[1] Univ Massachusetts, Sch Med, Chem Biol Program, Dept Biochem & Mol Pharmacol, Worcester, MA 01605 USA
[2] MIT, Dept Chem & Comp Sci, Cambridge, MA 02139 USA
[3] MIT, Artificial Intelligence Lab, Cambridge, MA 02139 USA
[4] MIT, Biol Engn Div, Cambridge, MA 02139 USA
[5] MIT, Dept Elect Engn & Comp Sci, Cambridge, MA 02139 USA