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Guo Z, Wang L, Rao D, Liu W, Xue M, Fu Q, Lu M, Su L, Chen S, Wang B, Wu J. Conformational Switch of the 250s Loop Enables the Efficient Transglycosylation in GH Family 77. J Chem Inf Model 2023; 63:6118-6128. [PMID: 37768640 DOI: 10.1021/acs.jcim.3c00635] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/29/2023]
Abstract
Amylomaltases (AMs) play important roles in glycogen and maltose metabolism. However, the molecular mechanism is elusive. Here, we investigated the conformational dynamics of the 250s loop and catalytic mechanism of Thermus aquaticus TaAM using path-metadynamics and QM/MM MD simulations. The results demonstrate that the transition of the 250s loop from an open to closed conformation promotes polysaccharide sliding, leading to the ideal positioning of the acid/base. Furthermore, the conformational dynamics can also modulate the selectivity of hydrolysis and transglycosylation. The closed conformation of the 250s loop enables the tight packing of the active site for transglycosylation, reducing the energy penalty and efficiently preventing the penetration of water into the active site. Conversely, the partially closed conformation for hydrolysis results in a loosely packed active site, destabilizing the transition state. These computational findings guide mutation experiments and enable the identification of mutants with an improved disproportionation/hydrolysis ratio. The present mechanism is in line with experimental data, highlighting the critical role of conformational dynamics in regulating the catalytic reactivity of GHs.
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Affiliation(s)
- Zhiyong Guo
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, People's Republic of China
- School of Biotechnology and Key Laboratory of Industrial Biotechnology Ministry of Education, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, People's Republic of China
- International Joint Laboratory on Food Safety, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, People's Republic of China
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Key Laboratory of Industrial Biotechnology, School of Life Sciences, Hubei University, Wuhan 430062, People's Republic of China
| | - Lei Wang
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, People's Republic of China
- School of Biotechnology and Key Laboratory of Industrial Biotechnology Ministry of Education, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, People's Republic of China
- International Joint Laboratory on Food Safety, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, People's Republic of China
| | - Deming Rao
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, People's Republic of China
- School of Biotechnology and Key Laboratory of Industrial Biotechnology Ministry of Education, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, People's Republic of China
- International Joint Laboratory on Food Safety, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, People's Republic of China
- School of Life Science and Technology, Wuhan Polytechnic University, Wuhan 430023, People's Republic of China
| | - Weiqiong Liu
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, People's Republic of China
- School of Biotechnology and Key Laboratory of Industrial Biotechnology Ministry of Education, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, People's Republic of China
- International Joint Laboratory on Food Safety, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, People's Republic of China
| | - Miaomiao Xue
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, People's Republic of China
- School of Biotechnology and Key Laboratory of Industrial Biotechnology Ministry of Education, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, People's Republic of China
- International Joint Laboratory on Food Safety, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, People's Republic of China
| | - Qisheng Fu
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, People's Republic of China
- School of Biotechnology and Key Laboratory of Industrial Biotechnology Ministry of Education, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, People's Republic of China
- International Joint Laboratory on Food Safety, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, People's Republic of China
| | - Mengwei Lu
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, People's Republic of China
- School of Biotechnology and Key Laboratory of Industrial Biotechnology Ministry of Education, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, People's Republic of China
- International Joint Laboratory on Food Safety, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, People's Republic of China
| | - Lingqia Su
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, People's Republic of China
- School of Biotechnology and Key Laboratory of Industrial Biotechnology Ministry of Education, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, People's Republic of China
- International Joint Laboratory on Food Safety, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, People's Republic of China
| | - Sheng Chen
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, People's Republic of China
- School of Biotechnology and Key Laboratory of Industrial Biotechnology Ministry of Education, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, People's Republic of China
- International Joint Laboratory on Food Safety, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, People's Republic of China
| | - Binju Wang
- State Key Laboratory of Physical Chemistry of Solid Surfaces and Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, People's Republic of China
| | - Jing Wu
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, People's Republic of China
- School of Biotechnology and Key Laboratory of Industrial Biotechnology Ministry of Education, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, People's Republic of China
- International Joint Laboratory on Food Safety, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, People's Republic of China
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Li X, Wang Y, Wu J, Jin Z, Dijkhuizen L, Svensson B, Bai Y. Designing starch derivatives with desired structures and functional properties via rearrangements of glycosidic linkages by starch-active transglycosylases. Crit Rev Food Sci Nutr 2023:1-14. [PMID: 37051937 DOI: 10.1080/10408398.2023.2198604] [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: 04/14/2023]
Abstract
Modification of starch by transglycosylases from glycoside hydrolase families has attracted much attention recently; these enzymes can produce starch derivatives with novel properties, i.e. processability and functionality, employing highly efficient and safe methods. Starch-active transglycosylases cleave starches and transfer linear fragments to acceptors introducing α-1,4 and/or linear/branched α-1,6 glucosidic linkages, resulting in starch derivatives with excellent properties such as complexing and resistance to digestion characteristics, and also may be endowed with new properties such as thermo-reversible gel formation. This review summarizes the effects of variations in glycosidic linkage composition on structure and properties of modified starches. Starch-active transglycosylases are classified into 4 groups that form compounds: (1) in cyclic with α-1,4 glucosidic linkages, (2) with linear chains of α-1,4 glucosidic linkages, (3) with branched α-1,6 glucosidic linkages, and (4) with linear chains of α-1,6 glucosidic linkages. We discuss potential processability and functionality of starch derivatives with different linkage combinations and structures. The changes in properties caused by rearrangements of glycosidic linkages provide guidance for design of starch derivatives with desired structures and properties, which promotes the development of new starch products and starch processing for the food industry.
