+ Most Popular
Cunninghamia lanceolata plantations in China
Mammalian lairs in paleo ecological studies and palynology
Studies on technological possibilities in utilization of anhydrous milk fat for production of recombined butter-like products
Should right-sided fibroelastomas be operated upon?
Large esophageal lipoma
Apoptosis in the mammalian thymus during normal histogenesis and under various in vitro and in vivo experimental conditions
Poissons characoides nouveaux ou non signales de l'Ilha do Bananal, Bresil
Desensitizing efficacy of Colgate Sensitive Maximum Strength and Fresh Mint Sensodyne dentifrices
Administration of fluid by subcutaneous infusion: revival of a forgotten method
Tundra mosquito control - an impossible dream?
Schizophrenia for primary care providers: how to contribute to the care of a vulnerable patient population
Geochemical pattern analysis; method of describing the Southeastern limestone regional aquifer system
Incidence of low birth weights in a hospital of Mexico City
Graded management intensity of grassland systems for enhancing floristic diversity
Microbiology and biochemistry of cheese and fermented milk
The ember tetra: a new pygmy characid tetra from the Rio das Mortes, Brazil, Hyphessobrycon amandae sp. n. (Pisces, Characoidei)
Risk factors of contrast-induced nephropathy in patients after coronary artery intervention
Renovation of onsite domestic wastewater in a poorly drained soil
Observations of the propagation velocity and formation mechanism of burst fractures caused by gunshot
Systolic blood pressure in a population of infants in the first year of life: the Brompton study
Haematological studies in rats fed with metanil yellow
Studies on pasteurellosis. I. A new species of Pasteurella encountered in chronic fowl cholera
Dormancy breaking and germination of Acacia salicina Lindl. seeds
therapy of lupus nephritis. a two-year prospective study

Unravelling the details of vitamin D photosynthesis by non-adiabatic molecular dynamics simulations

Unravelling the details of vitamin D photosynthesis by non-adiabatic molecular dynamics simulations

Physical Chemistry Chemical Physics: Pccp 13(47): 20986-20998

ISSN/ISBN: 1463-9076

PMID: 22020179

DOI: 10.1039/c1cp21292c

We investigate the photodynamics of vitamin D derivatives by a fully analytical implementation of the linear response time-dependent density functional theory surface hopping method (LR-TDDFT-SH). Our study elucidates the dynamics of the processes involved in vitamin D formation at the molecular level and with femtosecond resolution. We explain the major experimental findings and provide new insights that cannot directly be obtained from experiments: firstly, we investigate the dynamics of the photoinduced ring-opening of provitamin D (Pro) and cyclohexadiene (CHD) and the subsequent rotational isomerization. In agreement with recent experiments and CC2 calculations, only the bright S(1) state is involved in the ring-opening reaction. Our calculations confirm the experimentally reported 5 : 1 ratio between the excited state lifetimes of Pro and CHD. The longer lifetimes of Pro are attributed to steric constraints of the steroid skeleton and to temperature effects, both emerging directly from our simulations. For CHD and Pro, we present an explanation of the biexponential decay recently reported by Sension and coworkers [Tang et al., J. Phys. Chem., 2011, 134, 104503]: our calculations suggest that the fast and slow components arise from a reactive and an unreactive reaction pathway, respectively. Secondly, we assess the wavelength dependent photochemistry of previtamin D (Pre). Using replica exchange molecular dynamics we sample the Pre conformers present at thermal equilibrium. Based on this ensemble we explain the conformation dependent absorption and the essential features of Pre photochemistry. Consistent with the experiments, we find ring-closure to occur mostly after excitation of the cZc conformers and at lower energies, whereas Z/E isomerization of the central double bond preferably occurs after excitation at higher energies. For the isomerization we provide the first theoretical evidence of the proposed hula-twist mechanism. Our results show that LR-TDDFT-SH is a highly valuable tool for studying the photochemistry of moderately large systems, even though challenges remain in the vicinity of conical intersections.

Please choose payment method:

(PDF emailed within 0-6 h: $19.90)

Accession: 056767430

Download citation: RISBibTeXText

Related references

The role of tachysterol in vitamin D photosynthesis - a non-adiabatic molecular dynamics study. Physical Chemistry Chemical Physics: Pccp 19(8): 5763-5777, 2017

Stereoselective binding of agonists to the β 2 -adrenergic receptor: insights into molecular details and thermodynamics from molecular dynamics simulations. Molecular Biosystems 13(5): 910-920, 2017

Molecular-dynamics simulations of non-adiabatic processes at surfaces. Phase Transitions 78(9-11): 773-786, 2005

Unravelling the nature of glyphosate binding to goethite surfaces by ab initio molecular dynamics simulations. Physical Chemistry Chemical Physics: Pccp 20(3): 1531-1539, 2018

Observe while it happens: catching photoactive proteins in the act with non-adiabatic molecular dynamics simulations. Current Opinion in Structural Biology 61: 106-112, 2020

Unravelling the hydration structure of ThX4 (X = Br, Cl) water solutions by molecular dynamics simulations and X-ray absorption spectroscopy. Journal of Physical Chemistry. B 116(22): 6465-6475, 2012

Nonequilibrium adiabatic molecular dynamics simulations of methane clathrate hydrate decomposition. Journal of Chemical Physics 132(14): 144703, 2010

Time-resolved photoelectron imaging spectra from non-adiabatic molecular dynamics simulations. Journal of Chemical Physics 139(13): 134104, 2013

Photodissociation, electronic relaxation and recombination of HCl in Arn(HCl) clusters Non-adiabatic molecular dynamics simulations. Faraday Discussions 108: 243-254, 1997

Free energy calculations from adaptive molecular dynamics simulations with adiabatic reweighting. Journal of Chemical Physics 140(10): 104108, 2014

Atomistic Details of the Dynein Motor Mechanism Revealed by Molecular Dynamics Simulations. Biophysical Journal 116(3): 408a-409a, 2019

Molecular dynamics simulations in photosynthesis. Photosynthesis Research 144(2): 273-295, 2020

A new approach to molecular dynamics with non-adiabatic and spin-orbit effects with applications to QM/MM simulations of thiophene and selenophene. Journal of Chemical Physics 146(11): 114101, 2017

Gramicidin A backbone and side chain dynamics evaluated by molecular dynamics simulations and nuclear magnetic resonance experiments. I: molecular dynamics simulations. Journal of Physical Chemistry. B 115(22): 7417-7426, 2011

Targeting N-Terminal Human Maltase-Glucoamylase to Unravel Possible Inhibitors Using Molecular Docking, Molecular Dynamics Simulations, and Adaptive Steered Molecular Dynamics Simulations. Frontiers in Chemistry 9: 711242, 2021