1
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Xu P, Ou YC, Smith M, Paulson J, Schmidt MA, Kandari L, Parsons R, Khetan A. Application of fucosylation inhibitors for production of afucosylated antibody. Biotechnol Prog 2024; 40:e3438. [PMID: 38415431 DOI: 10.1002/btpr.3438] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Revised: 12/21/2023] [Accepted: 01/24/2024] [Indexed: 02/29/2024]
Abstract
Fucosylation is an important quality attribute for therapeutic antibodies. Afucosylated antibodies exhibit higher therapeutic efficacies than their fucosylated counterparts through antibody-dependent cellular cytotoxicity (ADCC) mechanism. Since higher potency is beneficial in reducing dose or duration of the treatment, afucosylated antibodies have attracted a great deal of interest in biotherapeutics development. In this study, novel small molecules GDP-D-Rhamnose and its derivatives (Ac-GDP-D-Rhamnose and rhamnose sodium phosphate) were synthesized to inhibit the enzyme in the GDP-fucose synthesis pathway. Addition of these compounds into cell culture increased antibody afucosylation levels in a dose-dependent manner and had no significant impact on other protein quality attributes. A novel and effective mechanism to generate afucosylated antibody is demonstrated for biologics discovery, analytical method development, process development, and other applications.
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Affiliation(s)
- Ping Xu
- Biologics Development, Global Product Development & Supply, Bristol Myers Squibb, New Brunswick, New Jersey, USA
| | - Yu Chuan Ou
- Biologics Development, Global Product Development & Supply, Bristol Myers Squibb, New Brunswick, New Jersey, USA
| | - Michael Smith
- Chemical Process Development, Global Product Development & Supply, Bristol Myers Squibb, New Brunswick, New Jersey, USA
| | - Jim Paulson
- Chemical Process Development, Global Product Development & Supply, Bristol Myers Squibb, New Brunswick, New Jersey, USA
| | - Michael A Schmidt
- Chemical Process Development, Global Product Development & Supply, Bristol Myers Squibb, New Brunswick, New Jersey, USA
| | - Lakshmi Kandari
- Biologics Development, Global Product Development & Supply, Bristol Myers Squibb, New Brunswick, New Jersey, USA
| | - Rodney Parsons
- Chemical Process Development, Global Product Development & Supply, Bristol Myers Squibb, New Brunswick, New Jersey, USA
| | - Anurag Khetan
- Biologics Development, Global Product Development & Supply, Bristol Myers Squibb, New Brunswick, New Jersey, USA
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2
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Ghosh M, Narindoshvili T, Thoden JB, Schumann ME, Holden HM, Raushel FM. Biosynthesis of Cytidine Diphosphate-6-d-Glucitol for the Capsular Polysaccharides of Campylobacter jejuni. Biochemistry 2024; 63:699-710. [PMID: 38386885 PMCID: PMC10918830 DOI: 10.1021/acs.biochem.3c00706] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Revised: 01/12/2024] [Accepted: 02/02/2024] [Indexed: 02/24/2024]
Abstract
Campylobacter jejuni is a Gram-negative pathogenic bacterium commonly found in chickens and is the leading cause of human diarrheal disease worldwide. The various serotypes of C. jejuni produce structurally distinct capsular polysaccharides (CPSs) on the exterior surfaces of the cell wall. The capsular polysaccharide from C. jejuni serotype HS:5 is composed of a repeating sequence of d-glycero-d-manno-heptose and d-glucitol-6-phosphate. We previously defined the pathway for the production of d-glycero-d-manno-heptose in C. jejuni. Here, we elucidate the biosynthetic pathway for the assembly of cytidine diphosphate (CDP)-6-d-glucitol by the combined action of two previously uncharacterized enzymes. The first enzyme catalyzes the formation of CDP-6-d-fructose from cytidine triphosphate (CTP) and d-fructose-6-phosphate. The second enzyme reduces CDP-6-d-fructose with NADPH to generate CDP-6-d-glucitol. Using sequence similarity network (SSN) and genome neighborhood network (GNN) analyses, we predict that these pairs of proteins are responsible for the biosynthesis of CDP-6-d-glucitol and/or CDP-d-mannitol in the lipopolysaccharides (LPSs) and capsular polysaccharides in more than 200 other organisms. In addition, high resolution X-ray structures of the second enzyme are reported, which provide novel insight into the manner in which an open-chain nucleotide-linked sugar is harbored in an active site cleft.
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Affiliation(s)
- Manas
K. Ghosh
- Department
of Chemistry, Texas A&M University, College Station, Texas 77845, United States
| | - Tamari Narindoshvili
- Department
of Chemistry, Texas A&M University, College Station, Texas 77845, United States
| | - James B. Thoden
- Department
of Biochemistry, University of Wisconsin, Madison, Wisconsin 53706, United States
| | - Mitchell E. Schumann
- Department
of Biochemistry, University of Wisconsin, Madison, Wisconsin 53706, United States
| | - Hazel M. Holden
- Department
of Biochemistry, University of Wisconsin, Madison, Wisconsin 53706, United States
| | - Frank M. Raushel
- Department
of Chemistry, Texas A&M University, College Station, Texas 77845, United States
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3
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Kortright KE, Chan BK, Evans BR, Turner PE. Arms race and fluctuating selection dynamics in Pseudomonas aeruginosa bacteria coevolving with phage OMKO1. J Evol Biol 2022; 35:1475-1487. [PMID: 36168737 DOI: 10.1111/jeb.14095] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Revised: 08/03/2022] [Accepted: 08/22/2022] [Indexed: 11/28/2022]
Abstract
Experimental evolution studies have examined coevolutionary dynamics between bacteria and lytic phages, where two models for antagonistic coevolution dominate: arms-race dynamics (ARD) and fluctuating-selection dynamics (FSD). Here, we tested the ability for Pseudomonas aeruginosa to coevolve with phage OMKO1 during 10 passages in the laboratory, whether ARD versus FSD coevolution occurred, and how coevolution affected a predicted phenotypic trade-off between phage resistance and antibiotic sensitivity. We used a unique "deep" sampling design, where 96 bacterial clones per passage were obtained from the three replicate coevolving communities. Next, we examined phenotypic changes in growth ability, susceptibility to phage infection and resistance to antibiotics. Results confirmed that the bacteria and phages coexisted throughout the study with one community undergoing ARD, whereas the other two showed evidence for FSD. Surprisingly, only the ARD bacteria demonstrated the anticipated trade-off. Whole genome sequencing revealed that treatment populations of bacteria accrued more de novo mutations, relative to a control bacterial population. Additionally, coevolved bacteria presented mutations in genes for biosynthesis of flagella, type-IV pilus and lipopolysaccharide, with three mutations fixing contemporaneously with the occurrence of the phenotypic trade-off in the ARD-coevolved bacteria. Our study demonstrates that both ARD and FSD coevolution outcomes are possible in a single interacting bacteria-phage system and that occurrence of predicted phage-driven evolutionary trade-offs may depend on the genetics underlying evolution of phage resistance in bacteria. These results are relevant for the ongoing development of lytic phages, such as OMKO1, in personalized treatment of human patients, as an alternative to antibiotics.
