title: Nonadiabatic histidine dissociation of hexacoordinate heme in neuroglobin protein.
abstract: In the present work, density functional theory and canonical nonadiabatic Monte Carlo transition state theory have been used to investigate the histidine dissociation process from hexacoordinate heme in Ngb protein. The potential energy surfaces (PES) of the lowest singlet, triplet, and quintet states are calculated by stepwise optimization along with the histidine dissociation pathway. Based on the calculated two-dimensional PES, the histidine dissociation rates for the spin-forbidden processes via singlet to triplet and singlet to quintet transitions have been calculated by the nonadiabatic Monte Carlo transition state theory in canonical ensemble. The present study provides a quantitative description on spin-forbidden histidine dissociation processes.
authors.affiliation: Theoretical Chemistry, School of Biotechnology, Royal Institute of Technology, S-10691 Stockholm, Sweden.
authors.forename: Feng
authors.initials: F
authors.lastname: Zhang
authors.forename: Yue-Jie
authors.initials: YJ
authors.lastname: Ai
authors.forename: Yi
authors.initials: Y
authors.lastname: Luo
authors.forename: Wei-Hai
authors.initials: WH
authors.lastname: Fang
mesh_terms: D003198:Computer Simulation; D005914:Globins / Q000737:chemistry*; D006418:Heme / Q000737:chemistry*; D006639:Histidine / Q000737:chemistry*; D008958:Models, Molecular; D009010:Monte Carlo Method; D009419:Nerve Tissue Proteins / Q000737:chemistry*; D000078787:Neuroglobin; D011789:Quantum Theory
chemical_list: D009419:Nerve Tissue Proteins; D000078787:Neuroglobin; D006418:Heme; D006639:Histidine; D005914:Globins