......................................................................................................................................... 6 Introduction .................................................................................................................................... 6 Materials and Methods .................................................................................................................... 9 Results and Discussion ................................................................................................................. 10 Chapter 3 Structural Insights into PDZ-mediated Interaction of NHERF2 and LPA2, a Cellular Event Implicated in CFTR Channel Regulation........................................................ 20 Abstract ........................................................................................................................................ 20 Introduction .................................................................................................................................. 20 Materials and Methods .................................................................................................................. 22....................................................................................................................................... 20 Introduction .................................................................................................................................. 20 Materials and Methods .................................................................................................................. 22 Results and Discussion ................................................................................................................. 24 Chapter 4 PDZ Structure and Implication in Selective Drug Design against Cystic Fibrosis ....................................................................................................................................................... 31 Abstract ........................................................................................................................................ 31....................................................................................................................................... 31