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Ma S, Gao J, Tian Y, Wen L. Recent progress in chemoenzymatic synthesis of human glycans. Org Biomol Chem 2024; 22:7767-7785. [PMID: 39246045 DOI: 10.1039/d4ob01006j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/10/2024]
Abstract
Glycan is an essential cell component that usually exists in either a free form or a glycoconjugated form. Glycosylation affects the regulatory function of glycoconjugates in health and disease development, indicating the key role of glycan in organisms. Because of the complexity and diversity of glycan structures, it is challenging to prepare structurally well-defined glycans, which hinders the investigation of biological functions at the molecular level. Chemoenzymatic synthesis is an attractive approach for preparing complex glycans, because it avoids tedious protecting group manipulations in chemical synthesis and ensures high regio- and stereo-selectivity of glucosides during glycan assembly. Herein, enzymes, such as glycosyltransferases (GTs) and glycosidases (GHs), and sugar donors involved in the chemoenzymatic synthesis of human glycans are initially discussed. Many state-of-the-art chemoenzymatic methodologies are subsequently displayed and summarized to illustrate the development of synthetic human glycans, for example, N- and O-linked glycans, human milk oligosaccharides, and glycosaminoglycans. Thus, we provide an overview of recent chemoenzymatic synthetic designs and applications for synthesizing complex human glycans, along with insights into the limitations and perspectives of the current methods.
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Affiliation(s)
- Shengzhou Ma
- Carbohydrate-Based Drug Research Center, State Key Laboratory of Chemical Biology, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China.
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jinhua Gao
- Carbohydrate-Based Drug Research Center, State Key Laboratory of Chemical Biology, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China.
| | - Yinping Tian
- Carbohydrate-Based Drug Research Center, State Key Laboratory of Chemical Biology, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China.
| | - Liuqing Wen
- Carbohydrate-Based Drug Research Center, State Key Laboratory of Chemical Biology, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China.
- University of Chinese Academy of Sciences, Beijing 100049, China
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2
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Sultana R, Kamihira M. Bioengineered heparin: Advances in production technology. Biotechnol Adv 2024; 77:108456. [PMID: 39326809 DOI: 10.1016/j.biotechadv.2024.108456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2024] [Revised: 09/16/2024] [Accepted: 09/18/2024] [Indexed: 09/28/2024]
Abstract
Heparin, a highly sulfated glycosaminoglycan, is considered an indispensable anticoagulant with diverse therapeutic applications and has been a mainstay in medical practice for nearly a century. Its potential extends beyond anticoagulation, showing promise in treating inflammation, cancer, and infectious diseases such as COVID-19. However, its current sourcing from animal tissues poses challenges due to variable structures and adulterations, impacting treatment efficacy and safety. Recent advancements in metabolic engineering and synthetic biology offer alternatives through bioengineered heparin production, albeit with challenges such as controlling molecular weight and sulfonation patterns. This review offers comprehensive insight into recent advancements, encompassing: (i) the metabolic engineering strategies in prokaryotic systems for heparin production; (ii) strides made in the development of bioengineered heparin; and (iii) groundbreaking approaches driving production enhancements in eukaryotic systems. Additionally, it explores the potential of recombinant Chinese hamster ovary cells in heparin synthesis, discussing recent progress, challenges, and future prospects, thereby opening up new avenues in biomedical research.
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Affiliation(s)
- Razia Sultana
- Department of Chemical Engineering, Faculty of Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan; Department of Biotechnology and Genetic Engineering, Faculty of Science, Noakhali Science and Technology University, Noakhali 3814, Bangladesh
| | - Masamichi Kamihira
- Department of Chemical Engineering, Faculty of Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan.
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3
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Hu S, Zhou S, Wang Y, Chen W, Yin G, Chen J, Du G, Kang Z. Coordinated optimization of the polymerization and transportation processes to enhance the yield of exopolysaccharide heparosan. Carbohydr Polym 2024; 333:121983. [PMID: 38494235 DOI: 10.1016/j.carbpol.2024.121983] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Revised: 02/22/2024] [Accepted: 02/23/2024] [Indexed: 03/19/2024]
Abstract
Heparosan as the precursor for heparin biosynthesis has attracted intensive attention while Escherichia coli Nissle 1917 (EcN) has been applied as a chassis for heparosan biosynthesis. Here, after uncovering the pivotal role of KfiB in heparosan biosynthesis, we further demonstrate KfiB is involved in facilitating KpsT to translocate the nascent heparosan polysaccharide chain. As a result, an artificial expression cassette KfiACB was constructed with optimized RBS elements, resulting in 0.77 g/L heparosan in shake flask culture. Moreover, in view of the intracellular accumulation of heparosan, we further investigated the effects of overexpression of the ABC transport system proteins on heparosan biosynthesis. By co-overexpressing KfiACB with KpsTME, the heparosan production in flask cultures was increased to 1.03 g/L with an extracellular concentration of 0.96 g/L. Eventually, the engineered strain EcN/pET-kfiACB3-galU-kfiD-glmM/pCDF-kpsTME produced 12.2 g/L heparosan in 5-L fed-batch cultures while the extracellular heparosan was about 11.2 g/L. The results demonstrate the high-efficiency of the strategy for co-optimizing the polymerization and transportation for heparosan biosynthesis. Moreover, this strategy should be also available for enhancing the production of other polysaccharides.
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Affiliation(s)
- Shan Hu
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China; The Science Center for Future Foods, Jiangnan University, Wuxi 214122, China; The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Siyan Zhou
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China; The Science Center for Future Foods, Jiangnan University, Wuxi 214122, China; The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Yang Wang
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China; The Science Center for Future Foods, Jiangnan University, Wuxi 214122, China; The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Wuxia Chen
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China; The Science Center for Future Foods, Jiangnan University, Wuxi 214122, China; The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Guobin Yin
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China; The Science Center for Future Foods, Jiangnan University, Wuxi 214122, China; The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Jian Chen
- The Science Center for Future Foods, Jiangnan University, Wuxi 214122, China; The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Guocheng Du
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China; The Science Center for Future Foods, Jiangnan University, Wuxi 214122, China
| | - Zhen Kang
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China; The Science Center for Future Foods, Jiangnan University, Wuxi 214122, China.
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4
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Sheng LL, Cai YM, Li Y, Huang SL, Sheng JZ. Advancements in heparosan production through metabolic engineering and improved fermentation. Carbohydr Polym 2024; 331:121881. [PMID: 38388039 DOI: 10.1016/j.carbpol.2024.121881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2023] [Revised: 01/25/2024] [Accepted: 01/26/2024] [Indexed: 02/24/2024]
Abstract
Heparin is one of the most widely used natural drugs, and has been the preferred anticoagulant and antithrombotic agent in the clinical setting for nearly a century. Heparin also shows increasing therapeutic potential for treating inflammation, cancer, and microbial and viral diseases, including COVID-19. With advancements in synthetic biology, heparin production through microbial engineering of heparosan offers a cost-effective and scalable alternative to traditional extraction from animal tissues. Heparosan serves as the starting carbon backbone for the chemoenzymatic synthesis of bioengineered heparin, possessing a chain length that is critically important for the production of heparin-based therapeutics with specific molecular weight (MW) distributions. Recent advancements in metabolic engineering of microbial cell factories have resulted in high-yield heparosan production. This review systematically analyzes the key modules involved in microbial heparosan biosynthesis and the latest metabolic engineering strategies for enhancing production, regulating MW, and optimizing the fermentation scale-up of heparosan. It also discusses future studies, remaining challenges, and prospects in the field.
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Affiliation(s)
- Li-Li Sheng
- Key Laboratory of Chemical Biology of Natural Products, Ministry of Education, School of Pharmaceutical Sciences, Cheeloo College of Medicine, Shandong University, Jinan 250012, China
| | - Yi-Min Cai
- Key Laboratory of Chemical Biology of Natural Products, Ministry of Education, School of Pharmaceutical Sciences, Cheeloo College of Medicine, Shandong University, Jinan 250012, China
| | - Yi Li
- Key Laboratory of Chemical Biology of Natural Products, Ministry of Education, School of Pharmaceutical Sciences, Cheeloo College of Medicine, Shandong University, Jinan 250012, China
| | - Si-Ling Huang
- Bloomage BioTechnology Corp., Ltd., Jinan 250010, China
| | - Ju-Zheng Sheng
- Key Laboratory of Chemical Biology of Natural Products, Ministry of Education, School of Pharmaceutical Sciences, Cheeloo College of Medicine, Shandong University, Jinan 250012, China; The State Key Laboratory of Microbial Technology, Shandong University, Qingdao 250100, China.
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5
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Wang D, Hu L, Xu R, Zhang W, Xiong H, Wang Y, Du G, Kang Z. Production of different molecular weight glycosaminoglycans with microbial cell factories. Enzyme Microb Technol 2023; 171:110324. [PMID: 37742407 DOI: 10.1016/j.enzmictec.2023.110324] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Revised: 09/04/2023] [Accepted: 09/08/2023] [Indexed: 09/26/2023]
Abstract
Glycosaminoglycans (GAGs) are naturally occurring acidic polysaccharides with wide applications in pharmaceuticals, cosmetics, and health foods. The diverse biological activities and physiological functions of GAGs are closely associated with their molecular weights and sulfation patterns. Except for the non-sulfated hyaluronan which can be synthesized naturally by group A Streptococcus, all the other GAGs such as heparin and chondroitin sulfate are mainly acquired from animal tissues. Microbial cell factories provide a more effective platform for the production of structurally homogeneous GAGs. Enhancing the production efficiency of polysaccharides, accurately regulating the GAGs molecular weight, and effectively controlling the sulfation degree of GAGs represent the major challenges of developing GAGs microbial cell factories. Several enzymatic, metabolic engineering, and synthetic biology strategies have been developed to tackle these obstacles and push forward the industrialization of biotechnologically produced GAGs. This review summarizes the recent advances in the construction of GAGs synthesis cell factories, regulation of GAG molecular weight, and modification of GAGs chains. Furthermore, the challenges and prospects for future research in this field are also discussed.
