1
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Dörnyei Á, Kilár A, Sándor V. Identification of a Chimera Mass Spectrum of Isomeric Lipid A Species Using Negative Ion Tandem Mass Spectrometry. Toxins (Basel) 2024; 16:322. [PMID: 39057962 PMCID: PMC11281664 DOI: 10.3390/toxins16070322] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2024] [Revised: 07/12/2024] [Accepted: 07/16/2024] [Indexed: 07/28/2024] Open
Abstract
The toxic nature of bacterial endotoxins is affected by the structural details of lipid A, including the variety and position of acyl chains and phosphate group(s) on its diglucosamine backbone. Negative-ion mode tandem mass spectrometry is a primary method for the structure elucidation of lipid A, used independently or in combination with separation techniques. However, it is challenging to accurately characterize constitutional isomers of lipid A extracts by direct mass spectrometry, as the elemental composition and molecular mass of these molecules are identical. Thus, their simultaneous fragmentation leads to a composite, so-called chimera mass spectrum. The present study focuses on the phosphopositional isomers of the classical monophosphorylated, hexaacylated Escherichia coli-type lipid A. Collision-induced dissociation (CID) was performed in an HPLC-ESI-QTOF system. Energy-resolved mass spectrometry (ERMS) was applied to uncover the distinct fragmentation profiles of the phosphorylation isomers. A fragmentation strategy applying multi-levels of collision energy has been proposed and applied to reveal sample complexity, whether it contains only a 4'-phosphorylated species or a mixture of 1- and 4'-phosphorylated variants. This comparative fragmentation study of isomeric lipid A species demonstrates the high potential of ERMS-derived information for the successful discrimination of co-ionized phosphorylation isomers of hexaacylated lipid A.
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Affiliation(s)
- Ágnes Dörnyei
- Department of Analytical and Environmental Chemistry and Szentágothai Research Centre, Faculty of Sciences, University of Pécs, Ifjúság útja 6., H-7624 Pécs, Hungary
| | - Anikó Kilár
- Institute of Bioanalysis, Medical School, University of Pécs, Szigeti út 12., H-7624 Pécs, Hungary; (A.K.); (V.S.)
| | - Viktor Sándor
- Institute of Bioanalysis, Medical School, University of Pécs, Szigeti út 12., H-7624 Pécs, Hungary; (A.K.); (V.S.)
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2
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Wang Z, Zhao A, Qiao J, Yu J, He F, Bi Y, Yu L, Wang X. Engineering Escherichia coli MG1655 to Efficiently Produce 3-Deacyl-4'-monophosphoryl Lipid A. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2023; 71:13376-13390. [PMID: 37656614 DOI: 10.1021/acs.jafc.3c00681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/03/2023]
Abstract
Monophosphoryl lipid A, derived from Salmonella minnesota R595, has been used in various adjuvant formulations. Escherichia coli can produce lipid A, but its structure is different. In this study, E. coli MG1655 has been engineered to efficiently produce the monophosphoryl lipid A. First, 126 genes relevant to the biosynthesis of the fimbriae, flagella, and ECA were deleted in MG1655, resulting in WQM027. Second, the genes pldA, mlaA, and mlaC related to the phospholipid transport system, the gene ptsG related to the carbohydrate phosphotransferase system, and the gene eptA encoding phosphoethanolamine transferase for lipid A modification were further deleted from WQM027, resulting in MW020. Third, lpxE from Francisella novicida and pagP and pagL from Salmonella were overexpressed in pFT24, resulting in pTEPL. pTEPL was transformed into MW020, resulting in MW020/pTEPL. Finally, fabI encoding an enoyl-ACP reductase was deleted from the genome of MW020/pTEPL, resulting in MW021/pTEPL. MW021/pTEPL could produce 85.31 mg/L of lipid A species after 26 h of fed-batch fermentation. Mainly two monophosphoryl lipid A species were produced in MW021/pTEPL, one is 3-deacyl-2-acyloxyacyl-4'-monophosphoryl lipid A and the other is 3-deacyl-4'-monophosphoryl lipid A. E. coli MW021/pTEPL constructed in this study could be an ideal host for the industrial production of monophosphoryl lipid A.
