title: Non-Equilibrium Isomer Distribution of the Gas-Phase Photoactive Yellow Protein Chromophore.
abstract: The conjugate base of para-coumaric acid, which can be conveniently generated in the gas phase by electrospray ionization (ESI), is a commonly used model system for the chromophore of the photoactive yellow protein. Here we report its gas-phase IR spectrum, which shows that the anion easily adopts a carboxylate structure lying 60 kJ/mol higher in energy than the global minimum phenoxide structure. Generation of the biologically more relevant phenoxide isomer by ESI can be achieved using dry acetonitrile as solvent.
authors: †FOM Institute for Plasma Physics Rijnhuizen, Edisonbaan 14, 3439MN Nieuwegein, The Netherlands.|‡van 't Hoff Institute for Molecular Sciences, University of Amsterdam, Science Park 904, 1098XH Amsterdam, The Netherlands.
authors: Mitra
authors: M
authors: Almasian
authors: †FOM Institute for Plasma Physics Rijnhuizen, Edisonbaan 14, 3439MN Nieuwegein, The Netherlands.
authors: Josipa
authors: J
authors: Grzetic
authors: †FOM Institute for Plasma Physics Rijnhuizen, Edisonbaan 14, 3439MN Nieuwegein, The Netherlands.|‡van 't Hoff Institute for Molecular Sciences, University of Amsterdam, Science Park 904, 1098XH Amsterdam, The Netherlands.
authors: Johanne
authors: J
authors: van Maurik
authors: †FOM Institute for Plasma Physics Rijnhuizen, Edisonbaan 14, 3439MN Nieuwegein, The Netherlands.
authors: Jeffrey D
authors: JD
authors: Steill
authors: †FOM Institute for Plasma Physics Rijnhuizen, Edisonbaan 14, 3439MN Nieuwegein, The Netherlands.
authors: Giel
authors: G
authors: Berden
authors: ‡van 't Hoff Institute for Molecular Sciences, University of Amsterdam, Science Park 904, 1098XH Amsterdam, The Netherlands.
authors: Steen
authors: S
authors: Ingemann
authors: ‡van 't Hoff Institute for Molecular Sciences, University of Amsterdam, Science Park 904, 1098XH Amsterdam, The Netherlands.
authors: Wybren Jan
authors: WJ
authors: Buma
authors: †FOM Institute for Plasma Physics Rijnhuizen, Edisonbaan 14, 3439MN Nieuwegein, The Netherlands.|‡van 't Hoff Institute for Molecular Sciences, University of Amsterdam, Science Park 904, 1098XH Amsterdam, The Netherlands.|§Radboud University Nijmegen, Institute for Molecules and Materials, Heyendaalseweg 135, 6525AJ Nijmegen, The Netherlands.
authors: Jos
authors: J
authors: Oomens
keywords: electrospray ionization; gas-phase anion; ion spectroscopy; para-coumaric acid; photoactive yellow protein