Development of an electrospary ionization source and vacuum interface for guided ion beam tandem mass spectrometry experiments: structural and energetic effects in the molecular recognition of amino acids by 18-crown-6

DEVELOPMENT OF AN ELECTROSPARY IONIZATION SOURCE AND VACUUMINTERFACE FOR GUIDED ION BEAM TANDEM MASS SPECTROMETRYEXPERIMENTS: STRUCTURAL AND ENERGETIC EFFECTS IN THE MOLECULARRECOGNITION OF AMINO ACIDS BY 18-CROWN-6byYU CHENAugust 2012Advisor: Professor Mary T. RodgersMajor: Analytical ChemistryDegree: Doctor of Philosophy Absolute 18-crown-6 (18C6) binding affinities of the side chains of AAs inpeptides and proteins were determined in a pedagogic fashion using guided ion beamtandem mass spectrometry techniques. The 18C6 binding affinities of ninepeptidomimetic bases (B) that serve as mimics for the side chains of lysine (Lys),histidine (His), and arginine (Arg), and the N-terminal amino group have been examinedto determine the intrinsic 18C6 binding affinities. The Bs were extended to naturallyoccurring AAs and further extended to acetylated AAs (AcAA) to determine the bindingaffinities of the side chains of AAs in peptides and proteins. The peptidomimetic basesexamined here include: isopropylamine (IPA), imidazole (Imid) and 4-methylimidazole(4MeImid), 1-methylguanidine (MGD), methylamine (MA), ethylamine (EA), n-propylamine (NPA), n-butylamine (NBA), and 1,5-diamino pentane (DAP). This workwas extended to include five amino acids (AA), glycine (Gly), alanine (Ala), Lys, His,