With love, to my parents (Genaro and Zenaida) and my brothers (Anibal, Samuel and Genaro) I would like to express my sincerest thanks and appreciation to my adviser, Professor Dr. Richard Garratt, for all his support, and vast knowledge on all things. Whenever I ran into trouble or had a question about the research, his office was always open. His observations and comments helped me to establish the overall direction of the research. I would like to specifically thank Prof. Dr. Jose Ribamar for the fruitful collaboration behind our mutational experiments, and for inspiring my creativity in research. I owe a debt of gratitude to Professor Dr. James Penner-Hahn for giving me the opportunity to work in his lab, for his absolute support of my thesis and for providing me with all the necessary facilities for our research collaboration. I am thankful to Prof. Dr. Pecoraro and Dr. Stuckey for the help and support during my stay in Michigan. I thank Dr. Annirudha and Postdoc Luis Basso for their assistance with the EPR experiments. I extend my gratitude also to Dr. Carol Ann Pitcairn for her care and precious friendship during my stay at the University of Michigan as well as her continued support and friendship thereafter.