[1] Boston Univ, Sch Med, Dept Biochem, Boston, MA 02118 USA
[2] Boston Univ, Sch Med, Dept Med, Sect Mol Med, Boston, MA 02118 USA
[3] Boston Univ, Sch Med, Cell & Mol Biol Program, Boston, MA 02118 USA
[4] Boston Univ, Sch Med, Mass Spectrometry Resource, Boston, MA 02118 USA
[5] Boston Univ, Sch Med, Dept Microbiol, Boston, MA 02118 USA