[1] Vanderbilt Univ, Sch Med, Ctr Mol Toxicol, Dept Biochem, Nashville, TN 37232 USA
[2] Vanderbilt Univ, Sch Med, Ctr Mol Toxicol, Dept Chem, Nashville, TN 37232 USA
[3] Univ Witwatersrand, Sch Mol & Cell Biol, Prot Struct Funct Res Unit, ZA-2050 Johannesburg, South Africa
[4] Maryland Biotechnol Inst, Ctr Adv Res Biotechnol, Rockville, MD 20850 USA
[5] Natl Inst Stand & Technol, Rockville, MD 20850 USA