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Hattori-Muroi K, Naganawa-Asaoka H, Kabumoto Y, Tsukamoto K, Fujisaki Y, Fujimura Y, Komiyama S, Kinashi Y, Kato M, Sato S, Takahashi D, Hase K. α-Glucosidase inhibitors boost gut immunity by inducing IgA responses in Peyer's patches. Front Immunol 2023; 14:1277637. [PMID: 38022673 PMCID: PMC10646501 DOI: 10.3389/fimmu.2023.1277637] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Accepted: 10/20/2023] [Indexed: 12/01/2023] Open
Abstract
Peyer's patches (PPs) are specialized gut-associated lymphoid tissues that initiate follicular helper T (Tfh)-mediated immunoglobulin A (IgA) response to luminal antigens derived from commensal symbionts, pathobionts, and dietary sources. IgA-producing B cells migrate from PPs to the small intestinal lamina propria and secrete IgA across the epithelium, modulating the ecological balance of the commensal microbiota and neutralizing pathogenic microorganisms. α-glucosidase inhibitors (α-GIs) are antidiabetic drugs that inhibit carbohydrate digestion in the small intestinal epithelium, leading to alterations in the commensal microbiota composition and metabolic activity. The commensal microbiota and IgA responses exhibit bidirectional interactions that modulate intestinal homeostasis and immunity. However, the effect of α-GIs on the intestinal IgA response remains unclear. We investigated whether α-GIs affect IgA responses by administering voglibose and acarbose to mice via drinking water. We analyzed Tfh cells, germinal center (GC) B cells, and IgA-producing B cells in PPs by flow cytometry. We also assessed pathogen-specific IgA responses. We discovered that voglibose and acarbose induced Tfh cells, GCB cells, and IgA-producing B cells in the PPs of the proximal small intestine in mice. This effect was attributed to the modification of the microbiota rather than a shortage of monosaccharides. Furthermore, voglibose enhanced secretory IgA (S-IgA) production against attenuated Salmonella Typhimurium. Our findings reveal a novel mechanism by which α-GIs augment antigen-specific IgA responses by stimulating Tfh-GCB responses in PPs, and suggest a potential therapeutic application as an adjuvant for augmenting mucosal vaccines.
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Affiliation(s)
- Kisara Hattori-Muroi
- Division of Biochemistry, Graduate School of Pharmaceutical Sciences, Keio University, Tokyo, Japan
| | - Hanako Naganawa-Asaoka
- Division of Biochemistry, Department of Pharmaceutical Sciences, Keio University Faculty of Pharmacy, Tokyo, Japan
| | - Yuma Kabumoto
- Division of Biochemistry, Graduate School of Pharmaceutical Sciences, Keio University, Tokyo, Japan
| | - Kei Tsukamoto
- Division of Biochemistry, Department of Pharmaceutical Sciences, Keio University Faculty of Pharmacy, Tokyo, Japan
| | - Yosuke Fujisaki
- Division of Biochemistry, Graduate School of Pharmaceutical Sciences, Keio University, Tokyo, Japan
| | - Yumiko Fujimura
- Division of Biochemistry, Department of Pharmaceutical Sciences, Keio University Faculty of Pharmacy, Tokyo, Japan
| | - Seiga Komiyama
- Division of Biochemistry, Graduate School of Pharmaceutical Sciences, Keio University, Tokyo, Japan
| | - Yusuke Kinashi
- Division of Biochemistry, Graduate School of Pharmaceutical Sciences, Keio University, Tokyo, Japan
| | - Miki Kato
- Division of Biochemistry, Department of Pharmaceutical Sciences, Keio University Faculty of Pharmacy, Tokyo, Japan
| | - Shintaro Sato
- Mucosal Vaccine Project, BIKEN Innovative Vaccine Research Alliance Laboratories, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan
- Department of Microbiology and Immunology, School of Pharmaceutical Sciences, Wakayama Medical University, Wakayama, Japan
| | - Daisuke Takahashi
- Division of Biochemistry, Graduate School of Pharmaceutical Sciences, Keio University, Tokyo, Japan
- Division of Biochemistry, Department of Pharmaceutical Sciences, Keio University Faculty of Pharmacy, Tokyo, Japan
| | - Koji Hase
- Division of Biochemistry, Graduate School of Pharmaceutical Sciences, Keio University, Tokyo, Japan
- Division of Biochemistry, Department of Pharmaceutical Sciences, Keio University Faculty of Pharmacy, Tokyo, Japan
- The Institute of Fermentation Sciences (IFeS), Faculty of Food and Agricultural Sciences, Fukushima University, Fukushima, Japan
- International Research and Development Center for Mucosal Vaccines, the Institute of Medical Science, The University of Tokyo (IMSUT), Tokyo, Japan
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Tian J, Li C, Dong Z, Yang Y, Xing J, Yu P, Xin Y, Xu F, Wang L, Mu Y, Guo X, Sun Q, Zhao G, Gu Y, Qin G, Jiang W. Inactivation of the antidiabetic drug acarbose by human intestinal microbial-mediated degradation. Nat Metab 2023; 5:896-909. [PMID: 37157031 DOI: 10.1038/s42255-023-00796-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Accepted: 03/30/2023] [Indexed: 05/10/2023]
Abstract
Drugs can be modified or degraded by the gut microbiota, which needs to be considered in personalized therapy. The clinical efficacy of the antidiabetic drug acarbose, an inhibitor of α-glucosidase, varies greatly among individuals for reasons that are largely unknown. Here we identify in the human gut acarbose-degrading bacteria, termed Klebsiella grimontii TD1, whose presence is associated with acarbose resistance in patients. Metagenomic analyses reveal that the abundance of K. grimontii TD1 is higher in patients with a weak response to acarbose and increases over time with acarbose treatment. In male diabetic mice, co-administration of K. grimontii TD1 reduces the hypoglycaemic effect of acarbose. Using induced transcriptome and protein profiling, we further identify an acarbose preferred glucosidase, Apg, in K. grimontii TD1, which can degrade acarbose into small molecules with loss of inhibitor function and is widely distributed in human intestinal microorganisms, especially in Klebsiella. Our results suggest that a comparatively large group of individuals could be at risk of acarbose resistance due to its degradation by intestinal bacteria, which may represent a clinically relevant example of non-antibiotic drug resistance.
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Affiliation(s)
- Jinzhong Tian
- Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences (CAS), Shanghai, PR China
| | - Chong Li
- Department of Endocrinology and Metabolism, First Affiliated Hospital of Zhengzhou University, Zhengzhou, PR China
| | - Zhixiang Dong
- Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences (CAS), Shanghai, PR China
- University of Chinese Academy of Sciences, Beijing, PR China
| | - Yunpeng Yang
- Institute of Comparative Medicine, College of Veterinary Medicine, Yangzhou University, Yangzhou, PR China
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, PR China
| | - Jing Xing
- Lingang Laboratory, Shanghai, PR China
| | - Peijun Yu
- University of Chinese Academy of Sciences, Beijing, PR China
- Institute of Neuroscience, CAS Key Laboratory of Primate Neurobiology, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, PR China
| | - Ying Xin
- Department of Endocrinology and Metabolism, First Affiliated Hospital of Zhengzhou University, Zhengzhou, PR China
| | - Fengmei Xu
- Department of Endocrinology and Metabolism, Hebi Coal (group) Ltd. General Hospital, Hebi, PR China
| | - Lianwei Wang
- Department of Endocrinology and Metabolism, Zhumadian Central Hospital, Zhumadian, PR China
| | - Yahui Mu
- Department of Endocrinology and Metabolism, Huanghe Sanmenxia Hospital, Sanmenxia, PR China
| | - Xiangyang Guo
- Department of Endocrinology and Metabolism, Xinyang Central Hospital, Xinyang, PR China
| | - Qiang Sun
- Institute of Neuroscience, CAS Key Laboratory of Primate Neurobiology, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, PR China
| | - Guoping Zhao
- Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences (CAS), Shanghai, PR China
| | - Yang Gu
- Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences (CAS), Shanghai, PR China.
| | - Guijun Qin
- Department of Endocrinology and Metabolism, First Affiliated Hospital of Zhengzhou University, Zhengzhou, PR China.
| | - Weihong Jiang
- Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences (CAS), Shanghai, PR China.
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Tsunoda T, Asamizu S, Mahmud T. Biochemical Characterization of GacI, a Bifunctional Glycosyltransferase-Phosphatase Enzyme Involved in Acarbose Biosynthesis in Streptomyces glaucescens GLA.O. Biochemistry 2022; 61:2628-2635. [PMID: 36288494 PMCID: PMC9669214 DOI: 10.1021/acs.biochem.2c00473] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Acarbose, a pseudotetrasaccharide produced by several strains of Actinoplanes and Streptomyces, is an α-glucosidase inhibitor clinically used to control type II diabetes. Bioinformatic analysis of the biosynthetic gene clusters of acarbose in Actinoplanes sp. SE50/110 (the acb cluster) and Streptomyces glaucescens GLA.O (the gac cluster) revealed their distinct genetic organizations and presumably biosynthetic pathways. However, to date, only the acarbose pathway in the SE50/110 strain has been extensively studied. Here, we report that GacI, one of the proteins that appear to be different between the two pathways, is a bifunctional glycosyltransferase family 5 (GT5)-phosphatase (PP) enzyme that functions at two different steps in acarbose biosynthesis in S. glaucescens GLA.O. In the acb pathway, the GT and the PP reactions are performed by two different enzymes. Truncated GacI proteins having only the GT or the PP domain showed comparable catalytic activity with the full-length GacI, indicating that domain separation does not significantly affect their respective catalytic activity. GacI, which is widely distributed in many Streptomyces, represents the first example of naturally occurring GT5-PP bifunctional enzymes biochemically characterized.
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Affiliation(s)
- Takeshi Tsunoda
- Department of Pharmaceutical Sciences, Oregon State University, Corvallis, OR 97331-3507 (USA)
| | - Shumpei Asamizu
- Department of Pharmaceutical Sciences, Oregon State University, Corvallis, OR 97331-3507 (USA)
| | - Taifo Mahmud
- Department of Pharmaceutical Sciences, Oregon State University, Corvallis, OR 97331-3507 (USA)
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Wang Y, Dai K, Xie K, Weng C. [Biosynthesis and regulatory mechanism of acarbose and its structural analogs: a review]. Sheng Wu Gong Cheng Xue Bao 2022; 38:605-619. [PMID: 35234385 DOI: 10.13345/j.cjb.210248] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Acarbose is widely used as α-glucosidase inhibitor in the treatment of type Ⅱ diabetes. Actinoplanes sp. is used for industrial production of acarbose. As a secondary metabolite, the biosynthesis of acarbose is quite complex. In addition to acarbose, a few acarbose structural analogs are also accumulated in the culture broth of Actinoplanes sp., which are hard to remove. Due to lack of systemic understanding of the biosynthesis and regulation mechanisms of acarbose and its structural analogs, it is difficult to eliminate or reduce the biosynthesis of the structural analogs. Recently, the advances in omics technologies and molecular biology have facilitated the investigations of biosynthesis and regulatory mechanisms of acarbose and its structural analogs in Actinoplanes sp.. The genes involved in the biosynthesis of acarbose and its structural analogs and their regulatory mechanism have been extensively explored by using bioinformatics analysis, genetic manipulation and enzymatic characterization, which is summarized in this review.
