Mark A. White, Ph.D., Assistant Professor
Manager, UTMB X-Ray Crystallography Laboratory
Computational Biophysics and Crystallography: My research interests are in the areas of computational biophysics and crystallography. Crystallography is a tool for examining diverse structures of genomic proteins. Structural genomics combined with homology and 3D modeling of proteins promises to reveal the relationship between the structure and function of proteins. To speed structure discovery I am developing new computational crystallography and structure analysis tools. Some of these tools are available for download from the Protein Model Builder (PMB) web site. In addition, I am developing novel analytical crystallography methods that promise to reveal the role of protein dynamics in molecular function.
I am actively involved in many collaborative crystallographic structure solution projects. Some of the more recently published structures include that of human aldose reductase with a glutathione-like inhibitor bound and several cytochrome c P450 2B4 structures. To see a list of all my crystallographic structures click here. 
The cytochrome P450s are a range of enzymes of unique importance in the understanding of xenobiotic metabolism. In collaboration with Dr. Emily E. Scott. Dr. Yonghong ZHao, Dr. C. David Stout, and Dr. James R. Halpert, the structure of the mammalian cytochrome P450 2B4 was solved, with and without inhibitors. These structures demonstrated, for the first time, the extreme conformational flexibility of the P450s and yielded insights into the dynamics involved in substrate access, tight inhibitor binding, and coordination of substrate and redox partner binding.
Aldose reductase (AR) is implicated in diabetes, and has a role in lipid detoxification. In a collaborative project with Dr. S. R. Srivastava and Dr. S. J. Watowich, the structure of a glutathione conjugate bound to AR was determined. This structure will be the basis for developing inhibitors of glucose reduction by AR, which maintain its activity against toxic free aldehydes. Thereby possibly eliminating some of the clinical side-effects observed with the current AR inhibitors.