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Affiliation(s)
- Daoan Wang
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China; The Science Center for Future Foods, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China; Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China
| | - Litao Hu
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China; The Science Center for Future Foods, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China; Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China
| | - Ruirui Xu
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China; The Science Center for Future Foods, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China; Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China
| | - Weijiao Zhang
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China; The Science Center for Future Foods, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China; Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China
| | - Haibo Xiong
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China; The Science Center for Future Foods, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China; Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China
| | - Yang Wang
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China; The Science Center for Future Foods, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China
| | - Guocheng Du
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China; The Science Center for Future Foods, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China; Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China
| | - Zhen Kang
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China; The Science Center for Future Foods, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China; Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China.
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6
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Sulewska M, Berger M, Damerow M, Schwarzer D, Buettner FFR, Bethe A, Taft MH, Bakker H, Mühlenhoff M, Gerardy-Schahn R, Priem B, Fiebig T. Extending the enzymatic toolbox for heparosan polymerization, depolymerization, and detection. Carbohydr Polym 2023; 319:121182. [PMID: 37567694 DOI: 10.1016/j.carbpol.2023.121182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 07/04/2023] [Accepted: 07/06/2023] [Indexed: 08/13/2023]
Abstract
Heparosan is an acidic polysaccharide expressed as a capsule polymer by pathogenic and commensal bacteria, e.g. by E. coli K5. As a precursor in the biosynthesis of heparan sulfate and heparin, heparosan has a high biocompatibility and is thus of interest for pharmaceutical applications. However, due to its low immunogenicity, developing antibodies against heparosan and detecting the polymer in biological samples has been challenging. In this study, we exploited the enzyme repertoire of E. coli K5 and the E. coli K5-specific bacteriophage ΦK5B for the controlled synthesis and depolymerization of heparosan. A fluorescently labeled heparosan nonamer was used as a priming acceptor to study the elongation mechanism of the E. coli K5 heparosan polymerases KfiA and KfiC. We could demonstrate that the enzymes act in a distributive manner, producing labeled heparosan of low dispersity. The enzymatically synthesized heparosan was a useful tool to identify the tailspike protein KflB of ΦK5B as heparosan lyase and to characterize its endolytic depolymerization mechanism. Most importantly, using site-directed mutagenesis and rational construct design, we generated an inactive version of KflB for the detection of heparosan in ELISA-based assays, on blots, and on bacterial and mammalian cells.
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Affiliation(s)
- Małgorzata Sulewska
- Institute of Clinical Biochemistry, Hannover Medical School, Hannover, Germany; Centre de Recherche sur les Macromolécules Végétales, Groupe Chimie et Biotechnologie des Oligosaccharides, 601 rue de la Chimie, BP 53X, 38041 Grenoble, Cedex 09, France.
| | - Monika Berger
- Institute of Clinical Biochemistry, Hannover Medical School, Hannover, Germany.
| | - Manuela Damerow
- Institute of Clinical Biochemistry, Hannover Medical School, Hannover, Germany
| | - David Schwarzer
- Institute of Clinical Biochemistry, Hannover Medical School, Hannover, Germany.
| | - Falk F R Buettner
- Institute of Clinical Biochemistry, Hannover Medical School, Hannover, Germany.
| | - Andrea Bethe
- Institute of Clinical Biochemistry, Hannover Medical School, Hannover, Germany.
| | - Manuel H Taft
- Institute for Biophysical Chemistry, Hannover Medical School, Hannover, Germany.
| | - Hans Bakker
- Institute of Clinical Biochemistry, Hannover Medical School, Hannover, Germany.
| | - Martina Mühlenhoff
- Institute of Clinical Biochemistry, Hannover Medical School, Hannover, Germany.
| | - Rita Gerardy-Schahn
- Institute of Clinical Biochemistry, Hannover Medical School, Hannover, Germany.
| | - Bernard Priem
- Centre de Recherche sur les Macromolécules Végétales, Groupe Chimie et Biotechnologie des Oligosaccharides, 601 rue de la Chimie, BP 53X, 38041 Grenoble, Cedex 09, France.
| | - Timm Fiebig
- Institute of Clinical Biochemistry, Hannover Medical School, Hannover, Germany.
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Yu Y, Gong B, Wang H, Yang G, Zhou X. Chromosome evolution of Escherichia coli Nissle 1917 for high-level production of heparosan. Biotechnol Bioeng 2023; 120:1081-1096. [PMID: 36539926 DOI: 10.1002/bit.28315] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Revised: 12/11/2022] [Accepted: 12/17/2022] [Indexed: 12/24/2022]
Abstract
Heparosan is a crucial-polysaccharide precursor for the chemoenzymatic synthesis of heparin, a widely used anticoagulant drug. Presently, heparosan is mainly extracted with the potential risk of contamination from Escherichia coli strain K5, a pathogenic bacterium causing urinary tract infection. Here, a nonpathogenic probiotic, E. coli strain Nissle 1917 (EcN), was metabolically engineered to carry multiple copies of the 19-kb kps locus and produce heparosan to 9.1 g/L in fed-batch fermentation. Chromosome evolution driven by antibiotics was employed to amplify the kps locus, which governed the synthesis and export of heparosan from EcN at 21 mg L-1 OD-1 . The average copy number of kps locus increased from 1 to 24 copies per cell, which produced up to 104 mg L-1 OD-1 of heparosan in the shaking flask cultures of engineered strains. The following in-frame deletion of recA stabilized the recombinant duplicates of chromosomal kps locus and the productivity of heparosan in continuous culture for at least 56 generations. Fed-batch fermentation of the engineered strain EcN8 was carried out to bring the yield of heparosan up to 9.1 g/L. Heparosan from the fermentation culture was further purified at a 75% overall recovery. The structure of purified heparosan was characterized and further modified by N-sulfotransferase with 3'-phosphoadenosine-5'-phosphosulfate as the sulfo-donor. The analysis of element composition showed that heparosan was N-sulfated by over 80%. These results indicated that duplicating large DNA cassettes up to 19-kb, followed by high-cell-density fermentation, was promising in the large-scale preparation of chemicals and could be adapted to engineer other industrial-interest bacteria metabolically.
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Affiliation(s)
- Yanying Yu
- Department of Bioengineering, School of Biotechnology and Food Engineering, Hefei University of Technology, Hefei, China
| | - Bingxue Gong
- Department of Bioengineering, School of Biotechnology and Food Engineering, Hefei University of Technology, Hefei, China
| | - Huili Wang
- Department of Bioengineering, School of Biotechnology and Food Engineering, Hefei University of Technology, Hefei, China
| | - Guixia Yang
- Department of Bioengineering, School of Biotechnology and Food Engineering, Hefei University of Technology, Hefei, China
| | - Xianxuan Zhou
- Department of Bioengineering, School of Biotechnology and Food Engineering, Hefei University of Technology, Hefei, China
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Engineering the probiotic bacterium Escherichia coli Nissle 1917 as an efficient cell factory for heparosan biosynthesis. Enzyme Microb Technol 2022; 158:110038. [DOI: 10.1016/j.enzmictec.2022.110038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2021] [Revised: 03/22/2022] [Accepted: 04/02/2022] [Indexed: 11/19/2022]
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Dulaney SB, Huang X. Strategies in Synthesis of Heparin/Heparan Sulfate Oligosaccharides: 2000-Present. Adv Carbohydr Chem Biochem 2021; 80:121-164. [PMID: 34872655 DOI: 10.1016/bs.accb.2021.11.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Heparin and heparan sulfate are members of the glycosaminoglycan family that are involved in a multitude of biological processes. The great interests in the anticoagulant properties of heparin have stimulated major advances in synthetic strategies toward clinically effective analogues, as demonstrated importantly by the approval of the fully synthetic pentasaccharide fragment, termed fondaparinux (Arixtra®), of the heparin macromolecule for treatment of deep-vein thrombosis. Given the highly complex nature of heparin and heparan sulfate, the chemical synthesis of their components is a challenging endeavor. In the past decade, multiple approaches have been developed to improve the overall synthetic efficiency. New strategies have emerged that can generate libraries of oligosaccharide components of heparin and heparan sulfate. This article discusses recent developments in the assembly of heparin and heparan sulfate oligosaccharides and the associated challenges in their synthesis.
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Affiliation(s)
- Steven B Dulaney
- Department of Chemistry, Michigan State University, East Lansing, Michigan, USA
| | - Xuefei Huang
- Department of Chemistry, Michigan State University, East Lansing, Michigan, USA
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Nehru G, Tadi SRR, Sivaprakasam S. Application of Dual Promoter Expression System for the Enhanced Heparosan Production in Bacillus megaterium. Appl Biochem Biotechnol 2021; 193:2389-2402. [PMID: 33686628 DOI: 10.1007/s12010-021-03541-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Accepted: 02/26/2021] [Indexed: 10/22/2022]
Abstract
Heparosan, a capsular polysaccharide synthesized by certain pathogenic bacteria, is a promising precursor for heparin production. Heparosan production is catalyzed by the formation of KfiC-KfiA complex and the subsequent action of KfiC and KfiA proteins. Polycistronic expression of kfiC and kfiA in Bacillus megaterium yielded an unbalanced expression of KfiC and KfiA proteins resulted in decreased heparosan production. In this study, dual promoter plasmid system was constructed to increase the expression levels of KfiC and KfiA proteins. Dual promoter plasmid system along with UDP-glucuronic acid pathway overexpression (CADuet-DB) increased the heparosan production to 203 mg/L in shake flask experiments. Batch fermentation of strain CADuet-DB under controlled conditions yielded a maximum heparosan concentration of 627 mg/L, which is 59% higher than strain CA-DB. A modified logistic model is applied to describe the kinetics of heparosan production and biomass growth. Fed batch fermentation resulted in 3-fold enhancement in heparosan concentration (1.96 g/L), compared to batch fermentation. Nuclear magnetic resonance analysis revealed that heparosan from strain CADuet-DB was similar to Escherichia coli K5 heparosan. These results suggested that dual promoter expression system is a promising alternative to polycistronic expression system to produce heparosan in B. megaterium.
