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Träger J, Widder K, Kerth A, Harauz G, Hinderberger D. Effect of Cholesterol and Myelin Basic Protein (MBP) Content on Lipid Monolayers Mimicking the Cytoplasmic Membrane of Myelin. Cells 2020; 9:cells9030529. [PMID: 32106542 PMCID: PMC7140459 DOI: 10.3390/cells9030529] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2020] [Revised: 02/16/2020] [Accepted: 02/20/2020] [Indexed: 12/17/2022] Open
Abstract
Myelin basic protein (MBP) is located in the insulating covers of nerve cells in the brain and spinal cord. By interacting with lipid membranes, it is responsible for compaction of the myelin sheath in the central nervous system, which is weakened in demyelinating diseases. The lipid composition of the myelin leaflet has a high impact on the interaction between the membrane and MBP. Cholesterol is present in the cytoplasmic leaflet with a rather high amount of 44% (mol%). In this study, the focus is on the effect of cholesterol, mainly by varying its content, on the interaction of MBP with a lipid monolayer. Therefore, Langmuir lipid monolayers mimicking the cytoplasmic membrane of myelin and monolayers with variations of cholesterol content between 0% and 100% were measured at the air/water interface with additional imaging by fluorescence microscopy. All experiments were performed with and without bovine MBP to study the dependence of the interaction of the protein with the monolayers on the cholesterol content. The native amount of 44% cholesterol in the monolayer combines optima in the order of the monolayer (presumably correlating to compaction and thermodynamic stability) and protein interaction and shows unique features in comparison to lower or higher cholesterol contents.
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Affiliation(s)
- Jennica Träger
- Institut für Chemie, Martin-Luther-Universität Halle-Wittenberg, Von-Danckelmann-Platz 4, 06120 Halle (Saale), Germany; (J.T.); (K.W.); (A.K.)
- Interdisciplinary Research Center HALOmem at the Martin-Luther-Universität Halle-Wittenberg, 06120 Halle (Saale), Germany
| | - Katharina Widder
- Institut für Chemie, Martin-Luther-Universität Halle-Wittenberg, Von-Danckelmann-Platz 4, 06120 Halle (Saale), Germany; (J.T.); (K.W.); (A.K.)
- Interdisciplinary Research Center HALOmem at the Martin-Luther-Universität Halle-Wittenberg, 06120 Halle (Saale), Germany
| | - Andreas Kerth
- Institut für Chemie, Martin-Luther-Universität Halle-Wittenberg, Von-Danckelmann-Platz 4, 06120 Halle (Saale), Germany; (J.T.); (K.W.); (A.K.)
- Interdisciplinary Research Center HALOmem at the Martin-Luther-Universität Halle-Wittenberg, 06120 Halle (Saale), Germany
| | - George Harauz
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON N1G 2W1, Canada;
| | - Dariush Hinderberger
- Institut für Chemie, Martin-Luther-Universität Halle-Wittenberg, Von-Danckelmann-Platz 4, 06120 Halle (Saale), Germany; (J.T.); (K.W.); (A.K.)
- Interdisciplinary Research Center HALOmem at the Martin-Luther-Universität Halle-Wittenberg, 06120 Halle (Saale), Germany
- Correspondence: ; Tel.: +49-345-55-25230
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Lei Z, Runguang S, Changchun H, Huihui Y, Chengxi H. Thermodynamic Analysis of Myelin Basic Protein Adsorbed on Liquid Crystalline Dioleoylphosphatidylcholine Monolayer. SCANNING 2019; 2019:8175413. [PMID: 31819781 PMCID: PMC6885183 DOI: 10.1155/2019/8175413] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Revised: 07/15/2019] [Accepted: 08/13/2019] [Indexed: 06/10/2023]
Abstract
To investigate the stability and dynamic characteristics of monolayer adsorbed on unsaturated lipid dioleoylphosphatidylcholine (DOPC) with varying concentrations of myelin basic protein (MBP), the system is studied by applying Langmuir technique and making atomic force microscope (AFM) observation, which is based on the mass conservation equation analysis method referred to in the thermodynamics theory. As indicated by surface pressure-mean molecular area (π - A) and surface pressure-adsorption time (π - T) isotherms, the physical properties of monolayer derived from the interaction of varying concentrations of MBP with liquid crystalline unsaturated lipid DOPC molecules were qualitatively studied. As revealed by surface morphology analysis with AFM, the micro region was expanded as the concentration of MBP in the subphase was on the increase, suggesting that hydrophobic interactions led to the MBP insertion, thus causing accumulation of the MBP on the surface of the monolayer. Experimental results have demonstrated that the partition coefficient of the interaction between MBP and unsaturated phospholipid DOPC and the molecular area of MBP adsorbed on the monolayer film was calculated using the mass conservation equation. In addition, not only does the varying concentration of MBP in the subphase exerts significant effects on the arrangement and conformation of DOPC monolayer, it also has certain guiding significance to exploring the structural changes to biofilm supramolecular aggregates as well as the pathogenesis and treatment of related diseases.
