1. Contribution from Molecular Modeling Group, Indian Institute of Chemical Technology, Hyderabad 500-607, India, The Manchester Interdisciplinary Biocenter and the School of Chemical Engineering and Analytical Science, The University of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom, and Department of Chemistry and Nano Science, Department of Bioinspired Science, Centre for Biomimetic Systems, Ewha Womans University, Seoul 120-750, Korea