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Affiliation(s)
- Zhen Wang
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Aizhen Zhao
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Jun Qiao
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Jing Yu
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Fenfang He
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Yibing Bi
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Letong Yu
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Xiaoyuan Wang
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China
- International Joint Laboratory on Food Safety, Jiangnan University, Wuxi 214122, China
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
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3
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Guan XL, Loh JYX, Lizwan M, Chan SCM, Kwan JMC, Lim TP, Koh TH, Hsu LY, Lee BTK. LipidA-IDER to Explore the Global Lipid A Repertoire of Drug-Resistant Gram-Negative Bacteria. Anal Chem 2023; 95:602-611. [PMID: 36599414 PMCID: PMC9850412 DOI: 10.1021/acs.analchem.1c03566] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
With the global emergence of drug-resistant bacteria causing difficult-to-treat infections, there is an urgent need for a tool to facilitate studies on key virulence and antimicrobial resistant factors. Mass spectrometry (MS) has contributed substantially to the elucidation of the structure-function relationships of lipid A, the endotoxic component of lipopolysaccharide which also serves as an important protective barrier against antimicrobials. Here, we present LipidA-IDER, an automated structure annotation tool for system-level scale identification of lipid A from high-resolution tandem mass spectrometry (MS2) data. LipidA-IDER was validated against previously reported structures of lipid A in the reference bacteria, Escherichia coli and Pseudomonas aeruginosa. Using MS2 data of variable quality, we demonstrated LipidA-IDER annotated lipid A with a performance of 71.2% specificity and 70.9% sensitivity, offering greater accuracy than existing lipidomics software. The organism-independent workflow was further applied to a panel of six bacterial species: E. coli and Gram-negative members of ESKAPE pathogens. A comprehensive atlas comprising 188 distinct lipid A species, including remodeling intermediates, was generated and can be integrated with software including MS-DIAL and Metabokit for identification and semiquantitation. Systematic comparison of a pair of polymyxin-sensitive and polymyxin-resistant Acinetobacter baumannii isolated from a human patient unraveled multiple key lipid A structural features of polymyxin resistance within a single analysis. Probing the lipid A landscape of bacteria using LipidA-IDER thus holds immense potential for advancing our understanding of the vast diversity and structural complexity of a key lipid virulence and antimicrobial-resistant factor. LipidA-IDER is freely available at https://github.com/Systems-Biology-Of-Lipid-Metabolism-Lab/LipidA-IDER.
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Affiliation(s)
- Xue Li Guan
- Lee
Kong Chian School of Medicine, Nanyang Technological
University, Singapore 636921, Singapore,. Tel: +65 6592 3957
| | - Johnathan Yi-Xiong Loh
- Lee
Kong Chian School of Medicine, Nanyang Technological
University, Singapore 636921, Singapore
| | - Marco Lizwan
- Lee
Kong Chian School of Medicine, Nanyang Technological
University, Singapore 636921, Singapore
| | - Sharon Cui Mun Chan
- Lee
Kong Chian School of Medicine, Nanyang Technological
University, Singapore 636921, Singapore
| | - Jeric Mun Chung Kwan
- Lee
Kong Chian School of Medicine, Nanyang Technological
University, Singapore 636921, Singapore
| | - Tze Peng Lim
- Department
of Pharmacy, Singapore General Hospital, Singapore 169608, Singapore
| | - Tse Hsien Koh
- Department
of Microbiology, Singapore General Hospital, Singapore 169608, Singapore
| | - Li-Yang Hsu
- Saw Swee
Hock School of Public Health, National University
of Singapore, Singapore 117549, Singapore
| | - Bernett Teck Kwong Lee
- Lee
Kong Chian School of Medicine, Nanyang Technological
University, Singapore 636921, Singapore,Centre
for Biomedical Informatics, Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore 636921, Singapore,Singapore
Immunology Network (SIgN), Agency for Science, Technology and Research (A*STAR), Singapore 138648, Singapore
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Aissa I, Dörnyei Á, Sándor V, Kilár A. Complete Structural Elucidation of Monophosphorylated Lipid A by CID Fragmentation of Protonated Molecule and Singly Charged Sodiated Adducts. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2023; 34:92-100. [PMID: 36539922 PMCID: PMC9817073 DOI: 10.1021/jasms.2c00269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Revised: 12/02/2022] [Accepted: 12/05/2022] [Indexed: 06/17/2023]
Abstract
Lipid A, the inflammatory portion of lipopolysaccharides (LPS, endotoxins), is the main component of the outer membrane of Gram-negative bacteria. Its bioactivity in humans and animals is strictly related to its chemical structure. In the present work, the fragmentation patterns of the singly charged monosodium [M + Na]+ and disodium [M - H + 2Na]+ adducts, as well as the protonated form of monophosphorylated lipid A species were investigated in detail using positive-ion electrospray ionization-based tandem (MS/MS) and multistage mass spectrometry (MSn) with low-energy collision-induced dissociation (CID). Several synthetic and native lipid A samples were included in the study. We found that the fragmentation pattern of disodiated lipid A is quite similar to that of the well-characterized deprotonated lipid A molecule (typically detected in the negative-ion mode), while the fragmentation pattern of monosodiated lipid A contains fragment ions similar to those of both protonated and deprotonated lipid A molecules. In summary, we propose a new mass spectrometry approach based on the fragmentation regularities of only positively charged precursor ions to dissect the location of the phosphate group and fatty acid moieties on monophosphorylated lipid A. Moreover, this study provides a better understanding of the so-called "chimera mass spectra", which are commonly detected during the fragmentation of native lipid A samples containing both C-1 and C-4' phosphate positional isomers but rarely identified in negative-ion mode.
