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Thorsing M, Krogh TJ, Vitved L, Nawrocki A, Jakobsen R, Larsen MR, Chakraborty S, Bourgeois AL, Andersen AZ, Boysen A. Linking inherent O-Linked Protein Glycosylation of YghJ to Increased Antigen Potential. Front Cell Infect Microbiol 2021; 11:705468. [PMID: 34490144 PMCID: PMC8417355 DOI: 10.3389/fcimb.2021.705468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Accepted: 07/23/2021] [Indexed: 11/13/2022] Open
Abstract
Enterotoxigenic Escherichia coli (ETEC) is a WHO priority pathogen and vaccine target which causes infections in low-income and middle-income countries, travelers visiting endemic regions. The global urgent demand for an effective preventive intervention has become more pressing as ETEC strains have become increasingly multiple antibiotic resistant. However, the vaccine development pipeline has been slow to address this urgent need. To date, vaccine development has focused mainly on canonical antigens such as colonization factors and expressed toxins but due to genomic plasticity of this enteric pathogen, it has proven difficult to develop effective vaccines. In this study, we investigated the highly conserved non-canonical vaccine candidate YghJ/SsLE. Using the mass spectrometry-based method BEMAP, we demonstrate that YghJ is hyperglycosylated in ETEC and identify 54 O-linked Set/Thr residues within the 1519 amino acid primary sequence. The glycosylation sites are evenly distributed throughout the sequence and do not appear to affect the folding of the overall protein structure. Although the glycosylation sites only constitute a minor subpopulation of the available epitopes, we observed a notable difference in the immunogenicity of the glycosylated YghJ and the non-glycosylated protein variant. We can demonstrate by ELISA that serum from patients enrolled in an ETEC H10407 controlled infection study are significantly more reactive with glycosylated YghJ compared to the non-glycosylated variant. This study provides an important link between O-linked glycosylation and the relative immunogenicity of bacterial proteins and further highlights the importance of this observation in considering ETEC proteins for inclusion in future broad coverage subunit vaccine candidates.
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Affiliation(s)
| | | | - Lars Vitved
- Department of Cancer and Inflammation Research, University of Southern Denmark, Odense, Denmark
| | - Arkadiusz Nawrocki
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
| | | | - Martin R. Larsen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
| | - Subhra Chakraborty
- Center for Immunization Research, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, United States
| | - A. Louis Bourgeois
- Center for Vaccine Innovation and Access, PATH, Washington, DC, United States
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Andersen AZ, Duelund L, Brewer J, Nielsen PK, Birk T, Garde K, Kallipolitis B, Krebs N, Bagatolli L. Biophysical Evaluation of Food Decontamination Effects on Tissue and Bacteria. FOOD BIOPHYS 2011. [DOI: 10.1007/s11483-011-9205-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Olsen LF, Andersen AZ, Lunding A, Brasen JC, Poulsen AK. Regulation of glycolytic oscillations by mitochondrial and plasma membrane H+-ATPases. Biophys J 2009; 96:3850-61. [PMID: 19413991 DOI: 10.1016/j.bpj.2009.02.026] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2008] [Revised: 01/31/2009] [Accepted: 02/05/2009] [Indexed: 10/20/2022] Open
Abstract
We investigated the coupling between glycolytic and mitochondrial membrane potential oscillations in Saccharomyces cerevisiae under semianaerobic conditions. Glycolysis was measured as NADH autofluorescence, and mitochondrial membrane potential was measured using the fluorescent dye 3,3'-diethyloxacarbocyanine iodide. The responses of glycolytic and membrane potential oscillations to a number of inhibitors of glycolysis, mitochondrial electron flow, and mitochondrial and plasma membrane H(+)-ATPase were investigated. Furthermore, the glycolytic flux was determined as the rate of production of ethanol in a number of different situations (changing pH or the presence and absence of inhibitors). Finally, the intracellular pH was determined and shown to oscillate. The results support earlier work suggesting that the coupling between glycolysis and mitochondrial membrane potential is mediated by the ADP/ATP antiporter and the mitochondrial F(0)F(1)-ATPase. The results further suggest that ATP hydrolysis, through the action of the mitochondrial F(0)F(1)-ATPase and plasma membrane H(+)-ATPase, are important in regulating these oscillations. We conclude that it is glycolysis that drives the oscillations in mitochondrial membrane potential.
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Affiliation(s)
- Lars Folke Olsen
- CelCom, Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark.