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Affiliation(s)
- Kaitlyn E Kortright
- Program in Microbiology, Yale School of Medicine, New Haven, Connecticut, USA.,Department of Ecology and Evolutionary Biology, Yale University, New Haven, Connecticut, USA.,Center for Phage Biology and Therapy, Yale University, New Haven, Connecticut, USA
| | - Benjamin K Chan
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, Connecticut, USA.,Center for Phage Biology and Therapy, Yale University, New Haven, Connecticut, USA
| | - Benjamin R Evans
- Yale Center for Research Computing, Yale University, New Haven, Connecticut, USA
| | - Paul E Turner
- Program in Microbiology, Yale School of Medicine, New Haven, Connecticut, USA.,Department of Ecology and Evolutionary Biology, Yale University, New Haven, Connecticut, USA.,Center for Phage Biology and Therapy, Yale University, New Haven, Connecticut, USA
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4
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Li S, Chen F, Li Y, Wang L, Li H, Gu G, Li E. Rhamnose-Containing Compounds: Biosynthesis and Applications. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27165315. [PMID: 36014553 PMCID: PMC9415975 DOI: 10.3390/molecules27165315] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/09/2022] [Revised: 08/12/2022] [Accepted: 08/15/2022] [Indexed: 11/16/2022]
Abstract
Rhamnose-associated molecules are attracting attention because they are present in bacteria but not mammals, making them potentially useful as antibacterial agents. Additionally, they are also valuable for tumor immunotherapy. Thus, studies on the functions and biosynthetic pathways of rhamnose-containing compounds are in progress. In this paper, studies on the biosynthetic pathways of three rhamnose donors, i.e., deoxythymidinediphosphate-L-rhamnose (dTDP-Rha), uridine diphosphate-rhamnose (UDP-Rha), and guanosine diphosphate rhamnose (GDP-Rha), are firstly reviewed, together with the functions and crystal structures of those associated enzymes. Among them, dTDP-Rha is the most common rhamnose donor, and four enzymes, including glucose-1-phosphate thymidylyltransferase RmlA, dTDP-Glc-4,6-dehydratase RmlB, dTDP-4-keto-6-deoxy-Glc-3,5-epimerase RmlC, and dTDP-4-keto-Rha reductase RmlD, are involved in its biosynthesis. Secondly, several known rhamnosyltransferases from Geobacillus stearothermophilus, Saccharopolyspora spinosa, Mycobacterium tuberculosis, Pseudomonas aeruginosa, and Streptococcus pneumoniae are discussed. In these studies, however, the functions of rhamnosyltransferases were verified by employing gene knockout and radiolabeled substrates, which were almost impossible to obtain and characterize the products of enzymatic reactions. Finally, the application of rhamnose-containing compounds in disease treatments is briefly described.
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Affiliation(s)
- Siqiang Li
- School of Biological and Food Processing Engineering, Huanghuai University, Zhumadian 463000, China
- Institute of Agricultural Products Fermentation Engineering and Application, Huanghuai University, Zhumadian 463000, China
| | - Fujia Chen
- School of Biological and Food Processing Engineering, Huanghuai University, Zhumadian 463000, China
- Institute of Agricultural Products Fermentation Engineering and Application, Huanghuai University, Zhumadian 463000, China
| | - Yun Li
- School of Biological and Food Processing Engineering, Huanghuai University, Zhumadian 463000, China
- Institute of Agricultural Products Fermentation Engineering and Application, Huanghuai University, Zhumadian 463000, China
| | - Lizhen Wang
- Biology Institute, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250100, China
| | - Hongyan Li
- School of Biological and Food Processing Engineering, Huanghuai University, Zhumadian 463000, China
| | - Guofeng Gu
- National Glycoengineering Research Center, Shandong Key Laboratory of Carbohydrate Chemistry and Glycobiology, Shandong University, 72 Binhai Road, Qingdao 266237, China
- Correspondence: (G.G.); (E.L.)
| | - Enzhong Li
- School of Biological and Food Processing Engineering, Huanghuai University, Zhumadian 463000, China
- Institute of Agricultural Products Fermentation Engineering and Application, Huanghuai University, Zhumadian 463000, China
- Correspondence: (G.G.); (E.L.)
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5
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Xiang DF, Thoden JB, Ghosh MK, Holden HM, Raushel FM. Reaction Mechanism and Three-Dimensional Structure of GDP-d-glycero-α-d-manno-heptose 4,6-Dehydratase from Campylobacter jejuni. Biochemistry 2022; 61:1313-1322. [PMID: 35715226 DOI: 10.1021/acs.biochem.2c00244] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Campylobacter jejuni is a human pathogen and a leading cause of food poisoning in the United States and Europe. Surrounding the outside of the bacterium is a carbohydrate coat known as the capsular polysaccharide. Various strains of C. jejuni have different sequences of unusual sugars and an assortment of decorations. Many of the serotypes have heptoses with differing stereochemical arrangements at C2 through C6. One of the many common modifications is a 6-deoxy-heptose that is formed by dehydration of GDP-d-glycero-α-d-manno-heptose to GDP-6-deoxy-4-keto-d-lyxo-heptose via the action of the enzyme GDP-d-glycero-α-d-manno-heptose 4,6-dehydratase. Herein, we report the biochemical and structural characterization of this enzyme from C. jejuni 81-176 (serotype HS:23/36). The enzyme was purified to homogeneity, and its three-dimensional structure was determined to a resolution of 2.1 Å. Kinetic analyses suggest that the reaction mechanism proceeds through the formation of a 4-keto intermediate followed by the loss of water from C5/C6. Based on the three-dimensional structure, it is proposed that oxidation of C4 is assisted by proton transfer from the hydroxyl group to the phenolate of Tyr-159 and hydride transfer to the tightly bound NAD+ in the active site. Elimination of water at C5/C6 is most likely assisted by abstraction of the proton at C5 by Glu-136 and subsequent proton transfer to the hydroxyl at C6 via Ser-134 and Tyr-159. A bioinformatic analysis identified 19 additional 4,6-dehydratases from serotyped strains of C. jejuni that are 89-98% identical in the amino acid sequence, indicating that each of these strains should contain a 6-deoxy-heptose within their capsular polysaccharides.
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Affiliation(s)
- Dao Feng Xiang
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
| | - James B Thoden
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Manas K Ghosh
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
| | - Hazel M Holden
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Frank M Raushel
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States.,Department of Biochemistry & Biophysics, Texas A&M University, College Station, Texas 77843, United States
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6
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Wang S, Zhang J, Wei F, Li W, Wen L. Facile Synthesis of Sugar Nucleotides from Common Sugars by the Cascade Conversion Strategy. J Am Chem Soc 2022; 144:9980-9989. [PMID: 35583341 DOI: 10.1021/jacs.2c03138] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Sugar nucleotides are essential glycosylation donors in the carbohydrate metabolism. Naturally, most sugar nucleotides are derived from a limited number of common sugar nucleotides by de novo biosynthetic pathways, undergoing single or multiple reactions such as dehydration, epimerization, isomerization, oxidation, reduction, amination, and acetylation reactions. However, it is widely believed that such complex bioconversions are not practical for synthetic use due to the high preparation cost and great difficulties in product isolation. Therefore, most of the discovered sugar nucleotides are not readily available. Here, based on de novo biosynthesis mainly, 13 difficult-to-access sugar nucleotides were successfully prepared from two common sugars D-Man and sucrose in high yields, at a multigram scale, and without the need for tedious purification manipulations. This work demonstrated that de novo biosynthesis, although undergoing complex reactions, is also practical and cost-effective for synthetic use by employing a cascade conversion strategy.
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Affiliation(s)
- Shasha Wang
- School of Chinese Materia Medica, Nanjing University of Chinese Medicine, Nanjing, Jiang Su 210023, China
| | - Jiabin Zhang
- Carbohydrate-Based Drug Research Center, Shanghai Institute of Materia Media, Chinese Academy of Sciences, Shanghai 201203, China.,Zhongshan Institute for Drug Discovery, Shanghai Institute of Materia Media, Chinese Academy of Sciences, Zhongshan, Guangdong 528400, China
| | - Fangyu Wei
- Carbohydrate-Based Drug Research Center, Shanghai Institute of Materia Media, Chinese Academy of Sciences, Shanghai 201203, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Wanjin Li
- Carbohydrate-Based Drug Research Center, Shanghai Institute of Materia Media, Chinese Academy of Sciences, Shanghai 201203, China
| | - Liuqing Wen
- Carbohydrate-Based Drug Research Center, Shanghai Institute of Materia Media, Chinese Academy of Sciences, Shanghai 201203, China.,University of Chinese Academy of Sciences, Beijing 100049, China.,School of Chinese Materia Medica, Nanjing University of Chinese Medicine, Nanjing, Jiang Su 210023, China
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7
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Biosynthesis of the Pseudomonas aeruginosa common polysaccharide antigen by D-Rhamnosyltransferases WbpX and WbpY. Glycoconj J 2022; 39:393-411. [PMID: 35166992 PMCID: PMC8853325 DOI: 10.1007/s10719-022-10040-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2021] [Revised: 11/28/2021] [Accepted: 01/12/2022] [Indexed: 12/28/2022]
Abstract
The Gram-negative bacterium Pseudomonas aeruginosa simultaneously expresses two O-antigenic glycoforms. While the O-specific antigen (OSA) is variable in composition, the common polysaccharide antigen (CPA) is highly conserved and is composed of a homopolymer of D-rhamnose (D-Rha) in trisaccharide repeating units [D-Rhaα1-2-D-Rhaα1-3-D-Rhaɑ1-3]n. We have previously reported that α3-D-Rha-transferase WbpZ transfers a D-Rha residue from GDP-D-Rha to D-GlcNAcα-O-PO3-PO3-(CH2)11-O-phenyl. Genes encoding two more D-Rha-transferases are found in the O antigen gene cluster (wbpX and wbpY). In this study we showed that WbpX and WbpY recombinantly expressed in E. coli differ in their donor and acceptor specificities and have properties of GT-B folded enzymes of the GT4 glycosyltransferase family. NMR spectroscopic analysis of the WbpY reaction product showed that WbpY transferred one D-Rha residue in α1-3 linkage to synthetic D-Rhaα1-3-D-GlcNAcα-O-PO3-PO3-(CH2)11-O-phenyl acceptor. WbpX synthesized several products that contained D-Rha in both α1-2 and α1-3 linkages. Mass spectrometry indicated that the mixture of WbpX and WbpY efficiently catalyzed the synthesis of D-Rha oligomers in a non-processive mechanism. Since O antigens are virulence factors, these findings open the door to advancing technology for antibacterial drug discovery and vaccine development.
