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Suzuki M, Saito A, Kobayashi M, Yokoyama T, Omiya S, Li J, Sugita K, Miki K, Saito JI, Ando A. Crystal structure of the GH-46 subclass III chitosanase from Bacillus circulans MH-K1 in complex with chitotetraose. Biochim Biophys Acta Gen Subj 2024; 1868:130549. [PMID: 38158023 DOI: 10.1016/j.bbagen.2023.130549] [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: 06/22/2023] [Revised: 12/12/2023] [Accepted: 12/21/2023] [Indexed: 01/03/2024]
Abstract
BACKGROUND Chitosanases (EC 3.2.1.132) hydrolyze chitosan which is a polymer of glucosamine (GlcN) linked by β - 1,4 bonds, and show cleavage specificity against partially acetylated chitosan containing N-acetylglucosamine (GlcNAc) residues. Chitosanases' structural underpinnings for cleavage specificity and the conformational switch from open to closed structures are still a mystery. METHODS The GH-46 subclass III chitosanase from Bacillus circulans MH-K1 (MH-K1 chitosanase), which also catalyzes the hydrolysis of GlcN-GlcNAc bonds in addition to GlcN-GlcN, has had its chitotetraose [(GlcN)4]-complexed crystal structure solved at 1.35 Å resolution. RESULTS The MH-K1 chitosanase's (GlcN)4-bound structure has numerous structural similarities to other GH-46 chitosanases in terms of substrate binding and catalytic processes. However, subsite -1, which is absolutely specific for GlcN, seems to characterize the structure of a subclass III chitosanase due to its distinctive length and angle of a flexible loop. According to a comparison of the (GlcN)4-bound and apo-form structures, the particular binding of a GlcN residue at subsite -2 through Asp77 causes the backbone helix to kink, which causes the upper- and lower-domains to approach closely when binding a substrate. CONCLUSIONS Although GH-46 chitosanases vary in the finer details of the subsites defining cleavage specificity, they share similar structural characteristics in substrate-binding, catalytic processes, and potentially in conformational change. GENERAL SIGNIFICANCE The precise binding of a GlcN residue to the -2 subsite is essential for the conformational shift that occurs in all GH-46 chitosanases, as shown by the crystal structures of the apo- and substrate-bound forms of MH-K1 chitosanase.
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Affiliation(s)
- Michihiko Suzuki
- Molecular Analysis Center, Research Unit, R&D Division, Kyowa Kirin, Sunto-gun, Shizuoka 411-8731, Japan
| | - Akihiro Saito
- Department of Nanobiology, Graduate School of Advanced and Integration Science, Chiba University, Matsudo, Chiba 271-8510, Japan; Department of Materials and Life Science, Faculty of Science and Technology, Shizuoka Institute of Science and Technology, Fukuroi, Shizuoka 437-8555, Japan.
| | - Mariko Kobayashi
- Department of Nanobiology, Graduate School of Advanced and Integration Science, Chiba University, Matsudo, Chiba 271-8510, Japan
| | - Tomofumi Yokoyama
- Department of Nanobiology, Graduate School of Advanced and Integration Science, Chiba University, Matsudo, Chiba 271-8510, Japan
| | - Shoko Omiya
- Department of Nanobiology, Graduate School of Advanced and Integration Science, Chiba University, Matsudo, Chiba 271-8510, Japan
| | - Jian Li
- Department of Nanobiology, Graduate School of Advanced and Integration Science, Chiba University, Matsudo, Chiba 271-8510, Japan
| | - Kei Sugita
- Department of Nanobiology, Graduate School of Advanced and Integration Science, Chiba University, Matsudo, Chiba 271-8510, Japan
| | - Kunio Miki
- Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Jun-Ichi Saito
- Molecular Analysis Center, Research Unit, R&D Division, Kyowa Kirin, Sunto-gun, Shizuoka 411-8731, Japan
| | - Akikazu Ando
- Department of Nanobiology, Graduate School of Advanced and Integration Science, Chiba University, Matsudo, Chiba 271-8510, Japan
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Paudel L, Pardhe BD, Han SR, Lee JH, Oh TJ. Identification and evaluation of CAZyme genes, along with functional characterization of a new GH46 chitosanase from Streptomyces sp. KCCM12257. Int J Biol Macromol 2023; 253:127457. [PMID: 37844821 DOI: 10.1016/j.ijbiomac.2023.127457] [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: 07/30/2023] [Revised: 10/12/2023] [Accepted: 10/13/2023] [Indexed: 10/18/2023]
Abstract
The genomic analysis of Streptomyces sp. KCCM12257 presented 233 CAZyme genes with a predominant glycosyl hydrolase family. This contributes degradation of various polysaccharides including chitin and chitosan, and other promising candidates for the production of different oligosaccharides. We screened the strain providing different polysaccharides as a sole source of carbon and strain KCCM12257, showed higher activity towards colloidal chitosan. Further, we identified and characterized a new chitosanase (MDI5907146) of GH46 family. There was no activity towards chitin, carboxymethylcellulose, or even with chitosan powder. This enzyme acts on colloidal chitosan and hydrolyzes it down into monoacetyl chitobiose, which consists of two glucosamine units with an acetyl group attached to them. The maximum enzyme activity was observed at pH 6.5 and 40 °C using colloidal chitosan as a substrate. The Co2+ metal ions almost double the reaction as compared to other metal ions. The dissociation constant (Km) and of colloidal chitosan (≥90 % and ≥75%DD) were 3.03 mg/ml and 5.01 mg/ml respectively, while maximum velocity (Vmax) values were found to be 36 mg/ml, and 30 μM/μg/min, respectively. Similarly, catalytic efficiency (Kcat/Km) of colloidal chitosan with ≥90 %DD was 1.9 fold higher than colloidal chitosan with ≥75%DD.
