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Kale D, Sachsenheimer T, Sickmann A, Brügger B. A New, Rapid Method for the Quantification of Dolichyl Phosphates in Cell Cultures Using TMSD Methylation Combined with LC-MS Analysis. Bio Protoc 2023; 13:e4880. [PMID: 38023789 PMCID: PMC10665631 DOI: 10.21769/bioprotoc.4880] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 08/16/2023] [Accepted: 08/29/2023] [Indexed: 12/01/2023] Open
Abstract
Dolichyl phosphates (DolP) are ubiquitous lipids that are present in almost all eukaryotic membranes. They play a key role in several protein glycosylation pathways and the formation of glycosylphosphatidylinositol anchors. These lipids constitute only ~0.1% of total phospholipids, and their analysis by reverse phase (RP) liquid chromatography-high-resolution mass spectrometry (LC-HRMS) is challenging due to their high lipophilicity (log P > 20), poor ionization efficiency, and relatively low abundance. To overcome these challenges, we have introduced a new approach for DolP analysis by combining trimethylsilyldiazomethane (TMSD)-based phosphate methylation and HRMS analysis. The analytical method was validated for its reproducibility, sensitivity, and accuracy. The established workflow was successfully applied for the simultaneous characterization and quantification of DolP species with different isoprene units in lipid extracts of HeLa and Saccharomyces cerevisiae cells.
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Affiliation(s)
- Dipali Kale
- Heidelberg University Biochemistry Center (BZH), Heidelberg, Germany
- Leibniz-Institut für Analytische Wissenschaften-ISAS-e.V., Dortmund, Germany
| | | | - Albert Sickmann
- Leibniz-Institut für Analytische Wissenschaften-ISAS-e.V., Dortmund, Germany
| | - Britta Brügger
- Heidelberg University Biochemistry Center (BZH), Heidelberg, Germany
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2
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Kale D, Kikul F, Phapale P, Beedgen L, Thiel C, Brügger B. Quantification of Dolichyl Phosphates Using Phosphate Methylation and Reverse-Phase Liquid Chromatography-High Resolution Mass Spectrometry. Anal Chem 2023; 95:3210-3217. [PMID: 36716239 PMCID: PMC9933046 DOI: 10.1021/acs.analchem.2c03623] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Dolichyl monophosphates (DolPs) are essential lipids in glycosylation pathways that are highly conserved across almost all domains of life. The availability of DolP is critical for all glycosylation processes, as these lipids serve as membrane-anchored building blocks used by various types of glycosyltransferases to generate complex post-translational modifications of proteins and lipids. The analysis of DolP species by reverse-phase liquid chromatography-mass spectrometry (RPLC-MS) remains a challenge due to their very low abundance and wide range of lipophilicities. Until now, a method for the simultaneous qualitative and quantitative assessment of DolP species from biological membranes has been lacking. Here, we describe a novel approach based on simple sample preparation, rapid and efficient trimethylsilyl diazomethane-dependent phosphate methylation, and RPLC-MS analysis for quantification of DolP species with different isoprene chain lengths. We used this workflow to selectively quantify DolP species from lipid extracts derived of Saccharomyces cerevisiae, HeLa, and human skin fibroblasts from steroid 5-α-reductase 3- congenital disorders of glycosylation (SRD5A3-CDG) patients and healthy controls. Integration of this workflow with global lipidomics analyses will be a powerful tool to expand our understanding of the role of DolPs in pathophysiological alterations of metabolic pathways downstream of HMG-CoA reductase, associated with CDGs, hypercholesterolemia, neurodegeneration, and cancer.
