[1] Univ Kansas, Ctr Computat Biol, Lawrence, KS 66045 USA
[2] Univ Kansas, Dept Mol Biosci, Lawrence, KS 66045 USA
[3] Univ Calif San Diego, Dept Pharmacol, La Jolla, CA 92093 USA
[4] Univ Calif San Diego, Dept Chem & Biochem, La Jolla, CA 92093 USA