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Affiliation(s)
- Xiaoxiao Li
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, China
| | - Yu Wang
- Enzyme and Protein Chemistry, Department of Biotechnology and Biomedicine, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - Jing Wu
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, China
- Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, Jiangnan University, Wuxi, Jiangsu, China
| | - Zhengyu Jin
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, China
- Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, Jiangnan University, Wuxi, Jiangsu, China
- School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, China
| | - Lubbert Dijkhuizen
- CarbExplore Research B.V, Groningen, The Netherlands
- Microbiology, Groningen Biomolecular Sciences and Biotechnology Institute (GBB), University of Groningen, Groningen, The Netherlands
| | - Birte Svensson
- Enzyme and Protein Chemistry, Department of Biotechnology and Biomedicine, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - Yuxiang Bai
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, China
- Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, Jiangnan University, Wuxi, Jiangsu, China
- School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, China
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3
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Leoni C, Gattulli BAR, Pesole G, Ceci LR, Volpicella M. Amylomaltases in Extremophilic Microorganisms. Biomolecules 2021; 11:biom11091335. [PMID: 34572549 PMCID: PMC8465469 DOI: 10.3390/biom11091335] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 09/06/2021] [Accepted: 09/08/2021] [Indexed: 11/16/2022] Open
Abstract
Amylomaltases (4-α-glucanotransferases, E.C. 2.4.1.25) are enzymes which can perform a double-step catalytic process, resulting in a transglycosylation reaction. They hydrolyse glucosidic bonds of α-1,4'-d-glucans and transfer the glucan portion with the newly available anomeric carbon to the 4'-position of an α-1,4'-d-glucan acceptor. The intramolecular reaction produces a cyclic α-1,4'-glucan. Amylomaltases can be found only in prokaryotes, where they are involved in glycogen degradation and maltose metabolism. These enzymes are being studied for possible biotechnological applications, such as the production of (i) sugar substitutes; (ii) cycloamyloses (molecules larger than cyclodextrins), which could potentially be useful as carriers and encapsulating agents for hydrophobic molecules and also as effective protein chaperons; and (iii) thermoreversible starch gels, which could be used as non-animal gelatin substitutes. Extremophilic prokaryotes have been investigated for the identification of amylomaltases to be used in the starch modifying processes, which require high temperatures or extreme conditions. The aim of this article is to present an updated overview of studies on amylomaltases from extremophilic Bacteria and Archaea, including data about their distribution, activity, potential industrial application and structure.
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Affiliation(s)
- Claudia Leoni
- Institute of Biomembranes, Bioenergetics and Molecular Biotechnologies, Consiglio Nazionale delle Ricerche, Via Amendola, 70126 Bari, Italy; (C.L.); (B.A.R.G.); (G.P.)
| | - Bruno A. R. Gattulli
- Institute of Biomembranes, Bioenergetics and Molecular Biotechnologies, Consiglio Nazionale delle Ricerche, Via Amendola, 70126 Bari, Italy; (C.L.); (B.A.R.G.); (G.P.)
| | - Graziano Pesole
- Institute of Biomembranes, Bioenergetics and Molecular Biotechnologies, Consiglio Nazionale delle Ricerche, Via Amendola, 70126 Bari, Italy; (C.L.); (B.A.R.G.); (G.P.)
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari Aldo Moro, Via Amendola 165/A, 70126 Bari, Italy
| | - Luigi R. Ceci
- Institute of Biomembranes, Bioenergetics and Molecular Biotechnologies, Consiglio Nazionale delle Ricerche, Via Amendola, 70126 Bari, Italy; (C.L.); (B.A.R.G.); (G.P.)
- Correspondence: (L.R.C.); (M.V.); Tel.: +39-080-544-3311 (L.R.C. & M.V.)
| | - Mariateresa Volpicella
- Institute of Biomembranes, Bioenergetics and Molecular Biotechnologies, Consiglio Nazionale delle Ricerche, Via Amendola, 70126 Bari, Italy; (C.L.); (B.A.R.G.); (G.P.)
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari Aldo Moro, Via Amendola 165/A, 70126 Bari, Italy
- Correspondence: (L.R.C.); (M.V.); Tel.: +39-080-544-3311 (L.R.C. & M.V.)
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A putative novel starch-binding domain revealed by in silico analysis of the N-terminal domain in bacterial amylomaltases from the family GH77. 3 Biotech 2021; 11:229. [PMID: 33968573 DOI: 10.1007/s13205-021-02787-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Accepted: 04/09/2021] [Indexed: 10/21/2022] Open
Abstract
The family GH77 contains 4-α-glucanotransferase acting on α-1,4-glucans, known as amylomaltase in prokaryotes and disproportionating enzyme in plants. A group of bacterial GH77 members, represented by amylomaltases from Escherichia coli and Corynebacterium glutamicum, possesses an N-terminal extension that forms a distinct immunoglobulin-like fold domain, of which no function has been identified. Here, in silico analysis of 100 selected sequences of N-terminal domain homologues disclosed several well-conserved residues, among which Tyr108 (E. coli amylomaltase numbering) may be involved in α-glucan binding. These N-terminal domains, therefore, may represent a new type of starch-binding domain and define a new CBM family. This hypothesis is supported by docking of maltooligosaccharides to the N-terminal domain in amylomaltases, representing the four clusters of the phylogenetic tree. SUPPLEMENTARY INFORMATION The online version contains supplementary material available at 10.1007/s13205-021-02787-8.