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Affiliation(s)
- Lakshan Paudel
- Department of Life Science and Biochemical Engineering, Graduate School, SunMoon University, Asan 31460, Republic of Korea
| | - Bashu Dev Pardhe
- Department of Life Science and Biochemical Engineering, Graduate School, SunMoon University, Asan 31460, Republic of Korea
| | - So-Ra Han
- Department of Life Science and Biochemical Engineering, Graduate School, SunMoon University, Asan 31460, Republic of Korea; Genome-based BioIT Convergence Institute, Asan 31460, Republic of Korea; Bio Big Data-based Chungnam Smart Clean Research Leader Training Program, SunMoon University, Asan 31460, Republic of Korea
| | - Jun Hyuck Lee
- Research Unit of Cryogenic Novel Materials, Korea Polar Research Institute, Incheon 21990, Republic of Korea.
| | - Tae-Jin Oh
- Department of Life Science and Biochemical Engineering, Graduate School, SunMoon University, Asan 31460, Republic of Korea; Genome-based BioIT Convergence Institute, Asan 31460, Republic of Korea; Bio Big Data-based Chungnam Smart Clean Research Leader Training Program, SunMoon University, Asan 31460, Republic of Korea; Department of Pharmaceutical Engineering and Biotechnology, SunMoon University, Asan 31460, Republic of Korea.
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Su H, Sun J, Guo C, Wang Y, Secundo F, Dong H, Mao X. Structure-based mining of a chitosanase with distinctive degradation mode and product specificity. Appl Microbiol Biotechnol 2023; 107:6859-6871. [PMID: 37713113 DOI: 10.1007/s00253-023-12741-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 08/10/2023] [Accepted: 08/24/2023] [Indexed: 09/16/2023]
Abstract
Chitosan derivates with varying degrees of polymerization (DP) have attracted great concern due to their excellent biological activities. Increasing the abundance of chitosanases with different degradation modes contributes to revealing their catalytic mechanisms and facilitating the production of chitosan derivates. However, the identification of endo-chitosanases capable of producing chitobiose and D-glucosamine (GlcN) from chitosan substrates has remained elusive. Herein, an endo-chitosanase (CsnCA) belonging to the GH46 family was identified based on structural analysis in phylogenetic evolution. Moreover, we demonstrate that CsnCA acts in a random endo-acting manner, producing chitosan derivatives with DP ≤ 2. The in-depth analysis of CsnCA revealed that (GlcN)3 serves as the minimal substrate, undergoing cleavage in the mode that occupies the subsites - 2 to + 1, resulting in the release of GlcN. This study succeeded in discovering a chitosanase with distinctive degradation modes, which could facilitate the mechanistic understanding of chitosanases, further empowering the production of chitosan derivates with specific DP. KEY POINTS: • Structural docking and evolutionary analysis guide to mining the chitosanase. • The endo-chitosanase exhibits a unique GlcN-producing cleavage pattern. • The cleavage direction of chitosanase to produce GlcN was identified.
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Affiliation(s)
- Haipeng Su
- Qingdao Key Laboratory of Food Biotechnology, College of Food Science and Engineering, Ocean University of China, Qingdao, 266404, China
- Key Laboratory of Biological Processing of Aquatic Products, China National Light Industry, Qingdao, 266404, China
| | - Jianan Sun
- Qingdao Key Laboratory of Food Biotechnology, College of Food Science and Engineering, Ocean University of China, Qingdao, 266404, China
- Key Laboratory of Biological Processing of Aquatic Products, China National Light Industry, Qingdao, 266404, China
| | - Chaoran Guo
- Qingdao Key Laboratory of Food Biotechnology, College of Food Science and Engineering, Ocean University of China, Qingdao, 266404, China
- Key Laboratory of Biological Processing of Aquatic Products, China National Light Industry, Qingdao, 266404, China
| | - Yongzhen Wang
- Qingdao Key Laboratory of Food Biotechnology, College of Food Science and Engineering, Ocean University of China, Qingdao, 266404, China
- Key Laboratory of Biological Processing of Aquatic Products, China National Light Industry, Qingdao, 266404, China
| | - Francesco Secundo
- Consiglio Nazionale Delle Ricerche, Istituto Di Scienze E Tecnologie Chimiche "Giulio Natta", Via Bianco Mario, 9, 20131, Milan, Italy
| | - Hao Dong
- Qingdao Key Laboratory of Food Biotechnology, College of Food Science and Engineering, Ocean University of China, Qingdao, 266404, China.
- Key Laboratory of Biological Processing of Aquatic Products, China National Light Industry, Qingdao, 266404, China.
| | - Xiangzhao Mao
- Qingdao Key Laboratory of Food Biotechnology, College of Food Science and Engineering, Ocean University of China, Qingdao, 266404, China
- Key Laboratory of Biological Processing of Aquatic Products, China National Light Industry, Qingdao, 266404, China
- Laboratory for Marine Drugs and Bioproducts of Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, China
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Xu Y, Li L, Cao S, Zhu B, Yao Z. An updated comprehensive review of advances on structural features, catalytic mechanisms, modification methods and applications of chitosanases. Process Biochem 2022. [DOI: 10.1016/j.procbio.2022.05.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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Su H, Sun J, Guo C, Jia Z, Mao X. New Insights into Bifunctional Chitosanases with Hydrolysis Activity toward Chito- and Cello-Substrates. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2022; 70:6168-6176. [PMID: 35549271 DOI: 10.1021/acs.jafc.2c01577] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
In the present study, we carried out a comprehensive investigation of glycoside hydrolase (GH) 46 model-chitosanases based on cleavage specificity classification to understand their unknown bifunctional activity. We for the first time show that GH46 chitosanase CsnMHK1 from Bacillus circulans MH-K1, which was previously thought to be strictly exclusive to chitosan, can hydrolyze both chito- and cello-substrates. We determined the digestion direction of bifunctional chitosanase CsnMHK1 from class III and compared it with class II chitosanase belonging to GH8, providing insight into unique substrate specificities and a new perspective on its reclassification. The results lead us to challenge the current understanding of chitosanase substrate specificity based on GH taxonomy classification and suggest that the prevalence from the common bifunctional activity may have occurred. Altogether, these data contribute to the understanding of chitosanase recognition and hydrolysis toward chito- and cello-substrates, which is valuable for future studies on chitosanases.