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Affiliation(s)
- Zhang Lei
- Department of Experimental Teaching Center for Optoelectronic Science and Information Engineering, Xi'an Aeronautical University, Xi'an, 710077 Shaanxi, China
| | - Sun Runguang
- Schools of Physics and Information Technology, Shaanxi Normal University, Xi'an, 710119 Shaanxi, China
| | - Hao Changchun
- Schools of Physics and Information Technology, Shaanxi Normal University, Xi'an, 710119 Shaanxi, China
| | - Yang Huihui
- Department of Experimental Teaching Center for Optoelectronic Science and Information Engineering, Xi'an Aeronautical University, Xi'an, 710077 Shaanxi, China
| | - Hu Chengxi
- Department of Experimental Teaching Center for Optoelectronic Science and Information Engineering, Xi'an Aeronautical University, Xi'an, 710077 Shaanxi, China
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Widder K, Träger J, Kerth A, Harauz G, Hinderberger D. Interaction of Myelin Basic Protein with Myelin-like Lipid Monolayers at Air-Water Interface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:6095-6108. [PMID: 29722987 DOI: 10.1021/acs.langmuir.8b00321] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Interaction of myelin basic protein (MBP) and the cytoplasmic leaflets of the oligodendrocyte membrane is essential for the formation and compaction of the myelin sheath of the central nervous system and is altered aberrantly and implicated in the pathogenesis of neurodegenerative diseases like multiple sclerosis. To gain more detailed insights into this interaction, the adsorption of MBP to model lipid monolayers of similar composition to the myelin of the central nervous system was studied at the air-water interface with monolayer adsorption experiments. Measuring the surface pressure and the related maximum insertion pressure of MBP for different myelin-like lipid monolayers provided information about the specific role of each of the single lipids in the myelin. Depending on the ratio of negatively charged lipids to uncharged lipids and the distance between charges, the adsorption process was found to be determined by two counteracting effects: (i) protein incorporation, resulting in an increasing surface pressure and (ii) lipid condensation due to electrostatic interaction between the positively charged protein and negatively charged lipids, resulting in a decreasing surface pressure. Although electrostatic interactions led to high insertion pressures, the associated lipid condensation lowered the fluidity of the myelin-like monolayer.
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Affiliation(s)
- Katharina Widder
- Institut für Chemie , Martin-Luther-Universität Halle-Wittenberg , Von-Danckelmann-Platz 4 , 06120 Halle (Saale) , Germany
| | - Jennica Träger
- Institut für Chemie , Martin-Luther-Universität Halle-Wittenberg , Von-Danckelmann-Platz 4 , 06120 Halle (Saale) , Germany
| | - Andreas Kerth
- Institut für Chemie , Martin-Luther-Universität Halle-Wittenberg , Von-Danckelmann-Platz 4 , 06120 Halle (Saale) , Germany
| | - George Harauz
- Department of Molecular and Cellular Biology , University of Guelph , 50 Stone Road East , Guelph , Ontario , Canada N1G 2W1
| | - Dariush Hinderberger
- Institut für Chemie , Martin-Luther-Universität Halle-Wittenberg , Von-Danckelmann-Platz 4 , 06120 Halle (Saale) , Germany
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A thermodynamic analysis of the effects of myelin basic protein (MBP) on DPPS and DPPG monolayers. Colloids Surf A Physicochem Eng Asp 2016. [DOI: 10.1016/j.colsurfa.2016.10.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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Oguz KK, Kurne A, Aksu AO, Karabulut E, Serdaroglu A, Teber S, Haspolat S, Senbil N, Kurul S, Anlar B. Assessment of citrullinated myelin by 1H-MR spectroscopy in early-onset multiple sclerosis. AJNR Am J Neuroradiol 2009; 30:716-21. [PMID: 19147724 DOI: 10.3174/ajnr.a1425] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Myelin instability and citrullinated myelin basic protein have been demonstrated in the brains of patients with chronic and fulminating forms of multiple sclerosis (MS). Our aim was to trace citrulline in the brains of patients