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Affiliation(s)
- Ganesh Nehru
- Bioprocess Analytical Technology Laboratory, Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, Assam, 781039, India
| | - Subbi Rami Reddy Tadi
- Bioprocess Analytical Technology Laboratory, Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, Assam, 781039, India
| | - Senthilkumar Sivaprakasam
- Bioprocess Analytical Technology Laboratory, Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, Assam, 781039, India.
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Metabolic engineering of non-pathogenic Escherichia coli strains for the controlled production of low molecular weight heparosan and size-specific heparosan oligosaccharides. Biochim Biophys Acta Gen Subj 2020; 1865:129765. [PMID: 33069832 DOI: 10.1016/j.bbagen.2020.129765] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 10/08/2020] [Accepted: 10/13/2020] [Indexed: 10/23/2022]
Abstract
BACKGROUND Heparin, a lifesaving blood thinner used in over 100 million surgical procedures worldwide annually, is currently isolated from over 700 million pigs and ~200 million cattle in slaughterhouses worldwide. Though animal-derived heparin has been in use over eight decades, it is a complex mixture that poses a risk for chemical adulteration, and its availability is highly vulnerable. Therefore, there is an urgent need in devising bioengineering approaches for the production of heparin polymers, especially low molecular weight heparin (LMWH), and thus, relying less on animal sources. One of the main challenges, however, is the rapid, cost-effective production of low molecular weight heparosan, a precursor of LMWH and size-defined heparosan oligosaccharides. Another challenge is N-sulfation of N-acetyl heparosan oligosaccharides efficiently, an essential modification required for subsequent enzymatic modifications, though chemical and enzymatic N-sulfation is effectively performed at the polymer level. METHODS To devise a strategy to produce low molecular weight heparosan and heparosan oligosaccharides, several non-pathogenic E. coli strains are engineered by transforming the essential heparosan biosynthetic genes with or without the eliminase gene (elmA) from pathogenic E. coli K5. RESULTS The metabolically engineered non-pathogenic strains are shown to produce ~5 kDa heparosan, a precursor for low molecular weight heparin, for the first time. Additionally, heparosan oligosaccharides of specific sizes ranging from tetrasaccharide to dodecasaccharide are directly generated, in a single step, from the recombinant bacterial strains that carry both heparosan biosynthetic genes and the eliminase gene. Various modifications, such as chemical N-sulfation of N-acetyl heparosan hexasaccharide following the selective protection of reducing end GlcNAc residue, enzymatic C5-epimerization of N-sulfo heparosan tetrasaccharide and complete 6-O sulfation of N-sulfo heparosan hexasaccharide, are shown to be feasible. CONCLUSIONS We engineered non-pathogenic E. coli strains to produce low molecular weight heparosan and a range of size-specific heparosan oligosaccharides in a controlled manner through modulating culture conditions. We have also shown various chemical and enzymatic modifications of heparosan oligosaccharides. GENERAL SIGNIFICANCE Heparosan is a precursor of heparin and the methods to produce low molecular weight heparosan is widely awaited. The methods described herein are promising and will pave the way for potential large scale production of low molecular weight heparin anticoagulants and bioactive heparin oligosaccharides in the coming decade.
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12
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Production and characterization of low molecular weight heparosan in Bacillus megaterium using Escherichia coli K5 glycosyltransferases. Int J Biol Macromol 2020; 160:69-76. [DOI: 10.1016/j.ijbiomac.2020.05.159] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Revised: 05/14/2020] [Accepted: 05/18/2020] [Indexed: 01/31/2023]
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Williams A, Gedeon KS, Vaidyanathan D, Yu Y, Collins CH, Dordick JS, Linhardt RJ, Koffas MAG. Metabolic engineering of Bacillus megaterium for heparosan biosynthesis using Pasteurella multocida heparosan synthase, PmHS2. Microb Cell Fact 2019; 18:132. [PMID: 31405374 PMCID: PMC6691538 DOI: 10.1186/s12934-019-1187-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Accepted: 08/07/2019] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Heparosan is the unsulfated precursor of heparin and heparan sulfate and its synthesis is typically the first step in the production of bioengineered heparin. In addition to its utility as the starting material for this important anticoagulant and anti-inflammatory drug, heparosan is a versatile compound that possesses suitable chemical and physical properties for making a variety of high-quality tissue engineering biomaterials, gels and scaffolds, as well as serving as a drug delivery vehicle. The selected production host was the Gram-positive bacterium Bacillus megaterium, which represents an increasingly used choice for high-yield production of intra- and extracellular biomolecules for scientific and industrial applications. RESULTS We have engineered the metabolism of B. megaterium to produce heparosan, using a T7 RNA polymerase (T7 RNAP) expression system. This system, which allows tightly regulated and efficient induction of genes of interest, has been co-opted for control of Pasteurella multocida heparosan synthase (PmHS2). Specifically, we show that B. megaterium MS941 cells co-transformed with pT7-RNAP and pPT7_PmHS2 plasmids are capable of producing heparosan upon induction with xylose, providing an alternate, safe source of heparosan. Productivities of ~ 250 mg/L of heparosan in shake flasks and ~ 2.74 g/L in fed-batch cultivation were reached. The polydisperse Pasteurella heparosan synthase products from B. megaterium primarily consisted of a relatively high molecular weight (MW) heparosan (~ 200-300 kD) that may be appropriate for producing certain biomaterials; while the less abundant lower MW heparosan fractions (~ 10-40 kD) can be a suitable starting material for heparin synthesis. CONCLUSION We have successfully engineered an asporogenic and non-pathogenic B. megaterium host strain to produce heparosan for various applications, through a combination of genetic manipulation and growth optimization strategies. The heparosan products from B. megaterium display a different range of MW products than traditional E. coli K5 products, diversifying its potential applications and facilitating increased product utility.
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Affiliation(s)
- Asher Williams
- Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, Troy, NY, 12180, USA
| | - Kamil S Gedeon
- Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, Troy, NY, 12180, USA
| | - Deepika Vaidyanathan
- Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, Troy, NY, 12180, USA
| | - Yanlei Yu
- Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, USA
| | - Cynthia H Collins
- Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, Troy, NY, 12180, USA
| | - Jonathan S Dordick
- Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, Troy, NY, 12180, USA
- Department of Biology, Rensselaer Polytechnic Institute, Troy, NY, 12180, USA
| | - Robert J Linhardt
- Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, Troy, NY, 12180, USA
- Department of Chemistry and Chemical Biology, Rensselaer Polytechnic Institute, Troy, NY, 12180, USA
- Department of Biology, Rensselaer Polytechnic Institute, Troy, NY, 12180, USA
| | - Mattheos A G Koffas
- Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, Troy, NY, 12180, USA.
- Department of Biology, Rensselaer Polytechnic Institute, Troy, NY, 12180, USA.
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Zhao X, Chen Z, Gu G, Guo Z. Recent advances in the research of bacterial glucuronosyltransferases. J Carbohydr Chem 2016. [DOI: 10.1080/07328303.2016.1205597] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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15
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Chaperone-assisted expression of KfiC glucuronyltransferase from Escherichia coli K5 leads to heparosan production in Escherichia coli BL21 in absence of the stabilisator KfiB. Appl Microbiol Biotechnol 2016; 100:10355-10361. [DOI: 10.1007/s00253-016-7745-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Revised: 07/03/2016] [Accepted: 07/20/2016] [Indexed: 10/21/2022]
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16
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Jin P, Zhang L, Yuan P, Kang Z, Du G, Chen J. Efficient biosynthesis of polysaccharides chondroitin and heparosan by metabolically engineered Bacillus subtilis. Carbohydr Polym 2016; 140:424-32. [DOI: 10.1016/j.carbpol.2015.12.065] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Revised: 12/07/2015] [Accepted: 12/27/2015] [Indexed: 10/22/2022]
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17
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Wu B, Wei N, Thon V, Wei M, Yu Z, Xu Y, Chen X, Liu J, Wang PG, Li T. Facile chemoenzymatic synthesis of biotinylated heparosan hexasaccharide. Org Biomol Chem 2015; 13:5098-101. [PMID: 25858766 PMCID: PMC4472006 DOI: 10.1039/c5ob00462d] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
A biotinylated heparosan hexasaccharide was synthesized using a one-pot multi-enzyme strategy, in situ activation and transfer of N-trifluoroacetylglucosamine (GlcNTFA) to a heparin backbone significantly improved the synthetic efficiency. The biotinylated hexasaccharide could serve as a flexible core to diversify its conversion into heparan sulfate isoforms with potential biological applications and therapeutics.