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5
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Tumhom S, Nimpiboon P, Wangkanont K, Pongsawasdi P. Streptococcus agalactiae amylomaltase offers insight into the transglycosylation mechanism and the molecular basis of thermostability among amylomaltases. Sci Rep 2021; 11:6740. [PMID: 33762620 PMCID: PMC7990933 DOI: 10.1038/s41598-021-85769-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Accepted: 03/04/2021] [Indexed: 11/09/2022] Open
Abstract
Amylomaltase (AM) catalyzes transglycosylation of starch to form linear or cyclic oligosaccharides with potential applications in biotechnology and industry. In the present work, a novel AM from the mesophilic bacterium Streptococcus agalactiae (SaAM), with 18–49% sequence identity to previously reported AMs, was characterized. Cyclization and disproportionation activities were observed with the optimum temperature of 30 °C and 40 °C, respectively. Structural determination of SaAM, the first crystal structure of small AMs from the mesophiles, revealed a glycosyl-enzyme intermediate derived from acarbose and a second acarbose molecule attacking the intermediate. This pre-transglycosylation conformation has never been before observed in AMs. Structural analysis suggests that thermostability in AMs might be mainly caused by an increase in salt bridges since SaAM has a lower number of salt bridges compared with AMs from the thermophiles. Increase in thermostability by mutation was performed. C446 was substituted with A/S/P. C446A showed higher activities and higher kcat/Km values for starch in comparison to the WT enzyme. C446S exhibited a 5 °C increase in optimum temperature and the threefold increase in half-life time at 45 °C, most likely resulting from H-bonding interactions. For all enzymes, the main large-ring cyclodextrin (LR-CD) products were CD24-CD26 with CD22 as the smallest. C446S produced more CD35-CD42, especially at a longer incubation time.
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Affiliation(s)
- Suthipapun Tumhom
- Starch and Cyclodextrin Research Unit, Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok, 10330, Thailand
| | - Pitchanan Nimpiboon
- Starch and Cyclodextrin Research Unit, Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok, 10330, Thailand
| | - Kittikhun Wangkanont
- Center of Excellence for Molecular Biology and Genomics of Shrimp, Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok, 10330, Thailand. .,Molecular Crop Research Unit, Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok, 10330, Thailand.
| | - Piamsook Pongsawasdi
- Starch and Cyclodextrin Research Unit, Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok, 10330, Thailand.
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6
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Imamura K, Matsuura T, Nakagawa A, Kitamura S, Kusunoki M, Takaha T, Unno H. Structural analysis and reaction mechanism of the disproportionating enzyme (D-enzyme) from potato. Protein Sci 2020; 29:2085-2100. [PMID: 32808707 PMCID: PMC7513719 DOI: 10.1002/pro.3932] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Revised: 08/14/2020] [Accepted: 08/14/2020] [Indexed: 11/06/2022]
Abstract
Starch produced by plants is a stored form of energy and is an important dietary source of calories for humans and domestic animals. Disproportionating enzyme (D-enzyme) catalyzes intramolecular and intermolecular transglycosylation reactions of α-1, 4-glucan. D-enzyme is essential in starch metabolism in the potato. We present the crystal structures of potato D-enzyme, including two different types of complex structures: a primary Michaelis complex (substrate binding mode) for 26-meric cycloamylose (CA26) and a covalent intermediate for acarbose. Our study revealed that the acarbose and CA26 reactions catalyzed by potato D-enzyme involve the formation of a covalent intermediate with the donor substrate. HPAEC of reaction substrates and products revealed the activity of the potato D-enzyme on acarbose and CA26 as donor substrates. The structural and chromatography analyses provide insight into the mechanism of the coupling reaction of CA and glucose catalyzed by the potato D-enzyme. The enzymatic reaction mechanism does not involve residual hydrolysis. This could be particularly useful in preventing unnecessary starch degradation leading to reduced crop productivity. Optimization of this mechanism would be important for improvements of starch storage and productivity in crops.
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Affiliation(s)
- Kayo Imamura
- Laboratory of Enzyme Chemistry, Graduate School of Agriculture and Biological ScienceOsaka Prefecture UniversityOsakaJapan
| | | | | | - Shinichi Kitamura
- Laboratory of Biophysical Chemistry, Graduate School of Agriculture and Biological ScienceOsaka Prefecture UniversityOsakaJapan
- Present address:
Laboratory of Advanced Food Process EngineeringOsaka Prefecture University, 1‐2, Gakuen‐cho, Nakaku, Osaka, Sakai 599‐8570Japan
| | | | - Takeshi Takaha
- Biochemical Research LaboratoriesEzaki Glico Co., LtdOsakaJapan
- Present address:
Sanawa Starch Co., Ltd. 594 Unate, Kashihara, Nara 634‐8585Japan
| | - Hideaki Unno
- Graduate School of EngineeringNagasaki UniversityNagasakiJapan
- Organization for Marine Science and TechnologyNagasaki UniversityNagasakiJapan
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Structural and Functional Characterization of Three Novel Fungal Amylases with Enhanced Stability and pH Tolerance. Int J Mol Sci 2019; 20:ijms20194902. [PMID: 31623309 PMCID: PMC6801514 DOI: 10.3390/ijms20194902] [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: 09/16/2019] [Revised: 09/23/2019] [Accepted: 09/24/2019] [Indexed: 12/19/2022] Open
Abstract
Amylases are probably the best studied glycoside hydrolases and have a huge biotechnological value for industrial processes on starch. Multiple amylases from fungi and microbes are currently in use. Whereas bacterial amylases are well suited for many industrial processes due to their high stability, fungal amylases are recognized as safe and are preferred in the food industry, although they lack the pH tolerance and stability of their bacterial counterparts. Here, we describe three amylases, two of which have a broad pH spectrum extending to pH 8 and higher stability well suited for a broad set of industrial applications. These enzymes have the characteristic GH13 α-amylase fold with a central (β/α)8-domain, an insertion domain with the canonical calcium binding site and a C-terminal β-sandwich domain. The active site was identified based on the binding of the inhibitor acarbose in form of a transglycosylation product, in the amylases from Thamnidium elegans and Cordyceps farinosa. The three amylases have shortened loops flanking the nonreducing end of the substrate binding cleft, creating a more open crevice. Moreover, a potential novel binding site in the C-terminal domain of the Cordyceps enzyme was identified, which might be part of a starch interaction site. In addition, Cordyceps farinosa amylase presented a successful example of using the microseed matrix screening technique to significantly speed-up crystallization.
