W0027

Models of Dynamic Disorder in Protein Crystals; Theory and New Analysis. George N. Phillips, Jr., Jason McCoy, Ryan Bannen, and Sibsankar Kundu, Dept. of Biochemistry Univ. of Wisconsin-Madison Madison, WI 53706.

Although the end result of most crystallographic analyses is a static snapshot of a molecule, we know there is both static and dynamic disorder in the system. The effect of this disorder is not fully accounted for by the usual Debye-Waller treatment, whether isotropic or anisotropic. Especially for large molecules, methods that include the effects of coupled motions are needed to fully account for the observed intensities. Some new methods that extend beyond TLS treatment will be presented, and a simplified model of protein motions in crystals that includes the effects of crystal contacts will be described and compared with experimental results.