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Affiliation(s)
- Ibrahim Aissa
- Department
of Analytical and Environmental Chemistry, Faculty of Sciences, University of Pécs, Ifjúság útja 6, H-7624 Pécs, Hungary
| | - Ágnes Dörnyei
- Department
of Analytical and Environmental Chemistry, Faculty of Sciences, University of Pécs, Ifjúság útja 6, H-7624 Pécs, Hungary
| | - Viktor Sándor
- Institute
of Bioanalysis, Medical School and Szentágothai Research Centre, University of Pécs, Szigeti út 12, H-7624 Pécs, Hungary
| | - Anikó Kilár
- Institute
of Bioanalysis, Medical School and Szentágothai Research Centre, University of Pécs, Szigeti út 12, H-7624 Pécs, Hungary
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5
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Structural differences in bacterial lipopolysaccharides determine atherosclerotic plaque progression by regulating the accumulation of neutrophils. Atherosclerosis 2022; 358:1-11. [DOI: 10.1016/j.atherosclerosis.2022.08.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Revised: 07/28/2022] [Accepted: 08/10/2022] [Indexed: 11/21/2022]
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6
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Yang H, Smith RD, Chandler CE, Johnson JK, Jackson SN, Woods AS, Scott AJ, Goodlett DR, Ernst RK. Lipid A Structural Determination from a Single Colony. Anal Chem 2022; 94:7460-7465. [PMID: 35576511 PMCID: PMC9392460 DOI: 10.1021/acs.analchem.1c05394] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
We describe an innovative use for the recently reported fast lipid analysis technique (FLAT) that allows for the generation of MALDI tandem mass spectrometry data suitable for lipid A structure analysis directly from a single Gram-negative bacterial colony. We refer to this tandem MS version of FLAT as FLATn. Neither technique requires sophisticated sample preparation beyond the selection of a single bacterial colony, which significantly reduces overall analysis time (∼1 h), as compared to conventional methods. Moreover, the tandem mass spectra generated by FLATn provides comprehensive information on fragments of lipid A, for example, ester bonded acyl chain dissociations, cross-ring cleavages, and glycosidic bond dissociations, all of which allow the facile determination of novel lipid A structures or confirmation of expected structures. In addition to generating tandem mass spectra directly from single colonies, we also show that FLATn can be used to analyze lipid A structures taken directly from a complex biological clinical sample without the need for ex vivo growth. From a urine sample from a patient with an E. coli infection, FLATn identified the organism and demonstrated that this clinical isolate carried the mobile colistin resistance-1 gene (mcr-1) that results in the addition of a phosphoethanolamine moiety and subsequently resistance to the antimicrobial, colistin (polymyxin E). Moreover, FLATn allowed for the determination of the existence of a structural isomer in E. coli lipid A that had either a 1- or 4'-phosphate group modification by phosphoethanolamine generated by a change of bacterial culture conditions.
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Affiliation(s)
- Hyojik Yang
- Department of Microbial Pathogenesis, School of Dentistry, University of Maryland, Baltimore, MD 21201 USA
| | - Richard D. Smith
- Department of Microbial Pathogenesis, School of Dentistry, University of Maryland, Baltimore, MD 21201 USA
- Department of Pathology, School of Medicine, University of Maryland, Baltimore, MD 21201 USA
| | - Courtney E. Chandler
- Department of Microbial Pathogenesis, School of Dentistry, University of Maryland, Baltimore, MD 21201 USA
| | - J. Kristie Johnson
- Department of Pathology, School of Medicine, University of Maryland, Baltimore, MD 21201 USA
| | - Shelley N. Jackson
- Translational Analytical Core, NIDA IRP, NIH, Biomedical Research Center, 251 Bayview Boulevard, Suite 200, Room 01B216, Baltimore, MD 21224, USA
| | - Amina S. Woods
- Structural Biology Core, NIDA IRP, NIH, 333 Cassell Drive, Room 1120, Baltimore, MD 21224, USA
- Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine. Baltimore, MD 21205 USA
| | - Alison J. Scott
- Department of Microbial Pathogenesis, School of Dentistry, University of Maryland, Baltimore, MD 21201 USA
- Maastricht MultiModal Molecular Imaging (M4I) Institute, Maastricht University, Maastricht 6229 ER, Netherlands
| | - David R. Goodlett
- Department of Biochemistry and Microbiology, University of Victoria, 3800 Finnerty Road. Victoria, BC V8P 5C2, Canada
- International Centre for Cancer Vaccine Science, University of Gdańsk, ul. Kładki 24 80-822 Gdańsk, Poland
| | - Robert K. Ernst
- Department of Microbial Pathogenesis, School of Dentistry, University of Maryland, Baltimore, MD 21201 USA
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7
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Mohr AE, Crawford M, Jasbi P, Fessler S, Sweazea KL. Lipopolysaccharide and the gut microbiota: Considering structural variation. FEBS Lett 2022; 596:849-875. [PMID: 35262962 DOI: 10.1002/1873-3468.14328] [Citation(s) in RCA: 37] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 02/16/2022] [Accepted: 02/17/2022] [Indexed: 11/10/2022]
Abstract
Systemic inflammation is associated with chronic disease and is purported to be a main pathogenic mechanism underlying metabolic conditions. Microbes harbored in the host gastrointestinal tract release signaling byproducts from their cell wall, such as lipopolysaccharides (LPS), which can act locally and, after crossing the gut barrier and entering circulation, also systemically. Defined as metabolic endotoxemia, elevated concentrations of LPS in circulation are associated with metabolic conditions and chronic disease. As such, measurement of LPS is highly prevalent in animal and human research investigating these states. Indeed, LPS can be a potent stimulant of host immunity but this response depends on the microbial species' origin, a parameter often overlooked in both preclinical and clinical investigations. Indeed, the lipid A portion of LPS is mutable and comprises the main virulence and endotoxic component, thus contributing to the structural and functional diversity among LPSs from microbial species. In this review, we discuss how such structural differences in LPS can induce differential immunological responses in the host.