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Zhoukun L, Wenwen Z, Lei Z, Yanxin W, Yajuan Z, Yan Q, Xue L, Yan H, Zhongli C. Gene Expression and Biochemical Characterization of a GH77 4‐α‐Glucanotransferase CcGtase FromCorallococcussp. EGB. STARCH-STARKE 2019. [DOI: 10.1002/star.201800254] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Li Zhoukun
- Key Laboratory of Agricultural Environmental MicrobiologyMinistry of AgricultureCollege of Life ScienceNanjing Agricultural UniversityNanjing 210095P. R. China
| | - Zheng Wenwen
- Key Laboratory of Agricultural Environmental MicrobiologyMinistry of AgricultureCollege of Life ScienceNanjing Agricultural UniversityNanjing 210095P. R. China
| | - Zhang Lei
- Key Laboratory of Agricultural Environmental MicrobiologyMinistry of AgricultureCollege of Life ScienceNanjing Agricultural UniversityNanjing 210095P. R. China
| | - Wang Yanxin
- Key Laboratory of Agricultural Environmental MicrobiologyMinistry of AgricultureCollege of Life ScienceNanjing Agricultural UniversityNanjing 210095P. R. China
| | - Zhang Yajuan
- Key Laboratory of Agricultural Environmental MicrobiologyMinistry of AgricultureCollege of Life ScienceNanjing Agricultural UniversityNanjing 210095P. R. China
| | - Qiao Yan
- Key Laboratory of Agricultural Environmental MicrobiologyMinistry of AgricultureCollege of Life ScienceNanjing Agricultural UniversityNanjing 210095P. R. China
| | - Luo Xue
- Key Laboratory of Agricultural Environmental MicrobiologyMinistry of AgricultureCollege of Life ScienceNanjing Agricultural UniversityNanjing 210095P. R. China
| | - Huang Yan
- Key Laboratory of Agricultural Environmental MicrobiologyMinistry of AgricultureCollege of Life ScienceNanjing Agricultural UniversityNanjing 210095P. R. China
| | - Cui Zhongli
- Key Laboratory of Agricultural Environmental MicrobiologyMinistry of AgricultureCollege of Life ScienceNanjing Agricultural UniversityNanjing 210095P. R. China
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Gangoiti J, Corwin SF, Lamothe LM, Vafiadi C, Hamaker BR, Dijkhuizen L. Synthesis of novel α-glucans with potential health benefits through controlled glucose release in the human gastrointestinal tract. Crit Rev Food Sci Nutr 2018; 60:123-146. [PMID: 30525940 DOI: 10.1080/10408398.2018.1516621] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The glycemic carbohydrates we consume are currently viewed in an unfavorable light in both the consumer and medical research worlds. In significant part, these carbohydrates, mainly starch and sucrose, are looked upon negatively due to their rapid and abrupt glucose delivery to the body which causes a high glycemic response. However, dietary carbohydrates which are digested and release glucose in a slow manner are recognized as providing health benefits. Slow digestion of glycemic carbohydrates can be caused by several factors, including food matrix effect which impedes α-amylase access to substrate, or partial inhibition by plant secondary metabolites such as phenolic compounds. Differences in digestion rate of these carbohydrates may also be due to their specific structures (e.g. variations in degree of branching and/or glycosidic linkages present). In recent years, much has been learned about the synthesis and digestion kinetics of novel α-glucans (i.e. small oligosaccharides or larger polysaccharides based on glucose units linked in different positions by α-bonds). It is the synthesis and digestion of such structures that is the subject of this review.
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Affiliation(s)
- Joana Gangoiti
- Microbial Physiology, Groningen Biomolecular Sciences and Biotechnology Institute (GBB), University of Groningen, Groningen, The Netherlands
| | - Sarah F Corwin
- Whistler Center for Carbohydrate Research, Department of Food Science, Purdue University, West Lafayette, IN, USA
| | - Lisa M Lamothe
- Nestlé Research Center, Vers-Chez-Les-Blanc, Lausanne, Switzerland
| | | | - Bruce R Hamaker
- Whistler Center for Carbohydrate Research, Department of Food Science, Purdue University, West Lafayette, IN, USA
| | - Lubbert Dijkhuizen
- Microbial Physiology, Groningen Biomolecular Sciences and Biotechnology Institute (GBB), University of Groningen, Groningen, The Netherlands
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10
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Yoon SH, Oh YK, Kim YR, Park J, Han SI, Kim YW. Complex formation of a 4-α-glucanotransferase using starch as a biocatalyst for starch modification. Food Sci Biotechnol 2017; 26:1659-1666. [PMID: 30263703 DOI: 10.1007/s10068-017-0203-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Revised: 08/07/2017] [Accepted: 08/30/2017] [Indexed: 11/26/2022] Open
Abstract
A 4-α-glucanotransferases from Thermus thermophilus (TTαGT) possesses an extra substrate binding site, leading to facile purification of the intact enzyme using amylose as an insoluble binding matrix. Due to the cost of amylose and low recovery yield, starch was replaced for amylose as an alternative capturer in this study. Using gelatinized corn starch at pH 9 with 36-h incubation in the presence of 1 M ammonium sulfate increased the TTαGT-starch complex formation yield from 2 to 56%. In preparative-scale production, TTαGT produced in Bacillus subtilis was recovered by 42.1% with the same specific activity as that of purified TTαGT. Structural and rheological analyses of the enzymatically modified starches revealed that the starch complex exhibited catalytic performance comparable to soluble TTαGT, suggesting that the starch complex can be used as a biocatalyst for modified starch production without elution of the enzyme from the complex.