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Affiliation(s)
- Haipeng Su
- College of Food Science and Engineering, Ocean University of China, Qingdao 266003, China
| | - Jianan Sun
- College of Food Science and Engineering, Ocean University of China, Qingdao 266003, China
| | - Chaoran Guo
- College of Food Science and Engineering, Ocean University of China, Qingdao 266003, China
| | - Zhenrong Jia
- College of Food Science and Engineering, Ocean University of China, Qingdao 266003, China
| | - Xiangzhao Mao
- College of Food Science and Engineering, Ocean University of China, Qingdao 266003, China
- Laboratory for Marine Drugs and Bioproducts, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China
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6
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Li Q, Wang T, Ye Y, Guan S, Cai B, Zhang S, Rong S. A temperature-induced chitosanase bacterial cell-surface display system for the efficient production of chitooligosaccharides. Biotechnol Lett 2021; 43:1625-1635. [PMID: 33993368 DOI: 10.1007/s10529-021-03139-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Accepted: 04/23/2021] [Indexed: 11/24/2022]
Abstract
OBJECTIVE To establish a temperature-induced chitosanase bacterial cell-surface display system to produce chitooligosaccharides (COSs) efficiently for industrial applications. RESULTS Temperature-inducible chitosanase CSN46A bacterial surface display systems containing one or two copies of ice nucleation protein (InaQ-N) as anchoring motifs were successfully constructed on the basis of Escherichia coli and named as InaQ-N-CSN46A (1 copy) and 2InaQ-N-CSN46A (2 copies). The specific enzyme activity of 2InaQ-N-CSN46A reached 761.34 ± 0.78 U/g cell dry weight, which was 45.6% higher than that of InaQ-N-CSN46A. However, few proteins were detected in the 2InaQ-N-CSN46A hydrolysis system. Therefore, 2InaQ-N-CSN46A had higher hydrolysis efficiency and stability than InaQ-N-CSN46A. Gel permeation chromatography revealed that under the optimum enzymatic hydrolysis temperature, the final products were mainly chitobiose and chitotriose. Chitopentaose accumulated (77.62%) when the hydrolysis temperature reached 60 °C. FTIR and NMR analysis demonstrated that the structures of the two hydrolysis products were consistent with those of COSs. CONCLUSIONS In this study, chitosanase was expressed on the surfaces of E. coli by increasing the induction temperature, and chitosan was hydrolysed directly without enzyme purification steps. This study provides a novel strategy for industrial COS production.
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Affiliation(s)
- Qianqian Li
- Department of Bioengineering, Shanghai Institute of Technology, 100 Haiquan Road, Shanghai, 201418, People's Republic of China
| | - Tuantuan Wang
- Department of Bioengineering, Shanghai Institute of Technology, 100 Haiquan Road, Shanghai, 201418, People's Republic of China
| | - Yangzhi Ye
- Department of Bioengineering, Shanghai Institute of Technology, 100 Haiquan Road, Shanghai, 201418, People's Republic of China
| | - Shimin Guan
- Department of Bioengineering, Shanghai Institute of Technology, 100 Haiquan Road, Shanghai, 201418, People's Republic of China
| | - Baoguo Cai
- Department of Bioengineering, Shanghai Institute of Technology, 100 Haiquan Road, Shanghai, 201418, People's Republic of China
| | - Shuo Zhang
- Department of Bioengineering, Shanghai Institute of Technology, 100 Haiquan Road, Shanghai, 201418, People's Republic of China
| | - Shaofeng Rong
- Department of Bioengineering, Shanghai Institute of Technology, 100 Haiquan Road, Shanghai, 201418, People's Republic of China.
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Bhuvanachandra B, Sivaramakrishna D, Alim S, Preethiba G, Rambabu S, Swamy MJ, Podile AR. New Class of Chitosanase from Bacillus amyloliquefaciens for the Generation of Chitooligosaccharides. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2021; 69:78-87. [PMID: 33393308 DOI: 10.1021/acs.jafc.0c05078] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Chitooligosaccharides (COS) generated from either chitin (chitin oligosaccharides) or chitosan (chitosan oligosaccharides) have a wide range of applications in agriculture, medicine, and other fields. Here, we report the characterization of a chitosanase from Bacillus amyloliquefaciens (BamCsn) and the importance of a tryptophan (Trp), W204, for BamCsn activity. BamCsn hydrolyzed the chitosan polymer by an endo mode. It also hydrolyzed chitin oligosaccharides and interestingly exhibited transglycosylation activity on chitotetraose and chitopentaose. Mutation of W204, a nonconserved amino acid in chitosanases, to W204A abolished the hydrolytic activity of BamCsn, with a change in the structure that resulted in a decreased affinity for the substrate and impaired the catalytic ability. Phylogenetic analysis revealed that BamCsn could belong to a new class of chitosanases that showed unique properties like transglycosylation, cleavage of chitin oligosaccharides, and the presence of W204 residues, which is important for activity. Chitosanases belonging to the BamCsn class showed a high potential to generate COS from chitinous substrates.