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Affiliation(s)
- Alex E Mohr
- College of Health Solutions, Arizona State University, Phoenix, Arizona, United States of America
| | - Meli'sa Crawford
- Biomedical Sciences, University of Riverside, California, Riverside, California, United States of America
| | - Paniz Jasbi
- College of Health Solutions, Arizona State University, Phoenix, Arizona, United States of America
| | - Samantha Fessler
- College of Health Solutions, Arizona State University, Phoenix, Arizona, United States of America
| | - Karen L Sweazea
- College of Health Solutions, Arizona State University, Phoenix, Arizona, United States of America.,School of Life Sciences, Arizona State University, Tempe, Arizona, United States of America
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8
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Aissa I, Kilár A, Dörnyei Á. Study on the CID Fragmentation Pathways of Deprotonated 4'-Monophosphoryl Lipid A. Molecules 2021; 26:5961. [PMID: 34641505 PMCID: PMC8512036 DOI: 10.3390/molecules26195961] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2021] [Revised: 09/25/2021] [Accepted: 09/27/2021] [Indexed: 11/25/2022] Open
Abstract
Lipid A, the membrane-bound phosphoglycolipid component of bacteria, is held responsible for the clinical syndrome of gram-negative sepsis. In this study, the fragmentation behavior of a set of synthetic lipid A derivatives was studied by electrospray ionization multistage mass spectrometry (ESI-MSn), in conjunction with tandem mass spectrometry (MS/MS), using low-energy collision-induced dissociation (CID). Genealogical insight about the fragmentation pathways of the deprotonated 4'-monophosphoryl lipid A structural analogs led to proposals of a number of alternative dissociation routes that have not been reported previously. Each of the fragment ions was interpreted using various possible mechanisms, consistent with the principles of reactions described in organic chemistry. Specifically, the hypothesized mechanisms are: (i) cleavage of the C-3 primary fatty acid leaves behind an epoxide group attached to the reducing sugar; (ii) cleavage of the C-3' primary fatty acid (as an acid) generates a cyclic phosphate connected to the nonreducing sugar; (iii) cleavage of the C-2' secondary fatty acid occurs both in acid and ketene forms; iv) the C-2 and C-2' primary fatty acids are eliminated as an amide and ketene, respectively; (v) the 0,2A2 cross-ring fragment contains a four-membered ring (oxetanose); (vi) the 0,4A2 ion is consecutively formed from the 0,2A2 ion by retro-aldol, retro-cycloaddition, and transesterification; and (vii) formations of H2PO4- and PO3- are associated with the formation of sugar epoxide. An understanding of the relation between 0,2A2 and 0,4A2-type sugar fragments and the different cleavage mechanisms of the two ester-linked primary fatty acids is invaluable for distinguishing lipid A isomers with different locations of a single ester-linked fatty acid (i.e., at C-3 or C-3'). Thus, in addition to a better comprehension of lipid A fragmentation processes in mass spectrometers, our observations can be applied for a more precise elucidation of naturally occurring lipid A structures.