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8
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Zheng M, Zheng M, Epstein S, Harnagel AP, Kim H, Lupoli TJ. Chemical Biology Tools for Modulating and Visualizing Gram-Negative Bacterial Surface Polysaccharides. ACS Chem Biol 2021; 16:1841-1865. [PMID: 34569792 DOI: 10.1021/acschembio.1c00341] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Bacterial cells present a wide diversity of saccharides that decorate the cell surface and help mediate interactions with the environment. Many Gram-negative cells express O-antigens, which are long sugar polymers that makeup the distal portion of lipopolysaccharide (LPS) that constitutes the surface of the outer membrane. This review highlights chemical biology tools that have been developed in recent years to facilitate the modulation of O-antigen synthesis and composition, as well as related bacterial polysaccharide pathways, and the detection of unique glycan sequences. Advances in the biochemistry and structural biology of O-antigen biosynthetic machinery are also described, which provide guidance for the design of novel chemical and biomolecular probes. Many of the tools noted here have not yet been utilized in biological systems and offer researchers the opportunity to investigate the complex sugar architecture of Gram-negative cells.
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Affiliation(s)
- Meng Zheng
- Department of Chemistry, New York University, New York, 10003 New York, United States
| | - Maggie Zheng
- Department of Chemistry, New York University, New York, 10003 New York, United States
| | - Samuel Epstein
- Department of Chemistry, New York University, New York, 10003 New York, United States
| | - Alexa P. Harnagel
- Department of Chemistry, New York University, New York, 10003 New York, United States
| | - Hanee Kim
- Department of Chemistry, New York University, New York, 10003 New York, United States
| | - Tania J. Lupoli
- Department of Chemistry, New York University, New York, 10003 New York, United States
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9
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Wagstaff BA, Zorzoli A, Dorfmueller HC. NDP-rhamnose biosynthesis and rhamnosyltransferases: building diverse glycoconjugates in nature. Biochem J 2021; 478:685-701. [PMID: 33599745 DOI: 10.1042/bcj20200505] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 01/25/2021] [Accepted: 01/26/2021] [Indexed: 11/17/2022]
Abstract
Rhamnose is an important 6-deoxy sugar present in many natural products, glycoproteins, and structural polysaccharides. Whilst predominantly found as the l-enantiomer, instances of d-rhamnose are also found in nature, particularly in the Pseudomonads bacteria. Interestingly, rhamnose is notably absent from humans and other animals, which poses unique opportunities for drug discovery targeted towards rhamnose utilizing enzymes from pathogenic bacteria. Whilst the biosynthesis of nucleotide-activated rhamnose (NDP-rhamnose) is well studied, the study of rhamnosyltransferases that synthesize rhamnose-containing glycoconjugates is the current focus amongst the scientific community. In this review, we describe where rhamnose has been found in nature, as well as what is known about TDP-β-l-rhamnose, UDP-β-l-rhamnose, and GDP-α-d-rhamnose biosynthesis. We then focus on examples of rhamnosyltransferases that have been characterized using both in vivo and in vitro approaches from plants and bacteria, highlighting enzymes where 3D structures have been obtained. The ongoing study of rhamnose and rhamnosyltransferases, in particular in pathogenic organisms, is important to inform future drug discovery projects and vaccine development.
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Affiliation(s)
- Ben A Wagstaff
- Manchester Institute of Biotechnology, University of Manchester, 131 Princess Street, Manchester, U.K
- Division of Molecular Microbiology, School of Life Sciences, University of Dundee, Dundee DD1 5EH, U.K
| | - Azul Zorzoli
- Division of Molecular Microbiology, School of Life Sciences, University of Dundee, Dundee DD1 5EH, U.K
| | - Helge C Dorfmueller
- Division of Molecular Microbiology, School of Life Sciences, University of Dundee, Dundee DD1 5EH, U.K
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10
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Yu M, Zhao Y. Cell permeability, β-lactamase activity, and transport contribute to high level of resistance to ampicillin in Lysobacter enzymogenes. Appl Microbiol Biotechnol 2019; 104:1149-1161. [PMID: 31822985 DOI: 10.1007/s00253-019-10266-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Revised: 11/12/2019] [Accepted: 11/22/2019] [Indexed: 11/26/2022]
Abstract
Discovery of multidrug resistance (MDR) in environmental microorganisms provides unique resources for uncovering antibiotic resistomes, which could be vital to predict future emergence of MDR pathogens. Our previous studies indicated that Lysobacter sp. conferred intrinsic resistance to multiple antibiotics at high levels, especially ampicillin, the first broad-spectrum β-lactam antibiotics against both Gram-positive and Gram-negative bacteria. However, the underlying molecular mechanisms for resistance to ampicillin in Lysobacter enzymogenes strain C3 (LeC3) remain unknown. In this study, screening a Tn5 transposon mutant library of LeC3 recovered 12 mutants with decreased ampicillin resistance, and three mutants (i.e., tatC, lebla, and lpp) were selected for further characterization. Our results revealed that genes encoding β-lactamase (lebla) and twin-arginine translocation (tatC) system for β-lactamase transport played a pivotal role in conferring ampicillin resistance in L. enzymogenes. It was also demonstrated that the lpp gene was not only involved in resistance against β-lactams but also conferred resistance to multiple antibiotics in L. enzymogenes. Permeability assay results indicated that decreased MDR in the lpp mutant was in part due to its higher cellular permeability. Furthermore, our results showed that the difference of LeC3 and L. antibioticus strain LaATCC29479 in ampicillin susceptibility was partly due to their differences in cellular permeability, but not due to β-lactamase activities.
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Affiliation(s)
- Menghao Yu
- Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Youfu Zhao
- Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.
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11
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Pfeiffer M, Johansson C, Krojer T, Kavanagh KL, Oppermann U, Nidetzky B. A Parsimonious Mechanism of Sugar Dehydration by Human GDP-Mannose-4,6-dehydratase. ACS Catal 2019; 9:2962-2968. [PMID: 30984471 PMCID: PMC6454399 DOI: 10.1021/acscatal.9b00064] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Revised: 02/22/2019] [Indexed: 01/25/2023]
Abstract
![]()
Biosynthesis
of 6-deoxy sugars, including l-fucose, involves
a mechanistically complex, enzymatic 4,6-dehydration of hexose nucleotide
precursors as the first committed step. Here, we determined pre- and
postcatalytic complex structures of the human GDP-mannose 4,6-dehydratase
at atomic resolution. These structures together with results of molecular
dynamics simulation and biochemical characterization of wildtype and
mutant enzymes reveal elusive mechanistic details of water elimination
from GDP-mannose C5″ and C6″, coupled to NADP-mediated
hydride transfer from C4″ to C6″. We show that concerted
acid–base catalysis from only two active-site groups, Tyr179 and Glu157, promotes a syn 1,4-elimination
from an enol (not an enolate) intermediate. We also show that the
overall multistep catalytic reaction involves the fewest position
changes of enzyme and substrate groups and that it proceeds under
conserved exploitation of the basic (minimal) catalytic machinery
of short-chain dehydrogenase/reductases.
