title: Conformer-selective photoelectron spectroscopy of α-lactalbumin derived multianions in the gas phase.
abstract: We have recorded conformer-selective, gas-phase photoelectron spectra of α-lactalbumin derived multianions generated by electrospraying solutions of both the native protein and its denatured form (as prepared by breaking the sulfur-sulfur bonds by chemical reduction). Three different groups of gas-phase multianion conformers have been observed and characterized. Highly-folded and partially-unfolded structures are obtained from solutions of the native protein. Only highly-elongated conformers are observed upon electrospraying the denatured protein. Adiabatic detachment energies were determined at several negative charge states for each conformer group. In comparison to highly-elongated conformations, highly-folded structures show a steeper decrease of electron binding energy with increasing negative charge. By comparing experimental detachment energies for highly-elongated structures with the predictions of a simple electrostatic model calculation, we have determined the effective dielectric shielding constant.
authors.affiliation: Institute of Physical Chemistry, Karlsruhe Institute of Technology (KIT), 76128 Karlsruhe, Germany. manfred.kappes@kit.edu.
authors.forename: Matthias
authors.initials: M
authors.lastname: Vonderach
authors.forename: Marc-Oliver
authors.initials: MO
authors.lastname: Winghart
authors.forename: Luke
authors.initials: L
authors.lastname: MacAleese
authors.forename: Fabien
authors.initials: F
authors.lastname: Chirot
authors.forename: Rodolphe
authors.initials: R
authors.lastname: Antoine
authors.forename: Philippe
authors.initials: P
authors.lastname: Dugourd
authors.forename: Patrick
authors.initials: P
authors.lastname: Weis
authors.forename: Oliver
authors.initials: O
authors.lastname: Hampe
authors.forename: Manfred M
authors.initials: MM
authors.lastname: Kappes
mesh_terms: D005740:Gases / Q000737:chemistry*; D007768:Lactalbumin / Q000737:chemistry*; D056951:Photoelectron Spectroscopy; D055672:Static Electricity; D013455:Sulfur / Q000737:chemistry
chemical_list: D005740:Gases; D013455:Sulfur; D007768:Lactalbumin