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Affiliation(s)
- Sun-Hee Yoon
- 1Department of Food and Biotechnology, Korea University, Sejong, 30019 Korea
| | - You-Kyung Oh
- 1Department of Food and Biotechnology, Korea University, Sejong, 30019 Korea
| | - Yong-Ro Kim
- 2Department of Biosystems and Biomaterials Science and Engineering, Seoul National University, Seoul, 08826 Republic of Korea
| | - Jiyoung Park
- 3Department of Central Area Crop Science, National Institute of Crop Science, Rural Development Administration, Suwon, Gyeonggi 16613 Korea
| | - Sang-Ick Han
- 4Department of Functional Crop, Functional Crop Resource Development Division, National Institute of Crop Science, Rural Development Administration, Miryang, Gyeongnam 50424 Korea
| | - Young-Wan Kim
- 1Department of Food and Biotechnology, Korea University, Sejong, 30019 Korea
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11
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Gangoiti J, Lamothe L, van Leeuwen SS, Vafiadi C, Dijkhuizen L. Characterization of the Paenibacillus beijingensis DSM 24997 GtfD and its glucan polymer products representing a new glycoside hydrolase 70 subfamily of 4,6-α-glucanotransferase enzymes. PLoS One 2017; 12:e0172622. [PMID: 28399167 PMCID: PMC5388325 DOI: 10.1371/journal.pone.0172622] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Accepted: 01/25/2017] [Indexed: 11/18/2022] Open
Abstract
Previously we have reported that the Gram-negative bacterium Azotobacter chroococcum NCIMB 8003 uses the 4,6-α-glucanotransferase GtfD to convert maltodextrins and starch into a reuteran-like polymer consisting of (α1→4) glucan chains connected by alternating (α1→4)/(α1→6) linkages and (α1→4,6) branching points. This enzyme constituted the single evidence for this reaction and product specificity in the GH70 family, mostly containing glucansucrases encoded by lactic acid bacteria (http://www.CAZy.org). In this work, 4 additional GtfD-like proteins were identified in taxonomically diverse plant-associated bacteria forming a new GH70 subfamily with intermediate characteristics between the evolutionary related GH13 and GH70 families. The GtfD enzyme encoded by Paenibacillus beijingensis DSM 24997 was characterized providing the first example of a reuteran-like polymer synthesizing 4,6-α-glucanotransferase in a Gram-positive bacterium. Whereas the A. chroococcum GtfD activity on amylose resulted in the synthesis of a high molecular polymer, in addition to maltose and other small oligosaccharides, two reuteran-like polymer distributions are produced by P. beijingensis GtfD: a high-molecular mass polymer and a low-molecular mass polymer with an average Mw of 27 MDa and 19 kDa, respectively. Compared to the A. chroooccum GtfD product, both P. beijingensis GtfD polymers contain longer linear (α1→4) sequences in their structure reflecting a preference for transfer of even longer glucan chains by this enzyme. Overall, this study provides new insights into the evolutionary history of GH70 enzymes, and enlarges the diversity of natural enzymes that can be applied for modification of the starch present in food into less and/or more slowly digestible carbohydrate structures.
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Affiliation(s)
- Joana Gangoiti
- Microbial Physiology, Groningen Biomolecular Sciences and Biotechnology Institute (GBB), University of Groningen, Groningen, The Netherlands
| | - Lisa Lamothe
- Nestlé Research Center, Vers-Chez-Les-Blanc, Lausanne, Switzerland
| | - Sander Sebastiaan van Leeuwen
- Microbial Physiology, Groningen Biomolecular Sciences and Biotechnology Institute (GBB), University of Groningen, Groningen, The Netherlands
| | | | - Lubbert Dijkhuizen
- Microbial Physiology, Groningen Biomolecular Sciences and Biotechnology Institute (GBB), University of Groningen, Groningen, The Netherlands
- * E-mail:
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12
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O'Neill EC, Stevenson CEM, Tantanarat K, Latousakis D, Donaldson MI, Rejzek M, Nepogodiev SA, Limpaseni T, Field RA, Lawson DM. Structural Dissection of the Maltodextrin Disproportionation Cycle of the Arabidopsis Plastidial Disproportionating Enzyme 1 (DPE1). J Biol Chem 2015; 290:29834-53. [PMID: 26504082 PMCID: PMC4705983 DOI: 10.1074/jbc.m115.682245] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Indexed: 11/06/2022] Open
Abstract
The degradation of transitory starch in the chloroplast to provide fuel for the plant during the night requires a suite of enzymes that generate a series of short chain linear glucans. However, glucans of less than four glucose units are no longer substrates for these enzymes, whereas export from the plastid is only possible in the form of either maltose or glucose. In order to make use of maltotriose, which would otherwise accumulate, disproportionating enzyme 1 (DPE1; a 4-α-glucanotransferase) converts two molecules of maltotriose to a molecule of maltopentaose, which can now be acted on by the degradative enzymes, and one molecule of glucose that can be exported. We have determined the structure of the Arabidopsis plastidial DPE1 (AtDPE1), and, through ligand soaking experiments, we have trapped the enzyme in a variety of conformational states. AtDPE1 forms a homodimer with a deep, long, and open-ended active site canyon contained within each subunit. The canyon is divided into donor and acceptor sites with the catalytic residues at their junction; a number of loops around the active site adopt different conformations dependent on the occupancy of these sites. The "gate" is the most dynamic loop and appears to play a role in substrate capture, in particular in the binding of the acceptor molecule. Subtle changes in the configuration of the active site residues may prevent undesirable reactions or abortive hydrolysis of the covalently bound enzyme-substrate intermediate. Together, these observations allow us to delineate the complete AtDPE1 disproportionation cycle in structural terms.
