title: A biomimetic molecular switch at work: coupling photoisomerization dynamics to peptide structural rearrangement.
abstract: In spite of considerable interest in the design of molecular switches towards photo-controllable (bio)materials, few studies focused on the major influence of the surrounding environment on the switch photoreactivities. We present a combined experimental and computational study of a retinal-like molecular switch linked to a peptide, elucidating the effects on the photoreactivity and on the α-helix secondary structure. Temperature-dependent, femtosecond UV-vis transient absorption spectroscopy and high-level hybrid quantum mechanics/molecular mechanics methods were applied to describe the photoisomerization process and the subsequent peptide rearrangement. It was found that the conformational heterogeneity of the ground state peptide controls the excited state potential energy surface and the thermally activated population decay. Still, a reversible α-helix to α-hairpin conformational change is predicted, paving the way for a fine photocontrol of different secondary structure elements, hence (bio)molecular functions, using retinal-inspired molecular switches.
authors.affiliation: Departamento de Química, Centro de Investigación en Síntesis Química (CISQ), Universidad de La Rioja, Madre de Dios 53, E-26006 Logroño, Spain. diego.sampedro@unirioja.es.
authors.forename: Cristina
authors.initials: C
authors.lastname: García-Iriepa
authors.forename: Moussa
authors.initials: M
authors.lastname: Gueye
authors.forename: Jérémie
authors.initials: J
authors.lastname: Léonard
authors.forename: David
authors.initials: D
authors.lastname: Martínez-López
authors.forename: Pedro J
authors.initials: PJ
authors.lastname: Campos
authors.forename: Luis Manuel
authors.initials: LM
authors.lastname: Frutos
authors.forename: Diego
authors.initials: D
authors.lastname: Sampedro
authors.forename: Marco
authors.initials: M
authors.lastname: Marazzi
mesh_terms: D032701:Biomimetics; D007536:Isomerism; D010455:Peptides / Q000737:chemistry*; D055668:Photochemical Processes; D011487:Protein Conformation
chemical_list: D010455:Peptides