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Affiliation(s)
- Martin Pfeiffer
- Institute of Biotechnology and Biochemical Engineering, Graz University of Technology, NAWI Graz, 8010 Graz, Austria
| | - Catrine Johansson
- Structural Genomics Consortium, University of Oxford, Oxford OX3 7DQ, United Kingdom
- Botnar Research Centre, University of Oxford, Oxford OX3 7LD, United Kingdom
| | - Tobias Krojer
- Structural Genomics Consortium, University of Oxford, Oxford OX3 7DQ, United Kingdom
| | - Kathryn L Kavanagh
- Structural Genomics Consortium, University of Oxford, Oxford OX3 7DQ, United Kingdom
| | - Udo Oppermann
- Structural Genomics Consortium, University of Oxford, Oxford OX3 7DQ, United Kingdom
- Botnar Research Centre, University of Oxford, Oxford OX3 7LD, United Kingdom
- Freiburg Institute for Advanced Studies (FRIAS), University of Freiburg, 79085 Freiburg, Germany
| | - Bernd Nidetzky
- Institute of Biotechnology and Biochemical Engineering, Graz University of Technology, NAWI Graz, 8010 Graz, Austria
- Austrian Centre of Industrial Biotechnology, 8010 Graz, Austria
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12
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Pseudomonas putida Responds to the Toxin GraT by Inducing Ribosome Biogenesis Factors and Repressing TCA Cycle Enzymes. Toxins (Basel) 2019; 11:toxins11020103. [PMID: 30744127 PMCID: PMC6410093 DOI: 10.3390/toxins11020103] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 01/29/2019] [Accepted: 02/07/2019] [Indexed: 11/21/2022] Open
Abstract
The potentially self-poisonous toxin-antitoxin modules are widespread in bacterial chromosomes, but despite extensive studies, their biological importance remains poorly understood. Here, we used whole-cell proteomics to study the cellular effects of the Pseudomonas putida toxin GraT that is known to inhibit growth and ribosome maturation in a cold-dependent manner when the graA antitoxin gene is deleted from the genome. Proteomic analysis of P. putida wild-type and ΔgraA strains at 30 °C and 25 °C, where the growth is differently affected by GraT, revealed two major responses to GraT at both temperatures. First, ribosome biogenesis factors, including the RNA helicase DeaD and RNase III, are upregulated in ΔgraA. This likely serves to alleviate the ribosome biogenesis defect of the ΔgraA strain. Secondly, proteome data indicated that GraT induces downregulation of central carbon metabolism, as suggested by the decreased levels of TCA cycle enzymes isocitrate dehydrogenase Idh, α-ketoglutarate dehydrogenase subunit SucA, and succinate-CoA ligase subunit SucD. Metabolomic analysis revealed remarkable GraT-dependent accumulation of oxaloacetate at 25 °C and a reduced amount of malate, another TCA intermediate. The accumulation of oxaloacetate is likely due to decreased flux through the TCA cycle but also indicates inhibition of anabolic pathways in GraT-affected bacteria. Thus, proteomic and metabolomic analysis of the ΔgraA strain revealed that GraT-mediated stress triggers several responses that reprogram the cell physiology to alleviate the GraT-caused damage.
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Dhaked DK, Bala Divya M, Guruprasad L. A structural and functional perspective on the enzymes of Mycobacterium tuberculosis involved in the L-rhamnose biosynthesis pathway. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2018; 145:52-64. [PMID: 30550737 DOI: 10.1016/j.pbiomolbio.2018.12.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2018] [Revised: 11/12/2018] [Accepted: 12/06/2018] [Indexed: 11/19/2022]
Abstract
Tuberculosis is one of the leading causes of death from bacterial infections. The multi-drug resistant strain has warranted the development of new drug molecules which can inhibit the growth of Mycobacterium tuberculosis (M.tb). Most of the known drugs inhibit the enzymes in the cell wall biosynthesis pathway. One such pathway is L-rhamnose, which involves four druggable enzymes RmlA, B, C and D. The 3D structure analyses of these protein models (RmlA, B and D) and crystal structure (RmlC) has been carried out. Multiple sequence alignments of homologs from distant species of 32 taxa and analyses of available structures were performed in order to study the conservation of sequence and structural motifs, and catalytically important residues. Based on these results and reported mechanism in other organisms, we have predicted putative catalytic mechanism of M.tb enzymes involved in the L-rhamnose biosynthesis pathway.
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Affiliation(s)
- Devendra K Dhaked
- School of Chemistry, University of Hyderabad, Hyderabad, Telangana, 500046, India
| | - M Bala Divya
- School of Chemistry, University of Hyderabad, Hyderabad, Telangana, 500046, India
| | - Lalitha Guruprasad
- School of Chemistry, University of Hyderabad, Hyderabad, Telangana, 500046, India.
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Li W, Zhu Z, Chen W, Feng Y, Dimitrov DS. Crystallizable Fragment Glycoengineering for Therapeutic Antibodies Development. Front Immunol 2017; 8:1554. [PMID: 29181010 PMCID: PMC5693878 DOI: 10.3389/fimmu.2017.01554] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Accepted: 10/31/2017] [Indexed: 11/23/2022] Open
Abstract
Monoclonal antibody (mAb)-based therapeutics are the fastest growing class of human pharmaceuticals. They are typically IgG1 molecules with N-glycans attached to the N297 residue on crystallizable fragment (Fc). Different Fc glycoforms impact their effector function, pharmacokinetics, stability, aggregation, safety, and immunogenicity. Fc glycoforms affect mAbs effector functions including antibody-dependent cell-mediated cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC) by modulating the Fc-FcγRs and Fc-C1q interactions. While the terminal galactose enhances CDC activity, the fucose significantly decreases ADCC. Defucosylated immunoglobulin Gs (IgGs) are thus highly pursued as next-generation therapeutic mAbs with potent ADCC at reduced doses. A plethora of cell glycoengineering and chemoenzymatic glycoengineering strategies is emerging to produce IgGs with homogenous glycoforms especially without core fucose. The chemoenzymatic glycosylation remodeling also offers useful avenues for site-specific conjugations of small molecule drugs onto mAbs. Herein, we review the current progress of IgG-Fc glycoengineering. We begin with the discussion of the structures of IgG N-glycans and biosynthesis followed by reviewing the impact of IgG glycoforms on antibody effector functions and the current Fc glycoengineering strategies with emphasis on Fc defucosylation. Furthermore, we briefly discuss two novel therapeutic mAbs formats: aglycosylated mAbs and Fc glycan specific antibody-drug conjugates (ADCs). The advances in the understanding of Fc glycobiology and development of novel glycoengineering technologies have facilitated the generation of therapeutic mAbs with homogenous glycoforms and improved therapeutic efficacy.
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Affiliation(s)
- Wei Li
- Protein Interactions Section, Cancer and Inflammation Program, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD, United States
| | - Zhongyu Zhu
- Protein Interactions Section, Cancer and Inflammation Program, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD, United States
| | - Weizao Chen
- Protein Interactions Section, Cancer and Inflammation Program, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD, United States
| | - Yang Feng
- Protein Interactions Section, Cancer and Inflammation Program, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD, United States
| | - Dimiter S. Dimitrov
- Protein Interactions Section, Cancer and Inflammation Program, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD, United States
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Yu X, Marshall MJE, Cragg MS, Crispin M. Improving Antibody-Based Cancer Therapeutics Through Glycan Engineering. BioDrugs 2017; 31:151-166. [DOI: 10.1007/s40259-017-0223-8] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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16
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Hong TP, Carter MQ, Struffi P, Casonato S, Hao Y, Lam JS, Lory S, Jousson O. Conjugative type IVb pilus recognizes lipopolysaccharide of recipient cells to initiate PAPI-1 pathogenicity island transfer in Pseudomonas aeruginosa. BMC Microbiol 2017; 17:31. [PMID: 28173753 PMCID: PMC5297154 DOI: 10.1186/s12866-017-0943-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Accepted: 02/03/2017] [Indexed: 12/31/2022] Open
Abstract
Background Pseudomonas aeruginosa pathogenicity island 1 (PAPI-1) is one of the largest genomic islands of this important opportunistic human pathogen. Previous studies have shown that PAPI-1 encodes several putative virulence factors, including a major regulator of biofilm formation and antibiotic-resistance traits. PAPI-1 is horizontally transferable into recipient strains lacking this island via conjugation mediated by the specialized type IV pilus. The PAPI-1 encodes a cluster of ten genes associated with the synthesis and assembly of the type IV pilus. The PAPI-1 acquisition mechanism is currently not well understood. Results In this study, we performed a series of conjugation experiments and identified determinants of PAPI-1 acquisition by analyzing transfer efficiency between the donor and a series of mutant recipient strains. Our data show that common polysaccharide antigen (CPA) lipopolysaccharide (LPS), a homopolymer of D-rhamnose, is required for initiating PAPI-1 transfer, suggesting that this structure acts as a receptor for conjugative type IV pilus in recipient strains. These results were substantiated by experimental evidence from PAPI-1 transfer assay experiments, in which outer membrane or LPS preparations from well-defined LPS mutants were added to the transfer mix to assess the role of P. aeruginosa LPS in PAPI-1 transfer and in vitro binding experiments between pilin fusion protein GST-pilV2’ and immobilized LPS molecules were performed. Our data also showed that P. aeruginosa strains that had already acquired a copy of PAPI-1 were unable to import additional copies of the island, and that such strains produced proportionally lower amounts of CPA LPS compared to the strains lacking PAPI-1. Conclusions These results suggest that a PAPI-1 exclusion mechanism exists in P. aeruginosa that might serve to regulate the avoidance of uncontrolled expansions of the bacterial genome. Electronic supplementary material The online version of this article (doi:10.1186/s12866-017-0943-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Toan Phuoc Hong
- Centre for Integrative Biology, University of Trento, 38123, Trento, Italy
| | - Michelle Q Carter
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA, 02115, USA
| | - Paolo Struffi
- Centre for Integrative Biology, University of Trento, 38123, Trento, Italy
| | - Stefano Casonato
- Centre for Integrative Biology, University of Trento, 38123, Trento, Italy
| | - Youai Hao
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON, N1G 2W1, Canada
| | - Joseph S Lam
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON, N1G 2W1, Canada
| | - Stephen Lory
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA, 02115, USA
| | - Olivier Jousson
- Centre for Integrative Biology, University of Trento, 38123, Trento, Italy.
