PROTEIN RACEMATE YIELDS CRYSTALS

Abstract

NEW WORK SUGGESTS that a technique called racemic crystallography could help structural biologists get high-quality protein crystals of tough-to-crystallize proteins. Chemistry professor Stephen B. H. Kent, postdoc Kalyaneswar Mandal, and coworkers at the University of Chicago show that they can readily obtain high-quality crystals of the protein BmBKTx1 from a chemically prepared racemic solution ( J. Am. Chem. Soc., DOI: 10.1021/ja8077973). Found in the venom of a scorpion native to Asia, the 31-residue protein toxin is a poster child of recalcitrance, having resisted extensive crystallization attempts by multiple labs. The idea that a racemic protein mixture would crystallize more readily than either enantiomer alone first came from UCLA structural biologist Todd O. Yeates back in 1995. The Kent lab’s work “has borne out that prediction,” Yeates says. The BmBKTx1 structure is one of only a handful of protein structures ever determined by racemic crystallography. The method has languished in relative ob...