+ Site Statistics
+ Search Articles
+ Subscribe to Site Feeds
Most Shared
PDF Full Text
+ PDF Full Text
Request PDF Full Text
+ Follow Us
Follow on Facebook
Follow on Twitter
Follow on LinkedIn
+ Translate
+ Recently Requested

Multifrequency electron spin resonance spectra of a spin-labeled protein calculated from molecular dynamics simulations

Multifrequency electron spin resonance spectra of a spin-labeled protein calculated from molecular dynamics simulations

Journal of the American Chemical Society 131(7): 2597-2605

Multifrequency electron spin resonance (ESR) spectra provide a wealth of structural and dynamic information about the local environment of the spin label and, indirectly, about the spin-labeled protein. Relating the features of the observed spectra to the underlying molecular motions and interactions is, however, challenging. To make progress toward a rigorous interpretation of ESR spectra, we perform extensive molecular dynamics (MD) simulations of fully solvated T4 Lysozyme, labeled with the spin label MTSSL at positions 72 and 131. These two sites have been the object of numerous experimental studies and are generally considered as prototypical solvent-exposed sites on the surfaces of alpha-helices. To extend the time window afforded by the MD simulations, stochastic Markov models reflecting the dynamics of the spin label side chains in terms of their rotameric states are constructed from the trajectories. The calculated multifrequency ESR spectra are in very good agreement with experiment for three different magnetic field strengths without adjusting any parameters. During the trajectories, the spin labels interconvert among a fairly large number of conformations and display a propensity to form interactions with protein residues other than their nearest neighbors along the helix. The detailed picture of the spin label emerging from the MD simulations provides useful insight into the molecular origins of the available spectroscopic and crystallographic data.

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

Accession: 054490981

Download citation: RISBibTeXText

PMID: 19191603

DOI: 10.1021/ja8073819

Related references

Multifrequency electron spin resonance study of the dynamics of spin labeled T4 lysozyme. Journal of Physical Chemistry. B 114(16): 5503-5521, 2010

The effect of divalent metal binding on the electron spin resonance spectra of spin-labeled actin. Evidence for spin-spin interactions involving manganese. II. Archives of Biochemistry and Biophysics 150(2): 792-796, 1972

Simulating electron spin resonance spectra of nitroxide spin labels from molecular dynamics and stochastic trajectories. Journal of Chemical Physics 128(16): 165106-165106, 2008

Simulation of electron paramagnetic resonance spectra of spin-labeled molecules from replica-exchange molecular dynamics. Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics 88(4): 042701-042701, 2014

Parametrization, molecular dynamics simulation, and calculation of electron spin resonance spectra of a nitroxide spin label on a polyalanine alpha-helix. Journal of Physical Chemistry. B 112(18): 5755-5767, 2008

Kinetics and motional dynamics of spin-labeled yeast iso-1-cytochrome c: 1. Stopped-flow electron paramagnetic resonance as a probe for protein folding/unfolding of the C-terminal helix spin-labeled at cysteine 102. Biochemistry 36(10): 2884-2897, 1997

Saturation transfer, continuous wave saturation, and saturation recovery electron spin resonance studies of chain-spin labeled phosphatidylcholines in the low temperature phases of dipalmitoyl phosphatidylcholine bilayers. Effects of rotational dynamics and spin-spin interactions. Biophysical Journal 61(4): 879-891, 1992

The effects of nucleotides and Mg 2+ on the electron spin resonance spectra of myosin spin labeled at the S 2 thiol groups. Archives of Biochemistry and Biophysics 152(2): 839-848, 1972

Effect of proteolysis on the electron spin resonance spectra of maleimide spin labeled erythrocyte membrane. Biochimica et Biophysica Acta 821(2): 175-178, 1985

Simulating electron spin resonance spectra of macromolecules labeled with two dipolar-coupled nitroxide spin labels from trajectories. Physical Chemistry Chemical Physics 13(28): 12785-12797, 2012

Simulations of the (1)H electron spin echo-electron nuclear double resonance and (2)H electron spin echo envelope modulation spectra of exchangeable hydrogen nuclei coupled to the S(2)-state photosystem II manganese cluster. Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences 357(1426): 1359-65; Discussion 1365-7, 2002

Force field impact and spin-probe modeling in molecular dynamics simulations of spin-labeled T4 lysozyme. Journal of Molecular Modeling 11(3): 210-225, 2005

Interaction of spin-labeled apocytochrome c and spin-labeled cytochrome c with negatively charged lipids studied by electron spin resonance. Biochemistry. 33(23): 7146-7156, 1994

The effects of ionic conditions, temperature, and chemical modification on the fluorescence of myosin during the steady state of ATP hydrolysis. A comparison of the fluorescnece and electron spin resonance spectra of the spin-labeled enzyme. Journal of Biological Chemistry 250(14): 5681-5687, 1975