Metal Ion Hydration and Peptide Fragmentation: Energetics, Structures, and Mechanisms
소속 :
연사 : Prof.Peter B. Armentrout (Department of Chemistry, University of Utah)
일시 : 2012-09-12 15:00 ~
장소 : 500동 L305호
일 시 : 2012년 9월 12일, 3:00 PM
장 소 : 500동 L305호
-Abstract-
Guided ion beam tandem mass spectrometry is a powerful tool to examine the energetics of a wide range of ion-molecule species. Judicious choices of the systems examined provides quantitative thermochemistry as well as insight into the kinetics and reactivity. After introducing the methodology used, the talk will illustrate progress made in two areas. 1) Hydration of metal cations is important in biological systems as well as environmental remediation efforts. We have recently begun to measure the inner shell hydration energies of metal dications for the first time. Periodic trends are being elucidated and complementary quantum chemical calculations and infrared multiple photon dissociation experiments provide structural information as well. 2) Examination of the energetics of metallated and protonated amino acids yields information relevant to understanding the thermodynamics of biological systems and elucidating the mechanisms for protein degradation, important in applications such as protein sequencing. We have begun to provide benchmark thermochemistry for further evaluation and the assessment of theoretical mechanisms, specifically for protonated glycine (G), protonated diglycine (GG), the simplest b2 ion (protonated 2-amino methyl-5-oxazolone, H+AMOx), protonated diketopiperazine (H+DKP), and the tripeptides, GGG, GGA, and GAG. Here, the energetic information combined with quantum chemical calculations allows structural information to be obtained as well.
장 소 : 500동 L305호
-Abstract-
Guided ion beam tandem mass spectrometry is a powerful tool to examine the energetics of a wide range of ion-molecule species. Judicious choices of the systems examined provides quantitative thermochemistry as well as insight into the kinetics and reactivity. After introducing the methodology used, the talk will illustrate progress made in two areas. 1) Hydration of metal cations is important in biological systems as well as environmental remediation efforts. We have recently begun to measure the inner shell hydration energies of metal dications for the first time. Periodic trends are being elucidated and complementary quantum chemical calculations and infrared multiple photon dissociation experiments provide structural information as well. 2) Examination of the energetics of metallated and protonated amino acids yields information relevant to understanding the thermodynamics of biological systems and elucidating the mechanisms for protein degradation, important in applications such as protein sequencing. We have begun to provide benchmark thermochemistry for further evaluation and the assessment of theoretical mechanisms, specifically for protonated glycine (G), protonated diglycine (GG), the simplest b2 ion (protonated 2-amino methyl-5-oxazolone, H+AMOx), protonated diketopiperazine (H+DKP), and the tripeptides, GGG, GGA, and GAG. Here, the energetic information combined with quantum chemical calculations allows structural information to be obtained as well.