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Affiliation(s)
- Yuanshan Wang
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, Zhejiang, China
| | - Kelei Dai
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, Zhejiang, China
| | - Kaxi Xie
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, Zhejiang, China
| | - Chunyue Weng
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, Zhejiang, China
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5
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Yang J, Wang X, Zhang C, Ma L, Wei T, Zhao Y, Peng X. Comparative study of inhibition mechanisms of structurally different flavonoid compounds on α-glucosidase and synergistic effect with acarbose. Food Chem 2021; 347:129056. [PMID: 33476922 DOI: 10.1016/j.foodchem.2021.129056] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Revised: 12/11/2020] [Accepted: 01/05/2021] [Indexed: 01/14/2023]
Abstract
Flavonoid compounds have anti-diabetic activity, which can control blood glucose levels by inhibiting α-glucosidase activity. In this paper, the inhibition mechanisms between four flavonoid compounds and α-glucosidase were studied by multispectroscopic methods and molecular docking. The results showed that the inhibitory activities of flavonoid compounds were higher than that of acarbose, and the sequence of inhibition effect was scutellarein > nepetin > apigenin > hispidulin > acarbose. Also, the synergistic effects of flavonoid compounds combined with acarbose on inhibiting α-glucosidase activity were observed. The fluorescence results showed that flavonoid compounds combined with α-glucosidase to form a stable complex. And the spectral analysis indicated that the microenvironmental and secondary structure of α-glucosidase were changed. The present study demonstrated that the molecular structure of flavonoid compounds played an important role in the inhibition process, namely, scutellarein with more hydroxyl groups on the A-ring might serve as the most effective α-glucosidase inhibitor.
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Affiliation(s)
- Jichen Yang
- School of Life Sciences, Tianjin University, Tianjin 300072, PR China
| | - Xiaoli Wang
- School of Life Sciences, Tianjin University, Tianjin 300072, PR China
| | - Chuanying Zhang
- School of Life Sciences, Tianjin University, Tianjin 300072, PR China
| | - Lun Ma
- Shaanxi Zhuyuanbang Medical Technology Co., Ltd, Xi'an 710048, PR China
| | - Tao Wei
- Shaanxi Zhuyuanbang Medical Technology Co., Ltd, Xi'an 710048, PR China
| | - Yajing Zhao
- School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, PR China
| | - Xin Peng
- School of Life Sciences, Tianjin University, Tianjin 300072, PR China; Tianjin Key Laboratory of Function and Application of Biological Macromolecular Structures, Tianjin University, Tianjin 300072, PR China.
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6
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Xu L, Li W, Chen Z, Guo Q, Wang C, Santhanam RK, Chen H. Inhibitory effect of epigallocatechin-3-O-gallate on α-glucosidase and its hypoglycemic effect via targeting PI3K/AKT signaling pathway in L6 skeletal muscle cells. Int J Biol Macromol 2018; 125:605-611. [PMID: 30529552 DOI: 10.1016/j.ijbiomac.2018.12.064] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Revised: 12/05/2018] [Accepted: 12/06/2018] [Indexed: 12/28/2022]
Abstract
Epigallocatechin-3-O-gallate (EGCG), a tea polyphenol is renowned for its anti-diabetic properties, however limited studies elucidate its hypoglycemic mechanism from multi-perspectives. In the present study, the interaction between EGCG and α-glucosidase was investigated through kinetics analysis, fluorescence spectra, Fourier transform infrared (FT-IR) spectra and molecular docking studies. Additionally, the effect of EGCG on glucose uptake and its related signaling pathway in L6 muscle cells were also investigated. The results showed that the α-glucosidase inhibitory activity of EGCG (IC50 = 19.5 ± 0.3 μM) was higher than that acarbose (IC50 = 278.7 ± 1.1 μM). EGCG inhibited α-glucosidase in a reversible and non-competitive manner. EGCG quenched the fluorescence of α-glucosidase due to the complex formation between EGCG and α-glucosidase, where the hydrogen bonds played a critical role. Microenvironment and the secondary structure of α-glucosidase were highly influenced by EGCG. Molecular docking results indicated that the binding sites on α-glucosidase for EGCG were close to the active site pocket of the enzyme. EGCG was also found to enhance the glucose uptake and promote GLUT4 translocation to plasma membrane via PI3K/AKT signaling pathway in L6 skeletal muscle cells. Overall, these results revealed the possible hypoglycemic mechanism of EGCG.
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Affiliation(s)
- Leilei Xu
- Tianjin Key Laboratory for Modern Drug Delivery & High-Efficiency, School of Pharmaceutical Science and Technology, Tianjin University, Tianjin 300072, PR China
| | - Weiwei Li
- Tianjin Key Laboratory for Modern Drug Delivery & High-Efficiency, School of Pharmaceutical Science and Technology, Tianjin University, Tianjin 300072, PR China
| | - Zhongqin Chen
- Tianjin Key Laboratory for Modern Drug Delivery & High-Efficiency, School of Pharmaceutical Science and Technology, Tianjin University, Tianjin 300072, PR China
| | - Qingwen Guo
- Tianjin Key Laboratory for Modern Drug Delivery & High-Efficiency, School of Pharmaceutical Science and Technology, Tianjin University, Tianjin 300072, PR China
| | - Chunli Wang
- Tianjin Key Laboratory for Modern Drug Delivery & High-Efficiency, School of Pharmaceutical Science and Technology, Tianjin University, Tianjin 300072, PR China
| | - Ramesh Kumar Santhanam
- Tianjin Key Laboratory for Modern Drug Delivery & High-Efficiency, School of Pharmaceutical Science and Technology, Tianjin University, Tianjin 300072, PR China
| | - Haixia Chen
- Tianjin Key Laboratory for Modern Drug Delivery & High-Efficiency, School of Pharmaceutical Science and Technology, Tianjin University, Tianjin 300072, PR China.
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Wolf T, Schneiker-Bekel S, Neshat A, Ortseifen V, Wibberg D, Zemke T, Pühler A, Kalinowski J. Genome improvement of the acarbose producer Actinoplanes sp. SE50/110 and annotation refinement based on RNA-seq analysis. J Biotechnol 2017; 251:112-123. [PMID: 28427920 DOI: 10.1016/j.jbiotec.2017.04.013] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Revised: 04/11/2017] [Accepted: 04/14/2017] [Indexed: 12/16/2022]
Abstract
Actinoplanes sp. SE50/110 is the natural producer of acarbose, which is used in the treatment of diabetes mellitus type II. However, until now the transcriptional organization and regulation of the acarbose biosynthesis are only understood rudimentarily. The genome sequence of Actinoplanes sp. SE50/110 was known before, but was resequenced in this study to remove assembly artifacts and incorrect base callings. The annotation of the genome was refined in a multi-step approach, including modern bioinformatic pipelines, transcriptome and proteome data. A whole transcriptome RNA-seq library as well as an RNA-seq library enriched for primary 5'-ends were used for the detection of transcription start sites, to correct tRNA predictions, to identify novel transcripts like small RNAs and to improve the annotation through the correction of falsely annotated translation start sites. The transcriptome data sets were also applied to identify 31 cis-regulatory RNA structures, such as riboswitches or RNA thermometers as well as three leaderless transcribed short peptides found in putative attenuators upstream of genes for amino acid biosynthesis. The transcriptional organization of the acarbose biosynthetic gene cluster was elucidated in detail and fourteen novel biosynthetic gene clusters were suggested. The accurate genome sequence and precise annotation of the Actinoplanes sp. SE50/110 genome will be the foundation for future genetic engineering and systems biology studies.
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Affiliation(s)
- Timo Wolf
- Microbial Genomics and Biotechnology, Center for Biotechnology, Bielefeld University, Universitätsstraße 27, 33615 Bielefeld, Germany
| | - Susanne Schneiker-Bekel
- Senior Research Group in Genome Research of Industrial Microorganisms, Center for Biotechnology, Bielefeld University, Universitätsstraße 27, 33615 Bielefeld, Germany
| | - Armin Neshat
- Microbial Genomics and Biotechnology, Center for Biotechnology, Bielefeld University, Universitätsstraße 27, 33615 Bielefeld, Germany
| | - Vera Ortseifen
- Senior Research Group in Genome Research of Industrial Microorganisms, Center for Biotechnology, Bielefeld University, Universitätsstraße 27, 33615 Bielefeld, Germany
| | - Daniel Wibberg
- Senior Research Group in Genome Research of Industrial Microorganisms, Center for Biotechnology, Bielefeld University, Universitätsstraße 27, 33615 Bielefeld, Germany
| | - Till Zemke
- Product Supply, Bayer Pharma AG, Friedrich Ebert Str. 217-475, 42117 Wuppertal, Germany
| | - Alfred Pühler
- Senior Research Group in Genome Research of Industrial Microorganisms, Center for Biotechnology, Bielefeld University, Universitätsstraße 27, 33615 Bielefeld, Germany
| | - Jörn Kalinowski
- Microbial Genomics and Biotechnology, Center for Biotechnology, Bielefeld University, Universitätsstraße 27, 33615 Bielefeld, Germany.
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Markiewicz M, Jungnickel C, Stolte S, Białk-Bielińska A, Kumirska J, Mrozik W. Primary degradation of antidiabetic drugs. J Hazard Mater 2017; 324:428-435. [PMID: 27829515 DOI: 10.1016/j.jhazmat.2016.11.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Revised: 10/05/2016] [Accepted: 11/02/2016] [Indexed: 06/06/2023]
Abstract
Type 2 diabetes is a chronic disease affecting a large portion of the world population and is treated by orally administered drugs. Since these drugs are often taken in high doses and are excreted unchanged or partially metabolised many of them are nowadays detected in surface waters or wastewater treatment plants effluents. Unmetabolised antidiabetics or some of their transformation products retain their pharmacological activity, therefore their presence in the environment is highly undesired. One of the main routes of elimination from wastewaters or surface waters is biodegradation. Within this work we tested primary biodegradation of: metformin and its metabolite guanylurea, acarbose, glibenclamide, gliclazide and glimepiride. We also inspected what might be the extent of the degradation by examining the products formed during the degradation using liquid chromatography coupled to tandem mass spectrometry. Transformation of diabetes staple drug metformin to dead-end product guanylurea was generally confirmed. An alternative, though rather minor pathway leading to complete mineralisation was also found. Complete primary degradation was observed for acarbose, glibenclamide and glimepiride whereas gliclazide was shown to be resistant to biodegradation. These results allow a preliminary assessment of environmental persistency of a very important group of pharmaceuticals and show need for implementing monitoring programs.