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Affiliation(s)
- Baolin Wu
- Center for Diagnostics and Therapeutics, Department of Chemistry, Georgia State University, Atlanta, GA 30303, USA
| | - Na Wei
- Center for Diagnostics and Therapeutics, Department of Chemistry, Georgia State University, Atlanta, GA 30303, USA
| | - Vireak Thon
- Center for Diagnostics and Therapeutics, Department of Chemistry, Georgia State University, Atlanta, GA 30303, USA
| | - Mohui Wei
- Center for Diagnostics and Therapeutics, Department of Chemistry, Georgia State University, Atlanta, GA 30303, USA
| | - Zaikuan Yu
- Center for Diagnostics and Therapeutics, Department of Chemistry, Georgia State University, Atlanta, GA 30303, USA
| | - Yongmei Xu
- Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Xi Chen
- Department of Chemistry, University of California, One Shields Avenue, Davis, CA 95616, USA
| | - Jian Liu
- Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Peng George Wang
- Center for Diagnostics and Therapeutics, Department of Chemistry, Georgia State University, Atlanta, GA 30303, USA
| | - Tiehai Li
- Center for Diagnostics and Therapeutics, Department of Chemistry, Georgia State University, Atlanta, GA 30303, USA
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18
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Nzakizwanayo J, Kumar S, Ogilvie LA, Patel BA, Dedi C, Macfarlane WM, Jones BV. Disruption of Escherichia coli Nissle 1917 K5 capsule biosynthesis, through loss of distinct kfi genes, modulates interaction with intestinal epithelial cells and impact on cell health. PLoS One 2015; 10:e0120430. [PMID: 25790373 PMCID: PMC4366286 DOI: 10.1371/journal.pone.0120430] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Accepted: 01/22/2015] [Indexed: 12/11/2022] Open
Abstract
Escherichia coli Nissle 1917 (EcN) is among the best characterised probiotics, with a proven clinical impact in a range of conditions. Despite this, the mechanisms underlying these "probiotic effects" are not clearly defined. Here we applied random transposon mutagenesis to identify genes relevant to the interaction of EcN with intestinal epithelial cells. This demonstrated mutants disrupted in the kfiB gene, of the K5 capsule biosynthesis cluster, to be significantly enhanced in attachment to Caco-2 cells. However, this phenotype was distinct from that previously reported for EcN K5 deficient mutants (kfiC null mutants), prompting us to explore further the role of kfiB in EcN:Caco-2 interaction. Isogenic mutants with deletions in kfiB (EcNΔkfiB), or the more extensively characterised K5 capsule biosynthesis gene kfiC (EcNΔkfiC), were both shown to be capsule deficient, but displayed divergent phenotypes with regard to impact on Caco-2 cells. Compared with EcNΔkfiC and the EcN wild-type, EcNΔkfiB exhibited significantly greater attachment to Caco-2 cells, as well as apoptotic and cytotoxic effects. In contrast, EcNΔkfiC was comparable to the wild-type in these assays, but was shown to induce significantly greater COX-2 expression in Caco-2 cells. Distinct differences were also apparent in the pervading cell morphology and cellular aggregation between mutants. Overall, these observations reinforce the importance of the EcN K5 capsule in host-EcN interactions, but demonstrate that loss of distinct genes in the K5 pathway can modulate the impact of EcN on epithelial cell health.
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Affiliation(s)
- Jonathan Nzakizwanayo
- School of Pharmacy and Biomolecular Sciences, University of Brighton, Brighton, East Sussex, United Kingdom
| | - Sandeep Kumar
- School of Pharmacy and Biomolecular Sciences, University of Brighton, Brighton, East Sussex, United Kingdom
| | - Lesley A. Ogilvie
- School of Pharmacy and Biomolecular Sciences, University of Brighton, Brighton, East Sussex, United Kingdom
| | - Bhavik A. Patel
- School of Pharmacy and Biomolecular Sciences, University of Brighton, Brighton, East Sussex, United Kingdom
| | - Cinzia Dedi
- School of Pharmacy and Biomolecular Sciences, University of Brighton, Brighton, East Sussex, United Kingdom
| | - Wendy M. Macfarlane
- School of Pharmacy and Biomolecular Sciences, University of Brighton, Brighton, East Sussex, United Kingdom
| | - Brian V. Jones
- School of Pharmacy and Biomolecular Sciences, University of Brighton, Brighton, East Sussex, United Kingdom
- Queen Victoria Hospital NHS Foundation Trust, East Grinstead, West Sussex, United Kingdom
- * E-mail:
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19
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KfoE encodes a fructosyltransferase involved in capsular polysaccharide biosynthesis in Escherichia coli K4. Biotechnol Lett 2014; 36:1469-77. [DOI: 10.1007/s10529-014-1502-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2014] [Accepted: 02/20/2014] [Indexed: 11/25/2022]
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20
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Willis LM, Whitfield C. Structure, biosynthesis, and function of bacterial capsular polysaccharides synthesized by ABC transporter-dependent pathways. Carbohydr Res 2013; 378:35-44. [PMID: 23746650 DOI: 10.1016/j.carres.2013.05.007] [Citation(s) in RCA: 150] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2013] [Revised: 05/06/2013] [Accepted: 05/11/2013] [Indexed: 12/11/2022]
Abstract
Bacterial capsules are formed primarily from long-chain polysaccharides with repeat-unit structures. A given bacterial species can produce a range of capsular polysaccharides (CPSs) with different structures and these help distinguish isolates by serotyping, as is the case with Escherichia coli K antigens. Capsules are important virulence factors for many pathogens and this review focuses on CPSs synthesized via ATP-binding cassette (ABC) transporter-dependent processes in Gram-negative bacteria. Bacteria utilizing this pathway are often associated with urinary tract infections, septicemia, and meningitis, and E. coli and Neisseria meningitidis provide well-studied examples. CPSs from ABC transporter-dependent pathways are synthesized at the cytoplasmic face of the inner membrane through the concerted action of glycosyltransferases before being exported across the inner membrane and translocated to the cell surface. A hallmark of these CPSs is a conserved reducing terminal glycolipid composed of phosphatidylglycerol and a poly-3-deoxy-d-manno-oct-2-ulosonic acid (Kdo) linker. Recent discovery of the structure of this conserved lipid terminus provides new insights into the early steps in CPS biosynthesis.
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Affiliation(s)
- Lisa M Willis
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada N1G 2W1
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21
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Donor substrate promiscuity of the N-acetylglucosaminyltransferase activities of Pasteurella multocida heparosan synthase 2 (PmHS2) and Escherichia coli K5 KfiA. Appl Microbiol Biotechnol 2013; 98:1127-34. [DOI: 10.1007/s00253-013-4947-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2013] [Revised: 04/19/2013] [Accepted: 04/23/2013] [Indexed: 02/05/2023]
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22
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Effect of eliminase gene (elmA) deletion on heparosan production and shedding in Escherichia coli K5. J Biotechnol 2013; 165:175-7. [PMID: 23583654 DOI: 10.1016/j.jbiotec.2013.03.018] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2013] [Accepted: 03/28/2013] [Indexed: 11/20/2022]
Abstract
Escherichia coli K5 produces heparosan and sheds it into the growth medium in a temperature dependent manner. The shedding is believed to be controlled, at least in part, by enzyme action on the cell-associated capsular polysaccharide, heparosan. One candidate enzyme in such shedding is eliminase. The eliminase gene (elmA) was deleted from the genome of E. coli K5 and its effect on secreted and cell-associated heparosan was investigated. Deletion of the eliminase gene resulted in a significant reduction in heparosan shedding into the medium and heparosan content in the capsule of the cells, indicating its pivotal role in heparosan synthesis and shedding by E. coli K5.
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23
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Production methods for heparosan, a precursor of heparin and heparan sulfate. Carbohydr Polym 2013; 93:38-47. [DOI: 10.1016/j.carbpol.2012.04.046] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2011] [Revised: 02/17/2012] [Accepted: 04/17/2012] [Indexed: 11/23/2022]
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24
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Greenfield LK, Richards MR, Vinogradov E, Wakarchuk WW, Lowary TL, Whitfield C. Domain organization of the polymerizing mannosyltransferases involved in synthesis of the Escherichia coli O8 and O9a lipopolysaccharide O-antigens. J Biol Chem 2012; 287:38135-49. [PMID: 22989876 PMCID: PMC3488083 DOI: 10.1074/jbc.m112.412577] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2012] [Revised: 09/16/2012] [Indexed: 11/06/2022] Open
Abstract
The Escherichia coli O9a and O8 polymannose O-polysaccharides (O-PSs) serve as model systems for the biosynthesis of bacterial polysaccharides by ATP-binding cassette transporter-dependent pathways. Both O-PSs contain a conserved primer-adaptor domain at the reducing terminus and a serotype-specific repeat unit domain. The repeat unit domain is polymerized by the serotype-specific WbdA mannosyltransferase. In serotype O9a, WbdA is a bifunctional α-(1→2)-, α-(1→3)-mannosyltransferase, and its counterpart in serotype O8 is trifunctional (α-(1→2), α-(1→3), and β-(1→2)). Little is known about the detailed structures or mechanisms of action of the WbdA polymerases, and here we establish that they are multidomain enzymes. WbdA(O9a) contains two separable and functionally active domains, whereas WbdA(O8) possesses three. In WbdC(O9a) and WbdB(O9a), substitution of the first Glu of the EX(7)E motif had detrimental effects on the enzyme activity, whereas substitution of the second had no significant effect on activity in vivo. Mutation of the Glu residues in the EX(7)E motif of the N-terminal WbdA(O9a) domain resulted in WbdA variants unable to synthesize O-PS. In contrast, mutation of the Glu residues in the motif of the C-terminal WbdA(O9a) domain generated an enzyme capable of synthesizing an altered O-PS repeat unit consisting of only α-(1→2) linkages. In vitro assays with synthetic acceptors unequivocally confirmed that the N-terminal domain of WbdA(O9a) possesses α-(1→2)-mannosyltransferase activity. Together, these studies form a framework for detailed structure-function studies on individual domains and a strategy applicable for dissection and analysis of other multidomain glycosyltransferases.
