ZONE ELECTROPHORESIS OF CALF THYMUS HISTONE IN STARCH GEL

Abstract

A total of 19 zones were detected by starch gel electrophoresis of calf thymus histone in buffers of 0.02 μ below pH 5.0. Of these, 18 were evident at pH 4.9 (acetate) and 15 at pH 3.9 (formate). Above pH 5.0, aggregation interfered with resolution, but by adding 4 M urea to the gel sufficient resolution was obtained between pH 4.4 and 8.7 to distinguish a total of 22 zones. Of this total, three fast components were present only occasionally in trace amounts, and three others were resolved from the immobile aggregated histone at low pH only. At least 16 zones appeared to be native histone components. Acid extraction of the histone did not appear to cause degradation since no new N-terminal amino acids were generated by this step. Two different methods of preparation produced histone extracts with essentially the same electrophoretic properties.