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Affiliation(s)
- Marta Markiewicz
- UFT-Centre for Environmental Research and Technology, Sustainable Chemistry Group, University of Bremen, Leobener Straße, D-28359 Bremen, Germany.
| | - Christian Jungnickel
- Department of Colloid and Lipid Science, Faculty of Chemistry, Gdańsk University of Technology, ul. Narutowicza 11/12, 80-233 Gdańsk, Poland
| | - Stefan Stolte
- UFT-Centre for Environmental Research and Technology, Sustainable Chemistry Group, University of Bremen, Leobener Straße, D-28359 Bremen, Germany; Department of Environmental Analysis, Faculty of Chemistry, University of Gdańsk, ul. W. Stwosza 63, 80-308 Gdańsk, Poland
| | - Anna Białk-Bielińska
- Department of Environmental Analysis, Faculty of Chemistry, University of Gdańsk, ul. W. Stwosza 63, 80-308 Gdańsk, Poland
| | - Jolanta Kumirska
- Department of Environmental Analysis, Faculty of Chemistry, University of Gdańsk, ul. W. Stwosza 63, 80-308 Gdańsk, Poland
| | - Wojciech Mrozik
- School of Civil Engineering and Geosciences, Cassie Building, Newcastle University, Newcastle upon Tyne NE1 7RU, UK; Department of Inorganic Chemistry, Faculty of Pharmacy, Medical University of Gdańsk, Al. Hallera 107, 80-416 Gdańsk, Poland
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9
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Li KT, Peng WF, Xia W, Huang L, Cheng X. Metabolic differences of industrial acarbose-producing Actinoplanes sp. A56 under various osmolality levels. World J Microbiol Biotechnol 2015; 32:3. [PMID: 26712618 DOI: 10.1007/s11274-015-1976-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Accepted: 10/14/2015] [Indexed: 11/26/2022]
Abstract
Many investigations have revealed that a certain concentration of osmolality was indispensable for efficient acarbose production, but little information was available on the response mechanism of acarbose-producing strains to osmotic stress. By using the gas chromatography-mass spectrometry (GC-MS) analysis coupled with the enzyme activity determination of central carbon metabolism, the present work investigated the metabolic characteristics of industrial acarbose-producing Actinoplanes sp. A56 under various osmolality levels. Relatively high osmolality (450-500 mOsm/kg) appeared to favor efficient acarbose production by Actinoplanes sp. A56, although it inhibited cell growth. Further GC-MS analysis showed that fatty acids were the uppermost differential intracellular metabolites under various osmolality levels, and the relatively high osmolality resulted in increases in levels of fatty acids.
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Affiliation(s)
- Kun-tai Li
- Nanchang Key Laboratory of Applied Fermentation Technology, Jiangxi Agricultural University, Nanchang, 330045, China
| | - Wei-fu Peng
- Nanchang Key Laboratory of Applied Fermentation Technology, Jiangxi Agricultural University, Nanchang, 330045, China
| | - Wei Xia
- Nanchang Key Laboratory of Applied Fermentation Technology, Jiangxi Agricultural University, Nanchang, 330045, China
| | - Lin Huang
- Nanchang Key Laboratory of Applied Fermentation Technology, Jiangxi Agricultural University, Nanchang, 330045, China
| | - Xin Cheng
- Nanchang Key Laboratory of Applied Fermentation Technology, Jiangxi Agricultural University, Nanchang, 330045, China.
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Mok SC, Teh AH, Saito JA, Najimudin N, Alam M. Crystal structure of a compact α-amylase from Geobacillus thermoleovorans. Enzyme Microb Technol 2013; 53:46-54. [PMID: 23683704 DOI: 10.1016/j.enzmictec.2013.03.009] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2012] [Revised: 03/01/2013] [Accepted: 03/04/2013] [Indexed: 11/17/2022]
Abstract
A truncated form of an α-amylase, GTA, from thermophilic Geobacillus thermoleovorans CCB_US3_UF5 was biochemically and structurally characterized. The recombinant GTA, which lacked both the N- and C-terminal transmembrane regions, functioned optimally at 70°C and pH 6.0. While enzyme activity was not enhanced by the addition of CaCl2, GTA's thermostability was significantly improved in the presence of CaCl2. The structure, in complex with an acarbose-derived pseudo-hexasaccharide, consists of the typical three domains and binds one Ca(2+) ion. This Ca(2+) ion was strongly bound and not chelated by EDTA. A predicted second Ca(2+)-binding site, however, was disordered. With limited subsites, two novel substrate-binding residues, Y147 and Y182, may help increase substrate affinity. No distinct starch-binding domain is present, although two regions rich in aromatic residues have been observed. GTA, with a smaller domain B and several shorter loops compared to other α-amylases, has one of the most compact α-amylase folds that may contribute greatly to its tight Ca(2+) binding and thermostability.
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Affiliation(s)
- Sook-Chen Mok
- Centre for Chemical Biology, Universiti Sains Malaysia, 11800 Penang, Malaysia
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11
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Li KT, Zhou J, Wei SJ, Cheng X. An optimized industrial fermentation processes for acarbose production by Actinoplanes sp. A56. Bioresour Technol 2012; 118:580-583. [PMID: 22704188 DOI: 10.1016/j.biortech.2012.05.013] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2012] [Revised: 05/01/2012] [Accepted: 05/03/2012] [Indexed: 06/01/2023]
Abstract
Acarbose, a competitive α-glucosidase inhibitor, is clinically and widely used in the treatment of type II diabetes mellitus. In order to improve the industrial acarbose productivity by Actinoplanes sp. A56, the classical fermentation conditions such as total sugar concentration in broths, pH value and dissolved oxygen (DO) level were systematically investigated in a 30000-l fermenter, respectively. It was observed that a high-concentration total sugar (75-80 g/l), 7.0-7.2 of pH value and 40-50% of DO concentration were favorable for acarbose production. As a result, the final acarbose yield was elevated to approximately 5000 mg/l at 168 h of fermentation.
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Affiliation(s)
- Kun-tai Li
- Nanchang Key Laboratory of Applied Fermentation Technology, Jiangxi Agricultural University, Nanchang 330045, China
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12
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Wang YJ, Liu LL, Wang YS, Xue YP, Zheng YG, Shen YC. Actinoplanes utahensis ZJB-08196 fed-batch fermentation at elevated osmolality for enhancing acarbose production. Bioresour Technol 2012; 103:337-342. [PMID: 22029955 DOI: 10.1016/j.biortech.2011.09.121] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2011] [Revised: 09/25/2011] [Accepted: 09/27/2011] [Indexed: 05/31/2023]
Abstract
Acarbose, a potent α-glucosidase inhibitor, is as an oral anti-diabetic drug for treatment of the type two, noninsulin-dependent diabetes. Actinoplanes utahensis ZJB-08196, an osmosis-resistant actinomycete, had a broad osmolality optimum between 309 mOsm kg(-1) and 719 mOsm kg(-1). Utilizing this unique feature, an fed-batch culture process under preferential osmolality was constructed through intermittently feeding broths with feed medium consisting of 14.0 g l(-1) maltose, 6.0 g l(-1) glucose and 9.0 g l(-1) soybean meal, at 48 h, 72 h, 96 h and 120 h. This intermittent fed-batch culture produced a peak acarbose titer of 4878 mg l(-1), increased by 15.9% over the batch culture.
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Affiliation(s)
- Ya-Jun Wang
- Institute of Bioengineering, Zhejiang University of Technology, Hangzhou 310014, PR China
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13
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Koropatkin NM, Smith TJ. SusG: a unique cell-membrane-associated alpha-amylase from a prominent human gut symbiont targets complex starch molecules. Structure 2010; 18:200-15. [PMID: 20159465 DOI: 10.1016/j.str.2009.12.010] [Citation(s) in RCA: 104] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2009] [Revised: 12/17/2009] [Accepted: 12/18/2009] [Indexed: 11/19/2022]
Abstract
SusG is an alpha-amylase and part of a large protein complex on the outer surface of the bacterial cell and plays a major role in carbohydrate acquisition by the animal gut microbiota. Presented here, the atomic structure of SusG has an unusual extended, bilobed structure composed of amylase at one end and an unprecedented internal carbohydrate-binding motif at the other. Structural studies further demonstrate that the carbohydrate-binding motif binds maltooligosaccharide distal to, and on the opposite side of, the amylase catalytic site. SusG has an additional starch-binding site on the amylase domain immediately adjacent to the active cleft. Mutagenesis analysis demonstrates that these two additional starch-binding sites appear to play a role in catabolism of insoluble starch. However, elimination of these sites has only a limited effect, suggesting that they may have a more important role in product exchange with other Sus components.
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14
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Li YQ, Zhou FC, Gao F, Bian JS, Shan F. Comparative evaluation of quercetin, isoquercetin and rutin as inhibitors of alpha-glucosidase. J Agric Food Chem 2009; 57:11463-8. [PMID: 19938837 DOI: 10.1021/jf903083h] [Citation(s) in RCA: 345] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Three flavonoids from tartary buckwheat bran, namely, quercetin (Que), isoquercetin (Iso) and rutin (Rut), have been evaluated as alpha-glucosidase inhibitors by fluorescence spectroscopy and enzymatic kinetics and have also been compared with the market diabetes healer, acarbose. The results indicated that Que, Iso and Rut could bind alpha-glucosidase to form a new complex, which exhibited a strong static fluorescence quenching via nonradiation energy transfer, and an obvious blue shift of maximum fluorescence. The sequence of binding constants (K(A)) was Que > Iso > Rut, and the number of binding sites was one for all of the three cases. The thermodynamic parameters were obtained by calculations based on data of binding constants. They revealed that the main driving force of the above-mentioned interaction was hydrophobic. Enzymatic kinetics measurements showed that all of the three compounds were effective inhibitors against alpha-glucosidase. Inhibitory modes all belonged to a mixed type of noncompetitive and anticompetitive. The sequence of affinity (1/K(i)) was in accordance with the results of binding constants (K(A)). The concentrations which gave 50% inhibition (IC(50)) were 0.017 mmol*L(-1), 0.185 mmol*L(-1) and 0.196 mmol*L(-1), compared with acarbose's IC(50) (0.091 mmol*L(-1)); the dose of acarbose was almost five times of that of Que and half of that of Iso and Rut. Our results explained why the inhibition on alpha-glucosidase of tartary buckwheat bran extractive substance (mainly Rut) was much weaker than that of its hydrolysis product (a mixture of Que, Iso and Rut). This work would be significant for the development of more powerful antidiabetes drugs and efficacious utilization of tartary buckwheat, which has been proved as an acknowledged food in the diet of diabetic patients.
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Affiliation(s)
- Yan Qin Li
- Key Laboratory of Chemical Biology and Molecular Engineering of the Ministry of Education, Shanxi University, Taiyuan, 030006, China.
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15
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Suzuki Y, Sano M, Hayashida K, Ohsawa I, Ohta S, Fukuda K. Are the effects of alpha-glucosidase inhibitors on cardiovascular events related to elevated levels of hydrogen gas in the gastrointestinal tract? FEBS Lett 2009; 583:2157-9. [PMID: 19505462 DOI: 10.1016/j.febslet.2009.05.052] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2009] [Revised: 05/28/2009] [Accepted: 05/31/2009] [Indexed: 01/13/2023]
Abstract
The major side-effect of treatment with alpha-glucosidase inhibitors, flatulence, occurs when undigested carbohydrates are fermented by colonic bacteria, resulting in gas formation. We propose that the cardiovascular benefits of alpha-glucosidase inhibitors are partly attributable to their ability to neutralise oxidative stress via increased production of H(2) in the gastrointestinal tract. Acarbose, which is an alpha-glucosidase inhibitor, markedly increased H(2) production, with a weaker effect on methane production. Our hypothesis is based on our recent discovery that H(2) acts as a unique antioxidant, and that when inhaled or taken orally as H(2)-dissolved water it ameliorates ischaemia-reperfusion injury and atherosclerosis development.