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Caffrey P, De Poire E, Sheehan J, Sweeney P. Polyene macrolide biosynthesis in streptomycetes and related bacteria: recent advances from genome sequencing and experimental studies. Appl Microbiol Biotechnol 2016; 100:3893-908. [PMID: 27023916 DOI: 10.1007/s00253-016-7474-z] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Revised: 03/13/2016] [Accepted: 03/15/2016] [Indexed: 02/07/2023]
Abstract
The polyene macrolide group includes important antifungal drugs, to which resistance does not arise readily. Chemical and biological methods have been used in attempts to make polyene antibiotics with fewer toxic side effects. Genome sequencing of producer organisms is contributing to this endeavour, by providing access to new compounds and by enabling yield improvement for polyene analogues obtained by engineered biosynthesis. This recent work is also enhancing bioinformatic methods for deducing the structures of cryptic natural products from their biosynthetic enzymes. The stereostructure of candicidin D has recently been determined by NMR spectroscopy. Genes for the corresponding polyketide synthase have been uncovered in several different genomes. Analysis of this new information strengthens the view that protein sequence motifs can be used to predict double bond geometry in many polyketides.Chemical studies have shown that improved polyenes can be obtained by modifying the mycosamine sugar that is common to most of these compounds. Glycoengineered analogues might be produced by biosynthetic methods, but polyene glycosyltransferases show little tolerance for donors other than GDP-α-D-mycosamine. Genome sequencing has revealed extending glycosyltransferases that add a second sugar to the mycosamine of some polyenes. NppY of Pseudonocardia autotrophica uses UDP-N-acetyl-α-D-glucosamine as donor whereas PegA from Actinoplanes caeruleus uses GDP-α-D-mannose. These two enzymes show 51 % sequence identity and are also closely related to mycosaminyltransferases. These findings will assist attempts to construct glycosyltransferases that transfer alternative UDP- or (d)TDP-linked sugars to polyene macrolactones.
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Affiliation(s)
- Patrick Caffrey
- School of Biomolecular and Biomedical Science, University College Dublin, Belfield, Dublin 4, Ireland.
| | - Eimear De Poire
- School of Biomolecular and Biomedical Science, University College Dublin, Belfield, Dublin 4, Ireland
| | - James Sheehan
- School of Biomolecular and Biomedical Science, University College Dublin, Belfield, Dublin 4, Ireland
| | - Paul Sweeney
- School of Biomolecular and Biomedical Science, University College Dublin, Belfield, Dublin 4, Ireland
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Abstract
N-acetylquinovosamine (2-acetamido-2,6-di-deoxy-d-glucose, QuiNAc) is a relatively rare amino sugar residue found in glycans of few pathogenic gram-negative bacteria where it can play a role in infection. However, little is known about QuiNAc-related polysaccharides in gram-positive bacteria. In a routine screen for bacillus glycan grown at defined medium, it was surprising to identify a QuiNAc residue in polysaccharides isolated from this gram-positive bacterium. To gain insight into the biosynthesis of these glycans, we report the identification of an operon in Bacillus cereus ATCC 14579 that contains two genes encoding activities not previously described in gram-positive bacteria. One gene encodes a UDP-N-acetylglucosamine C4,6-dehydratase, (abbreviated Pdeg) that converts UDP-GlcNAc to UDP-4-keto-4,6-d-deoxy-GlcNAc (UDP-2-acetamido-2,6-dideoxy-α-d-xylo-4-hexulose); and the second encodes a UDP-4-reductase (abbr. Preq) that converts UDP-4-keto-4,6-d-deoxy-GlcNAc to UDP-N-acetyl-quinovosamine in the presence of NADPH. Biochemical studies established that the sequential Pdeg and Preq reaction product is UDP-d-QuiNAc as determined by mass spectrometry and one- and two-dimensional NMR experiments. Also, unambiguous evidence for the conversions of the dehydratase product, UDP-α-d-4-keto-4,6-deoxy-GlcNAc, to UDP-α-d-QuiNAc was obtained using real-time 1H-NMR spectroscopy and mass spectrometry. The two genes overlap by 4 nucleotides and similar operon organization and identical gene sequences were also identified in a few other Bacillus species suggesting they may have similar roles in the lifecycle of this class of bacteria important to human health. Our results provide new information about the ability of Bacilli to form UDP-QuiNAc and will provide insight to evaluate their role in the biology of Bacillus.
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Affiliation(s)
- Soyoun Hwang
- Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia, United States of America
| | - Avi Aronov
- Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia, United States of America
| | - Maor Bar-Peled
- Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia, United States of America; Departments of Plant Biology, University of Georgia, Athens, Georgia, United States of America
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Biosynthesis of the Common Polysaccharide Antigen of Pseudomonas aeruginosa PAO1: Characterization and Role of GDP-D-Rhamnose:GlcNAc/GalNAc-Diphosphate-Lipid α1,3-D-Rhamnosyltransferase WbpZ. J Bacteriol 2015; 197:2012-9. [PMID: 25845842 DOI: 10.1128/jb.02590-14] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Accepted: 03/30/2015] [Indexed: 12/24/2022] Open
Abstract
UNLABELLED The opportunistic pathogen Pseudomonas aeruginosa produces two major cell surface lipopolysaccharides, characterized by distinct O antigens, called common polysaccharide antigen (CPA) and O-specific antigen (OSA). CPA contains a polymer of D-rhamnose (D-Rha) in α1-2 and α1-3 linkages. Three putative glycosyltransferase genes, wbpX, wbpY, and wbpZ, are part of the CPA biosynthesis cluster. To characterize the enzymatic function of the wbpZ gene product, we chemically synthesized the donor substrate GDP-D-Rha and enzymatically synthesized GDP-D-[(3)H]Rha. Using nuclear magnetic resonance (NMR) spectroscopy, we showed that WbpZ transferred one D-Rha residue from GDP-D-Rha in α1-3 linkage to both GlcNAc- and GalNAc-diphosphate-lipid acceptor substrates. WbpZ is also capable of transferring D-mannose (D-Man) to these acceptors. Therefore, WbpZ has a relaxed specificity with respect to both acceptor and donor substrates. The diphosphate group of the acceptor, however, is required for activity. WbpZ does not require divalent metal ion for activity and exhibits an unusually high pH optimum of 9. WbpZ from PAO1 is therefore a GDP-D-Rha:GlcNAc/GalNAc-diphosphate-lipid α1,3-D-rhamnosyltransferase that has significant activity of GDP-D-Man:GlcNAc/GalNAc-diphosphate-lipid α1,3-D-mannosyltransferase. We used site-directed mutagenesis to replace the Asp residues of the two DXD motifs with Ala. Neither of the mutant constructs of wbpZ (D172A or D254A) could be used to rescue CPA biosynthesis in the ΔwbpZ knockout mutant in a complementation assay. This suggested that D172 and D254 are essential for WbpZ function. This work is the first detailed characterization study of a D-Rha-transferase and a critical step in the development of CPA synthesis inhibitors. IMPORTANCE This is the first characterization of a D-rhamnosyltransferase and shows that it is essential in Pseudomonas aeruginosa for the synthesis of the common polysaccharide antigen.
