Solubilization of delipidated macrophage membrane proteins for analysis bytwo-dimensional electrophoresis

Two-dimensional electrophoresis of proteins is often precluded due to the l ack of solubilization of cell membrane extracts in an aqueous medium. Vario us additives and detergents have been used to circumvent the problem, but t heir efficacy may not be satisfactory. In this study, the removal of lipidi c components of the cell membrane extract with chloroform-methanol was used to achieve solubilization. Optimal delipidation was obtained with acetone washings. This procedure increased solubilization of membrane proteins from a murine macrophage cell line, thus showing a substantial improvement in g el resolution. The two-dimensional gels loaded with delipidated extract pro ved to be free of smearing and horizontal streaking. In addition, other pro tein spots were revealed that were not detected in the gels loaded with und elipidated cell membrane extract.