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Affiliation(s)
- Bhoopal Bhuvanachandra
- Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Gachibowli, Hyderabad 500 046, Telangana, India
| | - Dokku Sivaramakrishna
- Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Gachibowli, Hyderabad 500 046, Telangana, India
| | - Sk Alim
- School of Chemistry, University of Hyderabad, Gachibowli, Hyderabad 500 046, Telangana, India
| | - Gopi Preethiba
- Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Gachibowli, Hyderabad 500 046, Telangana, India
| | - Samudrala Rambabu
- Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Gachibowli, Hyderabad 500 046, Telangana, India
| | - Musti J Swamy
- School of Chemistry, University of Hyderabad, Gachibowli, Hyderabad 500 046, Telangana, India
| | - Appa Rao Podile
- Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Gachibowli, Hyderabad 500 046, Telangana, India
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Arnold ND, Brück WM, Garbe D, Brück TB. Enzymatic Modification of Native Chitin and Conversion to Specialty Chemical Products. Mar Drugs 2020; 18:E93. [PMID: 32019265 PMCID: PMC7073968 DOI: 10.3390/md18020093] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2019] [Revised: 01/27/2020] [Accepted: 01/28/2020] [Indexed: 12/19/2022] Open
Abstract
: Chitin is one of the most abundant biomolecules on earth, occurring in crustacean shells and cell walls of fungi. While the polysaccharide is threatening to pollute coastal ecosystems in the form of accumulating shell-waste, it has the potential to be converted into highly profitable derivatives with applications in medicine, biotechnology, and wastewater treatment, among others. Traditionally this is still mostly done by the employment of aggressive chemicals, yielding low quality while producing toxic by-products. In the last decades, the enzymatic conversion of chitin has been on the rise, albeit still not on the same level of cost-effectiveness compared to the traditional methods due to its multi-step character. Another severe drawback of the biotechnological approach is the highly ordered structure of chitin, which renders it nigh impossible for most glycosidic hydrolases to act upon. So far, only the Auxiliary Activity 10 family (AA10), including lytic polysaccharide monooxygenases (LPMOs), is known to hydrolyse native recalcitrant chitin, which spares the expensive first step of chemical or mechanical pre-treatment to enlarge the substrate surface. The main advantages of enzymatic conversion of chitin over conventional chemical methods are the biocompability and, more strikingly, the higher product specificity, product quality, and yield of the process. Products with a higher Mw due to no unspecific depolymerisation besides an exactly defined degree and pattern of acetylation can be yielded. This provides a new toolset of thousands of new chitin and chitosan derivatives, as the physio-chemical properties can be modified according to the desired application. This review aims to provide an overview of the biotechnological tools currently at hand, as well as challenges and crucial steps to achieve the long-term goal of enzymatic conversion of native chitin into specialty chemical products.
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Affiliation(s)
- Nathanael D. Arnold
- Werner Siemens Chair of Synthetic Biotechnology, Dept. of Chemistry, Technical University of Munich (TUM), 85748 Garching, Germany; (N.D.A.); (D.G.)
| | - Wolfram M. Brück
- Institute for Life Technologies, University of Applied Sciences Western Switzerland Valais-Wallis, 1950 Sion 2, Switzerland;
| | - Daniel Garbe
- Werner Siemens Chair of Synthetic Biotechnology, Dept. of Chemistry, Technical University of Munich (TUM), 85748 Garching, Germany; (N.D.A.); (D.G.)
| | - Thomas B. Brück
- Werner Siemens Chair of Synthetic Biotechnology, Dept. of Chemistry, Technical University of Munich (TUM), 85748 Garching, Germany; (N.D.A.); (D.G.)
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Aktuganov GE, Melentiev AI, Varlamov VP. Biotechnological Aspects of the Enzymatic Preparation of Bioactive Chitooligosaccharides (Review). APPL BIOCHEM MICRO+ 2019. [DOI: 10.1134/s0003683819040021] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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10
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Santos-Moriano P, Kidibule PE, Alleyne E, Ballesteros AO, Heras A, Fernandez-Lobato M, Plou FJ. Efficient conversion of chitosan into chitooligosaccharides by a chitosanolytic activity from Bacillus thuringiensis. Process Biochem 2018. [DOI: 10.1016/j.procbio.2018.07.017] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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Iinuma C, Saito A, Ohnuma T, Tenconi E, Rosu A, Colson S, Mizutani Y, Liu F, Świątek-Połatyńska M, van Wezel GP, Rigali S, Fujii T, Miyashita K. NgcE Sco Acts as a Lower-Affinity Binding Protein of an ABC Transporter for the Uptake of N,N'-Diacetylchitobiose in Streptomyces coelicolor A3(2). Microbes Environ 2018; 33:272-281. [PMID: 30089751 PMCID: PMC6167110 DOI: 10.1264/jsme2.me17172] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
In the model species Streptomyces coelicolor A3(2), the uptake of chitin-degradation byproducts, mainly N,N′- diacetylchitobiose ([GlcNAc]2) and N-acetylglucosamine (GlcNAc), is performed by the ATP-binding cassette (ABC) transporter DasABC-MsiK and the sugar-phosphotransferase system (PTS), respectively. Studies on the S. coelicolor chromosome have suggested the occurrence of additional uptake systems of GlcNAc-related compounds, including the SCO6005–7 cluster, which is orthologous to the ABC transporter NgcEFG of S. olivaceoviridis. However, despite conserved synteny between the clusters in S. coelicolor and S. olivaceoviridis, homology between them is low, with only 35% of residues being identical between NgcE proteins, suggesting different binding specificities. Isothermal titration calorimetry experiments revealed that recombinant NgcESco interacts with GlcNAc and (GlcNAc)2, with Kd values (1.15 and 1.53 μM, respectively) that were higher than those of NgcE of S. olivaceoviridis (8.3 and 29 nM, respectively). The disruption of ngcESco delayed (GlcNAc)2 consumption, but did not affect GlcNAc consumption ability. The ngcESco-dasA double mutation severely decreased the ability to consume (GlcNAc)2 and abolished the induction of chitinase production in the presence of (GlcNAc)2, but did not affect the GlcNAc consumption rate. The results of these biochemical and reverse genetic analyses indicate that NgcESco acts as a (GlcNAc)2- binding protein of the ABC transporter NgcEFGSco-MsiK. Transcriptional and biochemical analyses of gene regulation demonstrated that the ngcESco gene was slightly induced by GlcNAc, (GlcNAc)2, and chitin, but repressed by DasR. Therefore, a model was proposed for the induction of the chitinolytic system and import of (GlcNAc)2, in which (GlcNAc)2 generated from chitin by chitinase produced leakily, is mainly transported via NgcEFG-MsiK and induces the expression of chitinase genes and dasABCD.