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Herbst FA, Søndergaard MT, Kjeldal H, Stensballe A, Nielsen PH, Dueholm MS. Major Proteomic Changes Associated with Amyloid-Induced Biofilm Formation in Pseudomonas aeruginosa PAO1. J Proteome Res 2014; 14:72-81. [DOI: 10.1021/pr500938x] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Florian-Alexander Herbst
- Center for Microbial Communities; ‡Department of Biotechnology, Chemistry, and
Environmental Engineering; and §Department of Health Science and Technology, Aalborg University, DK-9000 Aalborg, Denmark
| | - Mads T. Søndergaard
- Center for Microbial Communities; ‡Department of Biotechnology, Chemistry, and
Environmental Engineering; and §Department of Health Science and Technology, Aalborg University, DK-9000 Aalborg, Denmark
| | - Henrik Kjeldal
- Center for Microbial Communities; ‡Department of Biotechnology, Chemistry, and
Environmental Engineering; and §Department of Health Science and Technology, Aalborg University, DK-9000 Aalborg, Denmark
| | - Allan Stensballe
- Center for Microbial Communities; ‡Department of Biotechnology, Chemistry, and
Environmental Engineering; and §Department of Health Science and Technology, Aalborg University, DK-9000 Aalborg, Denmark
| | - Per H. Nielsen
- Center for Microbial Communities; ‡Department of Biotechnology, Chemistry, and
Environmental Engineering; and §Department of Health Science and Technology, Aalborg University, DK-9000 Aalborg, Denmark
| | - Morten S. Dueholm
- Center for Microbial Communities; ‡Department of Biotechnology, Chemistry, and
Environmental Engineering; and §Department of Health Science and Technology, Aalborg University, DK-9000 Aalborg, Denmark
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Tiwari P, Singh N, Dixit A, Choudhury D. Multivariate sequence analysis reveals additional function impacting residues in the SDR superfamily. Proteins 2014; 82:2842-56. [DOI: 10.1002/prot.24647] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2014] [Revised: 06/19/2014] [Accepted: 07/15/2014] [Indexed: 11/08/2022]
Affiliation(s)
- Pratibha Tiwari
- School of Biotechnology, Jawaharlal Nehru University; New Delhi 110 067 India
| | - Noopur Singh
- School of Biotechnology, Jawaharlal Nehru University; New Delhi 110 067 India
| | - Aparna Dixit
- School of Biotechnology, Jawaharlal Nehru University; New Delhi 110 067 India
| | - Devapriya Choudhury
- School of Biotechnology, Jawaharlal Nehru University; New Delhi 110 067 India
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Li T, Simonds L, Kovrigin EL, Noel KD. In vitro biosynthesis and chemical identification of UDP-N-acetyl-d-quinovosamine (UDP-d-QuiNAc). J Biol Chem 2014; 289:18110-20. [PMID: 24817117 DOI: 10.1074/jbc.m114.555862] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
N-acetyl-d-quinovosamine (2-acetamido-2,6-dideoxy-d-glucose, QuiNAc) occurs in the polysaccharide structures of many Gram-negative bacteria. In the biosynthesis of QuiNAc-containing polysaccharides, UDP-QuiNAc is the hypothetical donor of the QuiNAc residue. Biosynthesis of UDP-QuiNAc has been proposed to occur by 4,6-dehydration of UDP-N-acetyl-d-glucosamine (UDP-GlcNAc) to UDP-2-acetamido-2,6-dideoxy-d-xylo-4-hexulose followed by reduction of this 4-keto intermediate to UDP-QuiNAc. Several specific dehydratases are known to catalyze the first proposed step. A specific reductase for the last step has not been demonstrated in vitro, but previous mutant analysis suggested that Rhizobium etli gene wreQ might encode this reductase. Therefore, this gene was cloned and expressed in Escherichia coli, and the resulting His6-tagged WreQ protein was purified. It was tested for 4-reductase activity by adding it and NAD(P)H to reaction mixtures in which 4,6-dehydratase WbpM had acted on the precursor substrate UDP-GlcNAc. Thin layer chromatography of the nucleotide sugars in the mixture at various stages of the reaction showed that WbpM converted UDP-GlcNAc completely to what was shown to be its 4-keto-6-deoxy derivative by NMR and that addition of WreQ and NADH led to formation of a third compound. Combined gas chromatography-mass spectrometry analysis of acid hydrolysates of the final reaction mixture showed that a quinovosamine moiety had been synthesized after WreQ addition. The two-step reaction progress also was monitored in real time by NMR. The final UDP-sugar product after WreQ addition was purified and determined to be UDP-d-QuiNAc by one-dimensional and two-dimensional NMR experiments. These results confirmed that WreQ has UDP-2-acetamido-2,6-dideoxy-d-xylo-4-hexulose 4-reductase activity, completing a pathway for UDP-d-QuiNAc synthesis in vitro.
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Affiliation(s)
- Tiezheng Li
- From the Departments of Biological Sciences and
| | | | | | - K Dale Noel
- From the Departments of Biological Sciences and
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Sharafi H, Abdoli M, Hajfarajollah H, Samie N, Alidoust L, Abbasi H, Fooladi J, Zahiri HS, Noghabi KA. First Report of a Lipopeptide Biosurfactant from Thermophilic Bacterium Aneurinibacillus thermoaerophilus MK01 Newly Isolated from Municipal Landfill Site. Appl Biochem Biotechnol 2014; 173:1236-49. [DOI: 10.1007/s12010-014-0928-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2014] [Accepted: 04/17/2014] [Indexed: 01/12/2023]
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Defects in D-rhamnosyl residue biosynthetic genes affect lipopolysaccharide structure, motility, and cell-surface hydrophobicity in Pseudomonas syringae pathovar glycinea race 4. Biosci Biotechnol Biochem 2013; 77:505-10. [PMID: 23470736 DOI: 10.1271/bbb.120736] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
D-rhamnose (D-Rha) residue is a major component of lipopolysaccharides (LPSs) in strains of the phytopathogen Pseudomonas syringae pathovar glycinea. To investigate the effects of a deficiency in GDP-D-rhamnose biosynthetic genes on LPS structure and pathogenicity, we generated three mutants defective in D-Rha biosynthetic genes, encoding proteins GDP-D-mannose 4,6-dehydratase (GMD), GDP-4-keto-6-deoxy-D-mannose reductase (RMD), and a putative α-D-rhamnosyltransferase (WbpZ) in P. syringae pv. glycinea race 4. The Δgmd, Δrmd, and ΔwbpZ mutants had a reduced O-antigen polysaccharide consisting of D-Rha residues as compared with the wild type (WT). The swarming motility of the Δgmd, Δrmd, and ΔwbpZ mutant strains decreased and hydrophobicity and adhesion ability increased as compared with WT. Although the mutants had truncated O-antigen polysaccharides, and altered surface properties, they showed virulence to soybean, as WT did.
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Sousa SA, Feliciano JR, Pinheiro PF, Leitão JH. Biochemical and functional studies on the Burkholderia cepacia complex bceN gene, encoding a GDP-D-mannose 4,6-dehydratase. PLoS One 2013; 8:e56902. [PMID: 23460819 PMCID: PMC3584063 DOI: 10.1371/journal.pone.0056902] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2012] [Accepted: 01/15/2013] [Indexed: 11/18/2022] Open
Abstract
This work reports the biochemical and functional analysis of the Burkholderia cenocepacia J2315 bceN gene, encoding a protein with GDP-D-mannose 4,6-dehydratase enzyme activity (E.C.4.2.1.47). Data presented indicate that the protein is active when in the tetrameric form, catalyzing the conversion of GDP-D-mannose into GDP-4-keto-6-deoxy-D-mannose. This sugar nucleotide is the intermediary necessary for the biosynthesis of GDP-D-rhamnose, one of the sugar residues of cepacian, the major exopolysaccharide produced by environmental and human, animal and plant pathogenic isolates of the Burkholderia cepacia complex species. Vmax and Km values of 1.5±0.2 µmol.min−1.mg−1 and 1024±123 µM, respectively, were obtained from the kinetic characterization of the B. cenocepacia J2315 BceN protein by NMR spectroscopy, at 25°C and in the presence of 1 mol MgCl2 per mol of protein. The enzyme activity was strongly inhibited by the substrate, with an estimated Ki of 2913±350 µM. The lack of a functional bceN gene in a mutant derived from B. cepacia IST408 slightly reduced cepacian production. However, in the B. multivorans ATCC17616 with bceN as the single gene in its genome with predicted GMD activity, a bceN mutant did not produce cepacian, indicating that this gene product is required for cepacian biosynthesis.
