A computational study of the origin of group I ion selectivity in biological molecules

An investigation of group I monovalent cation selectivity in biological molecules and macrocycles is presented in this thesis. This ion selectivity is responsible for many important and crucial biological processes such as shaping action potentials in excitable cells and the proper functioning of many enzymes. A number of mechanisms have been proposed as to how this is achieved and it is the intent of this thesis to elucidate and discuss known mechanisms, as well as to identify new ones. Computational techniques are used to undertake this study, allowing the probing of time, space and energies unattainable through traditional means of experiment. A coherent description of the means of generating ion selectivity is presented, leading to an explanation of selectivity in a wide range of molecules, as well as having ramifications for the design of novel ion selective structures. Chapter 1 introduces the history and the current state of the field. Chapter 2 contains a synopsis of the following chapters. Chapter 3 presents and explores the fundamental mechanisms of ion selectivity and their importance in a number of molecules. Chapter 4 expands on this, detailing situations where reality may deviate from these simple situations described in chapter 3.