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Affiliation(s)
- Laura K. Greenfield
- From the Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario N1G 2W1
| | - Michele R. Richards
- the Alberta Glycomics Centre and Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, and
| | - Evgeny Vinogradov
- the Institute for Biological Sciences, National Research Council of Canada, Ottawa, Ontario K1A 0R6, Canada
| | - Warren W. Wakarchuk
- the Institute for Biological Sciences, National Research Council of Canada, Ottawa, Ontario K1A 0R6, Canada
| | - Todd L. Lowary
- the Alberta Glycomics Centre and Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, and
| | - Chris Whitfield
- From the Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario N1G 2W1
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25
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Greenfield LK, Richards MR, Li J, Wakarchuk WW, Lowary TL, Whitfield C. Biosynthesis of the polymannose lipopolysaccharide O-antigens from Escherichia coli serotypes O8 and O9a requires a unique combination of single- and multiple-active site mannosyltransferases. J Biol Chem 2012; 287:35078-35091. [PMID: 22875852 DOI: 10.1074/jbc.m112.401000] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The Escherichia coli O9a and O8 O-antigen serotypes represent model systems for the ABC transporter-dependent synthesis of bacterial polysaccharides. The O9a and O8 antigens are linear mannose homopolymers containing conserved reducing termini (the primer-adaptor), a serotype-specific repeat unit domain, and a terminator. Synthesis of these glycans occurs on the polyisoprenoid lipid-linked primer, undecaprenol pyrophosphoryl-GlcpNAc, by two conserved mannosyltransferases, WbdC and WbdB, and a serotype-specific mannosyltransferase, WbdA. The glycan structure and pattern of conservation in the O9a and O8 mannosyltransferases are not consistent with the existing model of O9a biosynthesis. Here we establish a revised pathway using a combination of in vivo (mutant complementation) experiments and in vitro strategies with purified enzymes and synthetic acceptors. WbdC and WbdB synthesize the adaptor region, where they transfer one and two α-(1→3)-linked mannose residues, respectively. The WbdA enzymes are solely responsible for forming the repeat unit domains of these O-antigens. WbdA(O9a) has two predicted active sites and polymerizes a tetrasaccharide repeat unit containing two α-(1→3)- and two α-(1→2)-linked mannopyranose residues. In contrast, WbdA(O8) polymerizes trisaccharide repeat units containing single α-(1→3)-, α-(1→2)-, and β-(1→2)-mannopyranoses. These studies illustrate assembly systems exploiting several mannosyltransferases with flexible active sites, arranged in single- and multiple-domain formats.
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Affiliation(s)
- Laura K Greenfield
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario N1G 2W1, Canada
| | - Michele R Richards
- Alberta Glycomics Centre and Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| | - Jianjun Li
- Institute for Biological Sciences, National Research Council of Canada, Ottawa, Ontario K1A 0R6, Canada
| | - Warren W Wakarchuk
- Institute for Biological Sciences, National Research Council of Canada, Ottawa, Ontario K1A 0R6, Canada
| | - Todd L Lowary
- Alberta Glycomics Centre and Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| | - Chris Whitfield
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario N1G 2W1, Canada.
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26
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Zhang C, Liu L, Teng L, Chen J, Liu J, Li J, Du G, Chen J. Metabolic engineering of Escherichia coli BL21 for biosynthesis of heparosan, a bioengineered heparin precursor. Metab Eng 2012; 14:521-7. [PMID: 22781283 DOI: 10.1016/j.ymben.2012.06.005] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2012] [Revised: 06/06/2012] [Accepted: 06/28/2012] [Indexed: 11/29/2022]
Abstract
As a precursor of bioengineered heparin, heparosan is currently produced from Escherichia coli K5, which is pathogenic bacteria potentially causing urinary tract infection. Thus, it would be advantageous to develop an alternative source of heparosan from a non-pathogeneic strain. In this work we reported the biosynthesis of heparosan via the metabolic engineering of non-pathogenic E. coli BL21 as a production host. Four genes, KfiA, KfiB, KfiC and KfiD, encoding enzymes for the biosynthesis of heparosan in E. coli K5, were cloned into inducible plasmids pETDuet-1 and pRSFDuet-1 and further transformed into E. coli BL21, yielding six recombinant strains as follows: sA, sC, sAC, sABC, sACD and sABCD. The single expression of KfiA (sA) or KfiC (sC) in E. coli BL21 did not produce heparosan, while the co-expression of KfiA and KfiC (sAC) could produce 63 mg/L heparosan in shake flask. The strain sABC and sACD could produce 100 and 120 mg/L heparosan, respectively, indicating that the expression of KfiB or KfiD was beneficial for heparosan production. The strain sABCD could produce 334 mg/L heparosan in shake flask and 652 mg/L heparosan in 3-L batch bioreactor. The heparosan yield was further increased to 1.88 g/L in a dissolved oxygen-stat fed-batch culture in 3-L bioreactor. As revealed by the nuclear magnetic resonance analysis, the chemical structure of heparosan from recombinant E. coli BL21 and E. coli K5 was identical. The weight average molecular weight of heparosan from E. coli K5, sAC, sABC, sACD, and sABCD was 51.67, 39.63, 91.47, 64.51, and 118.30 kDa, respectively. This work provides a viable process for the production of heparosan as a precursor of bioengineered heparin from a safer bacteria strain.
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Affiliation(s)
- Chunyu Zhang
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China
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27
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Li P, Sheng J, Liu Y, Li J, Liu J, Wang F. Heparosan-derived heparan sulfate/heparin-like compounds: one kind of potential therapeutic agents. Med Res Rev 2012; 33:665-92. [PMID: 22495734 DOI: 10.1002/med.21263] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Heparan sulfate (HS) is a highly sulfated glycosaminoglycan and exists in all animal tissues. HS and heparin are very similar, except that heparin has higher level of sulfation and higher content of iduronic acid. Despite the fact that it is a century-old drug, heparin remains as a top choice for treating thrombotic disorders. Pharmaceutical heparin is derived from porcine intestine or bovine lung via a long supply chain. This supply chain is vulnerable to the contamination of animal pathogens. Therefore, new methods for manufacturing heparin or heparin-like substances devoid of animal tissues have been explored by many researchers, among which, modifications of heparosan, the capsular polysaccharide of Escherichia coli K5 strain, is one of the promising approaches. Heparosan has a structure similar to unmodified backbone of natural HS and heparin. It is feasible to obtain HS or heparin derivatives by modifying heparosan with chemical or enzymatic methods. These derivatives display different biological activities, such as anticoagulant, anti-inflammatory, anticancer, and antiviral activities. This review focuses on the recent studies of synthesis, activity, and structure-activity relationship of HS/heparin-like derivatives prepared from heparosan.
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Affiliation(s)
- Pingli Li
- Institute of Biochemical and Biotechnological Drug & National Glycoengineering Research Center, School of Pharmaceutical Sciences, Shandong University, Jinan 250012, China
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28
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DeAngelis PL. Glycosaminoglycan polysaccharide biosynthesis and production: today and tomorrow. Appl Microbiol Biotechnol 2012; 94:295-305. [PMID: 22391966 DOI: 10.1007/s00253-011-3801-6] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2011] [Revised: 11/29/2011] [Accepted: 12/01/2011] [Indexed: 10/28/2022]
Abstract
Glycosaminoglycans [GAGs] are essential heteropolysaccharides in vertebrate tissues that are also, in certain cases, employed as virulence factors by microbes. Hyaluronan [HA], heparin, and chondroitin sulfate [CS] are GAGs currently used in various medical applications and together are multi-billion dollar products thus targets for production by animal-free manufacture. By using bacteria as the source of GAGs, the pathogen's sword may be converted into a plowshare to help avoid potential liabilities springing from the use of animal-derived GAGs including adventitious agents (e.g., prions, pathogens), antigenicity, degradation of the environment, and depletion of endangered species. HA from microbes, which have a chemical structure identical to human HA, has already been commercialized and sold at the ton-scale. Substantial progress towards microbial heparin and CS has been made, but these vertebrate polymers are more complicated structurally than the unsulfated bacterial polysaccharide precursors thus require additional processing steps. This review provides an overview of GAG structure, medical applications, microbial biosynthesis, and the state of bacterial GAG production systems. Representatives of all glycosyltransferase enzymes that polymerize the sugar chains of the three main GAGs have been identified and serve as the core technology to harness, but the proteins involved in sugar precursor formation and chain export steps of biosynthesis are also essential to the GAG production process. In addition, this review discusses future directions and potential important issues. Overall, this area is poised to make great headway to produce safer (both increased purity and more secure supply chains) non-animal GAG-based therapeutics.
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Affiliation(s)
- Paul L DeAngelis
- Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73126, USA.
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29
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Otto NJ, Green DE, Masuko S, Mayer A, Tanner ME, Linhardt RJ, DeAngelis PL. Structure/function analysis of Pasteurella multocida heparosan synthases: toward defining enzyme specificity and engineering novel catalysts. J Biol Chem 2012; 287:7203-12. [PMID: 22235128 DOI: 10.1074/jbc.m111.311704] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The Pasteurella multocida heparosan synthases, PmHS1 and PmHS2, are homologous (∼65% identical) bifunctional glycosyltransferase proteins found in Type D Pasteurella. These unique enzymes are able to generate the glycosaminoglycan heparosan by polymerizing sugars to form repeating disaccharide units from the donor molecules UDP-glucuronic acid (UDP-GlcUA) and UDP-N-acetylglucosamine (UDP-GlcNAc). Although these isozymes both generate heparosan, the catalytic phenotypes of these isozymes are quite different. Specifically, during in vitro synthesis, PmHS2 is better able to generate polysaccharide in the absence of exogenous acceptor (de novo synthesis) than PmHS1. Additionally, each of these enzymes is able to generate polysaccharide using unnatural sugar analogs in vitro, but they exhibit differences in the substitution patterns of the analogs they will employ. A series of chimeric enzymes has been generated consisting of various portions of both of the Pasteurella heparosan synthases in a single polypeptide chain. In vitro radiochemical sugar incorporation assays using these purified chimeric enzymes have shown that most of the constructs are enzymatically active, and some possess novel characteristics including the ability to produce nearly monodisperse polysaccharides with an expanded range of sugar analogs. Comparison of the kinetic properties and the sequences of the wild-type enzymes with the chimeric enzymes has enabled us to identify regions that may be responsible for some aspects of both donor binding specificity and acceptor usage. In combination with previous work, these approaches have enabled us to better understand the structure/function relationship of this unique family of glycosyltransferases.