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Affiliation(s)
- Ellis C O'Neill
- From the Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, United Kingdom and
| | - Clare E M Stevenson
- From the Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, United Kingdom and
| | - Krit Tantanarat
- the Starch and Cyclodextrin Research Unit, Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
| | - Dimitrios Latousakis
- From the Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, United Kingdom and
| | - Matthew I Donaldson
- From the Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, United Kingdom and
| | - Martin Rejzek
- From the Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, United Kingdom and
| | - Sergey A Nepogodiev
- From the Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, United Kingdom and
| | - Tipaporn Limpaseni
- the Starch and Cyclodextrin Research Unit, Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
| | - Robert A Field
- From the Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, United Kingdom and
| | - David M Lawson
- From the Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, United Kingdom and
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13
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Weiss SC, Skerra A, Schiefner A. Structural Basis for the Interconversion of Maltodextrins by MalQ, the Amylomaltase of Escherichia coli. J Biol Chem 2015; 290:21352-64. [PMID: 26139606 DOI: 10.1074/jbc.m115.667337] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Indexed: 11/06/2022] Open
Abstract
Amylomaltase MalQ is essential for the metabolism of maltose and maltodextrins in Escherichia coli. It catalyzes transglycosylation/disproportionation reactions in which glycosyl or dextrinyl units are transferred among linear maltodextrins of various lengths. To elucidate the molecular basis of transglycosylation by MalQ, we have determined three crystal structures of this enzyme, i.e. the apo-form, its complex with maltose, and an inhibitor complex with the transition state analog acarviosine-glucose-acarbose, at resolutions down to 2.1 Å. MalQ represents the first example of a mesophilic bacterial amylomaltase with known structure and exhibits an N-terminal extension of about 140 residues, in contrast with previously described thermophilic enzymes. This moiety seems unique to amylomaltases from Enterobacteriaceae and folds into two distinct subdomains that associate with different parts of the catalytic core. Intriguingly, the three MalQ crystal structures appear to correspond to distinct states of this enzyme, revealing considerable conformational changes during the catalytic cycle. In particular, the inhibitor complex highlights the requirement of both a 3-OH group and a 4-OH group (or α1-4-glycosidic bond) at the acceptor subsite +1 for the catalytically competent orientation of the acid/base catalyst Glu-496. Using an HPLC-based MalQ enzyme assay, we could demonstrate that the equilibrium concentration of maltodextrin products depends on the length of the initial substrate; with increasing numbers of glycosidic bonds, less glucose is formed. Thus, both structural and enzymatic data are consistent with the extremely low hydrolysis rates observed for amylomaltases and underline the importance of MalQ for the metabolism of maltodextrins in E. coli.
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Affiliation(s)
- Simon C Weiss
- From the Lehrstuhl für Biologische Chemie, Technische Universität München, Emil-Erlenmeyer-Forum 5, 85350 Freising-Weihenstephan, Germany
| | - Arne Skerra
- From the Lehrstuhl für Biologische Chemie, Technische Universität München, Emil-Erlenmeyer-Forum 5, 85350 Freising-Weihenstephan, Germany
| | - André Schiefner
- From the Lehrstuhl für Biologische Chemie, Technische Universität München, Emil-Erlenmeyer-Forum 5, 85350 Freising-Weihenstephan, Germany
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14
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Srisimarat W, Murakami S, Pongsawasdi P, Krusong K. Crystallization and preliminary X-ray crystallographic analysis of the amylomaltase from Corynebacterium glutamicum. Acta Crystallogr Sect F Struct Biol Cryst Commun 2013; 69:1004-6. [PMID: 23989149 PMCID: PMC3758149 DOI: 10.1107/s1744309113020319] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2013] [Accepted: 07/22/2013] [Indexed: 11/10/2022]
Abstract
Amylomaltase (AM; EC 2.4.1.25) belongs to the 4-α-glucanotransferase group of the α-amylase family. The enzyme can produce cycloamylose or large-ring cyclodextrin through intramolecular transglycosylation or cyclization reactions of α-1,4-glucan. Amylomaltase from the mesophilic bacterium Corynebacterium glutamicum (CgAM) contains extra residues at the N-terminus for which the three-dimensional structure is not yet known. In this study, CgAM was overexpressed and purified to homogeneity using DEAE FF and Phenyl FF columns. The purified CgAM was crystallized by the vapour-diffusion method. Preliminary X-ray data showed that the CgAM crystal diffracted to 1.7 Å resolution and belonged to space group P2(1)2(1)2(1), with unit-cell parameters a = 73.28, b = 82.61, c = 118.64 Å. To obtain the initial phases, crystals of selenomethionyl-substituted amylomaltase were produced, and multiple-wavelength anomalous dispersion phasing and structure refinement are now in progress.
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Affiliation(s)
- Wiraya Srisimarat
- Starch and Cyclodextrin Research Unit, Department of Biochemistry, Faculty of Science, Chulalongkorn University, Phyathai Road, Bangkok 10330, Thailand
| | - Shuichiro Murakami
- Department of Agricultural Chemistry, Faculty of Agriculture, Meiji University, Higashimita, Tama-ku, Kawasaki 214-8571, Japan
| | - Piamsook Pongsawasdi
- Starch and Cyclodextrin Research Unit, Department of Biochemistry, Faculty of Science, Chulalongkorn University, Phyathai Road, Bangkok 10330, Thailand
| | - Kuakarun Krusong
- Starch and Cyclodextrin Research Unit, Department of Biochemistry, Faculty of Science, Chulalongkorn University, Phyathai Road, Bangkok 10330, Thailand
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15
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Møller MS, Abou Hachem M, Svensson B, Henriksen A. Structure of the starch-debranching enzyme barley limit dextrinase reveals homology of the N-terminal domain to CBM21. Acta Crystallogr Sect F Struct Biol Cryst Commun 2012; 68:1008-12. [PMID: 22949184 PMCID: PMC3433187 DOI: 10.1107/s1744309112031004] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2012] [Accepted: 07/07/2012] [Indexed: 11/10/2022]
Abstract
Barley limit dextrinase (HvLD) is a debranching enzyme from glycoside hydrolase family 13 subfamily 13 (GH13_13) that hydrolyses α-1,6-glucosidic linkages in limit dextrins derived from amylopectin. The structure of HvLD was solved and refined to 1.9 Å resolution. The structure has a glycerol molecule in the active site and is virtually identical to the structures of HvLD in complex with the competitive inhibitors α-cyclodextrin and β-cyclodextrin solved to 2.5 and 2.1 Å resolution, respectively. However, three loops in the N-terminal domain that are shown here to resemble carbohydrate-binding module family 21 were traceable and were included in the present HvLD structure but were too flexible to be traced and included in the structures of the two HvLD-inhibitor complexes.
