title: How Photoisomerization Drives Peptide Folding and Unfolding: Insights from QM/MM and MM Dynamics Simulations.
abstract: Photoswitchable azobenzene cross-linkers can control the folding and unfolding of peptides by photoisomerization and can thus regulate peptide affinities and enzyme activities. Using quantum mechanics/molecular mechanics (QM/MM) methods and classical MM force fields, we report the first molecular dynamics simulations of the photoinduced folding and unfolding processes in the azobenzene cross-linked FK-11 peptide. We find that the interactions between the peptide and the azobenzene cross-linker are crucial for controlling the evolution of the secondary structure of the peptide and responsible for accelerating the folding and unfolding events. They also modify the photoisomerization mechanism of the azobenzene cross-linker compared with the situation in vacuo or in solution.
authors.affiliation: Key Laboratory of Theoretical and Computational Photochemistry Ministry of Education, College of Chemistry, Beijing Normal University, Beijing, 100875, China.
authors.forename: Shu-Hua
authors.initials: SH
authors.lastname: Xia
authors.affiliation: Key Laboratory of Theoretical and Computational Photochemistry Ministry of Education, College of Chemistry, Beijing Normal University, Beijing, 100875, China. ganglong.cui@bnu.edu.cn.
authors.forename: Ganglong
authors.initials: G
authors.lastname: Cui
authors.affiliation: Key Laboratory of Theoretical and Computational Photochemistry Ministry of Education, College of Chemistry, Beijing Normal University, Beijing, 100875, China.
authors.forename: Wei-Hai
authors.initials: WH
authors.lastname: Fang
authors.affiliation: Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470, Mülheim an der Ruhr, Germany. thiel@mpg.kofo.de.
authors.forename: Walter
authors.initials: W
authors.lastname: Thiel
mesh_terms: D001391:Azo Compounds / Q000737:chemistry*; D003432:Cross-Linking Reagents / Q000737:chemistry; D056004:Molecular Dynamics Simulation; D010455:Peptides / Q000737:chemistry*; D055668:Photochemical Processes; D017510:Protein Folding; D058767:Protein Unfolding; D011789:Quantum Theory; D013237:Stereoisomerism
chemical_list: D001391:Azo Compounds; D003432:Cross-Linking Reagents; D010455:Peptides; C009850:azobenzene
keywords: azobenzene; conical intersections; folding and unfolding; nonadiabatic dynamics; quantum mechanics/molecular mechanics