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Affiliation(s)
- Sílvia A. Sousa
- Institute for Biotechnology and Bioengineering, Centre for Biological and Chemical Engineering, Instituto Superior Técnico, Lisboa, Portugal
| | - Joana R. Feliciano
- Institute for Biotechnology and Bioengineering, Centre for Biological and Chemical Engineering, Instituto Superior Técnico, Lisboa, Portugal
| | - Pedro F. Pinheiro
- Institute for Biotechnology and Bioengineering, Centre for Biological and Chemical Engineering, Instituto Superior Técnico, Lisboa, Portugal
| | - Jorge H. Leitão
- Institute for Biotechnology and Bioengineering, Centre for Biological and Chemical Engineering, Instituto Superior Técnico, Lisboa, Portugal
- Department of Bioenginneering, Instituto Superior Técnico, Universidade Técnica de Lisboa, Lisboa, Portugal
- * E-mail:
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Flores-Ramirez G, Janecek S, Miernyk JA, Skultety L. In silico biosynthesis of virenose, a methylated deoxy-sugar unique to Coxiella burnetii lipopolysaccharide. Proteome Sci 2012; 10:67. [PMID: 23150954 PMCID: PMC3539893 DOI: 10.1186/1477-5956-10-67] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2012] [Accepted: 11/05/2012] [Indexed: 12/22/2022] Open
Abstract
UNLABELLED BACKGROUND Coxiella burnetii is Gram-negative bacterium responsible for the zoonosis Q-fever. While it has an obligate intracellular growth habit, it is able to persist for extended periods outside of a host cell and can resist environmental conditions that would be lethal to most prokaryotes. It is these extracellular bacteria that are the infectious stage encountered by eukaryotic hosts. The intracellular form has evolved to grow and replicate within acidified parasitophorous vacuoles. The outer coat of C. burnetii comprises a complex lipopolysaccharide (LPS) component that includes the unique methylated-6-deoxyhexose, virenose. Although potentially important as a biomarker for C. burnetii, the pathway for its biosynthesis remains obscure. RESULTS The 6-deoxyhexoses constitute a large family integral to the LPS of many eubacteria. It is believed that precursors of the methylated-deoxyhexoses traverse common early biosynthetic steps as nucleotide-monosaccharides. As a prelude to a full biosynthetic characterization, we present herein the results from bioinformatics-based, proteomics-supported predictions of the pathway for virenose synthesis. Alternative possibilities are considered which include both GDP-mannose and TDP-glucose as precursors. CONCLUSION We propose that biosynthesis of the unique C. burnetii biomarker, virenose, involves an early pathway similar to that of other C-3'-methylated deoxysugars which then diverges depending upon the nucleotide-carrier involved. The alternatives yield either the D- or L-enantiomers of virenose. Both pathways require five enzymatic steps, beginning with either glucose-6-phosphate or mannose-6-phosphate. Our in silico results comprise a model for virenose biosynthesis that can be directly tested. Definition of this pathway should facilitate the development of therapeutic agents useful for treatment of Q fever, as well as allowing improvements in the methods for diagnosing this highly infectious disease.
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Affiliation(s)
- Gabriela Flores-Ramirez
- Department of Rickettsiology, Institute of Virology, Slovak Academy of Sciences, Dubravska cesta, 9, Bratislava, 845 05, Slovakia
| | - Stefan Janecek
- Laboratory of Protein Evolution, Institute of Molecular Biology, Slovak Academy of Sciences, Bratislava, 845 51, Slovakia
| | - Ján A Miernyk
- USDA, Agricultural Research Service, Plant Genetics Research Unit, Columbia, MO, 65211, USA
- Interdisciplinary Plant Group, University of Missouri, Columbia, MO, 65211, USA
- Department of Biochemistry, University of Missouri, Columbia, MO, 65211, USA
| | - Ludovit Skultety
- Department of Rickettsiology, Institute of Virology, Slovak Academy of Sciences, Dubravska cesta, 9, Bratislava, 845 05, Slovakia
- Centre for Molecular Medicine, Slovak Academy of Sciences, Bratislava, 831 01, Slovakia
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Chen Y, Xu L, Zhao W, Guo L, Yang L. Method for the Sequential Online Analysis of Enzyme Reactions Based on Capillary Electrophoresis. Anal Chem 2012; 84:2961-7. [DOI: 10.1021/ac3001644] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Yuanfang Chen
- Faculty of Chemistry, Northeast Normal University, Changchun, Jilin, 130024,
P.R.China
| | - Liangliang Xu
- College of Optical
and Electronical
Information, Changchun University of Science and Technology, Changchun, Jilin, 130012, P.R. China
| | - Wenwen Zhao
- Faculty of Chemistry, Northeast Normal University, Changchun, Jilin, 130024,
P.R.China
| | - Liping Guo
- Faculty of Chemistry, Northeast Normal University, Changchun, Jilin, 130024,
P.R.China
| | - Li Yang
- Faculty of Chemistry, Northeast Normal University, Changchun, Jilin, 130024,
P.R.China
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Ogorek C, Jordan I, Sandig V, von Horsten HH. Fucose-targeted glycoengineering of pharmaceutical cell lines. Methods Mol Biol 2012; 907:507-517. [PMID: 22907371 DOI: 10.1007/978-1-61779-974-7_29] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Glycosylation is known to have an impact on pharmacokinetics and pharmacodynamics of therapeutic proteins. While the production of pharmaceutically desirable glycosylation forms of a therapeutic protein can in certain cases be influenced by the upstream process parameters, certain specialized glycan structures can only be produced in large quantities from cell lines that have been genetically engineered.One particular case where a specialized glycostructure has a major impact on pharmacodynamic mode of action is the enhanced ADCC-effector function of afucosylated IgG1-type monoclonal antibodies. Here we describe the methodological details of a powerful yet simple glycoengineering approach targeted at the fucosylation machinery within eukaryotic cells. As an example we demonstrate the modification of the permanent avian cell line AGE1.CR.pIX which is characterized by a unique glycosylation machinery.
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Characterization of the dehydratase WcbK and the reductase WcaG involved in GDP-6-deoxy-manno-heptose biosynthesis in Campylobacter jejuni. Biochem J 2011; 439:235-48. [PMID: 21711244 DOI: 10.1042/bj20110890] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The capsule of Campylobacter jejuni strain 81-176 comprises the unusual 6-deoxy-α-D-altro-heptose, whose biosynthesis and function are not known. In the present study, we characterized enzymes of the capsular cluster, WcbK and WcaG, to determine their role in 6-deoxy-altro-heptose synthesis. These enzymes are similar to the Yersinia pseudotuberculosis GDP-manno-heptose dehydratase/reductase DmhA/DmhB that we characterized previously. Capillary electrophoresis and MS analyses showed that WcbK is a GDP-manno-heptose dehydratase whose product can be reduced by WcaG, and that WcbK/WcaG can use the substrate GDP-mannose, although with lower efficiency than heptose. Comparison of kinetic parameters for WcbK and DmhA indicated that the relaxed substrate specificity of WcbK comes at the expense of catalytic performance on GDP-manno-heptose. Moreover, although WcbK/WcaG and DmhA/DmhB are involved in altro- versus manno-heptose synthesis respectively, the enzymes can be used interchangeably in mixed reactions. NMR spectroscopy analyses indicated conservation of the sugar manno configuration during catalysis by WcbK/WcaG. Therefore additional capsular enzymes may perform the C3 epimerization necessary to generate 6-deoxy-altro-heptose. Finally, a conserved residue (Thr(187) in WcbK) potentially involved in substrate specificity was identified by structural modelling of mannose and heptose dehydratases. Site-directed mutagenesis and kinetic analyses demonstrated its importance for enzymatic activity on heptose and mannose substrates.