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Affiliation(s)
- Chiharu Iinuma
- Department of Nanobiology, Graduate School of Advanced Integration Science, Chiba University
| | - Akihiro Saito
- Department of Nanobiology, Graduate School of Advanced Integration Science, Chiba University.,Department of Materials and Life Science, Shizuoka Institute of Science and Technology
| | | | - Elodie Tenconi
- InBioS-Center for Protein Engineering, Institut de Chimie B6a, University of Liège
| | - Adeline Rosu
- InBioS-Center for Protein Engineering, Institut de Chimie B6a, University of Liège
| | - Séverine Colson
- InBioS-Center for Protein Engineering, Institut de Chimie B6a, University of Liège
| | - Yuuki Mizutani
- Department of Materials and Life Science, Shizuoka Institute of Science and Technology
| | - Feng Liu
- Department of Nanobiology, Graduate School of Advanced Integration Science, Chiba University
| | | | | | - Sébastien Rigali
- InBioS-Center for Protein Engineering, Institut de Chimie B6a, University of Liège
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Expression and characterization of a novel cold-adapted chitosanase suitable for chitooligosaccharides controllable preparation. Food Chem 2018; 253:139-147. [PMID: 29502814 DOI: 10.1016/j.foodchem.2018.01.137] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Revised: 10/01/2017] [Accepted: 01/22/2018] [Indexed: 01/20/2023]
Abstract
Chitooligosaccharide is widely used as a functional food additive and a valuable pharmacological agent. The transformation of chitinous biomass into valuable bioactive chitooligosaccharides is one of the most exciting applications of chitosanase. A novel glycoside hydrolase (GH) family 46 chitosanase (GsCsn46A) from rhizobacterium Gynuella sunshinyii was cloned and heterologously expressed in Escherichia coli. GsCsn46A showed maximal activity at pH 5.5 and 30 °C. GsCsn46A featured remarkable cold-adapted property, which controllably hydrolyzed chitosan to three types of chitooligosaccharides at the mild reaction condition (reaction condition: pH 5.5 at 30 °C; method for stopping the reaction: 50 °C for 30 min). The yields of three types of chitooligosaccharides products (degree of polymerization (DP): 2-7, 2-5 and 2-3) were 70.9%, 87.1% and 94.6% respectively. This novel cold-adapted chitosanase provides a cleaner production process for the controllable preparation of chitooligosaccharides with the specific DP.
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Shinya S, Fukamizo T. Interaction between chitosan and its related enzymes: A review. Int J Biol Macromol 2017; 104:1422-1435. [PMID: 28223213 DOI: 10.1016/j.ijbiomac.2017.02.040] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Revised: 01/17/2017] [Accepted: 02/09/2017] [Indexed: 10/20/2022]
Abstract
Chitosan-related enzymes including chitosanases, exo-β-glucosaminidases, and enzymes having chitosan-binding modules recognize ligands through electrostatic interactions between the acidic amino acids in proteins and amino groups of chitosan polysaccharides. However, in GH8 chitosanases, several aromatic residues are also involved in substrate recognition through stacking interactions, and these enzymes consequently hydrolyze β-1,4-glucan as well as chitosan. The binding grooves of these chitosanases are extended and opened at both ends of the grooves, so that the enzymes can clamp a long chitosan polysaccharide. The association/dissociation of positively charged glucosamine residues to/from the binding pocket of a GH2 exo-β-glucosaminidase controls the p Ka of the catalytic acid, thereby maintaining the high catalytic potency of the enzyme. In contrast to chitosanases, chitosan-binding modules only accommodate a couple of glucosamine residues, predominantly recognizing the non-reducing end glucosamine residue of chitosan by electrostatic interactions and a hydrogen-bonding network. These structural findings on chitosan-related enzymes may contribute to future applications for the efficient conversion of the chitin/chitosan biomass.
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Affiliation(s)
- Shoko Shinya
- Department of Advanced Bioscience, Kindai University, 3327-204 Nakamachi, Nara 631-8505, Japan
| | - Tamo Fukamizo
- Department of Advanced Bioscience, Kindai University, 3327-204 Nakamachi, Nara 631-8505, Japan.
