Amidosulfobetaines, a family of detergents with improved solubilization properties: application for isoelectric focusing under denaturing conditions.

The synthesis of a family of new detergents and their use for isoelectric focusing are described. These detergents differ from the conventional sulfobetaines by the presence of an amido group bridging the hydrophobic linear tail and the polar head, which increases their water solubility and urea tolerance considerably. Four different linear alkyl hydrophobic tails were tested, together with three different polar heads. The solubilization of red blood cell ghosts by the 12 resulting detergent performances was evaluated both in solution and in isoelectric focusing runs. Six chemicals gave performances equal or better than those of conventional detergents and could replace them for general use in focusing experiments. In addition, the synthesis of a whole range of compounds allowed valuable insights in the empirical understanding of protein-detergent interactions, which are extensively discussed.