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Affiliation(s)
- Ibrahim Aissa
- Department of Analytical and Environmental Chemistry, Faculty of Sciences, University of Pécs, Ifjúság útja 6, H-7624 Pécs, Hungary;
| | - Anikó Kilár
- Institute of Bioanalysis, Medical School and Szentágothai Research Centre, University of Pécs, Szigeti út 12, H-7624 Pécs, Hungary;
| | - Ágnes Dörnyei
- Department of Analytical and Environmental Chemistry, Faculty of Sciences, University of Pécs, Ifjúság útja 6, H-7624 Pécs, Hungary;
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9
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Analyses of Lipid A Diversity in Gram-Negative Intestinal Bacteria Using Liquid Chromatography-Quadrupole Time-of-Flight Mass Spectrometry. Metabolites 2021; 11:metabo11040197. [PMID: 33810392 PMCID: PMC8065654 DOI: 10.3390/metabo11040197] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Revised: 03/23/2021] [Accepted: 03/24/2021] [Indexed: 11/17/2022] Open
Abstract
Lipid A is a characteristic molecule of Gram-negative bacteria that elicits an immune response in mammalian cells. The presence of structurally diverse lipid A types in the human gut bacteria has been suggested before, and this appears associated with the immune response. However, lipid A structures and their quantitative heterogeneity have not been well characterized. In this study, a method of analysis for lipid A using liquid chromatography-quadrupole time-of-flight mass spectrometry (LC-QTOF/MS) was developed and applied to the analyses of Escherichia coli and Bacteroidetes strains. In general, phosphate compounds adsorb on stainless-steel piping and cause peak tailing, but the use of an ammonia-containing alkaline solvent produced sharp lipid A peaks with high sensitivity. The method was applied to E. coli strains, and revealed the accumulation of lipid A with abnormal acyl side chains in knockout strains as well as known diphosphoryl hexa-acylated lipid A in a wild-type strain. The analysis of nine representative strains of Bacteroidetes showed the presence of monophosphoryl penta-acylated lipid A characterized by a highly heterogeneous main acyl chain length. Comparison of the structures and amounts of lipid A among the strains suggested a relationship between lipid A profiles and the phylogenetic classification of the strains.
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10
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Froning M, Helmer PO, Hayen H. Identification and structural characterization of lipid A from Escherichia coli, Pseudomonas putida and Pseudomonas taiwanensis using liquid chromatography coupled to high-resolution tandem mass spectrometry. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2020; 34:e8897. [PMID: 32673427 DOI: 10.1002/rcm.8897] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 07/06/2020] [Accepted: 07/11/2020] [Indexed: 06/11/2023]
Abstract
RATIONALE Lipid A is a part of the lipopolysaccharide layer, which is a main component of the outer membrane from Gram-negative bacteria. It can be sensed by mammalians to identify the presence of Gram-negative bacteria in their tissues and plays a key role in the pathogenesis of bacterial infections. Lipid A is also used as an adjuvant in human vaccines, emphasizing the importance of its structural analysis. METHODS In order to distinguish and characterize various lipid A species, a liquid chromatography coupled to tandem mass spectrometry (LC/MS/MS) method was developed. Isolation of lipid A from different bacteria was carried out using a modified Bligh and Dyer extraction following a mild acid hydrolysis. Chromatography was performed using a bifunctional reversed-phase-based stationary phase. High-resolution MS using negative electrospray ionization was applied and MS/MS experiments utilizing high-energy collisional dissociation generated diagnostic product ions, which allowed the assignment of the side chains to distinct positions of the lipid A backbone. RESULTS The method was applied to lipid A isolations of Escherichia coli (E. coli), Pseudomonas putida (P. putida) and Pseudomonas taiwanensis (P. taiwanensis). Various lipid A species were identified by their accurate masses and their structures were characterized using MS/MS experiments. Previously described lipid A structures from E. coli were identified and their structures confirmed by MS/MS. For the biotechnologically relevant strains P. putida and P. taiwanensis, we confirmed species by MS/MS, which have previously only been analyzed using MS. In addition, several lipid A species were discovered that have not been previously described in the literature. CONCLUSIONS The combination of LC and MS/MS enabled the selective and sensitive identification and structural characterization of various lipid A species from Gram-negative bacteria. These species varied in their substituted side chains, speaking of fatty acids and phosphate groups. Characteristic product ions facilitated the assignment of side chains to distinct positions of the lipid A backbone.
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Affiliation(s)
- Matti Froning
- Institute of Inorganic and Analytical Chemistry, University of Münster, Corrensstraße 30, Münster, 48149, Germany
| | - Patrick O Helmer
- Institute of Inorganic and Analytical Chemistry, University of Münster, Corrensstraße 30, Münster, 48149, Germany
| | - Heiko Hayen
- Institute of Inorganic and Analytical Chemistry, University of Münster, Corrensstraße 30, Münster, 48149, Germany
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11
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Aldana J, Romero-Otero A, Cala MP. Exploring the Lipidome: Current Lipid Extraction Techniques for Mass Spectrometry Analysis. Metabolites 2020; 10:metabo10060231. [PMID: 32503331 PMCID: PMC7345237 DOI: 10.3390/metabo10060231] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Revised: 05/05/2020] [Accepted: 05/13/2020] [Indexed: 12/14/2022] Open
Abstract
In recent years, high-throughput lipid profiling has contributed to understand the biological, physiological and pathological roles of lipids in living organisms. Across all kingdoms of life, important cell and systemic processes are mediated by lipids including compartmentalization, signaling and energy homeostasis. Despite important advances in liquid chromatography and mass spectrometry, sample extraction procedures remain a bottleneck in lipidomic studies, since the wide structural diversity of lipids imposes a constrain in the type and amount of lipids extracted. Differences in extraction yield across lipid classes can induce a bias on down-stream analysis and outcomes. This review aims to summarize current lipid extraction techniques used for untargeted and targeted studies based on mass spectrometry. Considerations, applications, and limitations of these techniques are discussed when used to extract lipids in complex biological matrices, such as tissues, biofluids, foods, and microorganisms.