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14
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Yorinaga Y, Kumasaka T, Yamamoto M, Hamada K, Kawamukai M. Crystal structure of a family 80 chitosanase fromMitsuaria chitosanitabida. FEBS Lett 2017; 591:540-547. [DOI: 10.1002/1873-3468.12557] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Revised: 01/09/2017] [Accepted: 01/10/2017] [Indexed: 01/08/2023]
Affiliation(s)
- Yutaka Yorinaga
- Department of Life Science and Biotechnology; Faculty of Life and Environmental Science; Shimane University; Matsue Japan
| | - Takashi Kumasaka
- Japan Synchrotron Radiation Research Institute (JASRI); Sayo Hyogo Japan
| | | | - Kensaku Hamada
- X-ray Research Laboratory; Rigaku Co.; Akishima Tokyo Japan
| | - Makoto Kawamukai
- Department of Life Science and Biotechnology; Faculty of Life and Environmental Science; Shimane University; Matsue Japan
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15
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Chitosanases from Family 46 of Glycoside Hydrolases: From Proteins to Phenotypes. Mar Drugs 2015; 13:6566-87. [PMID: 26516868 PMCID: PMC4663542 DOI: 10.3390/md13116566] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Revised: 10/09/2015] [Accepted: 10/13/2015] [Indexed: 11/17/2022] Open
Abstract
Chitosanases, enzymes that catalyze the endo-hydrolysis of glycolytic links in chitosan, are the subject of numerous studies as biotechnological tools to generate low molecular weight chitosan (LMWC) or chitosan oligosaccharides (CHOS) from native, high molecular weight chitosan. Glycoside hydrolases belonging to family GH46 are among the best-studied chitosanases, with four crystallography-derived structures available and more than forty enzymes studied at the biochemical level. They were also subjected to numerous site-directed mutagenesis studies, unraveling the molecular mechanisms of hydrolysis. This review is focused on the taxonomic distribution of GH46 proteins, their multi-modular character, the structure-function relationships and their biological functions in the host organisms.
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16
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Characterization of Chitosanase of a Deep BiosphereBacillusStrain. Biosci Biotechnol Biochem 2014; 75:669-73. [DOI: 10.1271/bbb.100782] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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17
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Zhang J, Zhang H, Gao Z, Hu H, Dong C, Dong YH. Structural basis for recognition of the type VI spike protein VgrG3 by a cognate immunity protein. FEBS Lett 2014; 588:1891-8. [PMID: 24751834 DOI: 10.1016/j.febslet.2014.04.016] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Revised: 04/09/2014] [Accepted: 04/09/2014] [Indexed: 10/25/2022]
Abstract
The bacterial type VI secretion system (T6SS) is used by donor cells to inject toxic effectors into receptor cells. The donor cells produce the corresponding immunity proteins to protect themselves against the effector proteins, thereby preventing their self-intoxication. Recently, the C-terminal domain of VgrG3 was identified as a T6SS effector. Information on the molecular mechanism of VgrG3 and its immunity protein TsaB has been lacking. Here, we determined the crystal structures of native TsaB and the VgrG3C-TsaB complex. VgrG3C adopts a canonical phage-T4-lysozyme-like fold. TsaB interacts with VgrG3C through molecular mimicry, and inserts into the VgrG3C pocket.
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Affiliation(s)
- Jiulong Zhang
- Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, People's Republic of China; School of Life Sciences, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui 230027, People's Republic of China
| | - Heng Zhang
- State Key Laboratory of Protein and Plant Gene Research, and Biodynamic Optical Imaging Center (BIOPIC), School of Life Sciences, Peking University, No. 5 Yiheyuan Road, Beijing 100871, People's Republic of China
| | - Zengqiang Gao
- Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Haidai Hu
- Key Laboratory of Molecular Virology and Immunology, Institute Pasteur of Shanghai, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, People's Republic of China
| | - Cheng Dong
- Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, People's Republic of China; State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin 300071, People's Republic of China.
| | - Yu-Hui Dong
- Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, People's Republic of China.
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Production and purification of a fungal chitosanase and chitooligomers from Penicillium janthinellum D4 and discovery of the enzyme activators. Carbohydr Polym 2014; 108:331-7. [PMID: 24751281 DOI: 10.1016/j.carbpol.2014.02.053] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Revised: 02/13/2014] [Accepted: 02/16/2014] [Indexed: 11/20/2022]
Abstract
Chitosanases have received much attention because of their wide range of applications. Although most fungal chitosanases use sugar as their major carbon source, in the present work, a chitosanase was induced from a squid pen powder (SPP)-containing Penicillium janthinellum D4 medium and purified by ammonium sulphate precipitation and combined column chromatography. The purified D4 chitosanase exhibited optimum activity at pH 7-9, 60°C and was stable at pH 7-11, 25-50°C. The D4 chitosanase that was used for chitooligomers preparation was studied. The enzyme products revealed various chitooligomers with different degrees of polymerisation (DP) from 3 to 9, as determined by a MALDI-TOF mass spectrometer, confirming the endo-type nature of the D4 chitosanase. D4 chitosanase activity was significantly inhibited by Cu(2+), Mn(2+), and EDTA. However, Fe(2+) activated or inhibited D4 chitosanases at different concentrations. The D4 chitosanase was also activated by some small synthetic boron-containing molecules with boronate ester side chains.
