1. Department of Neuroscience and Cell Biology, Robert Wood Johnson Medical School, University of Medicine and Dentistry of New Jersey, 675 Hoes Lane, Piscataway, New Jersey 08854-5635, Center for Advanced Biotechnology and Medicine, 679 Hoes Lane, Piscataway, New Jersey 08954-5639, and Department of Chemistry, Rutgers University, 73 Warren St., Newark, New Jersey 07102