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Affiliation(s)
- Dipali Kale
- Heidelberg
University Biochemistry Center (BZH), 69120Heidelberg, Germany,Leibniz-Institut
für Analytische Wissenschaften-ISAS-e.V., 44139Dortmund, Germany,
| | - Frauke Kikul
- Heidelberg
University Biochemistry Center (BZH), 69120Heidelberg, Germany
| | - Prasad Phapale
- Leibniz-Institut
für Analytische Wissenschaften-ISAS-e.V., 44139Dortmund, Germany
| | - Lars Beedgen
- Centre
for Child and Adolescent Medicine, University
Hospital Heidelberg, 69120Heidelberg, Germany
| | - Christian Thiel
- Centre
for Child and Adolescent Medicine, University
Hospital Heidelberg, 69120Heidelberg, Germany
| | - Britta Brügger
- Heidelberg
University Biochemistry Center (BZH), 69120Heidelberg, Germany,
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Gharwalová L, Palyzová A, Marešová H, Kolouchová I, Kyselová L, Řezanka T. Identification of Homologous Polyprenols from Thermophilic Bacteria. Microorganisms 2021; 9:microorganisms9061168. [PMID: 34071687 PMCID: PMC8226974 DOI: 10.3390/microorganisms9061168] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 05/25/2021] [Accepted: 05/27/2021] [Indexed: 11/24/2022] Open
Abstract
Sixteen strains of five genera of thermophilic bacteria, i.e., Alicyclobacillus, Brevibacillus, Geobacillus, Meiothermus, and Thermus, were cultivated at a temperature from 42 to 70 °C. Twelve strains were obtained from the Czech Collection of Microorganisms, while four were directly isolated and identified by 16S rRNA gene sequencing from the hot springs of the world-famous Carlsbad spa (Czech Republic). Polyprenol homologs from C40 to C65 as well as free undecaprenol (C55), undecaprenyl phosphate, and undecaprenyl diphosphate were identified by shotgun analysis and RP-HPLC/MS-ESI+ (reverse phase high-performance liquid chromatography–high-resolution positive electrospray ionization mass spectrometry). The limit of detection (50 pM) was determined for individual homologs and free polyprenols and their phosphates. Thus, it has been shown that at least some thermophilic bacteria produce not just the major C55 polyprenol as previously described, but a mixture of homologs.
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Affiliation(s)
- Lucia Gharwalová
- Department of Biotechnology, Faculty of Food and Biochemical Technology, University of Chemistry and Technology Prague, 166 28 Prague, Czech Republic; (L.G.); (I.K.)
| | - Andrea Palyzová
- Institute of Microbiology, The Czech Academy of Sciences, 142 20 Prague, Czech Republic; (A.P.); (H.M.)
| | - Helena Marešová
- Institute of Microbiology, The Czech Academy of Sciences, 142 20 Prague, Czech Republic; (A.P.); (H.M.)
| | - Irena Kolouchová
- Department of Biotechnology, Faculty of Food and Biochemical Technology, University of Chemistry and Technology Prague, 166 28 Prague, Czech Republic; (L.G.); (I.K.)
| | - Lucie Kyselová
- Research Institute of Brewing and Malting, 120 44 Prague, Czech Republic;
| | - Tomáš Řezanka
- Institute of Microbiology, The Czech Academy of Sciences, 142 20 Prague, Czech Republic; (A.P.); (H.M.)
