| Abstrakt: |
A modified method is described of the isolation of neuro-specific S-100 protein from bovine brain tissue by means of thermal denaturation, ammonium sulphate fractionation, chromatography on DEAE-Sephadex A-50 and gel filtration through Sephadex G-100. Considerable heterogeneity of S-100 protein is discovered: it produces 4 fractions (f1--f4) under fractionation on DEAE-Sephadex A-50. The constant elution from the column of the main fraction, eluted with 0.325--0.35 M NaCl, and minor S-100 protein fractions, eluted with more high NaCl concentrations, is registered. At the same time, considerable variation in the quantitative yield of the main component of S-100 protein and in the relative content of main and minor components of S-100 protein is developed. Fast- (in f1 and f4 fractions) and slow-migrating (in f2 and f3 fractions) components are revealed under polyacrylamide gel electrophoresis. The f1 fraction is found to consist mainly of the component with molecular weight of 20 000 while fz, f3 and f4 fractions contain two components having molecular weight of 32 000 and 71 000. Antiserum to S-100 protein produced a positive immunodiffusion reaction with f1 and f2, and not with f3 and f4 fractions. |