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Affiliation(s)
- Yoshihiko Suzuki
- Department of Biochemistry and Cell Biology, Institute of Development and Aging Science, Graduate School of Medicine, Nippon Medical School, Kawasaki City, Japan
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16
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van Diggelen OP, Oemardien LF, van der Beek NAME, Kroos MA, Wind HK, Voznyi YV, Burke D, Jackson M, Winchester BG, Reuser AJJ. Enzyme analysis for Pompe disease in leukocytes; superior results with natural substrate compared with artificial substrates. J Inherit Metab Dis 2009; 32:416-23. [PMID: 19387865 DOI: 10.1007/s10545-009-1082-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2008] [Revised: 03/04/2009] [Accepted: 03/11/2009] [Indexed: 12/25/2022]
Abstract
Enzyme analysis for Pompe disease in leukocytes has been greatly improved by the introduction of acarbose, a powerful inhibitor of interfering alpha-glucosidases, which are present in granulocytes but not in lymphocytes. Here we show that the application of acarbose in the enzymatic assay employing the artificial substrate 4-methylumbelliferyl-alpha-D: -glucoside (MU-alphaGlc) is insufficient to clearly distinguish patients from healthy individuals in all cases. Also, the ratios of the activities without/with acarbose only marginally discriminated Pompe patients and healthy individuals. By contrast, when the natural substrate glycogen is used, the activity in leukocytes from patients (n = 82) with Pompe disease is at most 17% of the lowest control value. The use of artificial substrate in an assay with isolated lymphocytes instead of total leukocytes is a poor alternative as blood samples older than one day invariably yield lymphocyte preparations that are contaminated with granulocytes. To diagnose Pompe disease in leukocytes we recommend the use of glycogen as substrate in the presence of acarbose. This assay unequivocally excludes Pompe disease. To also exclude pseudo-deficiency of acid alpha-glucosidase caused by the sequence change c.271G>A (p.D91N or GAA2; homozygosity in approximately 1:1000 caucasians), a second assay employing MU-alphaGlc substrate plus acarbose or DNA analysis is required.
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Affiliation(s)
- O P van Diggelen
- Department of Clinical Genetics, Erasmus University Medical Centre, Ee 2402, PO Box 2040, Rotterdam 3000 CA, The Netherlands.
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Derosa G, Salvadeo SAT, D'Angelo A, Ferrari I, Mereu R, Palumbo I, Maffioli P, Randazzo S, Cicero AFG. Metabolic effect of repaglinide or acarbose when added to a double oral antidiabetic treatment with sulphonylureas and metformin: a double-blind, cross-over, clinical trial. Curr Med Res Opin 2009; 25:607-15. [PMID: 19232035 DOI: 10.1185/03007990802711024] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
OBJECTIVE To compare the metabolic effects of acarbose and repaglinide in type 2 diabetic patients who are being treated with a sulphonylurea-metformin combination therapy. The primary endpoint of the study was to evaluate which add-on treatment between acarbose and repaglinide is more efficacious in reducing PPG. The second endpoint was to evaluate which of these two treatment is more efficacious in the global management of glucose homeostasis in the enrolled patients. RESEARCH DESIGN AND METHODS After a 4-week run-in period with a sulphonylurea-metformin combination, 103 patients were randomised to receive in addition either repaglinide, up to 6 mg/day (2 mg three times a day) or acarbose, up to 300 mg/day (100 mg three times a day) with forced titration (independently of their glycaemic control, unless side-effects developed due to the drug dosage) for 15 weeks. The treatment was then crossed-over for further 12 weeks until the 27th week. We assessed body mass index (BMI), glycosylated haemoglobin (HbA(1c)), fasting plasma glucose (FPG), postprandial plasma glucose (PPG), fasting plasma insulin (FPI), postprandial plasma insulin (PPI), homeostatic model assessment (HOMA) index, systolic blood pressure (SBP), diastolic blood pressure (DBP), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C) and triglycerides (Tg), at baseline and at 1, 2, 15 and 27 weeks of treatment. RESULTS Seven patients did not complete the study, comprising one patient who was lost to follow-up and a further six through side-effects (two in week 1, one in week 15 and three after cross-over) Side-effects were classified as nausea (one in acarbose group), gastrointestinal events (four in acarbose group), and hypoglycaemia (one in repaglinide group). After 15 weeks of therapy, the repaglinide-treated patients experienced a significant decrease in HbA(1c) (-1.1%, p < 0.05), FPG (-9.5%, p < 0.05), and PPG (-14.9%, p < 0.05), when compared to the baseline values. However, the same treatment was associated with a significant increase in body weight (+2.3%, p < 0.05), BMI (+3.3%, p < 0.05) and FPI (+22.5%, p < 0.05); The increase was reversed during the cross-over phase. After 15 weeks of therapy, the acarbose-treated patients experienced a significant decrease in body weight (-1.9%, p < 0.05), BMI (-4.1%, p < 0.05), HbA(1c) (-1.4%, p < 0.05), FPG (-10.7%, p < 0.05), PPG (-16.2%, p < 0.05), FPI (-16.1%, p < 0.05), PPI (-26.9%, p < 0.05), HOMA index (-30.1%, p < 0.05), when compared to the baseline values. All these changes were reversed during the cross-over study phase, except those relating to HbA(1c), FPG and PPG. The only changes that significantly differed when directly comparing acarbose- and repaglinide-treated patients were those relating to FPI (-16.1% vs. +22.5%, respectively, p < 0.05) and HOMA index (-30.1% vs. +2.7%, p < 0.05). CONCLUSION In addition from having a similar effect to repaglinide on PPG, acarbose appeared to have a more comprehensive positive effect on glucose metabolism compared to repaglinide in this relatively small sample of type 2 diabetic patients when used as add-on therapy to sulphonylureas and metformin.
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Affiliation(s)
- Giuseppe Derosa
- Department of Internal Medicine and Therapeutics, University of Pavia, Pavia, Italy.
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18
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Abstract
A new method for the production of valienamine with the microbial degradation of acarbose is described. The microorganism was screened by our laboratory and identified as Stenotrophomonas maltrophilia. After separation, valienamine was analyzed with UV, IR, and 1H and 13C NMR. The yield was more than 60%.
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Affiliation(s)
- Xiaolong Chen
- Institute of Bioengineering, Zhejiang University of Technology, Hangzhou 310032, PR China.
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19
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Oh SW, Jang MU, Jeong CK, Kang HJ, Park JM, Kim TJ. Modulation of hydrolysis and transglycosylation activity of Thermus maltogenic amylase by combinatorial saturation mutagenesis. J Microbiol Biotechnol 2008; 18:1401-1407. [PMID: 18756100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The roles of conserved amino acid residues (Val329-Ala330- Asn331-Glu332), constituting an extra sugar-binding space (ESBS) of Thermus maltogenic amylase (ThMA), were investigated by combinatorial saturation mutagenesis. Various ThMA mutants were firstly screened on the basis of starch hydrolyzing activity and their enzymatic properties were characterized in detail. Most of the ThMA variants showed remarkable decreases in their hydrolyzing activity, but their specificity against various substrates could be altered by mutagenesis. Unexpectedly, mutant H-16 (Gly-Leu-Val-Tyr) showed almost identical hydrolyzing and transglycosylation activities to wild type, whereas K-33 (Ser-Gly-Asp-Glu) showed an extremely low transglycosylation activity. Interestingly, K-33 produced glucose, maltose, and acarviosine from acarbose, whereas ThMA hydrolyzed acarbose to only glucose and acarviosine-glucose, which proposes that the substrate specificity, or hydrolysis or transglycosylation activity of ThMA can be modulated by combinatorial mutations near the ESBS.
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Affiliation(s)
- Su-Won Oh
- Department of Food Science and Technology, Chungbuk National University, Cheongju 361-763, Korea
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20
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Choi WS, Wu X, Choeng YH, Mahmud T, Jeong BC, Lee SH, Chang YK, Kim CJ, Hong SK. Genetic organization of the putative salbostatin biosynthetic gene cluster including the 2-epi-5-epi-valiolone synthase gene in Streptomyces albus ATCC 21838. Appl Microbiol Biotechnol 2008; 80:637-45. [PMID: 18648803 DOI: 10.1007/s00253-008-1591-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2008] [Revised: 06/18/2008] [Accepted: 06/20/2008] [Indexed: 11/26/2022]
Abstract
The cyclization of sedoheptulose 7-phosphate to 2-epi-5-epi-valiolone, catalyzed by the 2-epi-5-epi-valiolone synthases, is the first committed step in the biosynthesis of C( 7 )N-aminocyclitol-containing natural products, such as validamycin and acarbose. These natural products contain in their structures a valienamine unit, which is important for their biological activity. The same core unit is also found in salbostatin, a related pseudodisaccharide that has strong trehalase inhibitory activity. In silico analysis of the putative biosynthetic gene cluster of salbostatin from Streptomyces albus ATCC 21838 revealed 20 open reading frames, including an acbC homolog gene (salQ), which is believed to be involved in the biosynthesis of salbostatin. The salQ gene was overexpressed in Escherichia coli and the catalytic function of the recombinant protein was confirmed to be a 2-epi-5-epi-valiolone synthase. In addition, SalF, SalL, SalM, SalN, SalO, and SalR were found to be homologous to AcbR, AcbM, AcbL, AcbN, AcbO, and AcbP from the acarbose pathway, respectively, which suggests that the biosynthesis of C(7)N-aminocyclitol moiety of salbostatin may be very similar to that of acarbose.
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Affiliation(s)
- Woo Sik Choi
- Department of Biological Science and Institute of Bioscience and Biotechnology, Myongji University, Yongin, 449-728, South Korea
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Lee YS, Lee MH, Lee HS, Lee SJ, Kim YW, Zhang R, Withers SG, Kim KS, Lee SJ, Park KH. Enzymatic synthesis of a selective inhibitor for alpha-glucosidases: alpha-acarviosinyl-(1-->9)-3-alpha-D-glucopyranosylpropen. J Agric Food Chem 2008; 56:5324-5330. [PMID: 18553919 DOI: 10.1021/jf703655k] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Here, we describe the enzymatic synthesis of novel inhibitors using acarviosine-glucose as a donor and 3-alpha-D-glucopyranosylpropen (alphaGP) as an acceptor. Maltogenic amylase from Thermus sp. (ThMA) catalyzed the transglycosylation of the acarviosine moiety to alphaGP. The two major reaction products were isolated using chromatographies. Structural analyses revealed that acarviosine was transferred to either C-7 or C-9 of the alphaGP, which correspond to C-4 and C-6 of glucose. Both inhibited rat intestine alpha-glucosidase competitively but displayed a mixed-type inhibition mode against human pancreatic alpha-amylase. The alpha-acarviosinyl-(1-->7)-3-alpha-D-glucopyranosylpropen showed weaker inhibition potency than acarbose against both alpha-glycosidases. In contrast, the alpha-acarviosinyl-(1-->9)-3-alpha-D-glucopyranosylpropen exhibited a 3.0-fold improved inhibition potency against rat intestine alpha-glucosidase with 0.3-fold inhibition potency against human pancreatic alpha-amylase relative to acarbose. In conclusion, alpha-acarviosinyl-(1-->9)-3-alpha-D-glucopyranosylpropen is a novel alpha-glucosidase-selective inhibitor with 10-fold enhanced selectivity toward alpha-glucosidase over alpha-amylase relative to acarbose, and it could be applied as a potent hypoglycemic agent.
