Figure 4-11. Polyacrylamide gel electrophoresis of myelin proteins in the presence of sodium dodecyl sulfate (SDS).

Figure 4-11

Polyacrylamide gel electrophoresis of myelin proteins in the presence of sodium dodecyl sulfate (SDS). The proteins of A: human PNS myelin, B: human CNS myelin, C: rat PNS myelin and D: rat CNS myelin were solubilized with the detergent SDS, electrophoresed and stained with Coomassie brilliant blue. The electrophoretic system separates proteins primarily according to their molecular size, with the smallest proteins migrating the farthest toward the bottom of the gel. The three myelin basic protein (MBP) bands in lanes A and B are the 17.2-, 18.5- and 21.5-kDa isoforms generated by alternative splicing of the mRNA in humans, and the four MBP bands in lanes C and D are the 14.0-, 17.0-, 18.5- and 21.5-kDa isoforms generated in rats (see Fig. 4-12). The 18.5-kDa MBP also is called P1 in the terminology for the PNS. The 26-kDa myelin-oligodendrocyte glycoprotein (MOG) is probably the faint band just above proteolipid protein (PLP), which is most apparent in lane D. 2′:3′-Cyclic nucleotide-3′-phosphodiesterase (CNPase) electrophoresis is a tight doublet, and the lower and upper bands are sometimes referred to as CNP1 and CNP2, respectively. T, tubulin; PMP-22, peripheral-myelin-protein-22. Note that the location shown for myelin-associated glycoprotein (MAG), which stains too faintly to be seen well on the gels, is just above a discrete Coomassie blue-stained band in lane D, which is probably the 96-kDa subunit of Na+, K+-ATPase. The 170-kDa glycoprotein in PNS myelin is labeled both as 170KG and SAG for the name of Schwann cell membrane glycoprotein (see text).

From: Characteristic Composition of Myelin

Cover of Basic Neurochemistry
Basic Neurochemistry: Molecular, Cellular and Medical Aspects. 6th edition.
Siegel GJ, Agranoff BW, Albers RW, et al., editors.
Philadelphia: Lippincott-Raven; 1999.
Copyright © 1999, American Society for Neurochemistry.

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