Physics Colloquium, Anouk Rijs, Radboud University, Nijmegen

Abstract:

To be able to control complex chemical reactions, to change the course of a disease at the molecular level or to direct the synthesis of functional biopolymers, it is necessary to fully understand the underlying molecular mechanism of these processes. This is often a major challenge as one needs to disentangle and probe molecular structures and transient intermediates hidden in heterogenic mixtures. What is necessary to reach this understanding is the ability to follow and structurally characterize the species present, i.e. to make the invisible processes visible by mapping the full molecular network.

Mass spectrometry is a vital tool for the identification and quantification of peptides, glycans, etc. and their non-covalent assemblies. However, despite its remarkable sensitivity, the structural resolution is limited. In contract, optical -and especially infrared- spectroscopy provides a diagnostic probe of molecular structure. Interfacing IR action spectroscopy to mass spectrometry and/or molecular beam techniques has enabled us to add an extra dimension to mass spectrometric analysis, providing structural characterization of lowly populated intermediates in heterogenic mixtures.

Here, we focus on two important complex (bio)chemical processes namely (1) self-assembly of peptides and proteins related to functional and pathological aggregate formation and (2) the chemical glycosylation reaction. In this presentation, we will see how a combination of IR and THz action spectroscopy with advanced mass spectrometry techniques can be used to structural identify key intermediates in order to obtain insights in the mechanism of these reactions.