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Takasuka TE, Bianchetti CM, Tobimatsu Y, Bergeman LF, Ralph J, Fox BG. Structure-guided analysis of catalytic specificity of the abundantly secreted chitosanase SACTE_5457 from Streptomyces
sp. SirexAA-E. Proteins 2014; 82:1245-57. [DOI: 10.1002/prot.24491] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2013] [Revised: 11/18/2013] [Accepted: 11/19/2013] [Indexed: 01/22/2023]
Affiliation(s)
- Taichi E. Takasuka
- Department of Biochemistry; University of Wisconsin-Madison; Madison Wisconsin 53706
- Great Lakes Bioenergy Research Center, College of Engineering; University of Wisconsin-Madison; Madison Wisconsin 53726
| | - Christopher M. Bianchetti
- Department of Biochemistry; University of Wisconsin-Madison; Madison Wisconsin 53706
- Great Lakes Bioenergy Research Center, College of Engineering; University of Wisconsin-Madison; Madison Wisconsin 53726
| | - Yuki Tobimatsu
- Department of Biochemistry; University of Wisconsin-Madison; Madison Wisconsin 53706
- Great Lakes Bioenergy Research Center, College of Engineering; University of Wisconsin-Madison; Madison Wisconsin 53726
| | - Lai F. Bergeman
- Department of Biochemistry; University of Wisconsin-Madison; Madison Wisconsin 53706
- Great Lakes Bioenergy Research Center, College of Engineering; University of Wisconsin-Madison; Madison Wisconsin 53726
| | - John Ralph
- Department of Biochemistry; University of Wisconsin-Madison; Madison Wisconsin 53706
- Great Lakes Bioenergy Research Center, College of Engineering; University of Wisconsin-Madison; Madison Wisconsin 53726
| | - Brian G. Fox
- Department of Biochemistry; University of Wisconsin-Madison; Madison Wisconsin 53706
- Great Lakes Bioenergy Research Center, College of Engineering; University of Wisconsin-Madison; Madison Wisconsin 53726
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20
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Tomita M, Kikuchi A, Kobayashi M, Yamaguchi M, Ifuku S, Yamashoji S, Ando A, Saito A. Characterization of antifungal activity of the GH-46 subclass III chitosanase from Bacillus circulans MH-K1. Antonie van Leeuwenhoek 2013; 104:737-48. [PMID: 23892828 DOI: 10.1007/s10482-013-9982-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2013] [Accepted: 07/22/2013] [Indexed: 10/26/2022]
Abstract
We characterized the antifungal activity of the Bacillus circulans subclass III MH-K1 chitosanase (MH-K1 chitosanase), which is one of the most intensively studied glycoside hydrolases (GHs) that belong to GH family 46. MH-K1 chitosanase inhibited the growth of zygomycetes fungi, Rhizopus and Mucor, even at 10 pmol (0.3 μg)/ml culture probably via its fungistatic effect. The amino acid substitution E37Q abolished the antifungal activity of MH-K1 chitosanase, but retained binding to chitotriose. The E37Q mutant was fused with green fluorescent protein (GFP) at its N-terminus and proved to act as a chitosan probe in combination with wheat-germ agglutinin (WGA), which is a chitin-specific binding lectin. The GFP-fused MH-K1 chitosanase mutant E37Q (GFP-E37Q) bound clearly to the hyphae of the Rhizopus and Mucor strains, indicating the presence of chitosan. In contrast, Cy5-labelled WGA (Cy5-WGA), but not GFP-E37Q, stained the hyphae of non-zygomycetes species, i.e. Fusarium oxysporum, Penicillium expansum, and Aspergillus awamori. When the mycelia of Rhizopus oryzae were treated with wild type MH-K1 chitosanase, they could not bind to GFP-E37Q but were stained instead by Cy5-WGA. We conclude that chitin is covered by chitosan in the cell walls of R. oryzae.
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Affiliation(s)
- Masayo Tomita
- Department of Nanobiology, Graduate School of Advanced Integration Science, Chiba University, 648 Matsudo, Matsudo, Chiba, 271-8510, Japan
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21
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Pechsrichuang P, Yoohat K, Yamabhai M. Production of recombinant Bacillus subtilis chitosanase, suitable for biosynthesis of chitosan-oligosaccharides. BIORESOURCE TECHNOLOGY 2013; 127:407-414. [PMID: 23138063 DOI: 10.1016/j.biortech.2012.09.130] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2012] [Revised: 08/10/2012] [Accepted: 09/28/2012] [Indexed: 06/01/2023]
Abstract
Chitosanases are enzymes that catalyse the hydrolysis of the β-1,4 glycosidic bond of chitosan. One of the most promising applications of this enzyme is for the bioconversion of chitosan into value-added chitosan-oligosaccharides (COS). GH46 chitosanase (Csn) from Bacillus subtilis 168 was expressed in Escherichia coli by fusing the gene encoding mature Csn to the E. coli OmpA signal peptide sequence. The recombinant enzyme was secreted into the culture supernatant. The recombinant Csn showed high specific activity and stability over a wide range of pH. The enzyme was >100 times more thermostable in the presence of the substrate, with a half-life time of activity (τ(1/2)) of approximately 20 h at 50 °C and pH 5.5. Efficient bioconversion of chitosan into different mixtures of COS, using crude culture supernatant containing secreted enzyme was demonstrated.
