1. Organic and Biological Mass Spectrometry Group, Chemical Sciences Division, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, Tennessee 37831-6131, Life Sciences Division, Oak Ridge National Laboratory, Oak Ridge Tennessee 37831, Graduate School of Genome Science and Technology, University of Tennessee- Oak Ridge National Laboratory, 1060 Commerce Park, Oak Ridge, Tennessee 37830-8026, and Biochemistry Cellular and Molecular Biology Department, University of Tennessee, Knoxville, Tennessee 37996