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12
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Sándor V, Berkics BV, Kilár A, Kocsis B, Kilár F, Dörnyei Á. NACE–ESI‐MS/MS method for separation and characterization of phosphorylation and acylation isomers of lipid A. Electrophoresis 2020; 41:1178-1188. [DOI: 10.1002/elps.201900251] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Revised: 04/10/2020] [Accepted: 04/17/2020] [Indexed: 01/17/2023]
Affiliation(s)
- Viktor Sándor
- Institute of Bioanalysis Medical School and Szentágothai Research Centre University of Pécs Pécs Hungary
| | - Balázs Viktor Berkics
- Institute of Bioanalysis Medical School and Szentágothai Research Centre University of Pécs Pécs Hungary
| | - Anikó Kilár
- Institute of Bioanalysis Medical School and Szentágothai Research Centre University of Pécs Pécs Hungary
| | - Béla Kocsis
- Department of Microbiology and Immunology, Medical School University of Pécs Pécs Hungary
| | - Ferenc Kilár
- Institute of Bioanalysis Medical School and Szentágothai Research Centre University of Pécs Pécs Hungary
- Department of Bioengineering Sapientia Hungarian University of Transylvania Miercurea Ciuc Romania
| | - Ágnes Dörnyei
- Department of Analytical and Environmental Chemistry, Faculty of Science University of Pécs Pécs Hungary
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13
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Klein DR, Powers MJ, Trent MS, Brodbelt JS. Top-Down Characterization of Lipooligosaccharides from Antibiotic-Resistant Bacteria. Anal Chem 2019; 91:9608-9615. [PMID: 31305072 PMCID: PMC6702669 DOI: 10.1021/acs.analchem.9b00940] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Modification of structures of lipooligosaccharides (LOS) represents one prevalent mechanism by which Gram-negative bacteria can become resistant to key antibiotics. Owing to the significant complexity of LOS, the structural characterization of these amphipathic lipids has largely focused on elucidation of the lipid A substructures. Analysis of intact LOS enables detection of core oligosaccharide modifications and gives insight into the heterogeneity that results from combinations of lipid A and oligosaccharide substructures. Top-down analysis of intact LOS also provides the opportunity to determine unknown oligosaccharide structures, which is particularly advantageous in the context of glycoconjugate vaccine development. Advances in mass spectrometry technologies, including the development of MSn capabilities and alternative ion activation techniques, have made top-down analysis an indispensable tool for structural characterization of complex biomolecules. Here we combine online chromatographic separations with MS3 utilizing ultraviolet photodissociation (UVPD) and higher-energy collisional dissociation (HCD). HCD generally provides information about the presence of labile modifications via neutral loss fragments in addition to the saccharide linkage arrangement, whereas UVPD gives more detailed insight about saccharide branching and the positions of nonstoichiometric modifications. This integrated approach was used to characterize LOS from Acinetobacter baumannii 1205 and 5075. Notably, MS3 analysis of A. baumannii 1205, an antibiotic-resistant strain, confirmed phosphoethanolamine and hexosamine modification of the lipid A substructure and further enabled derivation of a core oligosaccharide structure.
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Affiliation(s)
- Dustin R. Klein
- Department of Chemistry, The University of Texas at Austin, Austin, TX 78712
| | - Matthew J. Powers
- Department of Infectious Diseases, The University of Georgia, College of Veterinary Medicine, Athens, GA 30602
- Department of Microbiology, The University of Georgia, College of Arts and Sciences, Athens, GA 30602
| | - M. Stephen Trent
- Department of Infectious Diseases, The University of Georgia, College of Veterinary Medicine, Athens, GA 30602
- Department of Microbiology, The University of Georgia, College of Arts and Sciences, Athens, GA 30602
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Crittenden CM, Herrera CM, Williams PE, Ricci DP, Swem LR, Trent MS, Brodbelt JS. Mapping phosphate modifications of substituted lipid A via a targeted MS 3 CID/UVPD strategy. Analyst 2018; 143:3091-3099. [PMID: 29881855 PMCID: PMC6019210 DOI: 10.1039/c8an00561c] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Structural characterization of lipid A from Gram-negative bacteria remains a significant challenge, especially with respect to localizing modifications of the phosphate groups typically found on the reducing and non-reducing ends of the β-1',6-linked glucosamine disaccharide backbone of lipid A. As reported here, combining traditional collisional activated dissociation (CAD) and ultraviolet photodissociation (UVPD) in a hybrid MS3 approach facilitates identification and localization of substituents of the phosphate groups. The focus is on rapid identification and characterization of substituted lipid A species with specific emphasis on the modifications on the 1 and 4' phosphate moieties. Mapping these modifications, typically ones that modify the surface charges of lipopolysaccharides, is particularly important owing to the impact of these types of modifications on antibiotic resistance. The presence of phosphoethanolamine, aminoarabinose, and galactosamine moieties in hexaacylated and heptaacylated lipid A species, including ones from Enterobacter cloacae and Acinetobacter baumannii, are characterized using a targeted MS3 strategy to identify glycosidic product ions (1,5X1 and 0,4A2, typically) which allow localization of the substituents.