with early-onset MS by using proton MR spectroscopy ((1)H-MR spectroscopy). MATERIALS AND METHODS A short-echo single-voxel (1)H-MR spectroscopy by using the point-resolved proton spectroscopy sequence was performed in 27 patients with MS and 23 healthy subjects. Voxels of interest were chronic demyelinating lesions (CDLs, n = 25) and normal-appearing white matter (NAWM, n = 25) on T2-weighted imaging, and when available in patients with MS, enhancing demyelinating lesions (EDLs, n = 8). Frontal white matter (WM) was studied in control subjects. N-acetylaspartate, choline, and myo-inositol (mIns)-creatine (Cr) ratios and the presence of a citrulline peak were noted. RESULTS Citrulline peaks were more frequently observed in patients with MS than in control subjects (P = .035), located in the NAWM in 8/25 (32%), in CDLs in 7/25 (28%), and in EDLs of 1/8 (12.5%) patients with MS. The presence of citrulline and measured metabolite/Cr ratios was not related to age at imaging, age at disease onset, duration of disease, or number of relapses. There was no significant metabolic difference between the NAWM of patients with MS and the WM of the control subjects. mIns/Cr was significantly greater in CDLs compared with the NAWM of patients with MS and the WM of healthy subjects. CONCLUSIONS Citrulline was more frequently identified in the brains of patients with early-onset MS than in healthy subjects by (1)H-MR spectroscopy, suggesting an association of increased citrullination of myelin proteins with demyelinating diseases.
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Affiliation(s)
- K K Oguz
- Department of Radiology, Hacettepe University, Ankara, Turkey.
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Post-transcriptional regulation of myelin formation. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2008; 1779:486-94. [PMID: 18590840 DOI: 10.1016/j.bbagrm.2008.06.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2008] [Revised: 05/15/2008] [Accepted: 06/03/2008] [Indexed: 12/21/2022]
Abstract
Myelin is a specialized structure of the nervous system that both enhances electrical conductance and protects neurons from degeneration. In the central nervous system, extensively polarized oligodendrocytes form myelin by wrapping cellular processes in a spiral pattern around neuronal axons. Myelin formation requires the oligodendrocyte to regulate gene expression in response to changes in its extracellular environment. Because these changes occur at a distance from the cell body, post-transcriptional control of gene expression allows the cell to fine-tune its response. Here, we review the RNA-binding proteins that control myelin formation in the brain, highlighting the molecular mechanisms by which they control gene expression and drawing parallels from studies in other cell types.
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Liu G, Chen Y, Zhang G, Yang S. Protein resistance of (ethylene oxide)n monolayers at the air/water interface: effects of packing density and chain length. Phys Chem Chem Phys 2007; 9:6073-82. [PMID: 18167582 DOI: 10.1039/b711037e] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Protein adsorption on poly(ethylene oxide) (PEO) and oligo(ethylene oxide) (OEO) monolayers is studied at different packing densities using the Langmuir technique. In the case of a PEO monolayer, a protein adsorption minimum is revealed at sigma(-1) = 10 nm(2) for both lysozyme and fibrinogen. Manifested are two packing density regimes of steric repulsion and compressive attraction between PEO and a protein on top of the overall attraction of the protein to the air/water interface. The observed protein adsorption minimum coincides with the maximum of the surface segment density at sigma(-1) = 10 nm(2). However, OEO monolayer presents a different scenario, namely that the amount of protein adsorbed decreases monotonically with increasing packing density, indicating that the OEO chains merely act as a steric barrier to protein adsorption onto the air/water interface. Besides, in the adsorption of fibrinogen, three distinct kinetic regimes controlled by diffusion, penetration and rearrangement are recognized, whereas only the latter two were made out in the adsorption of lysozyme.