- Correspondence:
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Welti M, Hülsmeier AJ. Ethanol-induced impairment in the biosynthesis of N-linked glycosylation. J Cell Biochem 2014; 115:754-62. [PMID: 24243557 DOI: 10.1002/jcb.24713] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2013] [Accepted: 11/07/2013] [Indexed: 12/20/2022]
Abstract
Deficiency in N-linked protein glycosylation is a long-known characteristic of alcoholic liver disease and congenital disorders of glycosylation. Previous investigations of ethanol-induced glycosylation deficiency demonstrated perturbations in the early steps of substrate synthesis and in the final steps of capping N-linked glycans in the Golgi. The significance of the biosynthesis of N-glycan precursors in the endoplasmic reticulum, however, has not yet been addressed in alcoholic liver disease. Ethanol-metabolizing hepatoma cells were treated with increasing concentrations of ethanol. Transcript analysis of genes involved in the biosynthesis of N-glycans, activity assays of related enzymes, dolichol-phosphate quantification, and analysis of dolichol-linked oligosaccharides were performed. Upon treatment of cells with ethanol, we found a decrease in the final N-glycan precursor Dol-PP-GlcNAc(2) Man(9) Glc(3) and in C95- and C100-dolichol-phosphate levels. Transcript analysis of genes involved in N-glycosylation showed a 17% decrease in expression levels of DPM1, a subunit of the dolichol-phosphate-mannose synthase, and an 8% increase in RPN2, a subunit of the oligosaccharyl transferase. Ethanol treatment decreases the biosynthesis of dolichol-phosphate. Consequently, the formation of N-glycan precursors is affected, resulting in an aberrant precursor assembly. Messenger RNA levels of genes involved in N-glycan biosynthesis are slightly affected by ethanol treatment, indicating that the assembly of N-glycan precursors is not regulated at the transcriptional level. This study confirms that ethanol impairs N-linked glycosylation by affecting dolichol biosynthesis leading to impaired dolichol-linked oligosaccharide assembly. Together our data help to explain the underglycosylation phenotype observed in alcoholic liver disease and congenital disorders of glycosylation.
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Affiliation(s)
- Michael Welti
- Institute of Physiology, University of Zürich, Zürich, Switzerland
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Statins impair glucose uptake in tumor cells. Neoplasia 2012; 14:311-23. [PMID: 22577346 DOI: 10.1593/neo.12444] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2012] [Revised: 03/22/2012] [Accepted: 03/22/2012] [Indexed: 01/31/2023] Open
Abstract
Statins, HMG-CoA reductase inhibitors, are used in the prevention and treatment of cardiovascular diseases owing to their lipid-lowering effects. Previous studies revealed that, by modulating membrane cholesterol content, statins could induce conformational changes in cluster of differentiation 20 (CD20) tetraspanin. The aim of the presented study was to investigate the influence of statins on glucose transporter 1 (GLUT1)-mediated glucose uptake in tumor cells. We observed a significant concentration- and time-dependent decrease in glucose analogs' uptake in several tumor cell lines incubated with statins. This effect was reversible with restitution of cholesterol synthesis pathway with mevalonic acid as well as with supplementation of plasma membrane with exogenous cholesterol. Statins did not change overall GLUT1 expression at neither transcriptional nor protein levels. An exploratory clinical trial revealed that statin treatment decreased glucose uptake in peripheral blood leukocytes and lowered (18)F-fluorodeoxyglucose ((18)F-FDG) uptake by tumor masses in a mantle cell lymphoma patient. A bioinformatics analysis was used to predict the structure of human GLUT1 and to identify putative cholesterol-binding motifs in its juxtamembrane fragment. Altogether, the influence of statins on glucose uptake seems to be of clinical significance. By inhibiting (18)F-FDG uptake, statins can negatively affect the sensitivity of positron emission tomography, a diagnostic procedure frequently used in oncology.
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Welti M. Regulation of dolichol-linked glycosylation. Glycoconj J 2012; 30:51-6. [DOI: 10.1007/s10719-012-9417-y] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2012] [Revised: 06/06/2012] [Accepted: 06/11/2012] [Indexed: 11/28/2022]
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Guan Z, Eichler J. Liquid chromatography/tandem mass spectrometry of dolichols and polyprenols, lipid sugar carriers across evolution. Biochim Biophys Acta Mol Cell Biol Lipids 2011; 1811:800-6. [PMID: 21570481 DOI: 10.1016/j.bbalip.2011.04.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2010] [Revised: 04/12/2011] [Accepted: 04/24/2011] [Indexed: 10/18/2022]
Abstract
Across evolution, dolichols and polyprenols serve as sugar carriers in biosynthetic processes that include protein glycosylation and lipopolysaccharide biogenesis. Liquid chromatography coupled with electrospray ionization mass spectrometry offers a powerful tool for studying dolichols and polyprenols in their alcohol or glycan-modified forms in members of all three domains of life. In the following, recent examples of the how different versions of this analytical approach, namely reverse phase liquid chromatography-multiple reaction monitoring, normal phase liquid chromatography/tandem mass spectrometry and normal phase liquid chromatography-precursor ion scan detection have respectively served to address novel aspects of dolichol or polyprenol biology in Eukarya, Archaea and Bacteria.