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15
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Mass Spectrometry-based Structural Analysis and Systems Immunoproteomics Strategies for Deciphering the Host Response to Endotoxin. J Mol Biol 2018; 430:2641-2660. [PMID: 29949751 DOI: 10.1016/j.jmb.2018.06.032] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Revised: 05/23/2018] [Accepted: 06/15/2018] [Indexed: 02/06/2023]
Abstract
One cause of sepsis is systemic maladaptive immune response of the host to bacteria and specifically, to Gram-negative bacterial outer-membrane glycolipid lipopolysaccharide (LPS). On the host myeloid cell surface, proinflammatory LPS activates the innate immune system via Toll-like receptor-4/myeloid differentiation factor-2 complex. Intracellularly, LPS is also sensed by the noncanonical inflammasome through caspase-11 in mice and 4/5 in humans. The minimal functional determinant for innate immune activation is the membrane anchor of LPS called lipid A. Even subtle modifications to the lipid A scaffold can enable, diminish, or abolish immune activation. Bacteria are known to modify their LPS structure during environmental stress and infection of hosts to alter cellular immune phenotypes. In this review, we describe how mass spectrometry-based structural analysis of endotoxin helped uncover major determinations of molecular pathogenesis. Through characterization of LPS modifications, we now better understand resistance to antibiotics and cationic antimicrobial peptides, as well as how the environment impacts overall endotoxin structure. In addition, mass spectrometry-based systems immunoproteomics approaches can assist in elucidating the immune response against LPS. Many regulatory proteins have been characterized through proteomics and global/targeted analysis of protein modifications, enabling the discovery and characterization of novel endotoxin-mediated protein translational modifications.
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16
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Sándor V, Kilár A, Kilár F, Kocsis B, Dörnyei Á. Characterization of complex, heterogeneous lipid A samples using HPLC-MS/MS technique III. Positive-ion mode tandem mass spectrometry to reveal phosphorylation and acylation patterns of lipid A. JOURNAL OF MASS SPECTROMETRY : JMS 2018; 53:146-161. [PMID: 29144587 DOI: 10.1002/jms.4046] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Revised: 10/29/2017] [Accepted: 10/30/2017] [Indexed: 06/07/2023]
Abstract
In this study, we report the detailed analysis of the fragmentation patterns of positively charged lipid A species based on their tandem mass spectra obtained under low-energy collision-induced dissociation conditions of an electrospray quadrupole time-of-flight mass spectrometer. The tandem mass spectrometry experiments were performed after the separation of the compounds with a reversed-phase high performance liquid chromatography method. We found that both, phosphorylated and nonphosphorylated lipid A molecules can be readily ionized in the positive-ion mode by adduct formation with triethylamine added to the eluent. The tandem mass spectra of the lipid A triethylammonium adduct ions showed several product ions corresponding to inter-ring glycosidic cleavages of the sugar residues, as well as consecutive and competitive eliminations of fatty acids, phosphoric acid, and water following the neutral loss of triethylamine. Characteristic product ions provided direct information on the phosphorylation site(s), also when phosphorylation isomers (ie, containing either a C1 or a C4' phosphate group) were simultaneously present in the sample. Continuous series of high-abundance B-type and low-abundance Y-type inter-ring fragment ions were indicative of the fatty acyl distribution between the nonreducing and reducing ends of the lipid A backbone. The previously reported lipid A structures of Proteus morganii O34 and Escherichia coli O111 bacteria were used as standards. Although, the fragmentation pathways of the differently phosphorylated lipid A species significantly differed in the negative-ion mode, they were very similar in the positive-ion mode. The complementary use of positive-ion and negative-ion mode tandem mass spectrometry was found to be essential for the full structural characterization of the C1-monophosphorylated lipid A species.