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Affiliation(s)
- Nigel J Otto
- Department of Biochemistry and Molecular Biology, Oklahoma Center for Medical Glycobiology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73126, USA
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Dulaney SB, Huang X. Strategies in synthesis of heparin/heparan sulfate oligosaccharides: 2000-present. Adv Carbohydr Chem Biochem 2012; 67:95-136. [PMID: 22794183 PMCID: PMC3646295 DOI: 10.1016/b978-0-12-396527-1.00003-6] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Steven B Dulaney
- Department of Chemistry, Michigan State University, East Lansing, MI, USA
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31
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Chavaroche AAE, van den Broek LAM, Boeriu C, Eggink G. Synthesis of heparosan oligosaccharides by Pasteurella multocida PmHS2 single-action transferases. Appl Microbiol Biotechnol 2011; 95:1199-210. [PMID: 22198719 PMCID: PMC3418500 DOI: 10.1007/s00253-011-3813-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2011] [Revised: 11/29/2011] [Accepted: 12/01/2011] [Indexed: 12/15/2022]
Abstract
Pasteurella multocida heparosan synthase PmHS2 is a dual action glycosyltransferase that catalyzes the polymerization of heparosan polymers in a non-processive manner. The two PmHS2 single-action transferases, obtained previously by site-directed mutagenesis, have been immobilized on Ni(II)-nitrilotriacetic acid agarose during the purification step. A detailed study of the polymerization process in the presence of non-equal amounts of PmHS2 single-action transferases revealed that the glucuronyl transferase (PmHS2-GlcUA(+)) is the limiting catalyst in the polymerization process. Using experimental design, it was determined that the N-acetylglucosaminyl transferase (PmHS2-GlcNAc(+)) plays an important role in the control of heparosan chain elongation depending on the number of heparosan chains and the UDP-sugar concentrations present in the reaction mixture. Furthermore, for the first time, the synthesis of heparosan oligosaccharides alternately using PmHS2-GlcUA(+) and PmHS2-GlcNAc(+) is reported. It was shown that the synthesis of heparosan oligosaccharides by PmHS2 single-action transferases do not require the presence of template molecules in the reaction mixture.
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Affiliation(s)
- Anaïs A E Chavaroche
- Bioprocess Engineering Group, Wageningen University and Research Center, P.O. Box 8129, 6700 EV, Wageningen, the Netherlands
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Cimini D, Rosa MD, Schiraldi C. Production of glucuronic acid-based polysaccharides by microbial fermentation for biomedical applications. Biotechnol J 2011; 7:237-50. [PMID: 22125298 DOI: 10.1002/biot.201100242] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2011] [Revised: 08/05/2011] [Accepted: 09/08/2011] [Indexed: 11/10/2022]
Abstract
This review provides an overview of the properties, different biosynthetic machineries, and biotechnological production processes of four microbially derived glucuronic acid-based polysaccharides that are of interest for diverse biomedical purposes. In particular, the utilization of hyaluronic acid and heparin sulfate in high-value medical applications is already well established, whereas chondroitin sulfate and alginate show high potential within this ever-growing field. Furthermore, new strategies exploiting genetically engineered microorganisms generated through improving naturally existing pathways or de novo designed ones are described. These new developments result in increased fermentation titers, and thereby, pave the way towards feasible, or at least improved, process economy. Moreover, these strategies also allow for the future possibility of producing tailor-made biopolymers with specified characteristics, even novel molecules.
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Affiliation(s)
- Donatella Cimini
- Second University of Naples, Department of Experimental Medicine, Section of Biotechnology and Molecular Biology, Naples, Italy
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33
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Wang Z, Dordick JS, Linhardt RJ. Escherichia coli K5 heparosan fermentation and improvement by genetic engineering. Bioeng Bugs 2011; 2:63-7. [PMID: 21636991 DOI: 10.4161/bbug.2.1.14201] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
N-acetyl heparosan is the precursor for the biosynthesis of the important anticoagulant drug heparin. The E. coli K5 capsular heparosan polysaccharide provides a promising precursor for in vitro chemoenzymatic production of bioengineered heparin. This article explores the improvements of heparosan production for bioengineered heparin by fermentation process engineering and genetic engineering.
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Affiliation(s)
- Zhenyu Wang
- Department of Biology, Center for Biotechnology & Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, USA
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34
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Wang Z, Ly M, Zhang F, Zhong W, Suen A, Hickey AM, Dordick JS, Linhardt RJ. E. coli K5 fermentation and the preparation of heparosan, a bioengineered heparin precursor. Biotechnol Bioeng 2011; 107:964-73. [PMID: 20717972 DOI: 10.1002/bit.22898] [Citation(s) in RCA: 98] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Heparosan is an acidic polysaccharide natural product, which serves as the critical precursor in heparin biosynthesis and in the chemoenzymatic synthesis of bioengineered heparin. Heparosan is also the capsular polysaccharide of Escherichia coli K5 strain. The current study was focused on the examination of the fermentation of E. coli K5 with the goal of producing heparosan in high yield and volumetric productivity. The structure and molecular weight properties of this bacterial heparosan were determined using polyacrylamide gel electrophoresis (PAGE) and Fourier transform mass spectrometry. Fermentation of E. coli K5 in a defined medium using exponential fed-batch glucose addition with oxygen enrichment afforded heparosan at 15 g/L having a number average molecular weight of 58,000 Da and a weight average molecular weight of 84,000 Da.
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Affiliation(s)
- Zhenyu Wang
- Department of Biology, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York 12180, USA
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Chavaroche AAE, van den Broek LAM, Springer J, Boeriu C, Eggink G. Analysis of the polymerization initiation and activity of Pasteurella multocida heparosan synthase PmHS2, an enzyme with glycosyltransferase and UDP-sugar hydrolase activity. J Biol Chem 2010; 286:1777-85. [PMID: 21084307 DOI: 10.1074/jbc.m110.136754] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Heparosan synthase catalyzes the polymerization of heparosan (-4GlcUAβ1-4GlcNAcα1-)(n) by transferring alternatively the monosaccharide units from UDP-GlcUA and UDP-GlcNAc to an acceptor molecule. Details on the heparosan chain initiation by Pasteurella multocida heparosan synthase PmHS2 and its influence on the polymerization process have not been reported yet. By site-directed mutagenesis of PmHS2, the single action transferases PmHS2-GlcUA(+) and PmHS2-GlcNAc(+) were obtained. When incubated together in the standard polymerization conditions, the PmHS2-GlcUA(+)/PmHS2-GlcNAc(+) showed comparable polymerization properties as determined for PmHS2. We investigated the first step occurring in heparosan chain initiation by the use of the single action transferases and by studying the PmHS2 polymerization process in the presence of heparosan templates and various UDP-sugar concentrations. We observed that PmHS2 favored the initiation of the heparosan chains when incubated in the presence of an excess of UDP-GlcNAc. It resulted in a higher number of heparosan chains with a lower average molecular weight or in the synthesis of two distinct groups of heparosan chain length, in the absence or in the presence of heparosan templates, respectively. These data suggest that PmHS2 transfers GlcUA from UDP-GlcUA moiety to a UDP-GlcNAc acceptor molecule to initiate the heparosan polymerization; as a consequence, not only the UDP-sugar concentration but also the amount of each UDP-sugar is influencing the PmHS2 polymerization process. In addition, it was shown that PmHS2 hydrolyzes the UDP-sugars, UDP-GlcUA being more degraded than UDP-GlcNAc. However, PmHS2 incubated in the presence of both UDP-sugars favors the synthesis of heparosan polymers over the hydrolysis of UDP-sugars.
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Affiliation(s)
- Anais A E Chavaroche
- Bioprocess Engineering Group, Wageningen University and Research Center, P.O. Box 8129, 6700 EV Wageningen, The Netherlands
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Sugiura N, Baba Y, Kawaguchi Y, Iwatani T, Suzuki K, Kusakabe T, Yamagishi K, Kimata K, Kakuta Y, Watanabe H. Glucuronyltransferase activity of KfiC from Escherichia coli strain K5 requires association of KfiA: KfiC and KfiA are essential enzymes for production of K5 polysaccharide, N-acetylheparosan. J Biol Chem 2009; 285:1597-606. [PMID: 19915003 DOI: 10.1074/jbc.m109.023002] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Heparan sulfate is a ubiquitous glycosaminoglycan in the extracellular matrix of most animals. It interacts with various molecules and exhibits important biological functions. K5 antigen produced by Escherichia coli strain K5 is a linear polysaccharide N-acetylheparosan consisting of GlcUA beta1-4 and GlcNAc alpha1-4 repeating disaccharide, which forms the backbone of heparan sulfate. Region 2, located in the center of the K5-specific gene cluster, encodes four proteins, KfiA, KfiB, KfiC, and KfiD, for the biosynthesis of the K5 polysaccharide. Here, we expressed and purified the recombinant KfiA and KfiC proteins and then characterized these enzymes. Whereas the recombinant KfiC alone exhibited no GlcUA transferase activity, it did exhibit GlcUA transferase and polymerization activities in the presence of KfiA. In contrast, KfiA had GlcNAc transferase activity itself, which was unaffected by the presence of KfiC. The GlcNAc and GlcUA transferase activities were analyzed with various truncated and point mutants of KfiA and KfiC. The point mutants replacing aspartic acid of a DXD motif and lysine and glutamic acid of an ionic amino acid cluster, and the truncated mutants deleting the C-terminal and N-terminal sites, revealed the essential regions for GlcNAc and GlcUA transferase activity of KfiC and KfiA, respectively. The interaction of KfiC with KfiA is necessary for the GlcUA transferase activity of KfiC but not for the enzyme activity of KfiA. Together, these results indicate that the complex of KfiA and KfiC has polymerase activity to synthesize N-acetylheparosan, providing a useful tool toward bioengineering of defined heparan sulfate chains.
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Affiliation(s)
- Nobuo Sugiura
- Institute for Molecular Science of Medicine, Aichi Medical University, Yazako, Nagakute, Aichi 480-1195, Japan.