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Affiliation(s)
- Marie Sofie Møller
- Enzyme and Protein Chemistry, Department of Systems Biology, Technical University of Denmark, Søltofts Plads, Building 224, 2800 Kgs. Lyngby, Denmark
- Protein Chemistry Group, Carlsberg Laboratory, Gamle Carlsberg Vej 10, 2500 Valby, Denmark
| | - Maher Abou Hachem
- Enzyme and Protein Chemistry, Department of Systems Biology, Technical University of Denmark, Søltofts Plads, Building 224, 2800 Kgs. Lyngby, Denmark
| | - Birte Svensson
- Enzyme and Protein Chemistry, Department of Systems Biology, Technical University of Denmark, Søltofts Plads, Building 224, 2800 Kgs. Lyngby, Denmark
| | - Anette Henriksen
- Protein Chemistry Group, Carlsberg Laboratory, Gamle Carlsberg Vej 10, 2500 Valby, Denmark
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16
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Altered large-ring cyclodextrin product profile due to a mutation at Tyr-172 in the amylomaltase of Corynebacterium glutamicum. Appl Environ Microbiol 2012; 78:7223-8. [PMID: 22865069 DOI: 10.1128/aem.01366-12] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Corynebacterium glutamicum amylomaltase (CgAM) catalyzes the formation of large-ring cyclodextrins (LR-CDs) with a degree of polymerization of 19 and higher. The cloned CgAM gene was ligated into the pET-17b vector and used to transform Escherichia coli BL21(DE3). Site-directed mutagenesis of Tyr-172 in CgAM to alanine (Y172A) was performed to determine its role in the control of LR-CD production. Both the recombinant wild-type (WT) and Y172A enzymes were purified to apparent homogeneity and characterized. The Y172A enzyme exhibited lower disproportionation, cyclization, and hydrolysis activities than the WT. The k(cat)/K(m) of the disproportionation reaction of the Y172A enzyme was 2.8-fold lower than that of the WT enzyme. The LR-CD product profile from enzyme catalysis depended on the incubation time and the enzyme concentration. Interestingly, the Y172A enzyme showed a product pattern different from that of the WT CgAM at a long incubation time. The principal LR-CD products of the Y172A mutated enzyme were a cycloamylose mixture with a degree of polymerization of 28 or 29 (CD28 or CD29), while the principal LR-CD product of the WT enzyme was CD25 at 0.05 U of amylomaltase. These results suggest that Tyr-172 plays an important role in determining the LR-CD product profile of this novel CgAM.
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17
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Woo EJ, Lee S, Cha H, Park JT, Yoon SM, Song HN, Park KH. Structural insight into the bifunctional mechanism of the glycogen-debranching enzyme TreX from the archaeon Sulfolobus solfataricus. J Biol Chem 2008; 283:28641-8. [PMID: 18703518 DOI: 10.1074/jbc.m802560200] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
TreX is an archaeal glycogen-debranching enzyme that exists in two oligomeric states in solution, as a dimer and tetramer. Unlike its homologs, TreX from Sulfolobus solfataricus shows dual activities for alpha-1,4-transferase and alpha-1,6-glucosidase. To understand this bifunctional mechanism, we determined the crystal structure of TreX in complex with an acarbose ligand. The acarbose intermediate was covalently bound to Asp363, occupying subsites -1 to -3. Although generally similar to the monomeric structure of isoamylase, TreX exhibits two different active-site configurations depending on its oligomeric state. The N terminus of one subunit is located at the active site of the other molecule, resulting in a reshaping of the active site in the tetramer. This is accompanied by a large shift in the "flexible loop" (amino acids 399-416), creating connected holes inside the tetramer. Mutations in the N-terminal region result in a sharp increase in alpha-1,4-transferase activity and a reduced level of alpha-1,6-glucosidase activity. On the basis of geometrical analysis of the active site and mutational study, we suggest that the structural lid (acids 99-97) at the active site generated by the tetramerization is closely associated with the bifunctionality and in particular with the alpha-1,4-transferase activity. These results provide a structural basis for the modulation of activities upon TreX oligomerization that may represent a common mode of action for other glycogen-debranching enzymes in higher organisms.
