The protein composition of myelin in multiple sclerosis (MS) and orthochromatic leukodystrophy (OLD).

Abstract

In 4 cases of MS, in which the progression of disease differed, and in one case of infantile OLD the proteins of a homogenate and a myelin fraction with and without plaques were separated electrophoretically with polyacrylamide gels in a buffer system of phenol/formic acid/water. The relation of proteolipid protein to basic protein was estimated planimetrically and compared with control cases. In myelin from plaque material of chronic running MS cases an average decrease of 41% in basic protein was observed, while in an acute progressing case no obvious alterations could be discerned. Myelin from apparently normal MS white matter showed an average decrease of 13% in basic protein. The results of the OLD case were similar to those obtained from the chronic MS cases. The decrease of basic protein (chronic MS, OLD) was markedly more in the homogenate fraction than in the purified myelin. In a control case with autolytic alterations (autopsy after 24 hours) the content of basic protein was also diminished. Our findings indicate that the reduction of basic protein in myelin is a non-specific effect in demyelinating diseases.