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Affiliation(s)
- Viktor Sándor
- Institute of Bioanalysis, Medical School and Szentágothai Research Centre, University of Pécs, Szigeti út 12, 7624, Pécs, Hungary
| | - Anikó Kilár
- Institute of Bioanalysis, Medical School and Szentágothai Research Centre, University of Pécs, Szigeti út 12, 7624, Pécs, Hungary
- Department of Analytical and Environmental Chemistry, Faculty of Sciences, University of Pécs, Ifjúság útja 6, 7624, Pécs, Hungary
| | - Ferenc Kilár
- Institute of Bioanalysis, Medical School and Szentágothai Research Centre, University of Pécs, Szigeti út 12, 7624, Pécs, Hungary
- Department of Analytical and Environmental Chemistry, Faculty of Sciences, University of Pécs, Ifjúság útja 6, 7624, Pécs, Hungary
| | - Béla Kocsis
- Department of Medical Microbiology and Immunology, Medical School, University of Pécs, Szigeti út 12, 7624, Pécs, Hungary
| | - Ágnes Dörnyei
- Department of Analytical and Environmental Chemistry, Faculty of Sciences, University of Pécs, Ifjúság útja 6, 7624, Pécs, Hungary
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17
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Crittenden CM, Akin LD, Morrison LJ, Trent MS, Brodbelt JS. Characterization of Lipid A Variants by Energy-Resolved Mass Spectrometry: Impact of Acyl Chains. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2017; 28:1118-1126. [PMID: 27966172 PMCID: PMC5438766 DOI: 10.1007/s13361-016-1542-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Revised: 10/19/2016] [Accepted: 10/24/2016] [Indexed: 05/04/2023]
Abstract
Lipid A molecules consist of a diglucosamine sugar core with a number of appended acyl chains that vary in their length and connectivity. Because of the challenging nature of characterizing these molecules and differentiating between isomeric species, an energy-resolved MS/MS strategy was undertaken to track the fragmentation trends and map genealogies of product ions originating from consecutive cleavages of acyl chains. Generalizations were developed based on the number and locations of the primary and secondary acyl chains as well as variations in preferential cleavages arising from the location of the phosphate groups. Secondary acyl chain cleavage occurs most readily for lipid A species at the 3' position, followed by primary acyl chain fragmentation at both the 3' and 3 positions. In the instances of bisphosphorylated lipid A variants, phosphate loss occurs readily in conjunction with the most favorable primary and secondary acyl chain cleavages. Graphical Abstract ᅟ.
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Affiliation(s)
| | - Lucas D Akin
- Department of Chemistry, University of Texas, Austin, TX, 78712, USA
| | | | - M Stephen Trent
- Department of Infectious Diseases, University of Georgia, Athens, GA, 30602, USA
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18
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Sándor V, Kilár A, Kilár F, Kocsis B, Dörnyei Á. Characterization of complex, heterogeneous lipid A samples using HPLC-MS/MS technique II. Structural elucidation of non-phosphorylated lipid A by negative-ion mode tandem mass spectrometry. JOURNAL OF MASS SPECTROMETRY : JMS 2016; 51:615-628. [PMID: 28239963 DOI: 10.1002/jms.3786] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2015] [Revised: 05/09/2016] [Accepted: 05/11/2016] [Indexed: 06/06/2023]
Abstract
Non-phosphorylated lipid A species confer reduced inflammatory potential for the bacteria. Knowledge on their chemical structure and presence in bacterial pathogens may contribute to the understanding of bacterial resistance and activation of the host innate immune system. In this study, we report the fragmentation pathways of negatively charged, non-phosphorylated lipid A species under low-energy collision-induced dissociation conditions of an electrospray ionization quadrupole time-of-flight instrument. Charge-promoted consecutive and competitive eliminations of the acyl chains and cross-ring cleavages of the sugar residues were observed. The A-type fragment ion series and the complementary X-type fragment(s) with corresponding deprotonated carboxamide(s) were diagnostic for the distribution of the primary and secondary acyl residues on the non-reducing and the reducing ends, respectively, of the non-phosphorylated lipid A backbone. Reversed-phase liquid chromatography in combination with negative-ion electrospray ionization quadrupole time-of-flight tandem mass spectrometry could provide sufficient information on the primary and secondary acyl residues of a non-phosphorylated lipid A. As a standard, the hexa-acylated ion at m/z 1636 with the Escherichia coli-type acyl distribution (from E. coli O111) was used. The method was tested and refined with the analysis of other non-phosphorylated hexa- and several hepta-, penta-, and tetra-acylated lipid A species detected in crude lipid A fractions from E. coli O111 and Proteus morganii O34 bacteria. Copyright © 2016 John Wiley & Sons, Ltd.
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Affiliation(s)
- Viktor Sándor
- Institute of Bioanalysis and Szentágothai Research Centre, University of Pécs, Szigeti út 12., 7624, Pécs, Hungary
| | - Anikó Kilár
- MTA-PTE Molecular Interactions in Separation Science Research Group, Ifjúság útja 6., 7624, Pécs, Hungary
| | - Ferenc Kilár
- Institute of Bioanalysis and Szentágothai Research Centre, University of Pécs, Szigeti út 12., 7624, Pécs, Hungary
- Department of Analytical and Environmental Chemistry, Faculty of Sciences, University of Pécs, Ifjúság útja 6., 7624, Pécs, Hungary
| | - Béla Kocsis
- Department of Medical Microbiology and Immunology, Faculty of Medicine, University of Pécs, Szigeti út 12., 7624, Pécs, Hungary
| | - Ágnes Dörnyei
- Department of Analytical and Environmental Chemistry, Faculty of Sciences, University of Pécs, Ifjúság útja 6., 7624, Pécs, Hungary
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