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Affiliation(s)
- Eui-Jeon Woo
- Translational Research Center, Korea Research Institute of Bioscience and Biotechnology, 111 Gwahangno, Yuseong-gu, Daejeon 305-806
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18
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Fujii K, Minagawa H, Terada Y, Takaha T, Kuriki T, Shimada J, Kaneko H. Use of random and saturation mutageneses to improve the properties of Thermus aquaticus amylomaltase for efficient production of cycloamyloses. Appl Environ Microbiol 2005; 71:5823-7. [PMID: 16204493 PMCID: PMC1265922 DOI: 10.1128/aem.71.10.5823-5827.2005] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Amylomaltase from Thermus aquaticus catalyzes intramolecular transglycosylation of alpha-1,4 glucans to produce cyclic alpha-1,4 glucans (cycloamyloses) with degrees of polymerization of 22 and higher. Although the amylomaltase mainly catalyzes the transglycosylation reaction, it also has weak hydrolytic activity, which results in a reduction in the yield of the cycloamyloses. In order to obtain amylomaltase with less hydrolytic activity, random mutagenesis was perfromed for the enzyme gene. Tyr54 (Y54) was identified as the amino acid involved in the hydrolytic activity of the enzyme. When Y54 was replaced with all other amino acids by site-directed mutagenesis, the hydrolytic activities of the mutated enzymes were drastically altered. The hydrolytic activities of the Y54G, Y54P, Y54T, and Y54W mutated enzymes were remarkably reduced compared with that of the wild-type enzyme, while those of the Y54F and Y54K mutated enzymes were similar to that of the wild-type enzyme. Introducing an amino acid replacement at Y54 also significantly affected the cyclization activity of the amylomaltase. The Y54A, Y54L, Y54R, and Y54S mutated enzymes exhibited cyclization activity that was approximately twofold higher than that of the wild-type enzyme. When the Y54G mutated enzyme was employed for cycloamylose production, the yield of cycloamyloses was more than 90%, and there was no decrease until the end of the reaction.
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Affiliation(s)
- Kazutoshi Fujii
- Biochemical Research Laboratory, Ezaki Glico Co., Ltd., 4-6-5 Utajima, Nishiyodogawa-ku, Osaka 555-8502, Japan.
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19
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Kaper T, Talik B, Ettema TJ, Bos H, van der Maarel MJEC, Dijkhuizen L. Amylomaltase of Pyrobaculum aerophilum IM2 produces thermoreversible starch gels. Appl Environ Microbiol 2005; 71:5098-106. [PMID: 16151092 PMCID: PMC1214675 DOI: 10.1128/aem.71.9.5098-5106.2005] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2004] [Accepted: 04/02/2005] [Indexed: 11/20/2022] Open
Abstract
Amylomaltases are 4-alpha-glucanotransferases (EC 2.4.1.25) of glycoside hydrolase family 77 that transfer alpha-1,4-linked glucans to another acceptor, which can be the 4-OH group of an alpha-1,4-linked glucan or glucose. The amylomaltase-encoding gene (PAE1209) from the hyperthermophilic archaeon Pyrobaculum aerophilum IM2 was cloned and expressed in Escherichia coli, and the gene product (PyAMase) was characterized. PyAMase displays optimal activity at pH 6.7 and 95 degrees C and is the most thermostable amylomaltase described to date. The thermostability of PyAMase was reduced in the presence of 2 mM dithiothreitol, which agreed with the identification of two possible cysteine disulfide bridges in a three-dimensional model of PyAMase. The kinetics for the disproportionation of malto-oligosaccharides, inhibition by acarbose, and binding mode of the substrates in the active site were determined. Acting on gelatinized food-grade potato starch, PyAMase produced a thermoreversible starch product with gelatin-like properties. This thermoreversible gel has potential applications in the food industry. This is the first report on an archaeal amylomaltase.
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Affiliation(s)
- Thijs Kaper
- Centre for Carbohydrate Bioengineering TNO-University of Groningen, P.O. Box 14, 9750 AA Haren, The Netherlands
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20
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Kagawa M, Fujimoto Z, Momma M, Takase K, Mizuno H. Crystal structure of Bacillus subtilis alpha-amylase in complex with acarbose. J Bacteriol 2004; 185:6981-4. [PMID: 14617662 PMCID: PMC262715 DOI: 10.1128/jb.185.23.6981-6984.2003] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The crystal structure of Bacillus subtilis alpha-amylase, in complex with the pseudotetrasaccharide inhibitor acarbose, revealed an hexasaccharide in the active site as a result of transglycosylation. After comparison with the known structure of the catalytic-site mutant complexed with the native substrate maltopentaose, it is suggested that the present structure represents a mimic intermediate in the initial stage of the catalytic process.
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Affiliation(s)
- Masayuki Kagawa
- Department of Biochemistry, National Institute of Agrobiological Sciences, Tsukuba, Ibaraki 305-8602, Japan
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21
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Yanase M, Takata H, Takaha T, Kuriki T, Smith SM, Okada S. Cyclization reaction catalyzed by glycogen debranching enzyme (EC 2.4.1.25/EC 3.2.1.33) and its potential for cycloamylose production. Appl Environ Microbiol 2002; 68:4233-9. [PMID: 12200270 PMCID: PMC124075 DOI: 10.1128/aem.68.9.4233-4239.2002] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Glycogen debranching enzyme (GDE) has 4-alpha-glucanotransferase and amylo-1,6-glucosidase activities in the single polypeptide chain. We analyzed the detailed action profile of GDE from Saccharomyces cerevisiae on amylose and tested whether GDE catalyzes cyclization of amylose. GDE treatment resulted in a rapid reduction of absorbance of iodine-amylose complex and the accumulation of a product that was resistant to an exo-amylase (glucoamylase [GA]) but was degraded by an endo-type alpha-amylase to glucose and maltose. These results indicated that GDE catalyzed cyclization of amylose to produce cyclic alpha-1,4 glucan (cycloamylose). The formation of cycloamylose was confirmed by high-performance anion-exchange chromatography, and the size was shown to range from a degree of polymerization of 11 to a degree of polymerization around 50. The minimum size and the size distribution of cycloamylose were different from those of cycloamylose produced by other 4-alpha-glucanotransferases. GDE also efficiently produced cycloamylose even from the branched glucan substrate, starch, demonstrating its potential for industrial production of cycloamylose.
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Affiliation(s)
- Michiyo Yanase
- Biochemical Research Laboratory, Ezaki Glico Co., Ltd., Nishiyodogawa-ku, Osaka 555-8502, Japan.
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