Addition/Correction pubs.acs.org/JPCB
Correction to Comparison of Different TMAO Force Fields and Their Impact on the Folding Equilibrium of a Hydrophobic Polymer Francisco Rodríguez-Ropero, Philipp Rötzscher, and Nico F. A. van der Vegt* J. Phys. Chem. B 2016, 120 (34), 8757−8767. DOI: 10.1021/acs.jpcb.6b04100
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(Figure 3c). Results presented in our recent publication1 using the incorrect set of charges showed the opposite trend for the Osmotic model, i.e., decrease of the surface tension with increasing TMAO concentrations and accumulation of TMAO at the water−vapor interface. We sincerely apologize to the readers for any inconvenience caused by these errors.
n a recent publication,1 we mistakenly implemented the TMAO force-field parameters of the Osmotic model developed by Canchi et al.2 in our simulations of TMAO at water/air interfaces. In those simulations we erroneously used the set of atomic charges developed by Kast et al.3 The rest of the simulations reported in our publication were performed using the correct force-field parameters for the Osmotic model as well as for the remaining three TMAO models, so only the results reported in Figure 3a,c,d are affected. The corrected version of Figure 3 is included here. As seen in Figure 3a, surface tension calculated with the Osmotic model increases upon addition of TMAO osmolyte in a similar way as with the Dipole model.4 In agreement with this observation, TMAO is depleted from the water−vapor interface
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ACKNOWLEDGMENTS We thank Prof. William Noid and Michael Delyser for pointing out our error in the implementation of the force-field parameters in the Osmotic model.
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Figure 3. (A) Surface tension (γ) and (B) osmotic coefficient (φ) values calculated for different TMAO force fields. Osmotic coefficients are also compared with experimental values2 which are presented as purple triangles. (C) