
Collapse
|
9
|
Xia W, Bai Y, Shi P. Improving the Substrate Affinity and Catalytic Efficiency of β-Glucosidase Bgl3A from Talaromyces leycettanus JCM12802 by Rational Design. Biomolecules 2021; 11:biom11121882. [PMID: 34944526 PMCID: PMC8699594 DOI: 10.3390/biom11121882] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Revised: 12/08/2021] [Accepted: 12/09/2021] [Indexed: 12/31/2022] Open
Abstract
Improving the substrate affinity and catalytic efficiency of β-glucosidase is necessary for better performance in the enzymatic saccharification of cellulosic biomass because of its ability to prevent cellobiose inhibition on cellulases. Bgl3A from Talaromyces leycettanus JCM12802, identified in our previous work, was considered a suitable candidate enzyme for efficient cellulose saccharification with higher catalytic efficiency on the natural substrate cellobiose compared with other β-glucosidase but showed insufficient substrate affinity. In this work, hydrophobic stacking interaction and hydrogen-bonding networks in the active center of Bgl3A were analyzed and rationally designed to strengthen substrate binding. Three vital residues, Met36, Phe66, and Glu168, which were supposed to influence substrate binding by stabilizing adjacent binding site, were chosen for mutagenesis. The results indicated that strengthening the hydrophobic interaction between stacking aromatic residue and the substrate, and stabilizing the hydrogen-bonding networks in the binding pocket could contribute to the stabilized substrate combination. Four dominant mutants, M36E, M36N, F66Y, and E168Q with significantly lower Km values and 1.4–2.3-fold catalytic efficiencies, were obtained. These findings may provide a valuable reference for the design of other β-glucosidases and even glycoside hydrolases.
Collapse
Affiliation(s)
- Wei Xia
- Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing 100081, China;
| | - Yingguo Bai
- Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China
- Correspondence: (Y.B.); (P.S.)
| | - Pengjun Shi
- Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing 100081, China;
- Correspondence: (Y.B.); (P.S.)
| |
Collapse
|
10
|
Fungal cellulases: protein engineering and post-translational modifications. Appl Microbiol Biotechnol 2021; 106:1-24. [PMID: 34889986 DOI: 10.1007/s00253-021-11723-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2021] [Revised: 11/28/2021] [Accepted: 11/30/2021] [Indexed: 12/18/2022]
Abstract
Enzymatic degradation of lignocelluloses into fermentable sugars to produce biofuels and other biomaterials is critical for environmentally sustainable development and energy resource supply. However, there are problems in enzymatic cellulose hydrolysis, such as the complex cellulase composition, low degradation efficiency, high production cost, and post-translational modifications (PTMs), all of which are closely related to specific characteristics of cellulases that remain unclear. These problems hinder the practical application of cellulases. Due to the rapid development of computer technology in recent years, computer-aided protein engineering is being widely used, which also brings new opportunities for the development of cellulases. Especially in recent years, a large number of studies have reported on the application of computer-aided protein engineering in the development of cellulases; however, these articles have not been systematically reviewed. This article focused on the aspect of protein engineering and PTMs of fungal cellulases. In this manuscript, the latest literatures and the distribution of potential sites of cellulases for engineering have been systematically summarized, which provide reference for further improvement of cellulase properties. KEY POINTS: •Rational design based on virtual mutagenesis can improve cellulase properties. •Modifying protein side chains and glycans helps obtain superior cellulases. •N-terminal glutamine-pyroglutamate conversion stabilizes fungal cellulases.
Collapse
|
11
|
Enzymatic degradation of xyloglucans by Aspergillus species: a comparative view of this genus. Appl Microbiol Biotechnol 2021; 105:2701-2711. [PMID: 33760931 DOI: 10.1007/s00253-021-11236-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2021] [Revised: 02/25/2021] [Accepted: 03/14/2021] [Indexed: 10/21/2022]
Abstract
Aspergillus species are closely associated with humanity through fermentation, infectious disease, and mycotoxin contamination of food. Members of this genus produce various enzymes to degrade plant polysaccharides, including starch, cellulose, xylan, and xyloglucan. This review focus on the machinery of the xyloglucan degradation using glycoside hydrolases, such as xyloglucanases, isoprimeverose-producing oligoxyloglucan hydrolases, and α-xylosidases, in Aspergillus species. Some xyloglucan degradation-related glycoside hydrolases are well conserved in this genus; however, other enzymes are not. Cooperative actions of these glycoside hydrolases are crucial for xyloglucan degradation in Aspergillus species. KEY POINTS: •Xyloglucan degradation-related enzymes of Aspergillus species are reviewed. •Each Aspergillus species possesses a different set of glycoside hydrolases. •The machinery of xyloglucan degradation of A. oryzae is overviewed.
Collapse
|
12
|
Nath P, Goyal A. Structure and dynamics analysis of multi-domain putative β-1,4-glucosidase of family 3 glycoside hydrolase (PsGH3) from Pseudopedobacter saltans. J Mol Model 2021; 27:106. [PMID: 33694107 PMCID: PMC7945971 DOI: 10.1007/s00894-021-04721-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Accepted: 03/01/2021] [Indexed: 11/30/2022]
Abstract
Structure and conformational behaviour of a putative β-1,4-glucosidase of glycoside hydrolase family 3 (PsGH3) from Pseudopedobacter saltans was predicted by using in-silico tools. PsGH3 modeled structure constructed using Phyre2 displayed multidomain architecture comprising an N-terminal (β/α)8-fold domain followed by (α/β)6-sandwich domain, PA14 domain, and a C-terminal domain resembling an immunoglobulin fold. Ramachandran plot displayed 99.3% of amino acids in the allowed region and 0.7% residues in the disallowed region. Multiple sequence alignment (MSA) and structure superposition of PsGH3 with other homologues from GH3 family revealed the conserved residues, Asp274 and Glu624 present in loops LA and LB, respectively originating from N-terminal domain act as catalytic residues. The volume and area calculated for PsGH3 displayed a deep active-site conformation comparable with its homologues, β-1,4-glucosidases (GH3) of Kluyveromyces marxianus and Streptomyces venezuelae. Molecular dynamic (MD) simulation of PsGH3 structure for 80 ns suggested stable and compact structure. Molecular docking studies revealed deeper active site conformation of PsGH3 that could house larger cellooligosaccharides up to 7° of polymerization (DP7). The amino acid residues, Ala86, Leu88, Cys275, Pro483, Phe493, Asn417, Asn491, Pro492, and Leu495 created a binding pocket near the catalytic cleft, crucial for ligand binding. MD simulation of PsGH3 in the presence of cellooligosaccharides, viz., cellobiose and celloheptaose showed stability in terms of RMSD, Rg, and SASA values till 80 ns. The calculation of average number of hydrogen bond (H-bond), interaction energy, and binding free energy confirmed the stronger binding affinity of the larger cellooligosaccharides such as celloheptaose in the binding cavity of PsGH3.
Collapse
Affiliation(s)
- Priyanka Nath
- Carbohydrate Enzyme Biotechnology Laboratory, Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, Assam, 781039, India
| | - Arun Goyal
- Carbohydrate Enzyme Biotechnology Laboratory, Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, Assam, 781039, India.
| |
Collapse
|
13
|
Matsuyama K, Kishine N, Fujimoto Z, Sunagawa N, Kotake T, Tsumuraya Y, Samejima M, Igarashi K, Kaneko S. Unique active-site and subsite features in the arabinogalactan-degrading GH43 exo-β-1,3-galactanase from Phanerochaete chrysosporium. J Biol Chem 2020; 295:18539-18552. [PMID: 33093171 PMCID: PMC7939473 DOI: 10.1074/jbc.ra120.016149] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 10/20/2020] [Indexed: 12/27/2022] Open
Abstract
Arabinogalactan proteins (AGPs) are plant proteoglycans with functions in growth and development. However, these functions are largely unexplored, mainly because of the complexity of the sugar moieties. These carbohydrate sequences are generally analyzed with the aid of glycoside hydrolases. The exo-β-1,3-galactanase is a glycoside hydrolase from the basidiomycete Phanerochaete chrysosporium (Pc1,3Gal43A), which specifically cleaves AGPs. However, its structure is not known in relation to its mechanism bypassing side chains. In this study, we solved the apo and liganded structures of Pc1,3Gal43A, which reveal a glycoside hydrolase family 43 subfamily 24 (GH43_sub24) catalytic domain together with a carbohydrate-binding module family 35 (CBM35) binding domain. GH43_sub24 is known to lack the catalytic base Asp conserved among other GH43 subfamilies. Our structure in combination with kinetic analyses reveals that the tautomerized imidic acid group of Gln263 serves as the catalytic base residue instead. Pc1,3Gal43A has three subsites that continue from the bottom of the catalytic pocket to the solvent. Subsite -1 contains a space that can accommodate the C-6 methylol of Gal, enabling the enzyme to bypass the β-1,6-linked galactan side chains of AGPs. Furthermore, the galactan-binding domain in CBM35 has a different ligand interaction mechanism from other sugar-binding CBM35s, including those that bind galactomannan. Specifically, we noted a Gly → Trp substitution, which affects pyranose stacking, and an Asp → Asn substitution in the binding pocket, which recognizes β-linked rather than α-linked Gal residues. These findings should facilitate further structural analysis of AGPs and may also be helpful in engineering designer enzymes for efficient biomass utilization.
Collapse
Affiliation(s)
- Kaori Matsuyama
- Department of Biomaterial Sciences, Graduate School of Agricultural and Life Sciences, University of Tokyo, Tokyo, Japan
| | - Naomi Kishine
- Advanced Analysis Center, National Agriculture and Food Research Organization (NARO), Tsukuba, Ibaraki, Japan
| | - Zui Fujimoto
- Advanced Analysis Center, National Agriculture and Food Research Organization (NARO), Tsukuba, Ibaraki, Japan
| | - Naoki Sunagawa
- Department of Biomaterial Sciences, Graduate School of Agricultural and Life Sciences, University of Tokyo, Tokyo, Japan
| | - Toshihisa Kotake
- Department of Biochemistry and Molecular Biology, Faculty of Science, Saitama University, Saitama, Japan
| | - Yoichi Tsumuraya
- Department of Biochemistry and Molecular Biology, Faculty of Science, Saitama University, Saitama, Japan
| | - Masahiro Samejima
- Department of Biomaterial Sciences, Graduate School of Agricultural and Life Sciences, University of Tokyo, Tokyo, Japan; Faculty of Engineering, Shinshu University, Nagano, Japan
| | - Kiyohiko Igarashi
- Department of Biomaterial Sciences, Graduate School of Agricultural and Life Sciences, University of Tokyo, Tokyo, Japan; VTT Technical Research Centre of Finland, Espoo, Finland.
| | - Satoshi Kaneko
- Department of Subtropical Bioscience and Biotechnology, Faculty of Agriculture, University of the Ryukyus, Nishihara, Okinawa, Japan
| |
Collapse
|
14
|
Nieto-Domínguez M, Fernández de Toro B, de Eugenio LI, Santana AG, Bejarano-Muñoz L, Armstrong Z, Méndez-Líter JA, Asensio JL, Prieto A, Withers SG, Cañada FJ, Martínez MJ. Thioglycoligase derived from fungal GH3 β-xylosidase is a multi-glycoligase with broad acceptor tolerance. Nat Commun 2020; 11:4864. [PMID: 32978392 PMCID: PMC7519651 DOI: 10.1038/s41467-020-18667-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Accepted: 09/02/2020] [Indexed: 11/09/2022] Open
Abstract
The synthesis of customized glycoconjugates constitutes a major goal for biocatalysis. To this end, engineered glycosidases have received great attention and, among them, thioglycoligases have proved useful to connect carbohydrates to non-sugar acceptors. However, hitherto the scope of these biocatalysts was considered limited to strong nucleophilic acceptors. Based on the particularities of the GH3 glycosidase family active site, we hypothesized that converting a suitable member into a thioglycoligase could boost the acceptor range. Herein we show the engineering of an acidophilic fungal β-xylosidase into a thioglycoligase with broad acceptor promiscuity. The mutant enzyme displays the ability to form O-, N-, S- and Se- glycosides together with sugar esters and phosphoesters with conversion yields from moderate to high. Analyses also indicate that the pKa of the target compound was the main factor to determine its suitability as glycosylation acceptor. These results expand on the glycoconjugate portfolio attainable through biocatalysis.
Collapse
Affiliation(s)
- Manuel Nieto-Domínguez
- Biotechnology for Lignocellulosic Biomass Group, Centro de Investigaciones Biológicas Margarita Salas (CSIC), C/Ramiro de Maeztu 9, 28040, Madrid, Spain.
| | - Beatriz Fernández de Toro
- NMR and Molecular Recognition Group, Centro de Investigaciones Biológicas Margarita Salas (CSIC), C/Ramiro de Maeztu 9, 28040, Madrid, Spain
| | - Laura I de Eugenio
- Biotechnology for Lignocellulosic Biomass Group, Centro de Investigaciones Biológicas Margarita Salas (CSIC), C/Ramiro de Maeztu 9, 28040, Madrid, Spain
| | - Andrés G Santana
- Glycochemistry and Molecular recognition group, Instituto de Química Orgánica General (CSIC), C/Juan de la Cierva, 3, 28006, Madrid, Spain
| | - Lara Bejarano-Muñoz
- Biotechnology for Lignocellulosic Biomass Group, Centro de Investigaciones Biológicas Margarita Salas (CSIC), C/Ramiro de Maeztu 9, 28040, Madrid, Spain
| | - Zach Armstrong
- Department of Chemistry, Centre for High-Throughput Biology, University of British Columbia, Vancouver, Canada
| | - Juan Antonio Méndez-Líter
- Biotechnology for Lignocellulosic Biomass Group, Centro de Investigaciones Biológicas Margarita Salas (CSIC), C/Ramiro de Maeztu 9, 28040, Madrid, Spain
| | - Juan Luis Asensio
- Glycochemistry and Molecular recognition group, Instituto de Química Orgánica General (CSIC), C/Juan de la Cierva, 3, 28006, Madrid, Spain
| | - Alicia Prieto
- Biotechnology for Lignocellulosic Biomass Group, Centro de Investigaciones Biológicas Margarita Salas (CSIC), C/Ramiro de Maeztu 9, 28040, Madrid, Spain
| | - Stephen G Withers
- Department of Chemistry, Centre for High-Throughput Biology, University of British Columbia, Vancouver, Canada
| | - Francisco Javier Cañada
- NMR and Molecular Recognition Group, Centro de Investigaciones Biológicas Margarita Salas (CSIC), C/Ramiro de Maeztu 9, 28040, Madrid, Spain
| | - María Jesús Martínez
- Biotechnology for Lignocellulosic Biomass Group, Centro de Investigaciones Biológicas Margarita Salas (CSIC), C/Ramiro de Maeztu 9, 28040, Madrid, Spain.
| |
Collapse
|
15
|
Deepa P, Thirumeignanam D. Rising trend on the halogen and non-halogen derivatives (Br, Cl, CF 3, F, CH 3 and NH 2) in ruminal β-d-Xylopyranose - a quantum chemical perspective. J Biomol Struct Dyn 2020; 40:449-467. [PMID: 32880211 DOI: 10.1080/07391102.2020.1815577] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
The utmost aim of the current study is to find significance of the binding affinity in the halogen and non-halogen derivatives: Br, Cl, CF3, F, CH3 and NH2 of β-d-Xylopyranose with the hinge region amino acids of ruminant-β-glycosidase. The interaction energy analysis was carried out in detail through various density functional studies as M062X/def2-QZVP, M062X/LANL2DZ, B3LYP/LANL2DZ and M06HF/LANL2DZ level of theories. The total interaction energy of halogen derivatives: Br, Cl, F and CF3 are -618.21, -599.00, -720.45 and -553.08 kcal/mol respectively, and non-halogen derivative: amine group (NH2) is -87.96 kcal/mol at M062X/def2-QZVP level of theory, which exist with strong binding affinity. Ligand properties: dipole moment, polarizability, volume, molecular mass, electrostatic potential map was evaluated to understand its electrostatic and structural behavior. The nature of the bonds was inferred from the electrostatic potential map for all the halogen and non-halogen derivatives ligand. The stabilization energy from NBO analysis reveals the stability of single hydrogen and halogen bonds (N-H…Br, C-Br…O, N-H…Cl, C-Cl…O, O-H…F, C-H…F, N-H…F, C-F…O, N-H…O, O-H…O, N-H…N, O-H…N) in β-d-Xylopyranose and its derivatives. Overall, this study paves way for scientist and medicinal chemist in modelling new drugs. Further, it suggests mutations that increase the binding and may enhance the catalytic action and strengthen the complex diet in animals and hence recommended for experimental synthesis.Communicated by Ramaswamy H. Sarma.
Collapse
Affiliation(s)
- Palanisamy Deepa
- Department of Physics, Manonmaniam Sundaranar University, Tirunelveli, India
| | - Duraisamy Thirumeignanam
- Department of Animal Nutrition, Veterinary College and Research Institute, TamilNadu Veterinary and Animal Sciences University, Tirunelveli, India
| |
Collapse
|
16
|
Jiang X, Du J, He R, Zhang Z, Qi F, Huang J, Qin L. Improved Production of Majority Cellulases in Trichoderma reesei by Integration of cbh1 Gene From Chaetomium thermophilum. Front Microbiol 2020; 11:1633. [PMID: 32765463 PMCID: PMC7381231 DOI: 10.3389/fmicb.2020.01633] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2020] [Accepted: 06/23/2020] [Indexed: 11/17/2022] Open
Abstract
Lignocellulose is an abundant waste resource and has been considered as a promising material for production of biofuels or other valuable bio-products. Currently, one of the major bottlenecks in the economic utilization of lignocellulosic materials is the cost-efficiency of converting lignocellulose into soluble sugars for fermentation. One way to address this problem is to seek superior lignocellulose degradation enzymes or further improve current production yields of lignocellulases. In the present study, the lignocellulose degradation capacity of a thermophilic fungus Chaetomium thermophilum was firstly evaluated and compared to that of the biotechnological workhorse Trichoderma reesei. The data demonstrated that compared to T. reesei, C. thermophilum displayed substantially higher cellulose-utilizing efficiency with relatively lower production of cellulases, indicating that better cellulases might exist in C. thermophilum. Comparison of the protein secretome between C. thermophilum and T. reesei showed that the secreted protein categories were quite different in these two species. In addition, to prove that cellulases in C. thermophilum had better enzymatic properties, the major cellulase cellobiohydrolase I (CBH1) from C. thermophilum and T. reesei were firstly characterized, respectively. The data showed that the specific activity of C. thermophilum CBH1 was about 4.5-fold higher than T. reesei CBH1 in a wide range of temperatures and pH. To explore whether increasing CBH1 activity in T. reesei could contribute to improving the overall cellulose-utilizing efficiency of T. reesei, T. reesei cbh1 gene was replaced with C. thermophilum cbh1 gene by integration of C. thermophilum cbh1 gene into T. reesei cbh1 gene locus. The data surprisingly showed that this gene replacement not only increased the cellobiohydrolase activities by around 4.1-fold, but also resulted in stronger induction of other cellulases genes, which caused the filter paper activities, Azo-CMC activities and β-glucosidase activities increased by about 2.2, 1.9, and 2.3-fold, respectively. The study here not only provided new resources of superior cellulases genes and new strategy to improve the cellulase production in T. reesei, but also contribute to opening the path for fundamental research on C. thermophilum.
Collapse
Affiliation(s)
- Xianzhang Jiang
- National Joint Engineering Research Center of Industrial Microbiology and Fermentation Technology, College of Life Sciences, Fujian Normal University, Fuzhou, China
| | - Jiawen Du
- National Joint Engineering Research Center of Industrial Microbiology and Fermentation Technology, College of Life Sciences, Fujian Normal University, Fuzhou, China
| | - Ruonan He
- National Joint Engineering Research Center of Industrial Microbiology and Fermentation Technology, College of Life Sciences, Fujian Normal University, Fuzhou, China
| | - Zhengying Zhang
- National Joint Engineering Research Center of Industrial Microbiology and Fermentation Technology, College of Life Sciences, Fujian Normal University, Fuzhou, China
| | - Feng Qi
- National Joint Engineering Research Center of Industrial Microbiology and Fermentation Technology, College of Life Sciences, Fujian Normal University, Fuzhou, China
| | - Jianzhong Huang
- National Joint Engineering Research Center of Industrial Microbiology and Fermentation Technology, College of Life Sciences, Fujian Normal University, Fuzhou, China
| | - Lina Qin
- National Joint Engineering Research Center of Industrial Microbiology and Fermentation Technology, College of Life Sciences, Fujian Normal University, Fuzhou, China.,Provincial University Key Laboratory of Cellular Stress Response and Metabolic Regulation, College of Life Sciences, Fujian Normal University, Fuzhou, China
| |
Collapse
|
17
|
Structures of β-glycosidase LXYL-P1-2 reveals the product binding state of GH3 family and a specific pocket for Taxol recognition. Commun Biol 2020; 3:22. [PMID: 31925310 PMCID: PMC6954215 DOI: 10.1038/s42003-019-0744-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Accepted: 12/16/2019] [Indexed: 11/08/2022] Open
Abstract
LXYL-P1-2 is one of the few xylosidases that efficiently catalyze the reaction from 7-β-xylosyl-10-deacetyltaxol (XDT) to 10-deacetyltaxol (DT), and is a potential enzyme used in Taxol industrial production. Here we report the crystal structure of LXYL-P1-2 and its XDT binding complex. These structures reveal an enzyme/product complex with the sugar conformation different from the enzyme/substrate complex reported previously in GH3 enzymes, even in the whole glycohydrolases family. In addition, the DT binding pocket is identified as the structural basis for the substrate specificity. Further structure analysis reveals common features in LXYL-P1-2 and Taxol binding protein tubulin, which might provide useful information for designing new Taxol carrier proteins for drug delivery.
Collapse
|
18
|
Wang H, Lin X, Li S, Lin J, Xie C, Liu D, Yao D. Rational molecular design for improving digestive enzyme resistance of beta-glucosidase from Trichoderma viride based on inhibition of bound state formation. Enzyme Microb Technol 2019; 133:109465. [PMID: 31874695 DOI: 10.1016/j.enzmictec.2019.109465] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Revised: 11/05/2019] [Accepted: 11/06/2019] [Indexed: 11/18/2022]
Abstract
Beta-glucosidase (BGL1) is widely used in animal feed industries. However, degradation caused by digestive enzymes in the intestine hampers its application. Improving the resistance of feed enzymes against proteases is crucial in livestock farming. To improve the resistance of beta-glucosidase against pepsin and trypsin, a rational molecular design based on the inhibition of bound-state formation and secondary design was developed. The strategy includes: (1) prediction of the interaction surface of the pepsin-BGL1 complex structure, (2) prediction of key amino acids affecting the formation of the complex, (3) optimization of pepsin-resistant mutants by structural evaluation, (4) secondary molecular design based on pepsin-resistant mutants, and optimization of pepsin and trypsin-resistant mutants. Two BGL1 protein mutants (BGL1Q627C and BGL1Q627C/R543H/R646W) were constructed, and then mutated and wild-type BGL1s were expressed in Pichia pastoris. The half-life of BGL1Q627C and BGL1Q627C/R543H/R646W were 1.36 and 1.51 times that of the wild type upon pepsin exposure, respectively. For trypsin resistance, the half-life were 0.93 and 1.53 times that of the wild type, respectively. Compare to those of the wild type, most of the basic enzymatic properties of both mutants were not significantly changed except for increased Michaelis constants. The rational design method can be used as a guide for modifying other feed enzymes.
Collapse
Affiliation(s)
- Hao Wang
- Institute of Microbial Biotechnology, Jinan University, Guangzhou City, Guangdong Province, 510632, China; Department of Bioengineering, Jinan University, Guangzhou City, Guangdong Province, 510632, China
| | - Xiangna Lin
- Institute of Microbial Biotechnology, Jinan University, Guangzhou City, Guangdong Province, 510632, China; National Engineering Research Center of Genetic Medicine, Guangzhou City, Guangdong Province, 510632, China
| | - Shuang Li
- Institute of Microbial Biotechnology, Jinan University, Guangzhou City, Guangdong Province, 510632, China; Department of Bioengineering, Jinan University, Guangzhou City, Guangdong Province, 510632, China
| | - Jianlin Lin
- Institute of Microbial Biotechnology, Jinan University, Guangzhou City, Guangdong Province, 510632, China
| | - Chunfang Xie
- Institute of Microbial Biotechnology, Jinan University, Guangzhou City, Guangdong Province, 510632, China; Department of Bioengineering, Jinan University, Guangzhou City, Guangdong Province, 510632, China
| | - Daling Liu
- Institute of Microbial Biotechnology, Jinan University, Guangzhou City, Guangdong Province, 510632, China; Department of Bioengineering, Jinan University, Guangzhou City, Guangdong Province, 510632, China.
| | - Dongsheng Yao
- Institute of Microbial Biotechnology, Jinan University, Guangzhou City, Guangdong Province, 510632, China; National Engineering Research Center of Genetic Medicine, Guangzhou City, Guangdong Province, 510632, China.
| |
Collapse
|
19
|
Crystal Structure of a GH3 β-Glucosidase from the Thermophilic Fungus Chaetomium thermophilum. Int J Mol Sci 2019; 20:ijms20235962. [PMID: 31783503 PMCID: PMC6929035 DOI: 10.3390/ijms20235962] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Revised: 11/20/2019] [Accepted: 11/25/2019] [Indexed: 11/17/2022] Open
Abstract
Beta-glucosidases (β-glucosidases) have attracted considerable attention in recent years for use in various biotechnological applications. They are also essential enzymes for lignocellulose degradation in biofuel production. However, cost-effective biomass conversion requires the use of highly efficient enzymes. Thus, the search for new enzymes as better alternatives of the currently available enzyme preparations is highly important. Thermophilic fungi are nowadays considered as a promising source of enzymes with improved stability. Here, the crystal structure of a family GH3 β-glucosidase from the thermophilic fungus Chaetomium thermophilum (CtBGL) was determined at a resolution of 2.99 Å. The structure showed the three-domain architecture found in other β-glucosidases with variations in loops and linker regions. The active site catalytic residues in CtBGL were identified as Asp287 (nucleophile) and Glu517 (acid/base). Structural comparison of CtBGL with Protein Data Bank (PDB)-deposited structures revealed variations among glycosylated Asn residues. The enzyme displayed moderate glycosylation compared to other GH3 family β-glucosidases with similar structure. A new glycosylation site at position Asn504 was identified in CtBGL. Moreover, comparison with respect to several thermostability parameters suggested that glycosylation and charged residues involved in electrostatic interactions may contribute to the stability of the enzyme at elevated temperatures. The reported CtBGL structure provides additional insights into the family GH3 enzymes and could offer new ideas for further improvements in β-glucosidases for more efficient use in biotechnological applications regarding cellulose degradation.
Collapse
|
20
|
Rubio MV, Terrasan CRF, Contesini FJ, Zubieta MP, Gerhardt JA, Oliveira LC, de Souza Schmidt Gonçalves AE, Almeida F, Smith BJ, de Souza GHMF, Dias AHS, Skaf M, Damasio A. Redesigning N-glycosylation sites in a GH3 β-xylosidase improves the enzymatic efficiency. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:269. [PMID: 31754374 PMCID: PMC6854716 DOI: 10.1186/s13068-019-1609-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Accepted: 11/04/2019] [Indexed: 05/27/2023]
Abstract
BACKGROUND β-Xylosidases are glycoside hydrolases (GHs) that cleave xylooligosaccharides and/or xylobiose into shorter oligosaccharides and xylose. Aspergillus nidulans is an established genetic model and good source of carbohydrate-active enzymes (CAZymes). Most fungal enzymes are N-glycosylated, which influences their secretion, stability, activity, signalization, and protease protection. A greater understanding of the N-glycosylation process would contribute to better address the current bottlenecks in obtaining high secretion yields of fungal proteins for industrial applications. RESULTS In this study, BxlB-a highly secreted GH3 β-xylosidase from A. nidulans, presenting high activity and several N-glycosylation sites-was selected for N-glycosylation engineering. Several glycomutants were designed to investigate the influence of N-glycans on BxlB secretion and function. The non-glycosylated mutant (BxlBnon-glyc) showed similar levels of enzyme secretion and activity compared to the wild-type (BxlBwt), while a partially glycosylated mutant (BxlBN1;5;7) exhibited increased activity. Additionally, there was no enzyme secretion in the mutant in which the N-glycosylation context was changed by the introduction of four new N-glycosylation sites (BxlBCC), despite the high transcript levels. BxlBwt, BxlBnon-glyc, and BxlBN1;5;7 formed similar secondary structures, though the mutants had lower melting temperatures compared to the wild type. Six additional glycomutants were designed based on BxlBN1;5;7, to better understand its increased activity. Among them, the two glycomutants which maintained only two N-glycosylation sites each (BxlBN1;5 and BxlBN5;7) showed improved catalytic efficiency, whereas the other four mutants' catalytic efficiencies were reduced. The N-glycosylation site N5 is important for improved BxlB catalytic efficiency, but needs to be complemented by N1 and/or N7. Molecular dynamics simulations of BxlBnon-glyc and BxlBN1;5 reveals that the mobility pattern of structural elements in the vicinity of the catalytic pocket changes upon N1 and N5 N-glycosylation sites, enhancing substrate binding properties which may underlie the observed differences in catalytic efficiency between BxlBnon-glyc and BxlBN1;5. CONCLUSIONS This study demonstrates the influence of N-glycosylation on A. nidulans BxlB production and function, reinforcing that protein glycoengineering is a promising tool for enhancing thermal stability, secretion, and enzymatic activity. Our report may also support biotechnological applications for N-glycosylation modification of other CAZymes.
Collapse
Affiliation(s)
- Marcelo Ventura Rubio
- Department of Biochemistry and Tissue Biology, Institute of Biology, University of Campinas (UNICAMP), Rua Monteiro Lobato, 255, Cidade Universitária Zeferino Vaz, Campinas, SP 13083-862 Brazil
| | - César Rafael Fanchini Terrasan
- Department of Biochemistry and Tissue Biology, Institute of Biology, University of Campinas (UNICAMP), Rua Monteiro Lobato, 255, Cidade Universitária Zeferino Vaz, Campinas, SP 13083-862 Brazil
| | - Fabiano Jares Contesini
- Department of Biochemistry and Tissue Biology, Institute of Biology, University of Campinas (UNICAMP), Rua Monteiro Lobato, 255, Cidade Universitária Zeferino Vaz, Campinas, SP 13083-862 Brazil
| | - Mariane Paludetti Zubieta
- Department of Biochemistry and Tissue Biology, Institute of Biology, University of Campinas (UNICAMP), Rua Monteiro Lobato, 255, Cidade Universitária Zeferino Vaz, Campinas, SP 13083-862 Brazil
| | - Jaqueline Aline Gerhardt
- Department of Biochemistry and Tissue Biology, Institute of Biology, University of Campinas (UNICAMP), Rua Monteiro Lobato, 255, Cidade Universitária Zeferino Vaz, Campinas, SP 13083-862 Brazil
| | - Leandro Cristante Oliveira
- Department of Physics, Institute of Biosciences, Humanities and Exact Sciences, São Paulo State University (UNESP), São José do Rio Preto, SP 15054-000 Brazil
| | | | - Fausto Almeida
- Department of Biochemistry and Immunology, Ribeirão Preto Medical School, University of São Paulo (USP), Ribeirão Preto, SP 14049-900 Brazil
| | - Bradley Joseph Smith
- Department of Biochemistry and Tissue Biology, Institute of Biology, University of Campinas (UNICAMP), Rua Monteiro Lobato, 255, Cidade Universitária Zeferino Vaz, Campinas, SP 13083-862 Brazil
| | - Gustavo Henrique Martins Ferreira de Souza
- Department of Biochemistry and Tissue Biology, Institute of Biology, University of Campinas (UNICAMP), Rua Monteiro Lobato, 255, Cidade Universitária Zeferino Vaz, Campinas, SP 13083-862 Brazil
| | - Artur Hermano Sampaio Dias
- Institute of Chemistry and Center for Computing in Engineering and Sciences, University of Campinas (UNICAMP), Campinas, SP 13084-862 Brazil
| | - Munir Skaf
- Institute of Chemistry and Center for Computing in Engineering and Sciences, University of Campinas (UNICAMP), Campinas, SP 13084-862 Brazil
| | - André Damasio
- Department of Biochemistry and Tissue Biology, Institute of Biology, University of Campinas (UNICAMP), Rua Monteiro Lobato, 255, Cidade Universitária Zeferino Vaz, Campinas, SP 13083-862 Brazil
| |
Collapse
|
21
|
Weiz G, Mazzaferro LS, Kotik M, Neher BD, Halada P, Křen V, Breccia JD. The flavonoid degrading fungus Acremonium sp. DSM 24697 produces two diglycosidases with different specificities. Appl Microbiol Biotechnol 2019; 103:9493-9504. [PMID: 31705182 DOI: 10.1007/s00253-019-10180-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Revised: 09/30/2019] [Accepted: 10/09/2019] [Indexed: 01/01/2023]
Abstract
AbstractDiglycosidases hydrolyze the heterosidic linkage of diglycoconjugates, releasing the disaccharide and the aglycone. Usually, these enzymes do not hydrolyze or present only low activities towards monoglycosylated compounds. The flavonoid degrading fungus Acremonium sp. DSM 24697 produced two diglycosidases, which were termed 6-O-α-rhamnosyl-β-glucosidase I and II (αRβG I and II) because of their function of releasing the disaccharide rutinose (6-O-α-L-rhamnosyl-β-D-glucose) from the diglycoconjugates hesperidin or rutin. In this work, the genome of Acremonium sp. DSM 24697 was sequenced and assembled with a size of ~ 27 Mb. The genes encoding αRβG I and II were expressed in Pichia pastoris KM71 and the protein products were purified with apparent molecular masses of 42 and 82 kDa, respectively. A phylogenetic analysis showed that αRβG I grouped in glycoside hydrolase family 5, subfamily 23 (GH5), together with other fungal diglycosidases whose substrate specificities had been reported to be different from αRβG I. On the other hand, αRβG II grouped in glycoside hydrolase family 3 (GH3) and thus is the first GH3 member that hydrolyzes the heterosidic linkage of rutinosylated compounds. The substrate scopes of the enzymes were different: αRβG I showed exclusive specificity toward 7-O-β-rutinosyl flavonoids, whereas αRβG II hydrolyzed both 7-O-β-rutinosyl- and 3-O-β-rutinosyl- flavonoids. None of the enzymes displayed activity toward 7-O-β-neohesperidosyl- flavonoids. The recombinant enzymes also exhibited transglycosylation activities, transferring rutinose from hesperidin or rutin onto various alcoholic acceptors. The different substrate scopes of αRβG I and II may be part of an optimized strategy of the original microorganism to utilize different carbon sources.
Collapse
Affiliation(s)
- Gisela Weiz
- Facultad de Ciencias Exactas y Naturales, Instituto de Ciencias de la Tierra y Ambientales de La Pampa (INCITAP), Universidad Nacional de La Pampa - Consejo Nacional de Investigaciones Científicas y Técnicas (UNLPam-CONICET), Av. Uruguay 151, 6300, Santa Rosa, La Pampa, Argentina
| | - Laura S Mazzaferro
- Facultad de Ciencias Exactas y Naturales, Instituto de Ciencias de la Tierra y Ambientales de La Pampa (INCITAP), Universidad Nacional de La Pampa - Consejo Nacional de Investigaciones Científicas y Técnicas (UNLPam-CONICET), Av. Uruguay 151, 6300, Santa Rosa, La Pampa, Argentina
| | - Michael Kotik
- Laboratory of Biotransformation, Institute of Microbiology, Czech Academy of Sciences, Vídeňská 1083, 142 20, Prague, Czech Republic
| | - Bárbara D Neher
- Facultad de Ciencias Exactas y Naturales, Instituto de Ciencias de la Tierra y Ambientales de La Pampa (INCITAP), Universidad Nacional de La Pampa - Consejo Nacional de Investigaciones Científicas y Técnicas (UNLPam-CONICET), Av. Uruguay 151, 6300, Santa Rosa, La Pampa, Argentina
| | - Petr Halada
- Laboratory of Molecular Structure Characterization, Institute of Microbiology, Czech Academy of Sciences, Vídeňská 1083, 142 20, Prague, Czech Republic
| | - Vladimír Křen
- Laboratory of Biotransformation, Institute of Microbiology, Czech Academy of Sciences, Vídeňská 1083, 142 20, Prague, Czech Republic
| | - Javier D Breccia
- Facultad de Ciencias Exactas y Naturales, Instituto de Ciencias de la Tierra y Ambientales de La Pampa (INCITAP), Universidad Nacional de La Pampa - Consejo Nacional de Investigaciones Científicas y Técnicas (UNLPam-CONICET), Av. Uruguay 151, 6300, Santa Rosa, La Pampa, Argentina.
| |
Collapse
|
22
|
β-Xylosidases: Structural Diversity, Catalytic Mechanism, and Inhibition by Monosaccharides. Int J Mol Sci 2019; 20:ijms20225524. [PMID: 31698702 PMCID: PMC6887791 DOI: 10.3390/ijms20225524] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 11/02/2019] [Accepted: 11/04/2019] [Indexed: 12/20/2022] Open
Abstract
Xylan, a prominent component of cellulosic biomass, has a high potential for degradation into reducing sugars, and subsequent conversion into bioethanol. This process requires a range of xylanolytic enzymes. Among them, β-xylosidases are crucial, because they hydrolyze more glycosidic bonds than any of the other xylanolytic enzymes. They also enhance the efficiency of the process by degrading xylooligosaccharides, which are potent inhibitors of other hemicellulose-/xylan-converting enzymes. On the other hand, the β-xylosidase itself is also inhibited by monosaccharides that may be generated in high concentrations during the saccharification process. Structurally, β-xylosidases are diverse enzymes with different substrate specificities and enzyme mechanisms. Here, we review the structural diversity and catalytic mechanisms of β-xylosidases, and discuss their inhibition by monosaccharides.
Collapse
|
23
|
Rudakiya DM, Patel SH, Narra M. Structural insight into the fungal β-glucosidases and their interactions with organics. Int J Biol Macromol 2019; 138:1019-1028. [PMID: 31356936 DOI: 10.1016/j.ijbiomac.2019.07.177] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Revised: 07/20/2019] [Accepted: 07/25/2019] [Indexed: 11/30/2022]
Abstract
Fungal β-glucosidases (BGLs) have unceasingly utilized for industrial applications and recently, they possess a crucial role in bioethanol production. To engineer the BGLs, understanding their structures, intermolecular interactions and molecular docking is requisite, which is carried out in this work based on the glycosyl hydrolase (GH) family. Among 12 BGLs, protein sequence, structure, and conserved sites of GH1 BGLs are evidently diverged to GH3 BGLs. Even biophysical and chemical features of GH1 BGLs are utterly varied from GH3 BGLs, wherein pI, instability index, aliphatic index, surface & buried area, thermostability and thermodynamics are included. On the contrary, aromatic, charged, polar, and hydrophobic residues are significantly higher in GH1 BGLs as compared to that of GH3 BGLs. Moreover, molecular docking of BGLs with 12 substrates and 5 inhibitors revealed that the GH3 BGLs efficiently bound with laminaribose, gentibiose, aryl- and cello-substrates than GH1 BGLs; however, GH3 BGLs are noticeably inhibited by glucose, glucono-δ-lactone, methanetriamine. So, structural insight of BGLs provides an explicit knowledge regarding the catalytic residues, biophysical chemistry and notable binding ligands, which are most important factors for enzyme engineering.
Collapse
Affiliation(s)
- Darshan M Rudakiya
- Bioconversion Technology Division, Sardar Patel Renewable Energy Research Institute, Vallabh Vidyanagar, Anand, Gujarat, India.
| | - Shriram H Patel
- APC Microbiome Ireland, University College Cork, Cork, Ireland
| | - Madhuri Narra
- Bioconversion Technology Division, Sardar Patel Renewable Energy Research Institute, Vallabh Vidyanagar, Anand, Gujarat, India.
| |
Collapse
|
24
|
Valadares F, Gonçalves TA, Damasio A, Milagres AM, Squina FM, Segato F, Ferraz A. The secretome of two representative lignocellulose-decay basidiomycetes growing on sugarcane bagasse solid-state cultures. Enzyme Microb Technol 2019; 130:109370. [PMID: 31421724 DOI: 10.1016/j.enzmictec.2019.109370] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Revised: 06/27/2019] [Accepted: 07/02/2019] [Indexed: 12/14/2022]
Abstract
Secretome evaluations of lignocellulose-decay basidiomycetes can reveal new enzymes in selected fungal species that degrade specific substrates. Proteins discovered in such studies can support biorefinery development. Brown-rot (Gloeophyllum trabeum) and white-rot (Pleurotus ostreatus) fungi growing in sugarcane bagasse solid-state cultures produced 119 and 63 different extracellular proteins, respectively. Several of the identified enzymes are suitable for in vitro biomass conversion, including a range of cellulases (endoglucanases, cellobiohydrolases and β-glucosidases), hemicellulases (endoxylanases, α-arabinofuranosidases, α-glucuronidases and acetylxylan esterases) and carbohydrate-active auxiliary proteins, such as AA9 lytic polysaccharide monooxygenase, AA1 laccase and AA2 versatile peroxidase. Extracellular oxalate decarboxylase was also detected in both fungal species, exclusively in media containing sugarcane bagasse. Interestingly, intracellular AA6 quinone oxidoreductases were also exclusively produced under sugarcane bagasse induction in both fungi. These enzymes promote quinone redox cycling, which is used to produce Fenton's reagents by lignocellulose-decay fungi. Hitherto undiscovered hypothetical proteins that are predicted in lignocellulose-decay fungi genomes appeared in high relative abundance in the cultures containing sugarcane bagasse, which suggests undisclosed, new biochemical mechanisms that are used by lignocellulose-decay fungi to degrade sugarcane biomass. In general, lignocellulose-decay fungi produce a number of canonical hydrolases, as well as some newly observed enzymes, that are suitable for in vitro biomass digestion in a biorefinery context.
Collapse
Affiliation(s)
- Fernanda Valadares
- Departamento de Biotecnologia, Escola de Engenharia de Lorena, Universidade de São Paulo, 12602-810, Lorena, SP, Brazil
| | - Thiago A Gonçalves
- Programa de Processos Tecnológicos e Ambientais, Universidade de Sorocaba, 18023-000 Sorocaba, SP, Brazil; Institute of Biology, University of Campinas (UNICAMP), 13080-655, Campinas, SP, Brazil
| | - André Damasio
- Institute of Biology, University of Campinas (UNICAMP), 13080-655, Campinas, SP, Brazil
| | - Adriane Mf Milagres
- Departamento de Biotecnologia, Escola de Engenharia de Lorena, Universidade de São Paulo, 12602-810, Lorena, SP, Brazil
| | - Fabio M Squina
- Programa de Processos Tecnológicos e Ambientais, Universidade de Sorocaba, 18023-000 Sorocaba, SP, Brazil
| | - Fernando Segato
- Departamento de Biotecnologia, Escola de Engenharia de Lorena, Universidade de São Paulo, 12602-810, Lorena, SP, Brazil
| | - André Ferraz
- Departamento de Biotecnologia, Escola de Engenharia de Lorena, Universidade de São Paulo, 12602-810, Lorena, SP, Brazil.
| |
Collapse
|
25
|
Cai LN, Xu SN, Lu T, Lin DQ, Yao SJ. Directed expression of halophilic and acidophilic β-glucosidases by introducing homologous constitutive expression cassettes in marine Aspergillus niger. J Biotechnol 2019; 292:12-22. [DOI: 10.1016/j.jbiotec.2018.12.015] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Revised: 12/18/2018] [Accepted: 12/29/2018] [Indexed: 01/31/2023]
|
26
|
Geronimo I, Ntarima P, Piens K, Gudmundsson M, Hansson H, Sandgren M, Payne CM. Kinetic and molecular dynamics study of inhibition and transglycosylation in Hypocrea jecorina family 3 β-glucosidases. J Biol Chem 2019; 294:3169-3180. [PMID: 30602567 DOI: 10.1074/jbc.ra118.007027] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Indexed: 01/09/2023] Open
Abstract
β-Glucosidases enhance enzymatic biomass conversion by relieving cellobiose inhibition of endoglucanases and cellobiohydrolases. However, the susceptibility of these enzymes to inhibition and transglycosylation at high glucose or cellobiose concentrations severely limits their activity and, consequently, the overall efficiency of enzyme mixtures. We determined the impact of these two processes on the hydrolytic activity of the industrially relevant family 3 β-glucosidases from Hypocrea jecorina, HjCel3A and HjCel3B, and investigated the underlying molecular mechanisms through kinetic studies, binding free energy calculations, and molecular dynamics (MD) simulations. HjCel3B had a 7-fold higher specificity for cellobiose than HjCel3A but greater tendency for glucose inhibition. Energy decomposition analysis indicated that cellobiose has relatively weak electrostatic interactions with binding site residues, allowing it to be easily displaced by glucose and free to inhibit other hydrolytic enzymes. HjCel3A is, thus, preferable as an industrial β-glucosidase despite its lower activity caused by transglycosylation. This competing pathway to hydrolysis arises from binding of glucose or cellobiose at the product site after formation of the glycosyl-enzyme intermediate. MD simulations revealed that binding is facilitated by hydrophobic interactions with Trp-37, Phe-260, and Tyr-443. Targeting these aromatic residues for mutation to reduce substrate affinity at the product site would therefore potentially mitigate transglycosidic activity. Engineering improved variants of HjCel3A and other structurally similar β-glucosidases would have a significant economic effect on enzymatic biomass conversion in terms of yield and production cost as the process can be consequently conducted at higher substrate loadings.
Collapse
Affiliation(s)
- Inacrist Geronimo
- From the Department of Chemical and Materials Engineering, University of Kentucky, Lexington, Kentucky 40506-0046
| | - Patricia Ntarima
- the Department of Biochemistry and Microbiology, Ghent University, Ghent 9000, Belgium, and
| | - Kathleen Piens
- the Department of Biochemistry and Microbiology, Ghent University, Ghent 9000, Belgium, and
| | - Mikael Gudmundsson
- the Department of Molecular Sciences, Swedish University of Agricultural Sciences, Box 7015, 750 07 Uppsala, Sweden
| | - Henrik Hansson
- the Department of Molecular Sciences, Swedish University of Agricultural Sciences, Box 7015, 750 07 Uppsala, Sweden
| | - Mats Sandgren
- the Department of Molecular Sciences, Swedish University of Agricultural Sciences, Box 7015, 750 07 Uppsala, Sweden
| | - Christina M Payne
- From the Department of Chemical and Materials Engineering, University of Kentucky, Lexington, Kentucky 40506-0046, .,the Department of Molecular Sciences, Swedish University of Agricultural Sciences, Box 7015, 750 07 Uppsala, Sweden
| |
Collapse
|
27
|
Kao MR, Kuo HW, Lee CC, Huang KY, Huang TY, Li CW, Chen CW, Wang AHJ, Yu SM, Ho THD. Chaetomella raphigera β-glucosidase D2-BGL has intriguing structural features and a high substrate affinity that renders it an efficient cellulase supplement for lignocellulosic biomass hydrolysis. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:258. [PMID: 31700541 PMCID: PMC6825360 DOI: 10.1186/s13068-019-1599-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Accepted: 10/22/2019] [Indexed: 05/17/2023]
Abstract
BACKGROUND To produce second-generation biofuels, enzymatic catalysis is required to convert cellulose from lignocellulosic biomass into fermentable sugars. β-Glucosidases finalize the process by hydrolyzing cellobiose into glucose, so the efficiency of cellulose hydrolysis largely depends on the quantity and quality of these enzymes used during saccharification. Accordingly, to reduce biofuel production costs, new microbial strains are needed that can produce highly efficient enzymes on a large scale. RESULTS We heterologously expressed the fungal β-glucosidase D2-BGL from a Taiwanese indigenous fungus Chaetomella raphigera in Pichia pastoris for constitutive production by fermentation. Recombinant D2-BGL presented significantly higher substrate affinity than the commercial β-glucosidase Novozyme 188 (N188; K m = 0.2 vs 2.14 mM for p-nitrophenyl β-d-glucopyranoside and 0.96 vs 2.38 mM for cellobiose). When combined with RUT-C30 cellulases, it hydrolyzed acid-pretreated lignocellulosic biomasses more efficiently than the commercial cellulase mixture CTec3. The extent of conversion from cellulose to glucose was 83% for sugarcane bagasse and 63% for rice straws. Compared to N188, use of D2-BGL halved the time necessary to produce maximal levels of ethanol by a semi-simultaneous saccharification and fermentation process. We upscaled production of recombinant D2-BGL to 33.6 U/mL within 15 days using a 1-ton bioreactor. Crystal structure analysis revealed that D2-BGL belongs to glycoside hydrolase (GH) family 3. Removing the N-glycosylation N68 or O-glycosylation T431 residues by site-directed mutagenesis negatively affected enzyme production in P. pastoris. The F256 substrate-binding residue in D2-BGL is located in a shorter loop surrounding the active site pocket relative to that of Aspergillus β-glucosidases, and this short loop is responsible for its high substrate affinity toward cellobiose. CONCLUSIONS D2-BGL is an efficient supplement for lignocellulosic biomass saccharification, and we upscaled production of this enzyme using a 1-ton bioreactor. Enzyme production could be further improved using optimized fermentation, which could reduce biofuel production costs. Our structure analysis of D2-BGL offers new insights into GH3 β-glucosidases, which will be useful for strain improvements via a structure-based mutagenesis approach.
Collapse
Affiliation(s)
- Mu-Rong Kao
- Molecular and Cell Biology, Taiwan International Graduate Program, Academia Sinica and National Defense Medical Center, Taipei, Taiwan, ROC
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan, ROC
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan, ROC
| | - Hsion-Wen Kuo
- Department of Environmental Science and Engineering, Tunghai University, Taichung, Taiwan, ROC
| | - Cheng-Chung Lee
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan, ROC
| | - Kuan-Ying Huang
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan, ROC
| | - Ting-Yen Huang
- Department of Bioengineering, Tatung University, Taipei, Taiwan, ROC
| | - Chen-Wei Li
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan, ROC
| | - C. Will Chen
- Department of Bioengineering, Tatung University, Taipei, Taiwan, ROC
| | | | - Su-May Yu
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan, ROC
- Biotechnology Center, National Chung Hsing University, Taichung, Taiwan, ROC
| | - Tuan-Hua David Ho
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan, ROC
- Biotechnology Center, National Chung Hsing University, Taichung, Taiwan, ROC
| |
Collapse
|
28
|
Karkehabadi S, Hansson H, Mikkelsen NE, Kim S, Kaper T, Sandgren M, Gudmundsson M. Structural studies of a glycoside hydrolase family 3 β-glucosidase from the model fungus Neurospora crassa. Acta Crystallogr F Struct Biol Commun 2018; 74:787-796. [PMID: 30511673 PMCID: PMC6277957 DOI: 10.1107/s2053230x18015662] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Accepted: 11/05/2018] [Indexed: 11/29/2022] Open
Abstract
The glycoside hydrolase family 3 (GH3) β-glucosidases are a structurally diverse family of enzymes. Cel3A from Neurospora crassa (NcCel3A) belongs to a subfamily of key enzymes that are crucial for industrial biomass degradation. β-Glucosidases hydrolyse the β-1,4 bond at the nonreducing end of cellodextrins. The hydrolysis of cellobiose is of special importance as its accumulation inhibits other cellulases acting on crystalline cellulose. Here, the crystal structure of the biologically relevant dimeric form of NcCel3A is reported. The structure has been refined to 2.25 Å resolution, with an Rcryst and Rfree of 0.18 and 0.22, respectively. NcCel3A is an extensively N-glycosylated glycoprotein that shares 46% sequence identity with Hypocrea jecorina Cel3A, the structure of which has recently been published, and 61% sequence identity with the thermophilic β-glucosidase from Rasamsonia emersonii. NcCel3A is a three-domain protein with a number of extended loops that deepen the active-site cleft of the enzyme. These structures characterize this subfamily of GH3 β-glucosidases and account for the high cellobiose specificity of this subfamily.
Collapse
Affiliation(s)
- Saeid Karkehabadi
- Department of Molecular Sciences, Swedish University of Agricultural Sciences, PO Box 7015, SE-750 07 Uppsala, Sweden
| | - Henrik Hansson
- Department of Molecular Sciences, Swedish University of Agricultural Sciences, PO Box 7015, SE-750 07 Uppsala, Sweden
| | - Nils Egil Mikkelsen
- Department of Molecular Sciences, Swedish University of Agricultural Sciences, PO Box 7015, SE-750 07 Uppsala, Sweden
| | - Steve Kim
- DuPont Industrial Biosciences, 925 Page Mill Road, Palo Alto, CA 94304, USA
| | - Thijs Kaper
- DuPont Industrial Biosciences, 925 Page Mill Road, Palo Alto, CA 94304, USA
| | - Mats Sandgren
- Department of Molecular Sciences, Swedish University of Agricultural Sciences, PO Box 7015, SE-750 07 Uppsala, Sweden
| | - Mikael Gudmundsson
- Department of Molecular Sciences, Swedish University of Agricultural Sciences, PO Box 7015, SE-750 07 Uppsala, Sweden
| |
Collapse
|
29
|
Meng QS, Liu CG, Zhao XQ, Bai FW. Engineering Trichoderma reesei Rut-C30 with the overexpression of egl1 at the ace1 locus to relieve repression on cellulase production and to adjust the ratio of cellulolytic enzymes for more efficient hydrolysis of lignocellulosic biomass. J Biotechnol 2018; 285:56-63. [DOI: 10.1016/j.jbiotec.2018.09.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Revised: 08/06/2018] [Accepted: 09/03/2018] [Indexed: 01/25/2023]
|
30
|
Geronimo I, Payne CM, Sandgren M. Hydrolysis and Transglycosylation Transition States of Glycoside Hydrolase Family 3 β-Glucosidases Differ in Charge and Puckering Conformation. J Phys Chem B 2018; 122:9452-9459. [DOI: 10.1021/acs.jpcb.8b07118] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Inacrist Geronimo
- Department of Molecular Sciences, Swedish University of Agricultural Sciences, Box 7015, 750 07 Uppsala, Sweden
| | - Christina M. Payne
- Department of Chemical and Materials Engineering, University of Kentucky, Lexington, Kentucky 40506-0046, United States
| | - Mats Sandgren
- Department of Molecular Sciences, Swedish University of Agricultural Sciences, Box 7015, 750 07 Uppsala, Sweden
| |
Collapse
|
31
|
Harvey DJ. Analysis of carbohydrates and glycoconjugates by matrix-assisted laser desorption/ionization mass spectrometry: An update for 2013-2014. MASS SPECTROMETRY REVIEWS 2018; 37:353-491. [PMID: 29687922 DOI: 10.1002/mas.21530] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Accepted: 11/29/2016] [Indexed: 06/08/2023]
Abstract
This review is the eighth update of the original article published in 1999 on the application of Matrix-assisted laser desorption/ionization mass spectrometry (MALDI) mass spectrometry to the analysis of carbohydrates and glycoconjugates and brings coverage of the literature to the end of 2014. Topics covered in the first part of the review include general aspects such as theory of the MALDI process, matrices, derivatization, MALDI imaging, fragmentation, and arrays. The second part of the review is devoted to applications to various structural types such as oligo- and poly- saccharides, glycoproteins, glycolipids, glycosides, and biopharmaceuticals. Much of this material is presented in tabular form. The third part of the review covers medical and industrial applications of the technique, studies of enzyme reactions, and applications to chemical synthesis. © 2018 Wiley Periodicals, Inc. Mass Spec Rev 37:353-491, 2018.
Collapse
Affiliation(s)
- David J Harvey
- Target Discovery Institute, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford, OX3 7FZ, United Kingdom
| |
Collapse
|
32
|
Molecular Mechanism by which Prominent Human Gut Bacteroidetes Utilize Mixed-Linkage Beta-Glucans, Major Health-Promoting Cereal Polysaccharides. Cell Rep 2018; 21:417-430. [PMID: 29020628 DOI: 10.1016/j.celrep.2017.09.049] [Citation(s) in RCA: 88] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Revised: 08/30/2017] [Accepted: 09/14/2017] [Indexed: 12/18/2022] Open
Abstract
Microbial utilization of complex polysaccharides is a major driving force in shaping the composition of the human gut microbiota. There is a growing appreciation that finely tuned polysaccharide utilization loci enable ubiquitous gut Bacteroidetes to thrive on the plethora of complex polysaccharides that constitute "dietary fiber." Mixed-linkage β(1,3)/β(1,4)-glucans (MLGs) are a key family of plant cell wall polysaccharides with recognized health benefits but whose mechanism of utilization has remained unclear. Here, we provide molecular insight into the function of an archetypal MLG utilization locus (MLGUL) through a combination of biochemistry, enzymology, structural biology, and microbiology. Comparative genomics coupled with growth studies demonstrated further that syntenic MLGULs serve as genetic markers for MLG catabolism across commensal gut bacteria. In turn, we surveyed human gut metagenomes to reveal that MLGULs are ubiquitous in human populations globally, which underscores the importance of gut microbial metabolism of MLG as a common cereal polysaccharide.
Collapse
|
33
|
Structural and biochemical characterization of a GH3 β-glucosidase from the probiotic bacteria Bifidobacterium adolescentis. Biochimie 2018; 148:107-115. [DOI: 10.1016/j.biochi.2018.03.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 03/13/2018] [Indexed: 11/20/2022]
|
34
|
Structural and functional insights of β-glucosidases identified from the genome of Aspergillus fumigatus. J Mol Struct 2018. [DOI: 10.1016/j.molstruc.2017.11.078] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
35
|
Geronimo I, Payne CM, Sandgren M. The role of catalytic residue pKa on the hydrolysis/transglycosylation partition in family 3 β-glucosidases. Org Biomol Chem 2018; 16:316-324. [DOI: 10.1039/c7ob02558k] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The catalytic acid/base residue (E441) pKa, as modulated by its electrostatic environment, has potential impact on the hydrolysis/transglycosylation partition in β-glucosidases.
Collapse
Affiliation(s)
- Inacrist Geronimo
- Department of Molecular Sciences
- Swedish University of Agricultural Sciences
- 750 07 Uppsala
- Sweden
| | - Christina M. Payne
- Department of Chemical and Materials Engineering
- University of Kentucky
- Lexington
- USA
| | - Mats Sandgren
- Department of Molecular Sciences
- Swedish University of Agricultural Sciences
- 750 07 Uppsala
- Sweden
| |
Collapse
|
36
|
Hansson H, Karkehabadi S, Mikkelsen N, Douglas NR, Kim S, Lam A, Kaper T, Kelemen B, Meier KK, Jones SM, Solomon EI, Sandgren M. High-resolution structure of a lytic polysaccharide monooxygenase from Hypocrea jecorina reveals a predicted linker as an integral part of the catalytic domain. J Biol Chem 2017; 292:19099-19109. [PMID: 28900033 DOI: 10.1074/jbc.m117.799767] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Revised: 08/29/2017] [Indexed: 12/17/2022] Open
Abstract
For decades, the enzymes of the fungus Hypocrea jecorina have served as a model system for the breakdown of cellulose. Three-dimensional structures for almost all H. jecorina cellulose-degrading enzymes are available, except for HjLPMO9A, belonging to the AA9 family of lytic polysaccharide monooxygenases (LPMOs). These enzymes enhance the hydrolytic activity of cellulases and are essential for cost-efficient conversion of lignocellulosic biomass. Here, using structural and spectroscopic analyses, we found that native HjLPMO9A contains a catalytic domain and a family-1 carbohydrate-binding module (CBM1) connected via a linker sequence. A C terminally truncated variant of HjLPMO9A containing 21 residues of the predicted linker was expressed at levels sufficient for analysis. Here, using structural, spectroscopic, and biochemical analyses, we found that this truncated variant exhibited reduced binding to and activity on cellulose compared with the full-length enzyme. Importantly, a 0.95-Å resolution X-ray structure of truncated HjLPMO9A revealed that the linker forms an integral part of the catalytic domain structure, covering a hydrophobic patch on the catalytic AA9 module. We noted that the oxidized catalytic center contains a Cu(II) coordinated by two His ligands, one of which has a His-brace in which the His-1 terminal amine group also coordinates to a copper. The final equatorial position of the Cu(II) is occupied by a water-derived ligand. The spectroscopic characteristics of the truncated variant were not measurably different from those of full-length HjLPMO9A, indicating that the presence of the CBM1 module increases the affinity of HjLPMO9A for cellulose binding, but does not affect the active site.
Collapse
Affiliation(s)
- Henrik Hansson
- From the Department of Chemistry and Biotechnology, Swedish University of Agricultural Sciences, P.O. Box 7015, SE-750 07 Uppsala, Sweden
| | - Saeid Karkehabadi
- From the Department of Chemistry and Biotechnology, Swedish University of Agricultural Sciences, P.O. Box 7015, SE-750 07 Uppsala, Sweden
| | - Nils Mikkelsen
- From the Department of Chemistry and Biotechnology, Swedish University of Agricultural Sciences, P.O. Box 7015, SE-750 07 Uppsala, Sweden
| | | | - Steve Kim
- DuPont Industrial Biosciences, Palo Alto, California 94304, and
| | - Anna Lam
- DuPont Industrial Biosciences, Palo Alto, California 94304, and
| | - Thijs Kaper
- DuPont Industrial Biosciences, Palo Alto, California 94304, and
| | - Brad Kelemen
- DuPont Industrial Biosciences, Palo Alto, California 94304, and
| | - Katlyn K Meier
- the Department of Chemistry, Stanford University, Stanford, California 94305
| | - Stephen M Jones
- the Department of Chemistry, Stanford University, Stanford, California 94305
| | - Edward I Solomon
- the Department of Chemistry, Stanford University, Stanford, California 94305
| | - Mats Sandgren
- From the Department of Chemistry and Biotechnology, Swedish University of Agricultural Sciences, P.O. Box 7015, SE-750 07 Uppsala, Sweden,
| |
Collapse
|
37
|
Inactivation kinetics and conformation change of Hypocrea orientalis β-glucosidase with guanidine hydrochloride. J Biosci Bioeng 2017; 124:143-149. [DOI: 10.1016/j.jbiosc.2017.03.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2016] [Accepted: 03/08/2017] [Indexed: 01/05/2023]
|
38
|
Synergies in coupled hydrolysis and fermentation of cellulose using a Trichoderma reesei enzyme preparation and a recombinant Saccharomyces cerevisiae strain. World J Microbiol Biotechnol 2017; 33:140. [DOI: 10.1007/s11274-017-2308-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Accepted: 06/01/2017] [Indexed: 11/27/2022]
|
39
|
Cheng P, Liu B, Su Y, Hu Y, Hong Y, Yi X, Chen L, Su S, Chu JSC, Chen N, Xiong X. Genomics insights into different cellobiose hydrolysis activities in two Trichoderma hamatum strains. Microb Cell Fact 2017; 16:63. [PMID: 28420406 PMCID: PMC5395790 DOI: 10.1186/s12934-017-0680-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Accepted: 04/09/2017] [Indexed: 11/13/2022] Open
Abstract
Background Efficient biomass bioconversion is a promising solution to alternative energy resources and environmental issues associated with lignocellulosic wastes. The Trichoderma species of cellulolytic fungi have strong cellulose-degrading capability, and their cellulase systems have been extensively studied. Currently, a major limitation of Trichoderma strains is their low production of β-glucosidases. Results We isolated two Trichoderma hamatum strains YYH13 and YYH16 with drastically different cellulose degrading efficiencies. YYH13 has higher cellobiose-hydrolyzing efficiency. To understand mechanisms underlying such differences, we sequenced the genomes of YYH13 and YYH16, which are essentially identical (38.93 and 38.92 Mb, respectively) and are similar to that of the T. hamatum strain GD12. Using GeneMark-ES, we annotated 11,316 and 11,755 protein-coding genes in YYH13 and YYH16, respectively. Comparative analysis identified 13 functionally important genes in YYH13 under positive selection. Through examining orthologous relationships, we identified 172,655, and 320 genome-specific genes in YYH13, YYH16, and GD12, respectively. We found 15 protease families that show differences between YYH13 and YYH16. Enzymatic tests showed that exoglucanase, endoglucanase, and β-glucosidase activities were higher in YYH13 than YYH16. Additionally, YYH13 contains 10 families of carbohydrate-active enzymes, including GH1, GH3, GH18, GH35, and GH55 families of chitinases, glucosidases, galactosidases, and glucanases, which are subject to stronger positive selection pressure. Furthermore, we found that the β-glucosidase gene (YYH1311079) and pGEX-KG/YYH1311079 bacterial expression vector may provide valuable insight for designing β-glucosidase with higher cellobiose-hydrolyzing efficiencies. Conclusions This study suggests that the YYH13 strain of T. hamatum has the potential to serve as a model organism for producing cellulase because of its strong ability to efficiently degrade cellulosic biomass. The genome sequences of YYH13 and YYH16 represents a valuable resource for studying efficient production of biofuels. Electronic supplementary material The online version of this article (doi:10.1186/s12934-017-0680-2) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Peng Cheng
- Hunan Provincial Key Laboratory of Phytohormones and Growth Development, Hunan Provincial Key Laboratory for Crop Germplasm Innovation and Utilization, Hunan Agricultural University, Changsha, 410128, China. .,National Center for Citrus Improvement, Hunan Agricultural University, Changsha, 410128, China.
| | - Bo Liu
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Yi Su
- Hunan Provincial Key Laboratory of Phytohormones and Growth Development, Hunan Provincial Key Laboratory for Crop Germplasm Innovation and Utilization, Hunan Agricultural University, Changsha, 410128, China
| | - Yao Hu
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Yahui Hong
- Hunan Provincial Key Laboratory of Phytohormones and Growth Development, Hunan Provincial Key Laboratory for Crop Germplasm Innovation and Utilization, Hunan Agricultural University, Changsha, 410128, China
| | - Xinxin Yi
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Lei Chen
- Hunan Provincial Key Laboratory of Phytohormones and Growth Development, Hunan Provincial Key Laboratory for Crop Germplasm Innovation and Utilization, Hunan Agricultural University, Changsha, 410128, China
| | - Shengying Su
- Hunan Provincial Key Laboratory of Phytohormones and Growth Development, Hunan Provincial Key Laboratory for Crop Germplasm Innovation and Utilization, Hunan Agricultural University, Changsha, 410128, China
| | - Jeffrey S C Chu
- Wuhan Frasergen Bioinformatics Co. Ltd, 666 Gaoxin Road, East Lake High-tech Zone, Wuahn, 430075, China.
| | - Nansheng Chen
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China. .,Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, V5A 5S6, Canada.
| | - Xingyao Xiong
- Hunan Provincial Key Laboratory of Phytohormones and Growth Development, Hunan Provincial Key Laboratory for Crop Germplasm Innovation and Utilization, Hunan Agricultural University, Changsha, 410128, China
| |
Collapse
|
40
|
Méndez-Líter JA, Gil-Muñoz J, Nieto-Domínguez M, Barriuso J, de Eugenio LI, Martínez MJ. A novel, highly efficient β-glucosidase with a cellulose-binding domain: characterization and properties of native and recombinant proteins. BIOTECHNOLOGY FOR BIOFUELS 2017; 10:256. [PMID: 29142591 PMCID: PMC5674860 DOI: 10.1186/s13068-017-0946-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Accepted: 10/26/2017] [Indexed: 05/07/2023]
Abstract
BACKGROUND Cellulose, the most abundant biopolymer on earth, is an alternative for fossil fuels as a renewable feedstock for the production of second-generation biofuels and other chemicals. The discovery of novel, highly efficient β-glucosidases remains as one of the major bottlenecks for cellulose degradation. In this context, the ascomycete Talaromyces amestolkiae, isolated from cereal samples, has been studied as a promising source for these enzymes. RESULTS BGL-2 is the major β-glucosidase secreted by this fungus in the presence of cellulosic inductors. This enzyme possesses a CBD (Cellulose Binding Domain), an unusual feature among this type of proteins. Besides, when growing on cellulose, the fungus produced two different bgl-2 mRNAs that were cloned and expressed in Pichia pastoris. A complete recombinant protein (BGL-2*) and its truncated form, lacking CBD (BGL-2T*), have been purified, characterized and compared with the native enzyme (BGL-2). The three BGL-2 forms studied are highly stable in a wide pH range, but BGL-2T* showed an improved thermal stability at 50 °C after 72 h. Using p-nitrophenyl-β-d-glucopyranoside as a substrate, the steady-state kinetic characterization of the three proteins showed a similar Km and kcat for BGL-2 and BGL-2*, while the truncated protein displayed a threefold higher value for kcat . All tested BGL-2 enzymes were as well highly efficient using cellobiose and other short oligosaccharides as a substrate. In view of biotechnological applications, the recombinant T. amestolkiae enzymes in saccharification of brewers' spent grain were studied, being comparable to commercial β-glucosidase cocktails. CONCLUSION A new β-glucosidase from T. amestolkiae has been studied. The enzyme, containing a functional CBD, has been expressed in P. pastoris. The comparative analyses of the native protein and its recombinant forms, with and without CBD, suggest that they could be suitable tools for valorization of lignocellulosic biomass.
Collapse
Affiliation(s)
- J. A. Méndez-Líter
- Department of Environmental Biology, Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu 9, 28040 Madrid, Spain
| | - J. Gil-Muñoz
- Department of Environmental Biology, Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu 9, 28040 Madrid, Spain
| | - M. Nieto-Domínguez
- Department of Environmental Biology, Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu 9, 28040 Madrid, Spain
| | - J. Barriuso
- Department of Environmental Biology, Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu 9, 28040 Madrid, Spain
| | - L. I. de Eugenio
- Department of Environmental Biology, Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu 9, 28040 Madrid, Spain
| | - M. J. Martínez
- Department of Environmental Biology, Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu 9, 28040 Madrid, Spain
| |
Collapse
|
41
|
Ramírez-Escudero M, Del Pozo MV, Marín-Navarro J, González B, Golyshin PN, Polaina J, Ferrer M, Sanz-Aparicio J. Structural and Functional Characterization of a Ruminal β-Glycosidase Defines a Novel Subfamily of Glycoside Hydrolase Family 3 with Permuted Domain Topology. J Biol Chem 2016; 291:24200-24214. [PMID: 27679487 PMCID: PMC5104943 DOI: 10.1074/jbc.m116.747527] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Revised: 09/16/2016] [Indexed: 01/01/2023] Open
Abstract
Metagenomics has opened up a vast pool of genes for putative, yet uncharacterized, enzymes. It widens our knowledge on the enzyme diversity world and discloses new families for which a clear classification is still needed, as is exemplified by glycoside hydrolase family-3 (GH3) proteins. Herein, we describe a GH3 enzyme (GlyA1) from resident microbial communities in strained ruminal fluid. The enzyme is a β-glucosidase/β-xylosidase that also shows β-galactosidase, β-fucosidase, α-arabinofuranosidase, and α-arabinopyranosidase activities. Short cello- and xylo-oligosaccharides, sophorose and gentibiose, are among the preferred substrates, with the large polysaccharide lichenan also being hydrolyzed by GlyA1. The determination of the crystal structure of the enzyme in combination with deletion and site-directed mutagenesis allowed identification of its unusual domain composition and the active site architecture. Complexes of GlyA1 with glucose, galactose, and xylose allowed picturing the catalytic pocket and illustrated the molecular basis of the substrate specificity. A hydrophobic platform defined by residues Trp-711 and Trp-106, located in a highly mobile loop, appears able to allocate differently β-linked bioses. GlyA1 includes an additional C-terminal domain previously unobserved in GH3 members, but crystallization of the full-length enzyme was unsuccessful. Therefore, small angle x-ray experiments have been performed to investigate the molecular flexibility and overall putative shape. This study provided evidence that GlyA1 defines a new subfamily of GH3 proteins with a novel permuted domain topology. Phylogenetic analysis indicates that this topology is associated with microbes inhabiting the digestive tracts of ruminants and other animals, feeding on chemically diverse plant polymeric materials.
Collapse
Affiliation(s)
- Mercedes Ramírez-Escudero
- From the Department of Crystallography and Structural Biology, Institute of Physical-Chemistry "Rocasolano," Consejo Superior de Investigaciones Científicas, Serrano 119, 28006 Madrid, Spain
| | - Mercedes V Del Pozo
- the Institute of Catalysis and Petrochemistry, Consejo Superior de Investigaciones Científicas, Marie Curie 2, Cantoblanco, 28049 Madrid, Spain
| | - Julia Marín-Navarro
- the Institute of Agrochemistry and Food Technology, Consejo Superior de Investigaciones Científicas, Carrer Catedràtic Agustín Escardino Benlloch 7, 46980 Paterna, Valencia, Spain
| | - Beatriz González
- From the Department of Crystallography and Structural Biology, Institute of Physical-Chemistry "Rocasolano," Consejo Superior de Investigaciones Científicas, Serrano 119, 28006 Madrid, Spain
| | - Peter N Golyshin
- the School of Biological Sciences, Bangor University, LL57 2UW Gwynedd, United Kingdom, and.,the Immanuel Kant Baltic Federal University, 236040 Kaliningrad, Russia
| | - Julio Polaina
- the Institute of Agrochemistry and Food Technology, Consejo Superior de Investigaciones Científicas, Carrer Catedràtic Agustín Escardino Benlloch 7, 46980 Paterna, Valencia, Spain
| | - Manuel Ferrer
- the Institute of Catalysis and Petrochemistry, Consejo Superior de Investigaciones Científicas, Marie Curie 2, Cantoblanco, 28049 Madrid, Spain,
| | - Julia Sanz-Aparicio
- From the Department of Crystallography and Structural Biology, Institute of Physical-Chemistry "Rocasolano," Consejo Superior de Investigaciones Científicas, Serrano 119, 28006 Madrid, Spain,
| |
Collapse
|
42
|
Li C, Lin F, Li Y, Wei W, Wang H, Qin L, Zhou Z, Li B, Wu F, Chen Z. A β-glucosidase hyper-production Trichoderma reesei mutant reveals a potential role of cel3D in cellulase production. Microb Cell Fact 2016; 15:151. [PMID: 27585813 PMCID: PMC5009570 DOI: 10.1186/s12934-016-0550-3] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Accepted: 08/23/2016] [Indexed: 01/05/2023] Open
Abstract
Background The conversion of cellulose by cellulase to fermentable sugars for biomass-based products such as cellulosic biofuels, biobased fine chemicals and medicines is an environment-friendly and sustainable process, making wastes profitable and bringing economic benefits. Trichoderma reesei is the well-known major workhorse for cellulase production in industry, but the low β-glucosidase activity in T. reesei cellulase leads to inefficiency in biomass degradation and limits its industrial application. Thus, there are ongoing interests in research to develop methods to overcome this insufficiency. Moreover, although β-glucosidases have been demonstrated to influence cellulase production and participate in the regulation of cellulase production, the underlying mechanism remains unclear. Results The T. reesei recombinant strain TRB1 was constructed from T. reesei RUT-C30 by the T-DNA-based mutagenesis. Compared to RUT-C30, TRB1 displays a significant enhancement of extracellular β-glucosidase (BGL1) activity with 17-fold increase, a moderate increase of both the endoglucanase (EG) activity and the exoglucanase (CBH) activity, a minor improvement of the total filter paper activity, and a faster cellulase induction. This superiority of TRB1 over RUT-C30 is independent on carbon sources and improves the saccharification ability of TRB1 cellulase on pretreated corn stover. Furthermore, TRB1 shows better resistance to carbon catabolite repression than RUT-C30. Secretome characterization of TRB1 shows that the amount of CBH, EG and BGL in the supernatant of T. reesei TRB1 was indeed increased along with the enhanced activities of these three enzymes. Surprisingly, qRT-PCR and gene cloning showed that in TRB1 β-glucosidase cel3D was mutated through the random insertion by AMT and was not expressed. Conclusions The T. reesei recombinant strain TRB1 constructed in this study is more desirable for industrial application than the parental strain RUT-C30, showing extracellular β-glucosidase hyper production, high cellulase production within a shorter time and a better resistance to carbon catabolite repression. Disruption of β-glucosidase cel3D in TRB1 was identified, which might contribute to the superiority of TRB1 over RUT-C30 and might play a role in the cellulase production. These results laid a foundation for future investigations to further improve cellulase enzymatic efficiency and reduce cost for T. reesei cellulase production. Electronic supplementary material The online version of this article (doi:10.1186/s12934-016-0550-3) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Chengcheng Li
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, 210096, China
| | - Fengming Lin
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, 210096, China. .,, 37 Jinxianghe Road, Xuanwu District, Nanjing, 210008, Jiangsu Province, China.
| | - Yizhen Li
- State Key Laboratory of Medical Genomics, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Wei Wei
- Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200032, China
| | - Hongyin Wang
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, 210096, China
| | - Lei Qin
- Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Weijin Road 92, Nankai District, 300072, People's Republic of China
| | - Zhihua Zhou
- Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200032, China
| | - Bingzhi Li
- Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Weijin Road 92, Nankai District, 300072, People's Republic of China
| | - Fugen Wu
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, 210096, China
| | - Zhan Chen
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, MI, 48109, USA
| |
Collapse
|
43
|
Baba Y, Sumitani JI, Tanaka K, Tani S, Kawaguchi T. Site-saturation mutagenesis for β-glucosidase 1 from Aspergillus aculeatus to accelerate the saccharification of alkaline-pretreated bagasse. Appl Microbiol Biotechnol 2016; 100:10495-10507. [DOI: 10.1007/s00253-016-7726-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Revised: 06/30/2016] [Accepted: 07/04/2016] [Indexed: 01/05/2023]
|
44
|
Hemsworth GR, Thompson AJ, Stepper J, Sobala ŁF, Coyle T, Larsbrink J, Spadiut O, Goddard-Borger ED, Stubbs KA, Brumer H, Davies GJ. Structural dissection of a complex Bacteroides ovatus gene locus conferring xyloglucan metabolism in the human gut. Open Biol 2016; 6:160142. [PMID: 27466444 PMCID: PMC4967831 DOI: 10.1098/rsob.160142] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Accepted: 07/01/2016] [Indexed: 12/22/2022] Open
Abstract
The human gastrointestinal tract harbours myriad bacterial species, collectively termed the microbiota, that strongly influence human health. Symbiotic members of our microbiota play a pivotal role in the digestion of complex carbohydrates that are otherwise recalcitrant to assimilation. Indeed, the intrinsic human polysaccharide-degrading enzyme repertoire is limited to various starch-based substrates; more complex polysaccharides demand microbial degradation. Select Bacteroidetes are responsible for the degradation of the ubiquitous vegetable xyloglucans (XyGs), through the concerted action of cohorts of enzymes and glycan-binding proteins encoded by specific xyloglucan utilization loci (XyGULs). Extending recent (meta)genomic, transcriptomic and biochemical analyses, significant questions remain regarding the structural biology of the molecular machinery required for XyG saccharification. Here, we reveal the three-dimensional structures of an α-xylosidase, a β-glucosidase, and two α-l-arabinofuranosidases from the Bacteroides ovatus XyGUL. Aided by bespoke ligand synthesis, our analyses highlight key adaptations in these enzymes that confer individual specificity for xyloglucan side chains and dictate concerted, stepwise disassembly of xyloglucan oligosaccharides. In harness with our recent structural characterization of the vanguard endo-xyloglucanse and cell-surface glycan-binding proteins, the present analysis provides a near-complete structural view of xyloglucan recognition and catalysis by XyGUL proteins.
Collapse
Affiliation(s)
- Glyn R Hemsworth
- Department of Chemistry, York Structural Biology Laboratory, The University of York, Heslington, York YO10 5DD, UK
| | - Andrew J Thompson
- Department of Chemistry, York Structural Biology Laboratory, The University of York, Heslington, York YO10 5DD, UK
| | - Judith Stepper
- Department of Chemistry, York Structural Biology Laboratory, The University of York, Heslington, York YO10 5DD, UK
| | - Łukasz F Sobala
- Department of Chemistry, York Structural Biology Laboratory, The University of York, Heslington, York YO10 5DD, UK
| | - Travis Coyle
- School of Chemistry and Biochemistry, The University of Western Australia, Crawley, Western Australia 6009, Australia
| | - Johan Larsbrink
- Division of Glycoscience, School of Biotechnology, Royal Institute of Technology (KTH), AlbaNova University Centre, 106 91 Stockholm, Sweden Michael Smith Laboratories and Department of Chemistry, University of British Columbia, 2185 East Mall, Vancouver, British Columbia, Canada V6T 1Z4
| | - Oliver Spadiut
- Division of Glycoscience, School of Biotechnology, Royal Institute of Technology (KTH), AlbaNova University Centre, 106 91 Stockholm, Sweden Wallenberg Wood Science Center, Royal Institute of Technology (KTH), Teknikringen 56-58, 100 44 Stockholm, Sweden
| | - Ethan D Goddard-Borger
- The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville Victoria 3052, Australia
| | - Keith A Stubbs
- School of Chemistry and Biochemistry, The University of Western Australia, Crawley, Western Australia 6009, Australia
| | - Harry Brumer
- Division of Glycoscience, School of Biotechnology, Royal Institute of Technology (KTH), AlbaNova University Centre, 106 91 Stockholm, Sweden Michael Smith Laboratories and Department of Chemistry, University of British Columbia, 2185 East Mall, Vancouver, British Columbia, Canada V6T 1Z4
| | - Gideon J Davies
- Department of Chemistry, York Structural Biology Laboratory, The University of York, Heslington, York YO10 5DD, UK
| |
Collapse
|
45
|
Gudmundsson M, Hansson H, Karkehabadi S, Larsson A, Stals I, Kim S, Sunux S, Fujdala M, Larenas E, Kaper T, Sandgren M. Structural and functional studies of the glycoside hydrolase family 3 β-glucosidase Cel3A from the moderately thermophilic fungus Rasamsonia emersonii. ACTA CRYSTALLOGRAPHICA SECTION D-STRUCTURAL BIOLOGY 2016; 72:860-70. [PMID: 27377383 PMCID: PMC4932919 DOI: 10.1107/s2059798316008482] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Accepted: 05/25/2016] [Indexed: 12/16/2022]
Abstract
Cel3A from the thermophilic fungus R. emersonii has proven to be more efficient in the hydrolysis of β-glycosidic linkages than Cel3A from H. jecorina. The filamentous fungus Hypocrea jecorina produces a number of cellulases and hemicellulases that act in a concerted fashion on biomass and degrade it into monomeric or oligomeric sugars. β-Glucosidases are involved in the last step of the degradation of cellulosic biomass and hydrolyse the β-glycosidic linkage between two adjacent molecules in dimers and oligomers of glucose. In this study, it is shown that substituting the β-glucosidase from H. jecorina (HjCel3A) with the β-glucosidase Cel3A from the thermophilic fungus Rasamsonia emersonii (ReCel3A) in enzyme mixtures results in increased efficiency in the saccharification of lignocellulosic materials. Biochemical characterization of ReCel3A, heterologously produced in H. jecorina, reveals a preference for disaccharide substrates over longer gluco-oligosaccharides. Crystallographic studies of ReCel3A revealed a highly N-glycosylated three-domain dimeric protein, as has been observed previously for glycoside hydrolase family 3 β-glucosidases. The increased thermal stability and saccharification yield and the superior biochemical characteristics of ReCel3A compared with HjCel3A and mixtures containing HjCel3A make ReCel3A an excellent candidate for addition to enzyme mixtures designed to operate at higher temperatures.
Collapse
Affiliation(s)
- Mikael Gudmundsson
- Department of Chemistry and Biotechnology, Swedish University of Agricultural Sciences, Box 7015, 750 07 Uppsala, Sweden
| | - Henrik Hansson
- Department of Chemistry and Biotechnology, Swedish University of Agricultural Sciences, Box 7015, 750 07 Uppsala, Sweden
| | - Saeid Karkehabadi
- Department of Chemistry and Biotechnology, Swedish University of Agricultural Sciences, Box 7015, 750 07 Uppsala, Sweden
| | - Anna Larsson
- Department of Cell and Molecular Biology, Uppsala University, Box 596, 751 24 Uppsala, Sweden
| | - Ingeborg Stals
- Laboratory for Protein Biochemistry and Biomolecular Engineering, Ghent University, Ledeganckstraat 35, B-9000 Ghent, Belgium
| | - Steve Kim
- DuPont Industrial Biosciences, 925 Page Mill Road, Palo Alto, CA 94304, USA
| | - Sergio Sunux
- DuPont Industrial Biosciences, 925 Page Mill Road, Palo Alto, CA 94304, USA
| | - Meredith Fujdala
- DuPont Industrial Biosciences, 925 Page Mill Road, Palo Alto, CA 94304, USA
| | - Edmund Larenas
- DuPont Industrial Biosciences, 925 Page Mill Road, Palo Alto, CA 94304, USA
| | - Thijs Kaper
- DuPont Industrial Biosciences, 925 Page Mill Road, Palo Alto, CA 94304, USA
| | - Mats Sandgren
- Department of Chemistry and Biotechnology, Swedish University of Agricultural Sciences, Box 7015, 750 07 Uppsala, Sweden
| |
Collapse
|
46
|
Xia W, Bai Y, Cui Y, Xu X, Qian L, Shi P, Zhang W, Luo H, Zhan X, Yao B. Functional diversity of family 3 β-glucosidases from thermophilic cellulolytic fungus Humicola insolens Y1. Sci Rep 2016; 6:27062. [PMID: 27271847 PMCID: PMC4897640 DOI: 10.1038/srep27062] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Accepted: 05/09/2016] [Indexed: 11/09/2022] Open
Abstract
The fungus Humicola insolens is one of the most powerful decomposers of crystalline cellulose. However, studies on the β-glucosidases from this fungus remain insufficient, especially on glycosyl hydrolase family 3 enzymes. In the present study, we analyzed the functional diversity of three distant family 3 β-glucosidases from Humicola insolens strain Y1, which belonged to different evolutionary clades, by heterogeneous expression in Pichia pastoris strain GS115. The recombinant enzymes shared similar enzymatic properties including thermophilic and neutral optima (50-60 °C and pH 5.5-6.0) and high glucose tolerance, but differed in substrate specificities and kinetics. HiBgl3B was solely active towards aryl β-glucosides while HiBgl3A and HiBgl3C showed broad substrate specificities including both disaccharides and aryl β-glucosides. Of the three enzymes, HiBgl3C exhibited the highest specific activity (158.8 U/mg on pNPG and 56.4 U/mg on cellobiose) and catalytic efficiency and had the capacity to promote cellulose degradation. Substitutions of three key residues Ile48, Ile278 and Thr484 of HiBgl3B to the corresponding residues of HiBgl3A conferred the enzyme activity towards sophorose, and vice versa. This study reveals the functional diversity of GH3 β-glucosidases as well as the key residues in recognizing +1 subsite of different substrates.
Collapse
Affiliation(s)
- Wei Xia
- College of Animal Science, Zhejiang University, Hangzhou 310058, People's Republic of China.,Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, People's Republic of China
| | - Yingguo Bai
- Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, People's Republic of China
| | - Ying Cui
- Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, People's Republic of China
| | - Xinxin Xu
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, People's Republic of China
| | - Lichun Qian
- College of Animal Science, Zhejiang University, Hangzhou 310058, People's Republic of China
| | - Pengjun Shi
- Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, People's Republic of China
| | - Wei Zhang
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, People's Republic of China
| | - Huiying Luo
- Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, People's Republic of China
| | - Xiuan Zhan
- College of Animal Science, Zhejiang University, Hangzhou 310058, People's Republic of China
| | - Bin Yao
- Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, People's Republic of China
| |
Collapse
|
47
|
Valadares F, Gonçalves TA, Gonçalves DSPO, Segato F, Romanel E, Milagres AMF, Squina FM, Ferraz A. Exploring glycoside hydrolases and accessory proteins from wood decay fungi to enhance sugarcane bagasse saccharification. BIOTECHNOLOGY FOR BIOFUELS 2016; 9:110. [PMID: 27222665 PMCID: PMC4877993 DOI: 10.1186/s13068-016-0525-y] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Accepted: 05/10/2016] [Indexed: 05/25/2023]
Abstract
BACKGROUND Glycoside hydrolases (GHs) and accessory proteins are key components for efficient and cost-effective enzymatic hydrolysis of polysaccharides in modern, biochemically based biorefineries. Currently, commercialized GHs and accessory proteins are produced by ascomycetes. However, the role of wood decay basidiomycetes proteins in biomass saccharification has not been extensively pursued. Wood decay fungi degrade polysaccharides in highly lignified tissues in natural environments, and are a promising enzyme source for improving enzymatic cocktails that are designed for in vitro lignocellulose conversion. RESULTS GHs and accessory proteins were produced by representative brown- and white-rot fungi, Laetiporus sulphureus and Pleurotus ostreatus, respectively. Concentrated protein extracts were then used to amend commercial enzymatic cocktails for saccharification of alkaline-sulfite pretreated sugarcane bagasse. The main enzymatic activities found in the wood decay fungal protein extracts were attributed to endoglucanases, xylanases and β-glucosidases. Cellobiohydrolase (CBH) activities in the L. sulphureus and P. ostreatus extracts were low and nonexistent, respectively. The initial glucan conversion rates were boosted when the wood decay fungal proteins were used to replace half of the enzymes from the commercial cocktails. L. sulphureus proteins increased the glucan conversion levels, with values above those observed for the full load of commercial enzymes. Wood decay fungal proteins also enhanced the xylan conversion efficiency due to their high xylanase activities. Proteomic studies revealed 104 and 45 different proteins in the P. ostreatus and L. sulphureus extracts, respectively. The enhancement of the saccharification of alkaline-pretreated substrates by the modified enzymatic cocktails was attributed to the following protein families: GH5- and GH45-endoglucanases, GH3-β-glucosidases, and GH10-xylanases. CONCLUSIONS The extracellular proteins produced by wood decay fungi provide useful tools to improve commercial enzyme cocktails that are currently used for the saccharification of alkaline-pretreated lignocellulosic substrates. The relevant proteins encompass multiple glycoside hydrolase families, including the GH5- and GH45-endoglucanases, GH3-β-glucosidases, and GH10-xylanases.
Collapse
Affiliation(s)
- Fernanda Valadares
- />Departamento de Biotecnologia, Escola de Engenharia de Lorena, Universidade de São Paulo, Lorena, SP 12602-810 Brazil
| | - Thiago A. Gonçalves
- />Laboratório Nacional de Ciência & Tecnolologia do Bioetanol (CTBE), Centro Nacional de Pesquisa em Energia e Materiais (CNPEM), Campinas, SP 13083-970 Brazil
- />Departamento de Bioquímica, Instituto de Biologia (IB), Universidade Estadual de Campinas (UNICAMP), Campinas, SP 13083-862 Brazil
| | - Dayelle S. P. O. Gonçalves
- />Departamento de Biotecnologia, Escola de Engenharia de Lorena, Universidade de São Paulo, Lorena, SP 12602-810 Brazil
| | - Fernando Segato
- />Departamento de Biotecnologia, Escola de Engenharia de Lorena, Universidade de São Paulo, Lorena, SP 12602-810 Brazil
| | - Elisson Romanel
- />Departamento de Biotecnologia, Escola de Engenharia de Lorena, Universidade de São Paulo, Lorena, SP 12602-810 Brazil
| | - Adriane M. F. Milagres
- />Departamento de Biotecnologia, Escola de Engenharia de Lorena, Universidade de São Paulo, Lorena, SP 12602-810 Brazil
| | - Fabio M. Squina
- />Laboratório Nacional de Ciência & Tecnolologia do Bioetanol (CTBE), Centro Nacional de Pesquisa em Energia e Materiais (CNPEM), Campinas, SP 13083-970 Brazil
| | - André Ferraz
- />Departamento de Biotecnologia, Escola de Engenharia de Lorena, Universidade de São Paulo, Lorena, SP 12602-810 Brazil
| |
Collapse
|
48
|
Pei X, Zhao J, Cai P, Sun W, Ren J, Wu Q, Zhang S, Tian C. Heterologous expression of a GH3 β-glucosidase from Neurospora crassa in Pichia pastoris with high purity and its application in the hydrolysis of soybean isoflavone glycosides. Protein Expr Purif 2016; 119:75-84. [PMID: 26596358 DOI: 10.1016/j.pep.2015.11.010] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Revised: 09/30/2015] [Accepted: 11/10/2015] [Indexed: 01/30/2023]
Abstract
Previous studies have shown isoflavone aglycones to have more biological effects than their counterparts, isoflavone glycones. Some β-glucosidases can hydrolyze isoflavone glucosides to release aglycones, and discovery of these has attracted great interest. A glycoside hydrolase (GH) family 3 β-glucosidase (bgl2) gene from Neurospora crassa was heterologously expressed in Pichia pastoris with high purity. The recombinant BGL2 enzyme displayed its highest activity at pH 5.0 and 60 °C, and had its maximum activity against p-nitrophenyl-β-d-glucopyranoside (pNPG) (143.27 ± 4.79 U/mg), followed by cellobiose (74.99 ± 0.78 U/mg), gentiobiose (47.55 ± 0.15 U/mg), p-nitrophenyl-β-d-cellobioside (pNPC) (40.07 ± 0.87 U/mg), cellotriose (12.31 ± 0.36 U/mg) and cellotetraose (9.04 ± 0.14 U/mg). The kinetic parameters of Km and Vmax were 0.21 ± 0.01 mM and 147.93 ± 2.77 μM/mg/min for pNPG. The purified enzyme showed a heightened ability to convert the major soybean isoflavone glycosides (daidzin, genistin and glycitin) into their corresponding aglycone forms (daidzien, genistein and glycitein). With this activity against soybean isoflavone glycosides, BGL2 shows great potential for applications in the food, animal feed, and pharmaceutical industries.
Collapse
Affiliation(s)
- Xue Pei
- College of Plant Sciences, Jilin University, Changchun 130062, China; Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
| | - Junqi Zhao
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
| | - Pengli Cai
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
| | - Wenliang Sun
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
| | - Jie Ren
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
| | - Qiaqing Wu
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
| | - Shihong Zhang
- College of Plant Sciences, Jilin University, Changchun 130062, China
| | - Chaoguang Tian
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China.
| |
Collapse
|
49
|
Nakajima M, Yoshida R, Miyanaga A, Abe K, Takahashi Y, Sugimoto N, Toyoizumi H, Nakai H, Kitaoka M, Taguchi H. Functional and Structural Analysis of a β-Glucosidase Involved in β-1,2-Glucan Metabolism in Listeria innocua. PLoS One 2016; 11:e0148870. [PMID: 26886583 PMCID: PMC4757417 DOI: 10.1371/journal.pone.0148870] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2015] [Accepted: 01/25/2016] [Indexed: 11/18/2022] Open
Abstract
Despite the presence of β-1,2-glucan in nature, few β-1,2-glucan degrading enzymes have been reported to date. Recently, the Lin1839 protein from Listeria innocua was identified as a 1,2-β-oligoglucan phosphorylase. Since the adjacent lin1840 gene in the gene cluster encodes a putative glycoside hydrolase family 3 β-glucosidase, we hypothesized that Lin1840 is also involved in β-1,2-glucan dissimilation. Here we report the functional and structural analysis of Lin1840. A recombinant Lin1840 protein (Lin1840r) showed the highest hydrolytic activity toward sophorose (Glc-β-1,2-Glc) among β-1,2-glucooligosaccharides, suggesting that Lin1840 is a β-glucosidase involved in sophorose degradation. The enzyme also rapidly hydrolyzed laminaribiose (β-1,3), but not cellobiose (β-1,4) or gentiobiose (β-1,6) among β-linked gluco-disaccharides. We determined the crystal structures of Lin1840r in complexes with sophorose and laminaribiose as productive binding forms. In these structures, Arg572 forms many hydrogen bonds with sophorose and laminaribiose at subsite +1, which seems to be a key factor for substrate selectivity. The opposite side of subsite +1 from Arg572 is connected to a large empty space appearing to be subsite +2 for the binding of sophorotriose (Glc-β-1,2-Glc-β-1,2-Glc) in spite of the higher Km value for sophorotriose than that for sophorose. The conformations of sophorose and laminaribiose are almost the same on the Arg572 side but differ on the subsite +2 side that provides no interaction with a substrate. Therefore, Lin1840r is unable to distinguish between sophorose and laminaribiose as substrates. These results provide the first mechanistic insights into β-1,2-glucooligosaccharide recognition by β-glucosidase.
Collapse
Affiliation(s)
- Masahiro Nakajima
- Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, Noda, Chiba, Japan
- * E-mail:
| | - Ryuta Yoshida
- Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, Noda, Chiba, Japan
| | - Akimasa Miyanaga
- Department of Chemistry, Tokyo Institute of Technology, Meguro-ku, Tokyo, Japan
| | - Koichi Abe
- Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, Noda, Chiba, Japan
| | - Yuta Takahashi
- Graduate School of Science & Technology, Niigata University, Nishi-ku, Niigata, Japan
| | - Naohisa Sugimoto
- Graduate School of Science & Technology, Niigata University, Nishi-ku, Niigata, Japan
| | - Hiroyuki Toyoizumi
- Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, Noda, Chiba, Japan
| | - Hiroyuki Nakai
- Graduate School of Science & Technology, Niigata University, Nishi-ku, Niigata, Japan
| | - Motomitsu Kitaoka
- National Food Research Institute, National Agriculture and Food Research Organization, Tsukuba, Ibaraki, Japan
| | - Hayao Taguchi
- Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, Noda, Chiba, Japan
| |
Collapse
|
50
|
Agirre J, Ariza A, Offen WA, Turkenburg JP, Roberts SM, McNicholas S, Harris PV, McBrayer B, Dohnalek J, Cowtan KD, Davies GJ, Wilson KS. Three-dimensional structures of two heavily N-glycosylated Aspergillus sp. family GH3 β-D-glucosidases. Acta Crystallogr D Struct Biol 2016; 72:254-65. [PMID: 26894673 PMCID: PMC4756609 DOI: 10.1107/s2059798315024237] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Accepted: 12/16/2015] [Indexed: 01/25/2023] Open
Abstract
The industrial conversion of cellulosic plant biomass into useful products such as biofuels is a major societal goal. These technologies harness diverse plant degrading enzymes, classical exo- and endo-acting cellulases and, increasingly, cellulose-active lytic polysaccharide monooxygenases, to deconstruct the recalcitrant β-D-linked polysaccharide. A major drawback with this process is that the exo-acting cellobiohydrolases suffer from severe inhibition from their cellobiose product. β-D-Glucosidases are therefore important for liberating glucose from cellobiose and thereby relieving limiting product inhibition. Here, the three-dimensional structures of two industrially important family GH3 β-D-glucosidases from Aspergillus fumigatus and A. oryzae, solved by molecular replacement and refined at 1.95 Å resolution, are reported. Both enzymes, which share 78% sequence identity, display a three-domain structure with the catalytic domain at the interface, as originally shown for barley β-D-glucan exohydrolase, the first three-dimensional structure solved from glycoside hydrolase family GH3. Both enzymes show extensive N-glycosylation, with only a few external sites being truncated to a single GlcNAc molecule. Those glycans N-linked to the core of the structure are identified purely as high-mannose trees, and establish multiple hydrogen bonds between their sugar components and adjacent protein side chains. The extensive glycans pose special problems for crystallographic refinement, and new techniques and protocols were developed especially for this work. These protocols ensured that all of the D-pyranosides in the glycosylation trees were modelled in the preferred minimum-energy (4)C1 chair conformation and should be of general application to refinements of other crystal structures containing O- or N-glycosylation. The Aspergillus GH3 structures, in light of other recent three-dimensional structures, provide insight into fungal β-D-glucosidases and provide a platform on which to inform and inspire new generations of variant enzymes for industrial application.
Collapse
Affiliation(s)
- Jon Agirre
- York Structural Biology Laboratory, Department of Chemistry, The University of York, York YO10 5DD, England
| | - Antonio Ariza
- York Structural Biology Laboratory, Department of Chemistry, The University of York, York YO10 5DD, England
| | - Wendy A. Offen
- York Structural Biology Laboratory, Department of Chemistry, The University of York, York YO10 5DD, England
| | - Johan P. Turkenburg
- York Structural Biology Laboratory, Department of Chemistry, The University of York, York YO10 5DD, England
| | - Shirley M. Roberts
- York Structural Biology Laboratory, Department of Chemistry, The University of York, York YO10 5DD, England
| | - Stuart McNicholas
- York Structural Biology Laboratory, Department of Chemistry, The University of York, York YO10 5DD, England
| | | | | | - Jan Dohnalek
- York Structural Biology Laboratory, Department of Chemistry, The University of York, York YO10 5DD, England
| | - Kevin D. Cowtan
- York Structural Biology Laboratory, Department of Chemistry, The University of York, York YO10 5DD, England
| | - Gideon J. Davies
- York Structural Biology Laboratory, Department of Chemistry, The University of York, York YO10 5DD, England
| | - Keith S. Wilson
- York Structural Biology Laboratory, Department of Chemistry, The University of York, York YO10 5DD, England
| |
Collapse
|