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Affiliation(s)
- Guangming Liu
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
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Hu Y, Israelachvili J. Lateral reorganization of myelin lipid domains by myelin basic protein studied at the air-water interface. Colloids Surf B Biointerfaces 2007; 62:22-30. [PMID: 17997288 DOI: 10.1016/j.colsurfb.2007.09.028] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2006] [Revised: 09/10/2007] [Accepted: 09/10/2007] [Indexed: 01/01/2023]
Abstract
It has been speculated that adsorption of myelin basic protein (MBP) to the myelin lipid membrane leads to lateral reorganization of the lipid molecules within the myelin membrane. This hypothesis was tested in this study by surface pressure measurement and fluorescent imaging of a monolayer composed of a myelin lipid mixture. The properties of the lipid monolayer before and after addition of MBP into the subphase were monitored. Upon addition of MBP to the monolayer subphase, the surface pressure rose and significant rearrangement of the lipid domains was observed. These results suggest that binding and partial insertion of MBP into the lipid monolayer led to dramatic rearrangement and morphological changes of the lipid domains. A model of adsorption of MBP to the lipid domains and subsequent domain fusion promoted by minimization of electrostatic repulsion between the domains was proposed to account for the experimental observations. The significance of these results in light of the role of MBP in maintaining the myelin structural integrity is discussed.
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Affiliation(s)
- Yufang Hu
- Department of Molecular and Medical Pharmacology and Department of Urology, David Geffen School of Medicine at UCLA, University of California-Los Angeles, Los Angeles, CA 90095, USA.
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Cristofolini L, Berzina T, Erokhina S, Konovalov O, Erokhin V. Structural study of the DNA dipalmitoylphosphatidylcholine complex at the air-water interface. Biomacromolecules 2007; 8:2270-5. [PMID: 17539597 DOI: 10.1021/bm070322w] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We present here results that demonstrate the formation of a complex of DNA with zwitterionic dipalmitoylphosphatidylcholine (DPPC) monolayer at the air-water interface in the presence of Ca2+ ions; in particular, we show that the presence of Ca2+ cations is essential for the formation of the complex of DPPC with DNA. We characterize the resulting structure by X-ray reflectivity and by null-ellipsometry. We show that DNA maintains its native double helix form when attached to the zwitterionic lipid monolayer, at difference with the case of ammine containing monolayers. Our findings are discussed in view of other works that recently appeared on the interaction of DNA with zwitterionic phospholipids, emphasizing the role of DPPC as a potential vector for transfer of genetic material into mammalian cells by nonviral gene therapy and also suggesting Langmuir/Blodgett layers of zwitterionic phospoholipids as a method for nonconventional DNA immobilization.
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Affiliation(s)
- Luigi Cristofolini
- Department of Physics, University of Parma, Viale Usberti 7 A, Parma, Italy.
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Rispoli P, Carzino R, Svaldo-Lanero T, Relini A, Cavalleri O, Fasano A, Liuzzi GM, Carlone G, Riccio P, Gliozzi A, Rolandi R. A thermodynamic and structural study of myelin basic protein in lipid membrane models. Biophys J 2007; 93:1999-2010. [PMID: 17513373 PMCID: PMC1959534 DOI: 10.1529/biophysj.106.103820] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Myelin basic protein (MBP) is a major protein of the myelin membrane in the central nervous system. It is believed to play a relevant role in the structure and function of the myelin sheath and is a candidate autoantigen in demyelinating processes such as multiple sclerosis. MBP has many features typical of soluble proteins but is capable of strongly interacting with lipids, probably via a conformation change. Its structure in the lipid membrane as well as the details of its interaction with the lipid membrane are still to be resolved. In this article we study the interaction of MBP with Langmuir films of anionic and neutral phospholipids, used as experimental models of the lipid membrane. By analyzing the equilibrium surface pressure/area isotherms of these films, we measured the protein partition coefficient between the aqueous solution and the lipid membrane, the mixing ratio between protein and lipid, and the area of the protein molecules inserted in the lipid film. The penetration depth of MBP in the lipid monolayer was evaluated by x-ray reflectivity measurements. The mixing ratio and the MBP molecular area decrease as the surface pressure increases, and at high surface pressure the protein is preferentially located at the lipid/water interface for both anionic and neutral lipids. The morphology of MBP adsorbed on lipid films was studied by atomic force microscopy. MBP forms bean-like structures and induces a lateral compaction of the lipid surface. Scattered MBP particles have also been observed. These particles, which are 2.35-nm high, 4.7-nm wide, and 13.3-nm long, could be formed by protein-lipid complexes. On the basis of their size, they could also be either single MBP molecules or pairs of c-shaped interpenetrating molecules.