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Affiliation(s)
- Young-Su Lee
- Center for Agricultural Biomaterials and School of Agriculture and Biotechnology, Seoul National University, Seoul 151-921, Korea
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22
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Abstract
AIM This study was designed to investigate the effect of acarbose in patients with type 2 diabetes with newly initiated insulin treatment who had previously been insufficiently controlled with oral antihyperglycaemic agents [haemoglobin A(1c) (HbA(1c)) >/= 8%]. METHODS In this 20-week double-blind, placebo-controlled study, 163 patients were randomized to receive acarbose up to 100 mg three times a day or matching placebo. Both the groups were newly initiated with insulin, which was adjusted according to blood glucose values. Primary efficacy parameter was the change in HbA(1c) from baseline; changes in daily insulin doses were also assessed. RESULTS Mean HbA(1c) was significantly reduced by acarbose compared with placebo (2.31 vs. 1.81%, p = 0.033). Insulin doses were comparable at the end of the study. There was no difference in blood glucose and triglyceride levels between the treatment groups. Postprandial serum insulin levels increased in both treatment arms owing to insulin administration but less so under acarbose. In contrast to the placebo group, an increase in body mass index was prevented for acarbose-treated patients. CONCLUSION As adjunct administration to newly initiated insulin therapy, acarbose enhances the optimization of blood glucose control in patients with type 2 diabetes.
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Affiliation(s)
- O Schnell
- Diabetes Research Institute, Munich, Germany.
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Quezada-Calvillo R, Robayo-Torres CC, Opekun AR, Sen P, Ao Z, Hamaker BR, Quaroni A, Brayer GD, Wattler S, Nehls MC, Sterchi EE, Nichols BL. Contribution of mucosal maltase-glucoamylase activities to mouse small intestinal starch alpha-glucogenesis. J Nutr 2007; 137:1725-33. [PMID: 17585022 DOI: 10.1093/jn/137.7.1725] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Digestion of starch requires activities provided by 6 interactive small intestinal enzymes. Two of these are luminal endo-glucosidases named alpha-amylases. Four are exo-glucosidases bound to the luminal surface of enterocytes. These mucosal activities were identified as 4 different maltases. Two maltase activities were associated with sucrase-isomaltase. Two remaining maltases, lacking other identifying activities, were named maltase-glucoamylase. These 4 activities are better described as alpha-glucosidases because they digest all linear starch oligosaccharides to glucose. Because confusion persists about the relative roles of these 6 enzymes, we ablated maltase-glucoamylase gene expression by homologous recombination in Sv/129 mice. We assayed the alpha-glucogenic activities of the jejunal mucosa with and without added recombinant pancreatic alpha-amylase, using a range of food starch substrates. Compared with wild-type mucosa, null mucosa or alpha-amylase alone had little alpha-glucogenic activity. alpha-Amylase amplified wild-type and null mucosal alpha-glucogenesis. alpha-Amylase amplification was most potent against amylose and model resistant starches but was inactive against its final product limit-dextrin and its constituent glucosides. Both sucrase-isomaltase and maltase-glucoamylase were active with limit-dextrin substrate. These mucosal assays were corroborated by a 13C-limit-dextrin breath test. In conclusion, the global effect of maltase-glucoamylase ablation was a slowing of rates of mucosal alpha-glucogenesis. Maltase-glucoamylase determined rates of digestion of starch in normal mice and alpha-amylase served as an amplifier for mucosal starch digestion. Acarbose inhibition was most potent against maltase-glucoamylase activities of the wild-type mouse. The consortium of 6 interactive enzymes appears to be a mechanism for adaptation of alpha-glucogenesis to a wide range of food starches.
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Affiliation(s)
- Roberto Quezada-Calvillo
- CIEP-Facultad de Ciencias Quimicas, Universidad Autonoma de San Luis Potosi, Zona Universitaria, San Luis Potosí, S.L.P., Mexico 78360
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Lyhne-Iversen L, Hobley TJ, Kaasgaard SG, Harris P. Structure of Bacillus halmapalus alpha-amylase crystallized with and without the substrate analogue acarbose and maltose. Acta Crystallogr Sect F Struct Biol Cryst Commun 2006; 62:849-54. [PMID: 16946462 PMCID: PMC2242873 DOI: 10.1107/s174430910603096x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2006] [Accepted: 08/07/2006] [Indexed: 11/11/2022]
Abstract
Recombinant Bacillus halmapalus alpha-amylase (BHA) was studied in two different crystal forms. The first crystal form was obtained by crystallization of BHA at room temperature in the presence of acarbose and maltose; data were collected at cryogenic temperature to a resolution of 1.9 A. It was found that the crystal belonged to space group P2(1)2(1)2(1), with unit-cell parameters a = 47.0, b = 73.5, c = 151.1 A. A maltose molecule was observed and found to bind to BHA and previous reports of the binding of a nonasaccharide were confirmed. The second crystal form was obtained by pH-induced crystallization of BHA in a MES-HEPES-boric acid buffer (MHB buffer) at 303 K; the solubility of BHA in MHB has a retrograde temperature dependency and crystallization of BHA was only possible by raising the temperature to at least 298 K. Data were collected at cryogenic temperature to a resolution of 2.0 A. The crystal belonged to space group P2(1)2(1)2(1), with unit-cell parameters a = 38.6, b = 59.0, c = 209.8 A. The structure was solved using molecular replacement. The maltose-binding site is described and the two structures are compared. No significant changes were seen in the structure upon binding of the substrates.
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Affiliation(s)
- Louise Lyhne-Iversen
- Department of Chemistry, Technical University of Denmark, Building 207, DK-2800 Kgs. Lyngby, Denmark
| | - Timothy J. Hobley
- Center for Microbial Biotechnology, BioCentrum-DTU, Technical University of Denmark, Building 223, DK-2800 Kgs. Lyngby, Denmark
| | | | - Pernille Harris
- Department of Chemistry, Technical University of Denmark, Building 207, DK-2800 Kgs. Lyngby, Denmark
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Andrulionyte L, Laukkanen O, Chiasson JL, Laakso M. Single nucleotide polymorphisms of the HNF4alpha gene are associated with the conversion to type 2 diabetes mellitus: the STOP-NIDDM trial. J Mol Med (Berl) 2006; 84:701-8. [PMID: 16838170 DOI: 10.1007/s00109-006-0063-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2005] [Accepted: 02/22/2006] [Indexed: 10/24/2022]
Abstract
Hepatocyte nuclear factor 4alpha (HNF4alpha) is a transcription factor, which is necessary for normal function of human liver and pancreatic islets. We investigated whether single nucleotide polymorphisms (SNPs) of HNF4A, encoding HNF4alpha, influenced the conversion from impaired glucose tolerance (IGT) to type 2 diabetes mellitus in subjects of the STOP-NIDDM trial. This trial aimed at evaluating the effect of acarbose compared to placebo in the prevention of type 2 diabetes mellitus. Eight SNPs covering the intragenic and alternate P2 promoter regions of HNF4A were genotyped in study samples using the TaqMan Allelic Discrimination Assays. Three SNPs in the P2 promoter region (rs4810424, rs1884614, and rs2144908) were in almost complete association (D'>0.97, r (2)>0.95) and, therefore, only rs4810424 was included in further analyses. Female carriers of the less frequent C allele of rs4810424 had a 1.7-fold elevated risk [95% confidence interval (CI) 1.09-2.66; P=0.020] for the conversion to diabetes compared to women with the common genotype after the adjustment for age, treatment group (placebo or acarbose), smoking, weight at baseline, and weight change. No association was found in men. Haplotype analysis based on three SNPs (rs4810424, rs2071197, and rs3818247) representing the linkage disequilibrium blocks in our study population indicated that the conversion to type 2 diabetes mellitus was dependent on the number of risk alleles in different haplotypes in women. Our results suggest that SNPs of HNF4A and their haplotypes predispose to type 2 diabetes mellitus in female subjects of the STOP-NIDDM study population.
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Rossi EJ, Sim L, Kuntz DA, Hahn D, Johnston BD, Ghavami A, Szczepina MG, Kumar NS, Sterchi EE, Nichols BL, Pinto BM, Rose DR. Inhibition of recombinant human maltase glucoamylase by salacinol and derivatives. FEBS J 2006; 273:2673-83. [PMID: 16817895 DOI: 10.1111/j.1742-4658.2006.05283.x] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Inhibitors targeting pancreatic alpha-amylase and intestinal alpha-glucosidases delay glucose production following digestion and are currently used in the treatment of Type II diabetes. Maltase-glucoamylase (MGA), a family 31 glycoside hydrolase, is an alpha-glucosidase anchored in the membrane of small intestinal epithelial cells responsible for the final step of mammalian starch digestion leading to the release of glucose. This paper reports the production and purification of active human recombinant MGA amino terminal catalytic domain (MGAnt) from two different eukaryotic cell culture systems. MGAnt overexpressed in Drosophila cells was of quality and quantity suitable for kinetic and inhibition studies as well as future structural studies. Inhibition of MGAnt was tested with a group of prospective alpha-glucosidase inhibitors modeled after salacinol, a naturally occurring alpha-glucosidase inhibitor, and acarbose, a currently prescribed antidiabetic agent. Four synthetic inhibitors that bind and inhibit MGAnt activity better than acarbose, and at comparable levels to salacinol, were found. The inhibitors are derivatives of salacinol that contain either a selenium atom in place of sulfur in the five-membered ring, or a longer polyhydroxylated, sulfated chain than salacinol. Six-membered ring derivatives of salacinol and compounds modeled after miglitol were much less effective as MGAnt inhibitors. These results provide information on the inhibitory profile of MGAnt that will guide the development of new compounds having antidiabetic activity.
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Affiliation(s)
- Elena J Rossi
- Department of Medical Biophysics, University of Toronto, Canada
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27
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Sevcík J, Hostinová E, Solovicová A, Gasperík J, Dauter Z, Wilson KS. Structure of the complex of a yeast glucoamylase with acarbose reveals the presence of a raw starch binding site on the catalytic domain. FEBS J 2006; 273:2161-71. [PMID: 16649993 DOI: 10.1111/j.1742-4658.2006.05230.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Most glucoamylases (alpha-1,4-D-glucan glucohydrolase, EC 3.2.1.3) have structures consisting of both a catalytic and a starch binding domain. The structure of a glucoamylase from Saccharomycopsis fibuligera HUT 7212 (Glu), determined a few years ago, consists of a single catalytic domain. The structure of this enzyme with the resolution extended to 1.1 A and that of the enzyme-acarbose complex at 1.6 A resolution are presented here. The structure at atomic resolution, besides its high accuracy, shows clearly the influence of cryo-cooling, which is manifested in shrinkage of the molecule and lowering the volume of the unit cell. In the structure of the complex, two acarbose molecules are bound, one at the active site and the second at a site remote from the active site, curved around Tyr464 which resembles the inhibitor molecule in the 'sugar tongs' surface binding site in the structure of barley alpha-amylase isozyme 1 complexed with a thiomalto-oligosaccharide. Based on the close similarity in sequence of glucoamylase Glu, which does not degrade raw starch, to that of glucoamylase (Glm) from S. fibuligera IFO 0111, a raw starch-degrading enzyme, it is reasonable to expect the presence of the remote starch binding site at structurally equivalent positions in both enzymes. We propose the role of this site is to fix the enzyme onto the surface of a starch granule while the active site degrades the polysaccharide. This hypothesis is verified here by the preparation of mutants of glucoamylases Glu and Glm.
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Affiliation(s)
- Jozef Sevcík
- Institute of Molecular Biology, Slovak Academy of Sciences, Bratislava, Slovakia.