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Harvey H, Kus JV, Tessier L, Kelly J, Burrows LL. Pseudomonas aeruginosa D-arabinofuranose biosynthetic pathway and its role in type IV pilus assembly. J Biol Chem 2011; 286:28128-37. [PMID: 21676874 DOI: 10.1074/jbc.m111.255794] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Pseudomonas aeruginosa strains PA7 and Pa5196 glycosylate their type IVa pilins with α1,5-linked D-arabinofuranose (d-Araf), a rare sugar configuration identical to that found in cell wall polymers of the Corynebacterineae. Despite this chemical identity, the pathway for biosynthesis of α1,5-D-Araf in Gram-negative bacteria is unknown. Bioinformatics analyses pointed to a cluster of seven P. aeruginosa genes, including homologues of the Mycobacterium tuberculosis genes Rv3806c, Rv3790, and Rv3791, required for synthesis of a polyprenyl-linked d-ribose precursor and its epimerization to D-Araf. Pa5196 mutants lacking the orthologues of those genes had non-arabinosylated pilins, poor twitching motility, and significantly fewer surface pili than the wild type even in a retraction-deficient (pilT) background. The Pa5196 pilus system assembled heterologous non-glycosylated pilins efficiently, demonstrating that it does not require post-translationally modified subunits. Together the data suggest that pilins of group IV strains need to be glycosylated for productive subunit-subunit interactions. A recombinant P. aeruginosa PAO1 strain co-expressing the genes for d-Araf biosynthesis, the pilin modification enzyme TfpW, and the acceptor PilA(IV) produced arabinosylated pili, confirming that the Pa5196 genes identified are both necessary and sufficient. A P. aeruginosa epimerase knock-out could be complemented with the corresponding Mycobacterium smegmatis gene, demonstrating conservation between the systems of the Corynebacterineae and Pseudomonas. This work describes a novel Gram-negative pathway for biosynthesis of d-Araf, a key therapeutic target in Corynebacterineae.
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Affiliation(s)
- Hanjeong Harvey
- Michael G DeGroote Institute for Infectious Diseases Research and the Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario L8N 3Z5, Canada
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Xiao Y, Li S, Niu S, Ma L, Zhang G, Zhang H, Zhang G, Ju J, Zhang C. Characterization of tiacumicin B biosynthetic gene cluster affording diversified tiacumicin analogues and revealing a tailoring dihalogenase. J Am Chem Soc 2010; 133:1092-105. [PMID: 21186805 DOI: 10.1021/ja109445q] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The RNA polymerase inhibitor tiacumicin B is currently undergoing phase III clinical trial for treatment of Clostridium difficile associated diarrhea with great promise. To understand the biosynthetic logic and to lay a foundation for generating structural analogues via pathway engineering, the tiacumicin B biosynthetic gene cluster was identified and characterized from the producer Dactylosporangium aurantiacum subsp. hamdenensis NRRL 18085. Sequence analysis of a 110,633 bp DNA region revealed the presence of 50 open reading frames (orfs). Functional investigations of 11 orfs by in vivo inactivation experiments, preliminarily outlined the boundaries of the tia-gene cluster and suggested that 31 orfs were putatively involved in tiacumicin B biosynthesis. Functions of a halogenase (TiaM), two glycosyltransferases (TiaG1 and TiaG2), a sugar C-methyltransferase (TiaS2), an acyltransferase (TiaS6), and two cytochrome P450s (TiaP1 and TiaP2) were elucidated by isolation and structural characterization of the metabolites from the corresponding gene-inactivation mutants. Accumulation of 18 tiacumicin B analogues from 7 mutants not only provided experimental evidence to confirm the proposed functions of individual biosynthetic enzymes, but also set an example of accessing microbial natural product diversity via genetic approach. More importantly, biochemical characterization of the FAD-dependent halogenase TiaM reveals a sequentially acting dihalogenation step tailoring tiacumicin B biosynthesis.
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Affiliation(s)
- Yi Xiao
- CAS Key Laboratory of Marine Bio-resources Sustainable Utilization, RNAM Center for Marine Microbiology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, PR China
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Abstract
Complex glycoconjugates play critical roles in the biology of microorganisms. Despite the remarkable diversity in glycan structures and the bacteria that produce them, conserved themes are evident in the biosynthesis-export pathways. One of the primary pathways involves representatives of the ATP-binding cassette (ABC) transporter superfamily. These proteins are responsible for the export of a wide variety of cell surface oligo- and polysaccharides in both Gram-positive and Gram-negative bacteria. Recent investigations of the structure and function of ABC transporters involved in the export of lipopolysaccharide O antigens have revealed two fundamentally different strategies for coupling glycan polymerization to export. These mechanisms are distinguished by the presence (or absence) of characteristic nonreducing terminal modifications on the export substrates, which serve as chain termination and/or export signals, and by the presence (or absence) of a discrete substrate-binding domain in the nucleotide-binding domain polypeptide of the ABC transporter. A bioinformatic survey examining ABC exporters from known oligo- and polysaccharide biosynthesis loci identifies conserved nucleotide-binding domain protein families that correlate well with themes in the structures and assembly of glycans. The familial relationships among the ABC exporters generate hypotheses concerning the biosynthesis of structurally diverse oligo- and polysaccharides, which play important roles in the biology of bacteria with different lifestyles.
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High temporal resolution monitoring of enzyme reaction and inhibition using optically gated vacancy capillary electrophoresis and immobilized enzyme. Anal Chim Acta 2010; 683:136-42. [DOI: 10.1016/j.aca.2010.10.013] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2010] [Revised: 10/04/2010] [Accepted: 10/08/2010] [Indexed: 11/20/2022]
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von Horsten HH, Ogorek C, Blanchard V, Demmler C, Giese C, Winkler K, Kaup M, Berger M, Jordan I, Sandig V. Production of non-fucosylated antibodies by co-expression of heterologous GDP-6-deoxy-D-lyxo-4-hexulose reductase. Glycobiology 2010; 20:1607-18. [PMID: 20639190 DOI: 10.1093/glycob/cwq109] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
All IgG-type antibodies are N-glycosylated in their Fc part at Asn-297. Typically, a fucose residue is attached to the first N-acetylglucosamine of these complex-type N-glycans. Antibodies lacking core fucosylation show a significantly enhanced antibody-dependent cell-mediated cytotoxicity (ADCC) and an increased efficacy of anti-tumor activity. In cases where the clinical efficacy of an antibody is to some extent mediated by its ADCC effector function, afucosylated N-glycans could help to reduce dose requirement and save manufacturing costs. Using Chinese hamster ovary (CHO) cells as a model, we demonstrate here that heterologous expression of the prokaryotic enzyme GDP-6-deoxy-d-lyxo-4-hexulose reductase within the cytosol can efficiently deflect the fucose de novo pathway. Antibody-producing CHO cells that were modified in this way secrete antibodies lacking core fucose as demonstrated by MALDI-TOF mass spectrometry and HPAEC-PAD monosaccharide analysis. Engineering of the fucose de novo pathway has led to the construction of IgGs with a strongly enhanced ADCC effector function. The method described here should have broad practical applicability for the development of next-generation therapeutic antibodies.
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35
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Fan Y, Scriba GKE. Advances in capillary electrophoretic enzyme assays. J Pharm Biomed Anal 2010; 53:1076-90. [PMID: 20439145 DOI: 10.1016/j.jpba.2010.04.005] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2010] [Revised: 03/26/2010] [Accepted: 04/05/2010] [Indexed: 01/25/2023]
Abstract
In recent years, capillary electrophoresis (CE) has become a frequently used tool for enzyme assays due to its well-recognized advantages such as high separation efficiency, short analysis time, small sample and chemicals consumption. The published applications cover all aspects of enzyme characterization and analysis including the determination of the enzyme activity, substrate and modulator characterization and identification, as well as the investigation of enzyme-mediated metabolic pathways of bioactive molecules. The CE assays may be classified into two general categories: (1) pre-capillary assays where the reactions are performed offline followed by CE analysis of the substrates and products and (2) online assays when the enzyme reaction and separation of the analytes are performed in the same capillary. In online assays, the enzyme may be either immobilized or in solution. The latter is also referred to as electrophoretically mediated microanalysis (EMMA). The present review will highlight the literature of CE-based enzyme assays from 2006 to November 2009. One section will be devoted to applications of microfluidic devices.
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Affiliation(s)
- Yi Fan
- Department of Pharmaceutical Chemistry, School of Pharmacy, University of Jena, Philosophenweg 14, D-07743 Jena, Germany
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