Electrophoretic separation of histones and high-mobility-group proteins on acid-urea-Triton gels.

The electrophoretic mobilities of calf thymus histones and high-mobility-group (HMG) nonhistone proteins were studied on a newly modified polyacrylamide gel containing acetic acid, urea, and the nonionic detergent Triton X-100 in combination with glycine in the electrode buffer. This gel system avoids stacking gel, photopolymerization of acrylamide, and preelectrophoresis. Under extremely low Triton concentrations some H3 variant forms (H3.1) were preferentially separated by their slower migration from bulk H3. Under increasing concentrations of Triton in the gel in the presence of 3 or 6 M urea, the mobilities of H2A.1, H3.2, H2A.2, H4, and H2B were sequentially retarded. The mobilities of H1 and HMGs remained virtually unchanged under all conditions. This gel system is able to resolve charge-modified histones.