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Poulsen AK, Andersen AZ, Brasen JC, Scharff-Poulsen AM, Olsen LF. Probing Glycolytic and Membrane Potential Oscillations in Saccharomyces cerevisiae. Biochemistry 2008; 47:7477-84. [DOI: 10.1021/bi800396e] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Allan K. Poulsen
- CelCom, and Microbiology Group, Department of Biochemistry and Molecular Biology, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark, and Risoe National Laboratory, Technical University of Denmark, Biosystems Department, Post Office Box 49, Frederiksborgvej 399, DK-4000 Roskilde, Denmark
| | - Ann Zahle Andersen
- CelCom, and Microbiology Group, Department of Biochemistry and Molecular Biology, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark, and Risoe National Laboratory, Technical University of Denmark, Biosystems Department, Post Office Box 49, Frederiksborgvej 399, DK-4000 Roskilde, Denmark
| | - Jens Christian Brasen
- CelCom, and Microbiology Group, Department of Biochemistry and Molecular Biology, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark, and Risoe National Laboratory, Technical University of Denmark, Biosystems Department, Post Office Box 49, Frederiksborgvej 399, DK-4000 Roskilde, Denmark
| | - Anne Marie Scharff-Poulsen
- CelCom, and Microbiology Group, Department of Biochemistry and Molecular Biology, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark, and Risoe National Laboratory, Technical University of Denmark, Biosystems Department, Post Office Box 49, Frederiksborgvej 399, DK-4000 Roskilde, Denmark
| | - Lars Folke Olsen
- CelCom, and Microbiology Group, Department of Biochemistry and Molecular Biology, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark, and Risoe National Laboratory, Technical University of Denmark, Biosystems Department, Post Office Box 49, Frederiksborgvej 399, DK-4000 Roskilde, Denmark
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Andersen AZ, Poulsen AK, Brasen JC, Olsen LF. On-line measurements of oscillating mitochondrial membrane potential in glucose-fermenting Saccharomyces cerevisiae. Yeast 2007; 24:731-9. [PMID: 17568453 DOI: 10.1002/yea.1508] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
We employed the fluorescent cyanine dye DiOC(2)(3) to measure membrane potential in semi-anaerobic yeast cells under conditions where glycolysis was oscillating. Oscillations in glycolysis were studied by means of the naturally abundant nicotinamide adenine dinucleotide (NADH). We found that the mitochondrial membrane potential was oscillating, and that these oscillations displayed the same frequency and duration as the NADH oscillations. It was confirmed that DiOC(2)(3) localizes itself in the mitochondrial membrane and thus reports qualitative changes solely in mitochondrial membrane potential. Our studies showed that glycolytic oscillations perturb the mitochondrial membrane potential and that the mitochondria do not have any controlling effect on the dynamics of glycolysis under these conditions. Depolarization of the mitochondrial membrane by addition of FCCP quenched mitochondrial membrane potential oscillations and delocalized DiOC(2)(3), while glycolysis continued to oscillate unaffected.
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Affiliation(s)
- Ann Zahle Andersen
- University of Southern Denmark, Department of Biochemistry and Molecular Biology, CelCom, Campusvej 55, 5230 Odense M, Denmark.
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Andersen AZ, Lauritsen FR, Olsen LF. On-line monitoring of CO2 production inLactococcus lactis during physiological pH decrease using membrane inlet mass spectrometry with dynamic pH calibration. Biotechnol Bioeng 2005; 92:740-7. [PMID: 16224787 DOI: 10.1002/bit.20641] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Monitoring CO2 production in systems, where pH is changing with time is hampered by the chemical behavior and pH-dependent volatility of this compound. In this article, we present the first method where the concentration and production rate of dissolved CO2 can be monitored directly, continuously, and quantitatively under conditions where pH changes rapidly ( approximately 2 units in 15 min). The method corrects membrane inlet mass spectrometry (MIMS) measurements of CO2 for pH dependency using on-line pH analysis and an experimentally established calibration model. It is valid within the pH range of 3.5 to 7, despite pH-dependent calibration constants that vary in a non-linear fashion with more than a factor of 3 in this interval. The method made it possible to determine the carbon dioxide production during Lactococcus lactis fermentations, where pH drops up to 3 units during the fermentation. The accuracy was approximately 5%. We used the method to investigate the effect of initial extracellular pH on carbon dioxide production during anarobic glucose fermentation by non-growing Lactocoocus lactis and demonstrated that the carbon dioxide production rate increases considerably, when the initial pH was increased from 6 to 6.8.
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Affiliation(s)
- Ann Zahle Andersen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark.
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