| 1. |
- Sedzik, Jan, et al.
(författare)
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High-Resolution Structural Model of Porcine P2 Myelin Membrane Protein With Associated Fatty Acid Ligand : Fact or Artifact?
- 2011
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Ingår i: Journal of Neuroscience Research. - : Wiley. - 0360-4012 .- 1097-4547. ; 89:6, s. 909-920
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Tidskriftsartikel (refereegranskat)abstract
- Myelin membrane is a biological complex of glial cells origin; it is composed of 25% (w/w) proteins and 75% lipids, and more than 300 proteins are associated with central nervous system myelin (for peripheral nervous system myelin, such data are lacking). Myelin plays an important role in maintaining propagation of nerve signals. To uncover the nature of propagation phenomena, it is essential to study biochemistry of myelin proteins and lipids, myelin composition, and myelin structure. Nearly all myelin proteins are like antigens, causing clinically well-defined devastating diseases; multiple sclerosis and Guillain-Barre syndrome are two of them. In this article, a high-resolution study (1.8 angstrom) of porcine myelin P2 protein is presented. Myelin was purified from porcine intradural spinal roots, which were stored at -80 degrees C for 10 years before myelin and P2 protein were purified (spinal roots were a gift of Prof. Kunio Kitamura, Saitama Medical School). The three-dimensional structural analysis uncovered embedded 18-carbons-long fatty acid. Some speculative interpretation is presented, to uncover how this ligand of fatty acid may form cholesterol ester and stabilize the myelin structure or form simple raft microdomain. Protein crystallography indicates that the ligand may be 18-carbons-long fatty acid. This is unlike previous work with mass spectrometry, in which three ligands were determined. In other protein crystallography-based studies of P2 (bovine), an oleic fatty acid was suggested, but, for recombinant (human) protein, palmitic acid was found. There is no fatty acid ligand in equine P2 protein.
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| 2. |
- Sedzik, Jan, et al.
(författare)
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Sequence motifs of myelin membrane proteins : Towards the molecular basis of diseases
- 2013
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Ingår i: Journal of Neuroscience Research. - : Wiley. - 0360-4012 .- 1097-4547. ; 91:4, s. 479-493
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Tidskriftsartikel (refereegranskat)abstract
- The shortest sequence of amino acids in protein containing functional and structural information is a motif. To understand myelin protein functions, we intensively searched for motifs that can be found in myelin proteins. Some myelin proteins had several different motifs or repetition of the same motif. The most abundant motif found among myelin proteins was a myristoylation motif. Bovine MAG held 11 myristoylation motifs and human myelin basic protein held as many as eight such motifs. PMP22 had the fewest myristoylation motifs, which was only one; rat PMP22 contained no such motifs. Cholesterol recognition/interaction amino-acid consensus (CRAC) motif was not found in myelin basic protein. P2 protein of different species contained only one CRAC motif, except for P2 of horse, which had no such motifs. MAG, MOG, and P0 were very rich in CRAC, three to eight motifs per protein. The analysis of motifs in myelin proteins is expected to provide structural insight and refinement of predicted 3D models for which structures are as yet unknown. Analysis of motifs in mutant proteins associated with neurological diseases uncovered that some motifs disappeared in P0 with mutation found in neurological diseases. There are 2,500 motifs deposited in a databank, but 21 were found in myelin proteins, which is only 1% of the total known motifs. There was great variability in the number of motifs among proteins from different species. The appearance or disappearance of protein motifs after gaining point mutation in the protein related to neurological diseases was very interesting.
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| 3. |
- Maddalo, Gianluca, et al.
(författare)
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Porcine P2 myelin protein primary structure and bound fatty acids determined by mass spectrometry
- 2010
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Ingår i: Analytical and Bioanalytical Chemistry. - : Springer Science and Business Media LLC. - 1618-2642 .- 1618-2650. ; 397:5, s. 1903-1910
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Tidskriftsartikel (refereegranskat)abstract
- Complementary collision-induced/electron capture dissociation Fourier-transform ion cyclotron resonance mass spectrometry was used to fully sequence the protein P2 myelin basic protein. It is an antigenic fatty-acid-binding protein that can induce experimental autoimmune neuritis: an animal model of Guillain-Barre syndrome, a disorder similar in etiology to multiple sclerosis. Neither the primary structure of the porcine variant, nor the fatty acids bound by the protein have been well established to date. A 1.8-angstrom crystal structure shows but a bound ligand could not be unequivocally identified. A protocol for ligand extraction from protein crystals has been developed with subsequent gas chromatography MS analysis allowing determination that oleic, stearic, and palmitic fatty acids are associated with the protein. The results provide unique and general evidence of the utility of mass spectrometry for characterizing proteins from natural sources and generating biochemical information that may facilitate attempts to elucidate the causes for disorders such as demyelination.
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| 4. |
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| 5. |
- Sedzik, Jan, et al.
(författare)
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GLYCOMIX-P0 PROTEIN AND ITS GLYCANS
- 2010
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Ingår i: Journal of Neurochemistry. - 0022-3042 .- 1471-4159. ; 115, s. 25-25
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 6. |
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