Direct and indirect electron emission from the green fluorescent protein chromophore

Photoelectron spectra of the deprotonated green fluorescent protein chromophore have been measured in the gas phase at several wavelengths within and beyond the S(0)-S(1) photoabsorption band of the molecule. The vertical detachment energy (VDE) was determined to be 2.68 ± 0.1 eV. The data show that the first electronically excited state is bound in the Franck-Condon region, and that electron emission proceeds through an indirect (resonant) electron-emission channel within the corresponding absorption band.

Sub-microsecond photodissociation pathways of gas phase adenosine 5'-monophosphate nucleotide ions

The sub-microsecond dissociation pathways for the protonated and deprotonated forms of adenosine 5'-monophosphate were probed in the gas phase using a linear time of flight spectrometer. The studies show two dissociation pathways for the AMP ions indicating dominant ergodic pathways in the photodissociation of these species. The photofragmentation was determined to be a single photon process for the AMP ions. Photodetachment of the AMP anion excited at 266 nm was not observed, leaving dissociation as the prominent pathway for relaxation of the excess energy in the biomolecule. The photofragments were analysed at the electrostatic ion storage ring (ELISA) and found to be similar to collision induced fragments in the case of anions but different in the case of cations.