Nerve myelin

The liquid crystalline state may be identified as a distinct and unique state of matter which is characterised by properties which resemble those of both solids and liquids. It was first recognised in the middle of the last century through the study of nerve myelin and derivatives of cholesterol. The research in the area really gathered momentum, however, when as a result of the pioneering work of Gray in the early 1970 s organic compounds exhibiting liquid crystalline properties were shown to be suitable to form the basis of display devices in the electronic products. 

Erne, B., Sansano, S., Frank, M. et al. Rafts in adult peripheral nerve myelin contain major structural myelin proteins and myelin and lymphocyte protein (MAL) and CD59 as specific markers. /. Neurochem. 82, 550-562, 2002. 

Filbin, M. T., D Urso, D., Zhang, K., Wong, M., Doyle, J. P. and Colman, D. R. Protein zero of peripheral nerve myelin adhesion properties and functional models. Adv. Mol. Cell. Biol. 16 159-192,1996. 

Shapiro, L., Doyle, J. P., Hensley, P., Colman, D. R. and Hendrickson, W. A. Crystal structure of the extracellular domain from P0, the major structural protein of peripheral nerve myelin. Neuron 17 435-449,1996. 

Deficiencies of peripheral nerve myelin in common inherited human neuropathies are caused by mutations of genes for sheath proteins 648... 

M., Nelles, E., Willecke, K., Zielasek, J., et al. (1997) Structural abnormalities and deficient maintenance of peripheral nerve myelin in mice lacking the gap junction protein connexin 32. J Neurosci 17, 4545-4551. 

Peripheral neuropathy occurs in about 16% of patients with MGUS, being particularly common in those with an IgM monoclonal gammopathy [128], The IgM fraction of such patients includes antibodies to myelin-associated glycoprotein (MAG antibodies) that bind to determinants in peripheral nerve myelin, and, as shown by animal models, the antibodies mediate the myelin injury and secondary nerve damage [129]. The patients usually have a distal symmetric neuropathy, usually with predominant sensory affection, and the neurological symptoms frequently precede the detection of gammopathy [130]. 

Willem M, Garratt AN, Novak B, Citron M, Kauftnann S, et al. 2006. Control of peripheral nerve myelination by the beta-secretase BACE1. Science 314 664-666. 

Worthington, C. R. and Blaurock, A. E. (1969). A low-angle x-ray diffraction study of the swelling behavior of peripheral nerve myelin. Biochim. Biophys. Acta 173 427. 

Even though some plasma membranes, such as nerve myelin membranes, contain a high concentration of lipids that form gel phase bilayers, the presence of cholesterol keeps these membranes in a fluid phase. However, interaction with the rigid cholesterol ring affects hydrocarbon chains of lipids in the liquid crystal phase (L ) and leads to formation of a new phase, the liquid ordered (Lq) phase (27). The phase is well characterized by a variety of physical methods and does not exist in pure lipids or their mixtures. In the liquid ordered phase, the long axis rotation and lateral diffusion rates are similar to the La phase, but the acyl chains are predominantly in an all-trans conformation and, hence, the order parameters are similar to the Lp phase (see Table 1). Recently, the cholesterol-rich Lq phase has been strongly associated with microdomains in live cells—the so-called lipid rafts. ... 

Ogawa-Goto K, Funamoto N, Ohta Y, Abe T, Nagashima K (1992) Myelin gangliosides of human peripheral nervous system An enrichment of GMl in the motor nerve myelin isolated from cauda equina. J Neurochem 59 1844—1849. 

Zhu J, Mix E, Olsson T, Link H (1994) Cellular messenger-Rna expression of interferon-gamma, 11-4 and transforming growth-factor-beta (Tgf-Beta) by rat mononuclear-cells stimulated with peripheral-nerve myelin antigens in experimental allergic neuritis. Clin Exp Immunol 98 306—312. 

Sivron T, Schwab ME, Schwartz M (1994) Presence of growth inhibitors in fish optic nerve myelin Postinjury changes. J Comp Neurol 343 237-246. 

On the above view, NLSD is primarily a disease of defective phospholipid metabohsm and the TAG-derived route of phospholipid biosynthesis is essential for the normal functioning of skin, muscle, liver, and the central nervous system. Further studies on the fatty hver dystrophic mouse which bears a close resemblance to human NLSD [103] may identify fhe defective gene. Defective neutral phospholipid metabolism in this mouse model is reflected by a decreased phosphohpid content of peripheral nerve myelin [109]. The nature of the hpase(s) involved in normal TAG-to-phospholipid acyltransfer has not been characterized, but may be similar to a previously described microsomal neutral hpase [110] or to a carboxylesterase [111]. 

Van den Berg LH, Sadiq SA, Thomas FP, et al. Gharacterization of HNK-1 bearing glycoproteins in human peripheral nerve myelin. / Neurosci Res. 1990 25 295-299. 

Hammer JA, O Shannessy DJ, DeLeon M, et al. Immunoreac-tivity of PMP22, PO, and other 19 to 28 kD glycoproteins in peripheral nerve myelin of mammals and fish with HNK-1 and related antibodies. / Neurosci Res. 1993 35 546-558. 

V7. Vlassara, H., Brownlee, M., and Cerami, A., Accumulation of diabetic rat peripheral nerve myelin by macrophages increases with the presence of advanced glycosylation end products. /. Exp. Med. 160, 197-207 (1984). 

The results of JT-ray diffraction studies on frog sciatic nerve myelin have indicated that the major glycoprotein is inserted into the extracellular half of the myelin bilayer and that it extends into the extracellular space. Various glycopeptides containing L-fucose and 2-acetamido-2-deoxy-D-glucose, but no neuraminic acid, have been isolated from garfish olfactory nerve. ... 

J. C. Nelander and A. E. Blaurock, Disorder in Nerve Myelin Phasing the Higher Order Reflections by Means of the Diffuse Scatter, J. Mol. Biol. 118, 497-532 (1978). 

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