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In vitro synthesis of heparosan using recombinant Pasteurella multocida heparosan synthase PmHS2. Appl Microbiol Biotechnol 2009; 85:1881-91. [PMID: 19756580 PMCID: PMC2811250 DOI: 10.1007/s00253-009-2214-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2009] [Revised: 08/18/2009] [Accepted: 08/18/2009] [Indexed: 11/28/2022]
Abstract
In vertebrates and bacteria, heparosan the precursor of heparin is synthesized by glycosyltransferases via the stepwise addition of UDP-N-acetylglucosamine and UDP-glucuronic acid. As heparin-like molecules represent a great interest in the pharmaceutical area, the cryptic Pasteurella multocida heparosan synthase PmHS2 found to catalyze heparosan synthesis using substrate analogs has been studied. In this paper, we report an efficient way to purify PmHS2 and to maintain its activity stable during 6 months storage at −80 °C using His-tag purification and a desalting step. In the presence of 1 mM of each nucleotide sugar, purified PmHS2 synthesized polymers up to an average molecular weight of 130 kDa. With 5 mM of UDP-GlcUA and 5 mM of UDP-GlcNAc, an optimal specific activity, from 3 to 6 h of incubation, was found to be about 0.145 nmol/μg/min, and polymers up to an average of 102 kDa were synthesized in 24 h. In this study, we show that the chain length distribution of heparosan polymers can be controlled by change of the initial nucleotide sugar concentration. It was observed that low substrate concentration favors the formation of high molecular weight heparosan polymer with a low polydispersity while high substrate concentration did the opposite. Similarities in the polymerization mechanism between PmHS2, PmHS1, and PmHAS are discussed.
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Abstract
The capsule is a cell surface structure composed of long-chain polysaccharides that envelops many isolates of Escherichia coli. It protects the cell against host defenses or physical environmental stresses, such as desiccation. The component capsular polysaccharides (CPSs) are major surface antigens in E. coli. They are named K antigens (after the German word Kapsel). Due to variations in CPS structures, more than 80 serologically unique K antigens exist in E. coli. Despite the hypervariability in CPS structures, only two capsule-assembly strategies exist in E. coli. These have led to the assignment of group 1 and group 2 capsules, and many of the key elements of the corresponding assembly pathways have been resolved. Structural features, as well as genetic and regulatory variations, give rise to additional groups 3 and 4. These employ the same biosynthesis processes described in groups 2 and 1, respectively. Each isolate possesses a distinctive set of cytosolic and inner-membrane enzymes, which generate a precise CPS structure, defining a given K serotype. Once synthesized, a multiprotein complex is needed to translocate the nascent CPS across the Gram-negative cell envelope to the outer surface of the outer membrane, where the capsule structure is assembled. While the translocation machineries for group 1 and group 2 CPSs are fundamentally different from one another, they possess no specificity for a given CPS structure. Each is conserved in all isolates producing capsules belonging to a particular group.
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The Escherichia coli K5 capsule is not synthesized in a protected compartment within the cytoplasm. J Bacteriol 2008; 191:1716-8. [PMID: 19074385 DOI: 10.1128/jb.01371-08] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The intracellular expression of the K5 lyase enzyme, which degrades the K5 polysaccharide, decreased cell surface expression of the Escherichia coli K5 capsule. This indicates that biosynthesis of K5 polysaccharide in the cytoplasm is accessible to the action of K5 lyase and is not synthesized within a protected cytoplasmic compartment.
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Corbett D, Roberts IS. Capsular Polysaccharides in Escherichia coli. ADVANCES IN APPLIED MICROBIOLOGY 2008; 65:1-26. [DOI: 10.1016/s0065-2164(08)00601-1] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Sismey-Ragatz AE, Green DE, Otto NJ, Rejzek M, Field RA, DeAngelis PL. Chemoenzymatic synthesis with distinct Pasteurella heparosan synthases: monodisperse polymers and unnatural structures. J Biol Chem 2007; 282:28321-28327. [PMID: 17627940 DOI: 10.1074/jbc.m701599200] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Heparosan (-GlcUA-beta1,4-GlcNAc-alpha1,4-)(n) is a member of the glycosaminoglycan polysaccharide family found in the capsule of certain pathogenic bacteria as well as the precursor for the vertebrate polymers, heparin and heparan sulfate. The two heparosan synthases from the Gram-negative bacteria Pasteurella multocida, PmHS1 and PmHS2, were efficiently expressed and purified using maltose-binding protein fusion constructs. These relatively homologous synthases displayed distinct catalytic characteristics. PmHS1, but not PmHS2, was able to produce large molecular mass (100-800 kDa) monodisperse polymers in synchronized, stoichiometrically controlled reactions in vitro. PmHS2, but not PmHS1, was able to utilize many unnatural UDP-sugar analogs (including substrates with acetamido-containing uronic acids or longer acyl chain hexosamine derivatives) in vitro. Overall these findings reveal potential differences in the active sites of these two Pasteurella enzymes. In the future, these catalysts should allow the creation of a variety of heparosan and heparinoids with utility for medical applications.
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Affiliation(s)
- Alison E Sismey-Ragatz
- Department of Biochemistry and Molecular Biology, Oklahoma Center for Medical Glycobiology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104
| | - Dixy E Green
- Department of Biochemistry and Molecular Biology, Oklahoma Center for Medical Glycobiology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104
| | - Nigel J Otto
- Department of Biochemistry and Molecular Biology, Oklahoma Center for Medical Glycobiology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104
| | - Martin Rejzek
- Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Colney Lane, Norwich NR4 7UH, United Kingdom
| | - Robert A Field
- Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Colney Lane, Norwich NR4 7UH, United Kingdom
| | - Paul L DeAngelis
- Department of Biochemistry and Molecular Biology, Oklahoma Center for Medical Glycobiology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104.
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Klutts JS, Levery SB, Doering TL. A beta-1,2-xylosyltransferase from Cryptococcus neoformans defines a new family of glycosyltransferases. J Biol Chem 2007; 282:17890-9. [PMID: 17430900 DOI: 10.1074/jbc.m701941200] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Cryptococcus neoformans is an opportunistic fungal pathogen characterized by a prominent polysaccharide capsule that envelops the cell. Although this capsule is dispensable for in vitro growth, its presence is essential for virulence. The capsule is primarily made of two xylose-containing polysaccharides, glucuronoxylomannan and galactoxylomannan. There are likely to be multiple xylosyltransferases (XTs) involved in capsule synthesis, and the activities of these enzymes are potentially important for cryptococcal virulence. A beta-1,2-xylosyltransferase with specificity appropriate for capsule synthesis was purified approximately 3000-fold from C. neoformans, and the corresponding gene was identified and cloned. This sequence conferred XT activity when expressed in Saccharomyces cerevisiae, which lacks endogenous XT activity. The gene, termed CXT1 for cryptococcal xylosyltransferase 1, encodes a 79-kDa type II membrane protein with an N-linked glycosylation site and two DXD motifs. These latter motifs are believed to coordinate divalent cation binding in the activity of glycosyltransferases. Site-directed mutagenesis of one DXD motif abolished Cxt1p activity, even though this activity does not depend on the addition of a divalent cation. This may indicate a novel catalytic mechanism for glycosyl transfer. Five homologs of Cxt1p were found in the genome sequence of C. neoformans and 34 within the sequences of other fungi, although none were found in other organisms. Many of the homologous proteins are similar in size to Cxt1p, and all are conserved with respect to the essential DXD motif. These proteins represent a new family of glycosyltransferases, found exclusively within the fungal kingdom.
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Affiliation(s)
- J Stacey Klutts
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri 63110-1093, USA
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Chen M, Bridges A, Liu J. Determination of the substrate specificities of N-acetyl-d-glucosaminyltransferase. Biochemistry 2006; 45:12358-65. [PMID: 17014088 DOI: 10.1021/bi060844g] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Heparan sulfate plays a wide range of physiological and pathological roles. Heparan sulfate consists of glucosamine and glucuronic/iduronic acid repeating disaccharides with various sulfations. Synthesis of structurally defined heparan sulfate oligosaccharides remains a challenge. Access to nonsulfated and unepimerized heparan sulfate backbone structures represents an essential step toward de novo enzymatic synthesis of heparan sulfate. The nonsulfated, unepimerized backbone heparan sulfate is similar to the capsular polysaccharide from Escherichia coli strain K5. The biosynthesis of this capsular polysaccharide involves in N-acetylglucosaminyltransferase (KfiA) and d-glucuronyltransferase (KfiC). In this study, we report the characterization of purified KfiA. KfiA was expressed in a C-terminal six-His fusion protein in BL21 star cells coexpressing chaperone proteins GroEL and GroES. The recombinant KfiA was purified to homogeneity with a Ni-agarose column. The binding affinities of various UDP-sugars for KfiA were determined using isothermal calorimetry titration, indicating that both the N-acetyl group and sugar type may be essential for donor substrates to bind KfiA. Kinetic analysis of KfiA toward different sizes of oligosaccharide revealed that KfiA is less sensitive to the size of the acceptor substrates. The results from this study open a new approach for the synthesis of the heparan sulfate backbone.
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Affiliation(s)
- Miao Chen
- Division of Medicinal Chemistry and Natural Products, School of Pharmacy, University of North Carolina, Chapel Hill, North Carolina 27599, USA
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45
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Kane TA, White CL, DeAngelis PL. Functional characterization of PmHS1, a Pasteurella multocida heparosan synthase. J Biol Chem 2006; 281:33192-7. [PMID: 16959770 DOI: 10.1074/jbc.m606897200] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Heparosan synthase 1 (PmHS1) from Pasteurella multocida Type D is a dual action glycosyltransferase enzyme that transfers monosaccharide units from uridine diphospho (UDP) sugar precursors to form the polysaccharide heparosan (N-acetylheparosan), which is composed of alternating (-alpha4-GlcNAc-beta1,4-GlcUA-1-) repeats. We have used molecular genetic means to remove regions nonessential for catalytic activity from the amino- and the carboxyl-terminal regions as well as characterized the functional regions involved in GlcUA-transferase activity and in GlcNAc-transferase activity. Mutation of either one of the two regions containing aspartate-X-aspartate (DXD) residue-containing motifs resulted in complete or substantial loss of heparosan polymerizing activity. However, certain mutant proteins retained only GlcUA-transferase activity while some constructs possessed only GlcNAc-transferase activity. Therefore, it appears that the PmHS1 polypeptide is composed of two types of glycosyltransferases in a single polypeptide as was found for the Pasteurella multocida Type A PmHAS, the hyaluronan synthase that makes the alternating (-beta3-GlcNAc-beta1,4-GlcUA-1-) polymer. However, there is low amino acid similarity between the PmHAS and PmHS1 enzymes, and the relative placement of the GlcUA-transferase and GlcNAc-transferase domains within the two polypeptides is reversed. Even though the monosaccharide compositions of hyaluronan and heparosan are identical, such differences in the sequences of the catalysts are expected because the PmHAS employs only inverting sugar transfer mechanisms whereas PmHS1 requires both retaining and inverting mechanisms.