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Affiliation(s)
- Ziqiang Guan
- Department of Biochemistry, Duke University Medical Center, Durham, NC 27710, USA.
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Abstract
Glycosylation is a complex form of protein modification occurring in the secretory pathway. The addition of N- and O-glycans affects intracellular processes like the folding and trafficking of most glycoproteins. To better understand the impact of glycosylation in protein folding and maturation, parameters like glycosylation site occupancy and oligosaccharide structure must be measured quantitatively. In this chapter, we describe current methods enabling the determination of N-glycosylation by assessment of cellular dolichol phosphate levels, dolichol-linked oligosaccharides, and the occupancy of N-glycosylation sites. We also provide detailed methods for the analysis of O-glycosylation, whose role in intracellular protein maturation is often overlooked.
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Affiliation(s)
- Andreas J Hülsmeier
- Institute of Physiology, University of Zürich, Winterthurerstrasse, Zürich, Switzerland
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Haeuptle MA, Welti M, Troxler H, Hülsmeier AJ, Imbach T, Hennet T. Improvement of dolichol-linked oligosaccharide biosynthesis by the squalene synthase inhibitor zaragozic acid. J Biol Chem 2010; 286:6085-91. [PMID: 21183681 DOI: 10.1074/jbc.m110.165795] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The majority of congenital disorders of glycosylation (CDG) are caused by defects of dolichol (Dol)-linked oligosaccharide assembly, which lead to under-occupancy of N-glycosylation sites. Most mutations encountered in CDG are hypomorphic, thus leaving residual activity to the affected biosynthetic enzymes. We hypothesized that increased cellular levels of Dol-linked substrates might compensate for the low biosynthetic activity and thereby improve the output of protein N-glycosylation in CDG. To this end, we investigated the potential of the squalene synthase inhibitor zaragozic acid A to redirect the flow of the polyisoprene pathway toward Dol by lowering cholesterol biosynthesis. The addition of zaragozic acid A to CDG fibroblasts with a Dol-P-Man synthase defect led to the formation of longer Dol-P species and to increased Dol-P-Man levels. This treatment was shown to decrease the pathologic accumulation of incomplete Dol pyrophosphate-GlcNAc(2)Man(5) in Dol-P-Man synthase-deficient fibroblasts. Zaragozic acid A treatment also decreased the amount of truncated protein N-linked oligosaccharides in these CDG fibroblasts. The increased cellular levels of Dol-P-Man and possibly the decreased cholesterol levels in zaragozic acid A-treated cells also led to increased availability of the glycosylphosphatidylinositol anchor as shown by the elevated cell-surface expression of the CD59 protein. This study shows that manipulation of the cellular Dol pool, as achieved by zaragozic acid A addition, may represent a valuable approach to improve N-linked glycosylation in CDG cells.
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Affiliation(s)
- Micha A Haeuptle
- Institute of Physiology, University of Zürich, CH-8057 Zürich, Switzerland
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Ellesat KS, Tollefsen KE, Åsberg A, Thomas KV, Hylland K. Cytotoxicity of atorvastatin and simvastatin on primary rainbow trout (Oncorhynchus mykiss) hepatocytes. Toxicol In Vitro 2010; 24:1610-8. [DOI: 10.1016/j.tiv.2010.06.006] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2009] [Revised: 06/07/2010] [Accepted: 06/11/2010] [Indexed: 12/24/2022]
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