Chiral additives have proven useful to control the crystallization of small molecules, but the role of chirality in protein crystallization has yet to be investigated systematically. Previously, we discovered that the chirality of sodium tartrate affects the crystallization of thaumatin. For example, L- and D-tartrate produce different crystal habits due to a preferential interaction between thaumatin and the L enantiomer. To establish the generality of our findings, we are studying other protein-precipitant pairs. Here we present our results for lysozyme and 2-methyl-2,4-pentanediol (MPD); the racemic (RS) mixture of MPD is one of the most commonly used additives in protein crystallization.  We successfully crystallized lysozyme with enantiomerically pure R-MPD and S-MPD as well as with RS-MPD. We find that there is a preferential interaction between lysozyme and R-MPD producing more ordered crystals and higher resolution protein structures. These results support our hypothesis that chiral interactions are important in protein crystallization.

Effect of chiral additives on protein crystallization

243rd National Meeting (2012)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.