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28
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Abstract
We have a limited understanding of the details of molecular recognition of carbohydrates by proteins, which is critical to a multitude of biological processes. Furthermore, carbohydrate-modifying proteins such as glycosyl hydrolases and phosphorylases are of growing importance as potential drug targets. Interactions between proteins and carbohydrates have complex thermodynamics, and in general the specific positioning of only a few hydroxyl groups determines their binding affinities. A thorough understanding of both carbohydrate and protein structures is thus essential to predict these interactions. An atomic-level view of carbohydrate recognition through structures of carbohydrate-active enzymes complexed with transition-state inhibitors reveals some of the distinctive molecular features unique to protein-carbohydrate complexes. However, the inherent flexibility of carbohydrates and their often water-mediated hydrogen bonding to proteins makes simulation of their complexes difficult. Nonetheless, recent developments such as the parameterization of specific force fields and docking scoring functions have greatly improved our ability to predict protein-carbohydrate interactions. We review protein-carbohydrate complexes having defined molecular requirements for specific carbohydrate recognition by proteins, providing an overview of the different computational techniques available to model them.
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Affiliation(s)
- Alain Laederach
- Department of Chemical Engineering, Iowa State University, Ames, Iowa 50011-2230, USA
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Brunkhorst C, Schneider E. Characterization of maltose and maltotriose transport in the acarbose-producing bacterium Actinoplanes sp. Res Microbiol 2005; 156:851-7. [PMID: 15939574 DOI: 10.1016/j.resmic.2005.03.008] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2004] [Revised: 03/14/2005] [Accepted: 03/29/2005] [Indexed: 11/16/2022]
Abstract
Acarbose, a pseudomaltotetraose, is produced by strains of the genus Actinoplanes. The compound is an inhibitor of alpha-glucosidases and is used in the treatment of patients suffering from type II diabetes. The benefits of acarbose for the producer are not known; however, a role as carbophor has been proposed. Acarbose synthesis is induced in the presence of maltose and maltotriose. We have investigated the transport activities for these sugars in Actinoplanes sp. strain SN 223/29 grown on different carbon sources, including acarbose. Under the conditions used, Actinoplanes sp. utilized acarbose as sole source of carbon and energy, although growth ceased after 24 h, possibly due to the accumulation of a toxic degradation product in the cytosol. Maltose transport was observed in cells grown on each of the substrates tested except glucose. Maltose transport of acarbose-grown cells was inhibited by sucrose and trehalose and, to a lesser extent, by maltodextrins but not by acarbose. In contrast, in maltose/maltotriose-grown cells maltose uptake was inhibited by acarbose. Maltotriose uptake in these cells was less inhibited by maltose but was more sensitive to acarbose than in acarbose-grown cells. The Km and Vmax values of maltose uptake are in the range of those reported for binding protein-dependent sugar ATP-binding cassette (ABC) transport systems. A maltose-binding protein that does not bind acarbose was isolated from cells grown on either acarbose, glycerol or maltose. These results suggest that an acarbose-insensitive maltose/sucrose/trehalose transporter that also accepts maltodextrins operates in acarbose-grown cells while a maltodextrin transporter that accepts maltose/sucrose/trehalose and is moderately sensitive to acarbose is found in cells grown in maltose/maltotriose-containing media.
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Affiliation(s)
- Claudia Brunkhorst
- Humboldt Universität zu Berlin, Institut für Biologie/Bakterienphysiologie, Chausseestr. 117, 10115 Berlin, Germany
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Maurus R, Begum A, Kuo HH, Racaza A, Numao S, Andersen C, Tams JW, Vind J, Overall CM, Withers SG, Brayer GD. Structural and mechanistic studies of chloride induced activation of human pancreatic alpha-amylase. Protein Sci 2005; 14:743-55. [PMID: 15722449 PMCID: PMC2279296 DOI: 10.1110/ps.041079305] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
The mechanism of allosteric activation of alpha-amylase by chloride has been studied through structural and kinetic experiments focusing on the chloride-dependent N298S variant of human pancreatic alpha-amylase (HPA) and a chloride-independent TAKA-amylase. Kinetic analysis of the HPA variant clearly demonstrates the pronounced activating effect of chloride ion binding on reaction rates and its effect on the pH-dependence of catalysis. Structural alterations observed in the N298S variant upon chloride ion binding suggest that the chloride ion plays a variety of roles that serve to promote catalysis. One of these is having a strong influence on the positioning of the acid/base catalyst residue E233. Absence of chloride ion results in multiple conformations for this residue and unexpected enzymatic products. Chloride ion and N298 also appear to stabilize a helical region of polypeptide chain from which projects the flexible substrate binding loop unique to chloride-dependent alpha-amylases. This structural feature also serves to properly orient the catalytically essential residue D300. Comparative analyses show that the chloride-independent alpha-amylases compensate for the absence of bound chloride by substituting a hydrophobic core, altering the manner in which substrate interactions are made and shifting the placement of N298. These evolutionary differences presumably arise in response to alternative operating environments or the advantage gained in a particular product profile. Attempts to engineer chloride-dependence into the chloride-independent TAKA-amylase point out the complexity of this system, and the fact that a multitude of factors play a role in binding chloride ion in the chloride-dependent alpha-amylases.
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Affiliation(s)
- Robert Maurus
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC, Canada V6T 1Z3
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31
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Li C, Begum A, Numao S, Park KH, Withers SG, Brayer GD. Acarbose Rearrangement Mechanism Implied by the Kinetic and Structural Analysis of Human Pancreatic α-Amylase in Complex with Analogues and Their Elongated Counterparts†,‡. Biochemistry 2005; 44:3347-57. [PMID: 15736945 DOI: 10.1021/bi048334e] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A mechanistic study of the poorly understood pathway by which the inhibitor acarbose is enzymatically rearranged by human pancreatic alpha-amylase has been conducted by structurally examining the binding modes of the related inhibitors isoacarbose and acarviosine-glucose, and by novel kinetic measurements of all three inhibitors under conditions that demonstrate this rearrangement process. Unlike acarbose, isoacarbose has a unique terminal alpha-(1-6) linkage to glucose and is found to be resistant to enzymatic rearrangement. This terminal glucose unit is found to bind in the +3 subsite and for the first time reveals the interactions that occur in this part of the active site cleft with certainty. These results also suggest that the +3 binding subsite may be sufficiently flexible to bind the alpha-(1-6) branch points in polysaccharide substrates, and therefore may play a role in allowing efficient cleavage in the direct vicinity of such junctures. Also found to be resistant to enzymatic rearrangement was acarviosine-glucose, which has one fewer glucose unit than acarbose. Collectively, structural studies of all three inhibitors and the specific cleavage pattern of HPA make it possible to outline the simplest sequence of enzymatic reactions likely involved upon acarbose binding. Prominent features incorporated into the starting structure of acarbose to facilitate the synthesis of the final tightly bound pseudo-pentasaccharide product are the restricted availability of hydrolyzable bonds and the placement of the transition state-like acarviosine group. Additional "in situ" experiments designed to elongate and thereby optimize isoacarbose and acarviosine-glucose inhibition using the activated substrate alphaG3F demonstrate the feasibility of this approach and that the principles outlined for acarbose rearrangement can be used to predict the final products that were obtained.
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Affiliation(s)
- Chunmin Li
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
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32
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Brunkhorst C, Wehmeier UF, Piepersberg W, Schneider E. The acbH gene of Actinoplanes sp. encodes a solute receptor with binding activities for acarbose and longer homologs. Res Microbiol 2004; 156:322-7. [PMID: 15808935 DOI: 10.1016/j.resmic.2004.10.016] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2004] [Revised: 10/12/2004] [Accepted: 10/25/2004] [Indexed: 11/15/2022]
Abstract
Acarbose, a pseudomaltotetraose, is produced by strains of the genus Actinoplanes and is a potent inhibitor of alpha-glucosidases, including those from the human intestine. Therefore, it is used in the treatment of patients suffering from type 2 diabetes. The benefits of acarbose for the producer are not known; however, besides acting as an inhibitor of alpha-amylases secreted by competitors, a role as a 'carbophor' has been proposed. This would require a transport system mediating its uptake into the cytoplasm of Actinoplanes sp. A putative sugar ATP binding cassette (ABC) transport system, the genes of which are included within the biosynthetic gene cluster for acarbose, was suggested to be a possible candidate. The genes acbHFG encode a possible sugar binding protein (AcbH) and two membrane integral subunits (AcbFG). A gene coding for an ATPase component is missing. Since Actinoplanes sp. cannot yet be genetically manipulated we performed experiments to identify the substrate(s) of the putative transporter by assessing the substrate specificity of AcbH. The protein was overproduced in Escherichia coli as His10-fusion protein, purified under denaturating conditions and renatured. Refolding was verified by circular dichroism spectroscopy. Surface plasmon resonance studies revealed that AcbH binds acarbose and longer derivatives, but not maltodextrins, maltose or sucrose. Immunoblot analysis revealed the association of AcbH with the membrane fraction of Actinoplanes cells that were grown in the presence of maltose, maltodextrins or acarbose. Together, these findings suggest that the AcbHFG complex might be involved in the uptake of acarbose and are consistent with a role for acarbose as a 'carbophor'.
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Affiliation(s)
- Claudia Brunkhorst
- Humboldt Universität zu Berlin, Institut für Biologie/Bakterienphysiologie, Chausseestr. 117, 10115 Berlin, Germany
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33
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Konno M, Yoshino M, Watanabe S. [Effects of acarbose on amylase tests]. Rinsho Byori 2004; 52:955-60. [PMID: 15675340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/01/2023]
Abstract
Acarbose is an antidiabetic drug that inhibits alpha-D-glucosidase and alpha-amylase. We have found discrepancies of serum and urine amylase activities (AA) determined with different assay methods using samples collected from diabetes mellitus patients taking acarbose. As a result of our screening test using the urine samples, we found a 22% probability of discrepancy (the differences between the two methods were > or = 10% at AA > or = 100 U/l). We have measured acarbose in five discrepant samples by high-performance liquid chromatography/mass-spectrometry and quantified very low levels (0.36-0.93 micromol/l) of acarbose in three samples of urine. The inhibition of AA was known not only to be caused by acarbose but also its metabolites. We should suppose that the inhibitory effects of its metabolites on amylase measurements are larger than those of acarbose.
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Affiliation(s)
- Minoru Konno
- Department of Clinical Laboratory, Medical Center of Yokohama City University, School of Medicine, Yokohama 232-0024
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34
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Leemhuis H, Wehmeier UF, Dijkhuizen L. Single Amino Acid Mutations Interchange the Reaction Specificities of Cyclodextrin Glycosyltransferase and the Acarbose-Modifying Enzyme Acarviosyl Transferase. Biochemistry 2004; 43:13204-13. [PMID: 15476414 DOI: 10.1021/bi049015q] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Acarviosyl transferase (ATase) from Actinoplanes sp. SE50/110 is a bacterial enzyme that transfers the acarviosyl moiety of the diabetic drug acarbose to sugar acceptors. The enzyme exhibits 42% sequence identity with cyclodextrin glycosyltransferases (CGTase), and both enzymes are members of the alpha-amylase family, a large clan of enzymes acting on starch and related compounds. ATase is virtually inactive on starch, however. In contrast, ATase is the only known enzyme to efficiently use acarbose as substrate (2 micromol min(-1) mg(-1)); acarbose is a strong inhibitor of CGTase and of most other alpha-amylase family enzymes. This distinct reaction specificity makes ATase an interesting enzyme to investigate the variation in reaction specificity of alpha-amylase family enzymes. Here we show that a G140H mutation in ATase, introducing the typical His of the conserved sequence region I of the alpha-amylase family, changed ATase into an enzyme with 4-alpha-glucanotransferase activity (3.4 micromol min(-1) mg(-1)). Moreover, this mutation introduced cyclodextrin-forming activity into ATase, converting 2% of starch into cyclodextrins. The opposite experiment, removing this typical His side chain in CGTase (H140A), introduced acarviosyl transferase activity in CGTase (0.25 micromol min(-1) mg(-1)).
