Charge shift electrophoresis: simple method for distinguishing between amphiphilic and hydrophilic proteins in detergent solution

Abstract

Seventeen hydrophilic proteins and five amphiphilic membrane proteins were subjected to agarose gel electrophoresis in the presence of a nonionic detergent (Triton X-100), a mixture of anonionic and an anionic detergent (Triton X-100 and sodium deoxycholate), and a mixture of a nonionic and a cationic detergent (Triton X-100 and cetyltrimethylammonium bromide). The electrophoretic mobility of the hydrophilic proteins was unaffected in the three detergent mixtures. However, the mobility of the amphiphilic proteins shifted anodally in the Triton X-100-deoxycholate system and cathodally in the Triton X-100-cetyltrimethylammonium bromide system when compared to the mobility in Triton X-100 alone. The detergent-induced shift in mobility provides a simple, rapid, and sensitive method for distinguishing between hydrophilic and amphiphilic proteins.