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Affiliation(s)
- Tasha A Kane
- Department of Biochemistry and Molecular Biology, Oklahoma Center for Medical Glycobiology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104, USA
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46
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Abstract
Capsules are protective structures on the surfaces of many bacteria. The remarkable structural diversity in capsular polysaccharides is illustrated by almost 80 capsular serotypes in Escherichia coli. Despite this variation, the range of strategies used for capsule biosynthesis and assembly is limited, and E. coli isolates provide critical prototypes for other bacterial species. Related pathways are also used for synthesis and export of other bacterial glycoconjugates and some enzymes/processes have counterparts in eukaryotes. In gram-negative bacteria, it is proposed that biosynthesis and translocation of capsular polysaccharides to the cell surface are temporally and spatially coupled by multiprotein complexes that span the cell envelope. These systems have an impact on both a general understanding of membrane trafficking in bacteria and on bacterial pathogenesis.
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Affiliation(s)
- Chris Whitfield
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario N1G 2W1, Canada.
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47
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McNulty C, Thompson J, Barrett B, Lord L, Andersen C, Roberts IS. The cell surface expression of group 2 capsular polysaccharides in Escherichia coli: the role of KpsD, RhsA and a multi-protein complex at the pole of the cell. Mol Microbiol 2006; 59:907-22. [PMID: 16420360 DOI: 10.1111/j.1365-2958.2005.05010.x] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The export of large negatively charged capsular polysaccharides across the outer membrane represents a significant challenge to Gram negative bacteria. In the case of Escherichia coli group 2 capsular polysaccharides, the mechanism of export across the outer membrane was unknown, with no identified candidate outer membrane proteins. In this paper we demonstrate that the KpsD protein, previously believed to be a periplasmic protein, is an outer membrane protein involved in the export of group 2 capsular polysaccharides across the outer membrane. We demonstrate that KpsD and KpsE are located at the poles of the cell and that polysaccharide biosynthesis and export occurs at these polar sites. By in vivo chemical cross-linking and MALDI-TOF-MS analysis we demonstrate the presence of a multi-protein biosynthetic/export complex in which cytoplasmic proteins involved in polysaccharide biosynthesis could be cross-linked to proteins involved in export across the inner and outer membranes. In addition, we show that the RhsA protein, of previously unknown function, could be cross-linked to the complex and that a rhsA mutation reduces K5 biosynthesis suggesting a role for RhsA in coupling biosynthesis and export.
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Affiliation(s)
- Clodagh McNulty
- Faculty of Life Sciences, 1.800 Stopford Building, The University of Manchester, Oxford Road, Manchester M13 9PT, UK
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48
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Ni L, Sun M, Yu H, Chokhawala H, Chen X, Fisher AJ. Cytidine 5'-monophosphate (CMP)-induced structural changes in a multifunctional sialyltransferase from Pasteurella multocida. Biochemistry 2006; 45:2139-48. [PMID: 16475803 DOI: 10.1021/bi0524013] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Sialyltransferases catalyze reactions that transfer a sialic acid from CMP-sialic acid to an acceptor (a structure terminated with galactose, N-acetylgalactosamine, or sialic acid). They are key enzymes that catalyze the synthesis of sialic acid-containing oligosaccharides, polysaccharides, and glycoconjugates that play pivotal roles in many critical physiological and pathological processes. The structures of a truncated multifunctional Pasteurella multocida sialyltransferase (Delta24PmST1), in the absence and presence of CMP, have been determined by X-ray crystallography at 1.65 and 2.0 A resolutions, respectively. The Delta24PmST1 exists as a monomer in solution and in crystals. Different from the reported crystal structure of a bifunctional sialyltransferase CstII that has only one Rossmann domain, the overall structure of the Delta24PmST1 consists of two separate Rossmann nucleotide-binding domains. The Delta24PmST1 structure, thus, represents the first sialyltransferase structure that belongs to the glycosyltransferase-B (GT-B) structural group. Unlike all other known GT-B structures, however, there is no C-terminal extension that interacts with the N-terminal domain in the Delta24PmST1 structure. The CMP binding site is located in the deep cleft between the two Rossmann domains. Nevertheless, the CMP only forms interactions with residues in the C-terminal domain. The binding of CMP to the protein causes a large closure movement of the N-terminal Rossmann domain toward the C-terminal nucleotide-binding domain. Ser 143 of the N-terminal domain moves up to hydrogen-bond to Tyr 388 of the C-terminal domain. Both Ser 143 and Tyr 388 form hydrogen bonds to a water molecule, which in turn hydrogen-bonds to the terminal phosphate oxygen of CMP. These interactions may trigger the closure between the two domains. Additionally, a short helix near the active site seen in the apo structure becomes disordered upon binding to CMP. This helix may swing down upon binding to donor CMP-sialic acid to form the binding pocket for an acceptor.
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Affiliation(s)
- Lisheng Ni
- Department of Chemistry, University of California, One Shields Avenue, Davis, California 95616, USA
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Steenbergen SM, Vimr ER. Functional relationships of the sialyltransferases involved in expression of the polysialic acid capsules of Escherichia coli K1 and K92 and Neisseria meningitidis groups B or C. J Biol Chem 2003; 278:15349-59. [PMID: 12578835 DOI: 10.1074/jbc.m208837200] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Polysialic acid (PSA) capsules are cell-associated homopolymers of alpha2,8-, alpha2,9-, or alternating alpha2,8/2,9-linked sialic acid residues that function as essential virulence factors in neuroinvasive diseases caused by certain strains of Escherichia coli and Neisseria meningitidis. PSA chains structurally identical to the bacterial alpha2,8-linked capsular polysaccharides are also synthesized by the mammalian central nervous system, where they regulate neuronal function in association with the neural cell adhesion molecule (NCAM). Despite the structural identity between bacterial and NCAM PSAs, the respective polysialyltransferases (polySTs) responsible for polymerizing sialyl residues from donor CMP-sialic acid are not homologous glycosyltransferases. To better define the mechanism of capsule biosynthesis, we established the functional interchangeability of bacterial polySTs by complementation of a polymerase-deficient E. coli K1 mutant with the polyST genes from groups B or C N. meningitidis and the control E. coli K92 polymerase gene. The biochemical and immunochemical results demonstrated that linkage specificity is dictated solely by the source of the polymerase structural gene. To determine the molecular basis for linkage specificity, we created chimeras of the K1 and K92 polySTs by overlap extension PCR. Exchanging the first 52 N-terminal amino acids of the K1 NeuS with the C terminus of the K92 homologue did not alter specificity of the resulting chimera, whereas exchanging the first 85 or reciprocally exchanging the first 100 residues did. These results demonstrated that linkage specificity is dependent on residues located between positions 53 and 85 from the N terminus. Site-directed mutagenesis of the K92 polyST N terminus indicated that no single residue alteration was sufficient to affect specificity, consistent with the proposed function of this domain in orienting the acceptor. The combined results provide the first evidence for residues critical to acceptor binding and elongation in polysialyltransferase.
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Affiliation(s)
- Susan M Steenbergen
- Laboratory of Sialobiology, Department of Pathobiology, University of Illinois, Urbana, Illinois 61802, USA.
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DeAngelis PL. Evolution of glycosaminoglycans and their glycosyltransferases: Implications for the extracellular matrices of animals and the capsules of pathogenic bacteria. THE ANATOMICAL RECORD 2002; 268:317-26. [PMID: 12382327 DOI: 10.1002/ar.10163] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Glycosaminoglycans (linear polysaccharides with a repeating disaccharide backbone containing an amino sugar) are essential components of extracellular matrices of animals. These complex molecules play important structural, adhesion, and signaling roles in mammals. Direct detection of glycosaminoglycans has been reported in a variety of organisms, but perhaps more definitive tests for the glycosyltransferase genes should be utilized to clarify the distribution of glycosaminoglycans in metazoans. Recently, glycosyltransferases that form the hyaluronan, heparin/heparan, or chondroitin backbone were identified at the molecular level. The three types of glycosyltransferases appear to have evolved independently based on sequence comparisons and other characteristics. All metazoans appear to possess heparin/heparan. Chondroitin is found in some worms, arthropods, and higher animals. Hyaluronan is found only in two of the three main branches of chordates. The presence of several types of glycosaminoglycans in the body allows multiple communication channels and adhesion systems to operate simultaneously. Certain pathogenic bacteria produce extracellular coatings, called capsules, which are composed of glycosaminoglycans that increase their virulence during infection. The capsule helps shield the microbe from the host defenses and/or modulates host physiology. The bacterial and animal polysaccharides are chemically identical or at least very similar. Therefore, no immune response is generated, in contrast to the vast majority of capsular polymers from other bacteria. In microbial systems, it appears that in most cases functional convergent evolution of glycosaminoglycan glycosyltransferases occurred, rather than direct horizontal gene transfer from their vertebrate hosts.
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Affiliation(s)
- Paul L DeAngelis
- Department of Biochemistry and Molecular Biology, Oklahoma Center for Medical Glycobiology, University of Oklahoma Health Sciences Center, Oklahoma City 73104, USA.
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