Sodium dodecyl sulfate-polyacrylamide design

Thanh and Shibasaki (10) proposed a trimeric structure for the 7S and a hexamerlc structure for the 9S dimer. Urea/sodium dodecyl sulfate polyacrylamide gel electrophoresis resolves the 7S globulin into six isomeric forms which are made up of three types of subunits (a, a and B) in varying proportions (10, 14, 15). The composition of the six isomeric proteins has been designated as follows B.., B, aB2> B, aa B B,, a B ... 

A great variety of methods have been designed to extract acidic proteins from the chromosomes. They are all rather drastic, and it is not certain whether they allow the functional properties of the acidic proteins to survive the procedure. In one method designed in Bonner s laboratory [77] chromatin is prepared and then extracted with acid to exclude histones. After histone extraction, the residue is treated with sodium dodecyl sulfate. The DNA sediments and the proteins are collected in the supernatant. Ammonium sulfate precipitates the proteins, which can then be submitted to polyacrylamide gel electrophoresis. The polyacrylamide gel electrophoresis of such a preparation yields a multiband pattern. The patterns are similar for acid proteins extracted from rat kidney and liver, but different for acid protein extracted from pea bud chromatin and rat liver chromatin. 

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