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Affiliation(s)
- Phornsiri Pechsrichuang
- Molecular Biotechnology Laboratory, School of Biotechnology, Institute of Agricultural Technology, Suranaree University of Technology, Nakhon Ratchasima, Thailand
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22
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Peng N, Xu W, Wang F, Hu J, Ma M, Hu Y, Zhao S, Liang Y, Ge X. Mitsuaria chitosanase with unrevealed important amino acid residues: characterization and enhanced production in Pichia pastoris. Appl Microbiol Biotechnol 2012; 97:171-9. [PMID: 22322871 DOI: 10.1007/s00253-012-3901-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2011] [Revised: 01/11/2012] [Accepted: 01/12/2012] [Indexed: 10/14/2022]
Abstract
A chitosan plate assay was employed to screen for chitosanase-producing bacterial strains and isolate 141 was found to exhibit high activity. Characterization of this isolate revealed that it belonged to Mitsuaria (designated as Mitsuaria sp. 141). The encoded chitosanase (choA) gene was then cloned by PCR and the deduced amino acid sequence showed 98% identity to a formerly described Mitsuaria chitosanitabida 3001 ChoA (McChoA). Surprisingly, the ChoA encoded by Mitsuaria sp. 141 (MsChoA) appeared to have a much higher optimum temperature compared to McChoA. Site-directed mutagenesis was then employed to generate five MschoA mutant genes encoding MsChoA K204Q, R216K, T222N, R216K/T222N, or K204Q/R216K/T222N. All the ChoA mutants exhibited a much lower specific activity and a lower optimum temperature. The results confirmed that the substitution of three non-conserved amino acids accounts for the major reduction of the enzyme activity in MsChoA. Furthermore, the MschoA gene was cloned for over-expression in Pichia pastoris after coding sequence optimization. One of the P. pastoris transformants with Mut(S) phenotype was found to produce 1,480.2 ± 340.9 U ChoA mL(-1) of cell culture by high-cell-density fermentation. This represents the highest yield of recombinant ChoA production that has ever been reported thus far. The recombinant P. pastoris strain should therefore be well suited for industrial-scale production of chitosanase.
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Affiliation(s)
- Nan Peng
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China
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23
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Isogawa D, Fukuda T, Kuroda K, Kusaoke H, Kimoto H, Suye SI, Ueda M. Demonstration of catalytic proton acceptor of chitosanase from Paenibacillus fukuinensis by comprehensive analysis of mutant library. Appl Microbiol Biotechnol 2009; 85:95-104. [DOI: 10.1007/s00253-009-2041-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2009] [Revised: 05/09/2009] [Accepted: 05/10/2009] [Indexed: 10/20/2022]
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24
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Characterization of a novel fungal chitosanase Csn2 from Gongronella sp. JG. Carbohydr Res 2008; 343:2583-8. [DOI: 10.1016/j.carres.2008.08.004] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2008] [Revised: 07/28/2008] [Accepted: 08/02/2008] [Indexed: 11/21/2022]
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25
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Yao YY, Shrestha KL, Wu YJ, Tasi HJ, Chen CC, Yang JM, Ando A, Cheng CY, Li YK. Structural simulation and protein engineering to convert an endo-chitosanase to an exo-chitosanase. Protein Eng Des Sel 2008; 21:561-6. [DOI: 10.1093/protein/gzn033] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Lee HS, Jang JS, Choi SK, Lee DW, Kim EJ, Jung HC, Pan JG. Identification and expression of GH-8 family chitosanases from several Bacillus thuringiensis subspecies. FEMS Microbiol Lett 2008; 277:133-41. [PMID: 18031332 DOI: 10.1111/j.1574-6968.2007.00944.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
The Gram-positive spore-forming bacterium, Bacillus thuringiensis, a member of the Bacillus cereus group, produces chitosanases that catalyze the hydrolysis of chitosan to chitosan-oligosaccharides (COS). Although fungal and bacterial chitosanases belonging to other glycoside hydrolase (GH) families have been characterized in a variety of microorganisms, knowledge on the genetics and phylogeny of the GH-8 chitosanases remains limited. Nine genes encoding chitosanases were cloned from 29 different serovar strains of B. thuringiensis and they were expressed in Escherichia coli. The ORFs of the chitosanases contained 1,359 nucleotides and the protein products had high levels of sequence identity (>96%) to other Bacillus species GH-8 chitosanases. Thin-layer chromatography and HPLC analyses demonstrated that these enzymes hydrolyzed chitosan to a chitosan-trimer and a chitosan-tetramer as major products, and this could be useful in the production of COS. In addition, a simple plate assay was developed, involving a soluble chitosan, for high-throughput screening of chitosanases. This system allowed screening for mutant enzymes with higher enzyme activity generated by error-prone PCR, indicating that it can be used for directed chitosanase evolution.
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Zhou W, Yuan H, Wang J, Yao J. Production, purification and characterization of chitosanase produced by Gongronella sp. JG. Lett Appl Microbiol 2007; 46:49-54. [DOI: 10.1111/j.1472-765x.2007.02262.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Kawamura S, Ohno K, Ohkuma M, Chijiiwa Y, Torikata T. Experimental Verification of the Crucial Roles of Glu73 in the Catalytic Activity and Structural Stability of Goose Type Lysozyme. ACTA ACUST UNITED AC 2006; 140:75-85. [PMID: 16877771 DOI: 10.1093/jb/mvj125] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
The roles of Glu(73), which has been proposed to be a catalytic residue of goose type (G-type) lysozyme based on X-ray structural studies, were investigated by means of its replacement with Gln, Asp, and Ala using ostrich egg-white lysozyme (OEL) as a model. No remarkable differences in secondary structure or substrate binding ability were observed between the wild type and Glu(73)-mutated proteins, as evaluated by circular dichroism (CD) spectroscopy and chitin-coated celite chromatography. Substitution of Glu(73) with Gln or Ala abolished the enzymatic activity toward both the bacterial cell substrate and N-acetylglucosamine pentamer, (GlcNAc)(5), while substitution with Asp did not abolish but drastically reduced the activity of OEL. These results demonstrate that the carboxyl group of Glu(73) is directly involved in the catalytic action of G-type lysozyme. Furthermore, the stabilities of all three mutants, which were determined from the thermal and guanidine hydrochloride (GdnHCl) unfolding curves, respectively, were significantly decreased relative to those of the wild type. The results obtained clearly indicate the crucially important roles of Glu(73) in the structural stability as well as in the catalytic activity of G-type lysozyme.
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Affiliation(s)
- Shunsuke Kawamura
- Department of Bioscience, School of Agriculture, Kyushu Tokai University, Aso, Kumamoto 869-1404.
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