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Affiliation(s)
- Hans Leemhuis
- Department of Microbiology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Kerklaan 30, 9751 NN Haren, The Netherlands
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35
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Kanai R, Haga K, Akiba T, Yamane K, Harata K. Role of Phe283 in enzymatic reaction of cyclodextrin glycosyltransferase from alkalophilic Bacillus sp.1011: Substrate binding and arrangement of the catalytic site. Protein Sci 2004; 13:457-65. [PMID: 14739329 PMCID: PMC2286706 DOI: 10.1110/ps.03408504] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Cyclodextrin glycosyltransferase (CGTase) belonging to the alpha-amylase family mainly catalyzes transglycosylation and produces cyclodextrins from starch and related alpha-1,4-glucans. The catalytic site of CGTase specifically conserves four aromatic residues, Phe183, Tyr195, Phe259, and Phe283, which are not found in alpha-amylase. To elucidate the structural role of Phe283, we determined the crystal structures of native and acarbose-complexed mutant CGTases in which Phe283 was replaced with leucine (F283L) or tyrosine (F283Y). The temperature factors of the region 259-269 in native F283L increased >10 A(2) compared with the wild type. The complex formation with acarbose not only increased the temperature factors (>10 A(2)) but also changed the structure of the region 257-267. This region is stabilized by interactions of Phe283 with Phe259 and Leu260 and plays an important role in the cyclodextrin binding. The conformation of the side-chains of Glu257, Phe259, His327, and Asp328 in the catalytic site was altered by the mutation of Phe283 with leucine, and this indicates that Phe283 partly arranges the structure of the catalytic site through contacts with Glu257 and Phe259. The replacement of Phe283 with tyrosine decreased the enzymatic activity in the basic pH range. The hydroxyl group of Tyr283 forms hydrogen bonds with the carboxyl group of Glu257, and the pK(a) of Glu257 in F283Y may be lower than that in the wild type.
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Affiliation(s)
- Ryuta Kanai
- Biological Information Research Center, AIST Tsukuba Central 6, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8566, Japan
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36
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Numao S, Damager I, Li C, Wrodnigg TM, Begum A, Overall CM, Brayer GD, Withers SG. In situ extension as an approach for identifying novel alpha-amylase inhibitors. J Biol Chem 2004; 279:48282-91. [PMID: 15304511 DOI: 10.1074/jbc.m406804200] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
A new approach for the discovery and subsequent structural elucidation of oligosaccharide-based inhibitors of alpha-amylases based upon autoglucosylation of known alpha-glucosidase inhibitors is presented. This concept, highly analogous to what is hypothesized to occur with acarbose, is demonstrated with the known alpha-glucosidase inhibitor, d-gluconohydroximino-1,5-lactam. This was transformed from an inhibitor of human pancreatic alpha-amylase with a K(i) value of 18 mm to a trisaccharide analogue with a K(i) value of 25 mum. The three-dimensional structure of this complex was determined by x-ray crystallography and represents the first such structure determined with this class of inhibitors in any alpha-glycosidase. This approach to the discovery and structural analysis of amylase inhibitors should be generally applicable to other endoglucosidases and readily adaptable to a high throughput format.
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Affiliation(s)
- Shin Numao
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
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37
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Abstract
Since the onset of the AIDS epidemic, some 20 million people have died and the estimate is that today close to 40 million are living with type 1 human immunodeficiency virus (HIV)/AIDS. About 14 thousands people are infected worldwide daily with this disease. Still, only a few pharmaceuticals are available for AIDS chemotheraphy. Some pharmaceuticals act against the virus before the entrance of the HIV into the host cells. One of these targets is the glucosidase protein. This class of enzymes has been recently explored because the synthesis of viral glycoproteins depends on the activity of enzymes, such as glucosidase and transferase, for the elaboration of the polysaccharides. In this work we study several glucosidase inhibitors. The DFT method is used to compute atomic charges and the ligand/receptor interaction was simulated with docking software. Analysis of the interactions of the proposed pharmaceutical, a pseudodisaccharide, with the Thermotoga maritima 4-alpha-glucanotransferase in complex with modified acarbose, the scores from docking as well as the graphical superposition of all the ligands, suggest that our molecular designed pseudo-disaccharide may be a potent glucosidase inhibitor.
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Affiliation(s)
- C H T P Silva
- Departamento de Ciências Farmaceuticas Faculdade de Ciências Farmacêuticas de Ribeirão Preto Universidade de Sao Paulo, Av. do Cafe, s/n, Monte Alegre, 14040-903, Ribeirão Preto, Brasil
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38
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Abstract
The first genome of a virus infecting a representative of the eubacterial genus Actinoplanes is presented. Phage phiAsp2 has a circularly permutated chromosome that consists of 58,638 bp; its G/C-bias of 70.39% resembles the hosts G + C-content (71-73% within the genus). A total of 76 open reading frames (orfs) were identified, the majority of which (63) displaying equal transcriptional orientations. Functional gene clustering is obvious as orfs coding for head and tail proteins are located close to the center in the first half of the genome and putative DNA-modifying enzymes are encoded by centrally located genes; DNA repair and recombination functions are situated in the remaining part of the genome, adjacent to a small gene cluster, the predicted proteins of which are involved in DNA packaging. Close to the left terminus there are two small regions (approximately 4.5 kb each, separated by 2.8 kb) which are homologous to the recently sequenced mycobacteriophage rosebush, however, the unique overall structure of the phiAsp2-genome does not bear resemblance to any other known viral genome. The nucleotide sequence was deposited in GenBank with the accession no. AY576796.
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Affiliation(s)
- Martin Jarling
- Westfälische Wilhelms-Universität, Institut für Molekulare Mikrobiologie und Biotechnologie, Corrensstrasse 3, 48149 Münster, Germany
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Choi BT, Shin CS. Isolation and characterization of a novel intracellular glucosyltransferase from the acarbose producer Actinoplanes sp. CKD485-16. Appl Microbiol Biotechnol 2004; 65:273-80. [PMID: 15257419 DOI: 10.1007/s00253-004-1639-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2004] [Revised: 04/07/2004] [Accepted: 04/16/2004] [Indexed: 11/27/2022]
Abstract
A novel intracellular glucosyltransferase (GTase) was isolated from cells of Actinoplanes sp. CKD485-16-acarbose-producing cells. The enzyme was purified by DEAE-cellulose and G75-40 Sephadex chromatography. The molecular mass of the enzyme was estimated to be 62 kDa by SDS-polyacrylamide gel electrophoresis, and its isoelectric point (pI) was pH 4.3. The N-terminal sequence of the GTase consisted of NH(2)-Ser-Val-Pro-Leu-Ser-Leu-Pro-Ala-Glu-Trp. The optimum pH and temperature were 7.5 and 30 degrees C. The enzyme was stable in a pH range of 5.5-9.0 and below 40 degrees C. Enzymatic reactions were performed by incubating the GTase with various substrates. The GTase converted acarbose into component C, maltose into trehalose, and maltooligosaccharides into maltooligosyl trehaloses. The reactions were reversible. Various acarbose analogs were tested as inhibitors against the GTase as a means to suppress component C formation. Valienamine was the most potent, with an IC(50) value of 2.4x10(-3) mM and showed a competitive inhibition mode.
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Affiliation(s)
- B T Choi
- Department of Biotechnology, College of Engineering, Yonsei University, Seodaemun-gu, Seoul, 120-749, South Korea
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40
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Ohtaki A, Mizuno M, Tonozuka T, Sakano Y, Kamitori S. Complex Structures of Thermoactinomyces vulgaris R-47 α-Amylase 2 with Acarbose and Cyclodextrins Demonstrate the Multiple Substrate Recognition Mechanism. J Biol Chem 2004; 279:31033-40. [PMID: 15138257 DOI: 10.1074/jbc.m404311200] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Thermoactinomyces vulgaris R-47 alpha-amylase 2 (TVAII) has the unique ability to hydrolyze cyclodextrins (CDs), with various sized cavities, as well as starch. To understand the relationship between structure and substrate specificity, x-ray structures of a TVAII-acarbose complex and inactive mutant TVAII (D325N/D421N)/alpha-, beta- and gamma-CDs complexes were determined at resolutions of 2.9, 2.9, 2.8, and 3.1 A, respectively. In all complexes, the interactions between ligands and enzymes at subsites -1, -2, and -3 were almost the same, but striking differences in the catalytic site structure were found at subsites +1 and +2, where Trp(356) and Tyr(374) changed the conformation of the side chain depending on the structure and size of the ligands. Trp(356) and Tyr(374) are thought to be responsible for the multiple substrate-recognition mechanism of TVAII, providing the unique substrate specificity. In the beta-CD complex, the beta-CD maintains a regular conical structure, making it difficult for Glu(354) to protonate the O-4 atom at the hydrolyzing site as a previously proposed hydrolyzing mechanism of alpha-amylase. From the x-ray structures, it is suggested that the protonation of the O-4 atom is possibly carried out via a hydrogen atom of the inter-glucose hydrogen bond at the hydrolyzing site.
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Affiliation(s)
- Akashi Ohtaki
- Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo 184-8588, Japan
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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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Wehmeier UF, Piepersberg W. Biotechnology and molecular biology of the alpha-glucosidase inhibitor acarbose. Appl Microbiol Biotechnol 2003; 63:613-25. [PMID: 14669056 DOI: 10.1007/s00253-003-1477-2] [Citation(s) in RCA: 141] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2003] [Revised: 09/22/2003] [Accepted: 09/26/2003] [Indexed: 10/26/2022]
Abstract
The alpha-glucosidase inhibitor acarbose, O-[4,6-dideoxy-4[1 s-(1,4,6/5)-4,5,6-trihydroxy-3-hydroxymethyl-2-cyclohexen-1-yl]-amino-alpha-D-glucopyranosyl]-(1-->4)- O-alpha-D-glucopyranosyl-(1-->4)-D-glucopyranose, is produced in large-scale fermentation by the use of strains derived from Actinoplanes sp. SE50. It has been used since 1990 in many countries in the therapy of diabetes type II, in order to enable patients to better control blood sugar contents while living with starch-containing diets. Thus, it is one of the latest successful products of bacterial secondary metabolism to be introduced into the pharmaceutical world market. Cultures of Actinoplanes sp. also produce various other acarbose-like components, of which component C is hard to separate during downstream processing, which is one of the most modern work-up processes developed to date. The physiology, genetics and enzymology of acarbose biosynthesis and metabolism in the producer have been studied to some extent, leading to the proposal of a new pathway and metabolic cycle, the "carbophore". These data could give clues for further biotechnological developments, such as the suppression of side-products, enzymological or biocombinatorial production of new metabolites and the engineering of production rates via genetic regulation in future.
