Two-faced detergents

A new detergent with a structure that deviates from the conventional topology of amphiphilic molecules could help drug developers eke out hard-to-get structural information about membrane-bound protein targets (Angew. Chem. Int. Ed., DOI: 10.1002/anie.200701556). Detergents usually have a polar head group and a nonpolar alkyl tail, and one of their uses is mimicking cellular lipids to help preserve the structure and function of membrane proteins. To make the new detergent, a team led by Qinghai Zhang of Scripps Research Institute modified a steroid skeleton (shown, red) with polar sugar side groups (blue). The molecule's unmodified face packs against the membrane-spanning portion of a protein, leaving the side groups exposed as shown. The detergent has a larger surface area than conventional detergent molecules and can better maintain the proteins' integrity and catalytic activity than standard detergents, thus improving structural analysis, according to coauthor M. G. Finn.