The Isolation and Characterization of an Acid-Soluble Protein From Myelin

Abstract

Myelin was isolated from central white matter of beef and human brains. I t contained less than 8.1% ribonucleic acid, l e a than 8.63% deoxyribonucleic acid, and w s g l p l i p i d N-acetylneunminic acid. The preparation was 96% soluble in chioroform-methanol. Most of the insoluble materrai was sucrose. The myelin contained 19.6Y0 protein, 13.4y0 cholesterol, 86.1y0 phospholipid, and 23.6% galactslipid. A protein extracted from the rnyelin reparation with cold 0.2 N sulfuric acid gave a single sedimenting boundary in g e Spinco model E analytical ultracentrifuge. In 8 M ura-formate starch gels (pH 8.4) it migrated as a single band toward the cathode. Amino acid analysis revealed that the protein contained more than Z8Y0 dibasic amino acids, but little methisnine and no cystine. I t was rapidly hydrolyzed by trypsin. The molecular weight was estimated at 10,8W, When injected intradermally into guinea pigs, in suspension in Freund" adjuvant, it caused weight lms, a flaccid paralysis, occasional convulsions, and death, n pattern characteristic of experimental allergic encephalomyelitis. Evidence is cited for the presence of a t least one other protein in purified rnyelin.

Relationships between Antibodies and Experimental Allergic Encephalomyelitis

“…Since electrophoretic technics had revealed the encephalitogen to be highly cationic regardless of species source [10,11,14,15,IB,[23][24][25][26][27][29][30][31][32][33]35,[37][38][39][44][45][46][47]49 52,55,59], an attempt was made to separate the species-specific and organ-specific components by adsorption of the former onto DEAE-cellulose. Encephalitogenicity and skin tests for delayed hypersensitivity after injection of the frac- tions in Freund's complete adjuvants were first used to evaluate the effectiveness of the separation.…”

Endogenous phosphorylation of basic protein in myelin of varying degrees of compaction

“…The samples were centrifuged at 9000g for 15 min and the pellets resuspended in 0.2 N H2S04. Basic protein was extracted by stirring the suspension overnight at 4 OC (Lowden et al, 1966). The acid-soluble fraction was obtained by centrifuging the suspension at lOOOOg for 1 h and then dialyzing the soluble fraction extensively against H 2 0 .…”

Studies on chemically modified forms of the myelin basic protein: Requirements for encephalitogenicity

“…The basic protein was isolated from the myelin fraction of normal human white matter by the method of Lowden et al [6]. A sample of the bovine basic protein (A1) was kindly provided by Dr E. H. Eylar (Playfair Neurosciences Unit, 1 Spadina Crescent, Toronto) and the gastric inhibitory peptide [5] was a gift from Dr J, C. Brown (Dept.…”