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Affiliation(s)
- U F Wehmeier
- Chemische Mikrobiologie, Bergische Universitaet Wuppertal, Gauss-Strasse 20, 42097, Wuppertal, Germany
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Abstract
Acarbose fermentation was conducted by cultivation of Actinoplanes sp. CKD485-16. Approximately 2,300 mg/L of acarbose was produced at the end of cultivation along with 600 mg/L of the acarbose byproduct component C. Maltose, a known moiety of acarbose, should be maintained at high concentration levels in culture broths for efficient acarbose production. The acarbose yield increased with an increasing osmolality of the culture medium, with a maximum value of 3,200 mg/L obtained at 500 mOsm/kg. Component C was also produced in proportion to the osmolality. Conversion of acarbose to component C was accomplished with resting whole cells. Inhibitors of the conversion of acarbose to component C were sought since component C is probably derived from acarbose. Valienamine was found to be a potent inhibitor, resulting in a more than 90% reduction in component C formation at a 10 microM concentration. Effects were similar in a 1,500-L pilot fermentor with acarbose and component C yields of 3,490 and 43 mg/L at 500 mOsm/kg, respectively.
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Affiliation(s)
- Byoung Taek Choi
- Department of Biotechnology, College of Engineering, Yonsei University, Seodaemun-gu, Seoul 120-749, South Korea
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Abstract
Two inhibitors, acarbose and cyclodextrins (CD), were used to investigate the active site structure and function of barley alpha-amylase isozymes, AMY1 and AMY2. The hydrolysis of DP 4900-amylose, reduced (r) DP18-maltodextrin and maltoheptaose (catalysed by AMY1 and AMY2) was followed in the absence and in the presence of inhibitor. Without inhibitor, the highest activity was obtained with amylose, kcat/Km decreased 103-fold using rDP18-maltodextrin and 10(5) to 10(6)-fold using maltoheptaose as substrate. Acarbose is an uncompetitive inhibitor with inhibition constant (L1i) for amylose and maltodextrin in the micromolar range. Acarbose did not bind to the active site of the enzyme, but to a secondary site to give an abortive ESI complex. Only AMY2 has a second secondary binding site corresponding to an ESI2 complex. In contrast, acarbose is a mixed noncompetitive inhibitor of maltoheptaose hydrolysis. Consequently, in the presence of this oligosaccharide substrate, acarbose bound both to the active site and to a secondary binding site. alpha-CD inhibited the AMY1 and AMY2 catalysed hydrolysis of amylose, but was a very weak inhibitor compared to acarbose.beta- and gamma-CD are not inhibitors. These results are different from those obtained previously with PPA. However in AMY1, as already shown for amylases of animal and bacterial origin, in addition to the active site, one secondary carbohydrate binding site (s1) was necessary for activity whereas two secondary sites (s1 and s2) were required for the AMY2 activity. The first secondary site in both AMY1 and AMY2 was only functional when substrate was bound in the active site. This appears to be a general feature of the alpha-amylase family.
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Affiliation(s)
- Naïma Oudjeriouat
- IMRN, Institut Méditerranéen de Recherche en Nutrition, Faculté des Sciences et Techniques de St Jérome, Université d'Aix-Marseille, France
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Arakawa K, Bowers SG, Michels B, Trin V, Mahmud T. Biosynthetic studies on the α-glucosidase inhibitor acarbose: the chemical synthesis of isotopically labeled 2-epi-5-epi-valiolone analogs. Carbohydr Res 2003; 338:2075-82. [PMID: 14505874 DOI: 10.1016/s0008-6215(03)00315-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
2-epi-5-epi-valiolone is a cyclization product of the C(7) sugar phosphate, sedoheptulose 7-phosphate, involved in the biosynthesis of the aminocyclitol moieties of acarbose, validamycin, and pyralomicin. As part of our investigation into the pathway from 2-epi-5-epi-valiolone to the valienamine moiety of acarbose, we prepared 1-epi-5-epi-(6-(2)H(2))valiolol [(6-(2)H(2))-6], 5-epi-(6-(2)H(2))valiolol [(6-(2)H(2))-17], 1-epi-2-epi-5-epi-(6-(2)H(2))valiolol [(6-(2)H(2))-12] and 2-epi-5-epi-(6-(2)H(2))valiolamine [(6-(2)H(2))-11]. Compounds (6-(2)H(2))-6 and (6-(2)H(2))-17 were synthesized from 2,3,4,6-tetra-O-benzyl-D-glucopyranose in 10 and seven steps, respectively, whereas (6-(2)H(2))-12 and (6-(2)H(2))-11 were synthesized from 2,3,4,6-tetra-O-benzyl-D-mannopyranose in eight and 10 steps, respectively.
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Affiliation(s)
- Kenji Arakawa
- Department of Chemistry, University of Washington, Box 351700, Seattle, WA 98195-1700, USA
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Imamura H, Fushinobu S, Yamamoto M, Kumasaka T, Jeon BS, Wakagi T, Matsuzawa H. Crystal structures of 4-alpha-glucanotransferase from Thermococcus litoralis and its complex with an inhibitor. J Biol Chem 2003; 278:19378-86. [PMID: 12618437 DOI: 10.1074/jbc.m213134200] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Thermococcus litoralis 4-alpha-glucanotransferase (TLGT) belongs to glucoside hydrolase family 57 and catalyzes the disproportionation of amylose and the formation of large cyclic alpha-1,4-glucan (cycloamylose) from linear amylose. We determined the crystal structure of TLGT with and without an inhibitor, acarbose. TLGT is composed of two domains: an N-terminal domain (domain I), which contains a (beta/alpha)7 barrel fold, and a C-terminal domain (domain II), which has a twisted beta-sandwich fold. In the structure of TLGT complexed with acarbose, the inhibitor was bound at the cleft within domain I, indicating that domain I is a catalytic domain of TLGT. The acarbose-bound structure also clarified that Glu123 and Asp214 were the catalytic nucleophile and acid/base catalyst, respectively, and revealed the residues involved in substrate binding. It seemed that TLGT produces large cyclic glucans by preventing the production of small cyclic glucans by steric hindrance, which is achieved by three lids protruding into the active site cleft, as well as an extended active site cleft. Interestingly, domain I of TLGT shares some structural features with the catalytic domain of Golgi alpha-mannosidase from Drosophila melanogaster, which belongs to glucoside hydrolase family 38. Furthermore, the catalytic residue of the two enzymes is located in the same position. These observations suggest that families 57 and 38 evolved from a common ancestor.
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Affiliation(s)
- Hiromi Imamura
- Department of Biotechnology, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
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Zhang CS, Podeschwa M, Block O, Altenbach HJ, Piepersberg W, Wehmeier UF. Identification of a 1-epi-valienol 7-kinase activity in the producer of acarbose, Actinoplanes sp. SE50/110. FEBS Lett 2003; 540:53-7. [PMID: 12681482 DOI: 10.1016/s0014-5793(03)00222-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
In the biosynthesis of the C7-cyclitol moiety, valienol, of the alpha-glucosidase inhibitor acarbose in Actinoplanes sp. SE50/110 various cyclitol phosphates, such as 1-epi-valienol-7-phosphate, are postulated precursors. In the cell extracts of Actinoplanes SE50/110 we found a new kinase activity which specifically phosphorylates 1-epi-valienol; other C7-cyclitol analogs were only weakly or not phosphorylated. The purified product of the kinase reaction turned out to be 1-epi-valienol-7-phosphate in analyses by nuclear magnetic resonance spectroscopy. The enzyme seems not to be encoded by an acb gene and, therefore, plays a role in a salvage pathway rather than directly in the de novo biosynthesis of acarbose.
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Affiliation(s)
- Chang-Sheng Zhang
- Institute of Chemical Microbiology, Bergische University, Gauss-Str 20, D-42097 Wuppertal, Germany
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Zhang CS, Podeschwa M, Altenbach HJ, Piepersberg W, Wehmeier UF. The acarbose-biosynthetic enzyme AcbO from Actinoplanes sp. SE 50/110 is a 2-epi-5-epi-valiolone-7-phosphate 2-epimerase. FEBS Lett 2003; 540:47-52. [PMID: 12681481 DOI: 10.1016/s0014-5793(03)00221-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The C7-cyclitol 2-epi-5-epi-valiolone is the first precursor of the cyclitol moiety of the alpha-glucosidase inhibitor acarbose in Actinoplanes sp. SE50. The 2-epi-5-epi-valiolone becomes phosphorylated at C7 by the ATP dependent kinase AcbM prior to the next modifications. Preliminary data gave evidences that the AcbO protein could catalyse the first modification step of 2-epi-5-epi-valiolone-7-phosphate. Therefore, the AcbO protein, the encoding gene of which is also part of the acbKMLNOC operon, was overproduced and purified. Indeed the purified protein catalysed the 2-epimerisation of 2-epi-5-epi-valiolone-7-phosphate. The chemical structure of the purified reaction product was proven by nuclear magnetic resonance spectroscopy to be 5-epi-valiolone-7-phosphate.
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Affiliation(s)
- Chang-Sheng Zhang
- Institute of Chemical Microbiology, Bergische University, Gauss-Str 20, D-42097 Wuppertal, Germany
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49
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Abstract
The first crystal structures of a two-domain, prokaryotic glucoamylase were determined to high resolution from the clostridial species Thermoanaerobacterium thermosaccharolyticum with and without acarbose. The N-terminal domain has 18 antiparallel strands arranged in beta-sheets of a super-beta-sandwich. The C-terminal domain is an (alpha/alpha)(6) barrel, lacking the peripheral subdomain of eukaryotic glucoamylases. Interdomain contacts are common to all prokaryotic Family GH15 proteins. Domains similar to those of prokaryotic glucoamylases in maltose phosphorylases (Family GH65) and glycoaminoglycan lyases (Family PL8) suggest evolution from a common ancestor. Eukaryotic glucoamylases may have evolved from prokaryotic glucoamylases by the substitution of the N-terminal domain with the peripheral subdomain and by the addition of a starch-binding domain.
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Affiliation(s)
- Alexander E Aleshin
- Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, IA 50011, USA
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50
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Abstract
Cyclodextrin glycosyltransferase (CGTase) uses an alpha-retaining double displacement mechanism to catalyze three distinct transglycosylation reactions. To investigate these reactions as catalyzed by the CGTase from Thermoanaerobacterium thermosulfurigenes the enzyme was overproduced (8 mg.L(-1) culture) using Bacillus subtilis as a host. Detailed analysis revealed that the three reactions proceed via different kinetic mechanisms. The cyclization reaction (cyclodextrin formation from starch) is a one-substrate reaction, whereas the other two transglycosylation reactions are two-substrate reactions, which obey substituted enzyme mechanism kinetics (disproportionation reaction) or ternary complex mechanism kinetics (coupling reaction). Analysis of the effects of acarbose and cyclodextrins on the disproportionation reaction revealed that cyclodextrins are competitive inhibitors, whereas acarbose is a mixed type of inhibitor. Our results show that one molecule of acarbose binds either in the active site of the free enzyme, or at a secondary site of the enzyme-substrate complex. The mixed inhibition thus indicates the existence of a secondary sugar binding site near the active site of T. thermosulfurigenes CGTase.
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Affiliation(s)
- Hans Leemhuis
- Department of Microbiology, Groningen Biomolecular Sciences and Biotechnology Institute (GBB), University of Groningen, NN Haren, the Netherlands
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