| Abstract: | Of the total protein in an adult mouse brain, 35 per cent is water-soluble and 65 per cent water-insoluble. Using an extraction scheme of sequential treatment with water, Triton X-100, and sodium lauryl sulphate, it was possible to solubilize at least 90 per cent of this total in distinct groups. Qualitative analysis of the extracts was achieved by electro-phoresis in porosity gradient polyacrylamide gels. In this way, each fraction was resolved into 20-50 protein bands. This sequential extraction-fractionation procedure was employed in a study of the onto-genetic changes in mouse brain proteins. The most pronounced accumulation of protein and alteration of protein composition occurred during the first few weeks after birth. Beyond that period, both quantitative and qualitative changes were much less dramatic, except in the 1 % SLS fraction, which continued to increase in size throughout the mouse's lifespan. Whereas the aqueous-soluble proteins predominated during the very early stages of development, the detergent-soluble constituents accounted subsequently for a steadily increasing proportion of the total protein. |