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Affiliation(s)
- P Rispoli
- Department of Physics, University of Genoa, 16146 Genova, Italy
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Musse AA, Harauz G. Molecular "negativity" may underlie multiple sclerosis: role of the myelin basic protein family in the pathogenesis of MS. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2007; 79:149-72. [PMID: 17531841 DOI: 10.1016/s0074-7742(07)79007-4] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Myelin basic protein (MBP) binds to negatively charged lipids on the cytosolic surface of oligodendrocyte membranes and is responsible for adhesion of these surfaces in the multilayered myelin sheath. The pattern of extensive posttranslational modifications of MBP is dynamic during normal central nervous system development and during myelin degeneration in multiple sclerosis (MS), affecting its interactions with the myelin membranes and other proteins. In particular, the degree of deimination (or citrullination) of MBP is correlated with the severity of MS, and may represent a primary defect that precedes neurodegeneration due to autoimmune attack. That MBP deimination also affects topological accessibility of an otherwise partially buried immunodominant epitope of the protein indicates that this modification may play a major role in the autoimmune pathogenesis of the disease. In this chapter, we describe the structural and functional consequences of MBP deimination in healthy and diseased myelin.
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Affiliation(s)
- Abdiwahab A Musse
- Department of Molecular and Cellular Biology, Biophysics Interdepartmental Group, University of Guelph, Ontario N1G 2W1, Canada
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Moscarello MA, Mastronardi FG, Wood DD. The role of citrullinated proteins suggests a novel mechanism in the pathogenesis of multiple sclerosis. Neurochem Res 2006; 32:251-6. [PMID: 17031564 PMCID: PMC1794624 DOI: 10.1007/s11064-006-9144-5] [Citation(s) in RCA: 189] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2006] [Accepted: 08/18/2006] [Indexed: 12/03/2022]
Abstract
The pathogenesis of MS is unknown. In our studies, we have demonstrated an important role for citrullinated myelin basic protein (MBP). The accompanying loss of positive charge compromises the ability of MBP to interact with the lipid bilayer. The conversion of arginine to citrulline in brain is carried out by an enzyme peptidyl arginine deiminase (PAD) 2. The amount of PAD 2 in brain was increased in MS normal-appearing white matter. The mechanism responsible for this increase involved hypomethylation of the promoter region in the PAD 2 gene in MS, but no change (compared to normal) was found in thymus tissue DNA from the same MS patients. In addition, no change was observed in other neurological diseases, including Alzheimer’s, Parkinson’s, and Huntington’s. We propose that citrullinated MBP, resulting from elevated levels of PAD 2 represents an important biochemical pathway in the pathogenesis of MS.
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Affiliation(s)
- Mario A Moscarello
- Department of Structural Biology and Biochemistry, Hospital for Sick Children, 555 University Avenue, M5G 1X8, Toronto, ON, Canada.
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Harauz G, Musse AA. A Tale of Two Citrullines—Structural and Functional Aspects of Myelin Basic Protein Deimination in Health and Disease. Neurochem Res 2006; 32:137-58. [PMID: 16900293 DOI: 10.1007/s11064-006-9108-9] [Citation(s) in RCA: 103] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/28/2006] [Indexed: 02/03/2023]
Abstract
Myelin basic protein (MBP) binds to negatively charged lipids on the cytosolic surface of oligodendrocyte membranes and is responsible for adhesion of these surfaces in the multilayered myelin sheath. The pattern of extensive post-translational modifications of MBP is dynamic during normal central nervous system (CNS) development and during myelin degeneration in multiple sclerosis (MS), affecting its interactions with the myelin membranes and with other molecules. In particular, the degree of deimination (or citrullination) of MBP is correlated with the severity of MS, and may represent a primary defect that precedes neurodegeneration due to autoimmune attack. That the degree of MBP deimination is also high in early CNS development indicates that this modification plays major physiological roles in myelin assembly. In this review, we describe the structural and functional consequences of MBP deimination in healthy and diseased myelin.
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Affiliation(s)
- George Harauz
- Department of Molecular and Cellular Biology, and Biophysics Interdepartmental Group, University of Guelph, 50 Stone Road East, Guelph, ON, Canada, N1G 2W1.
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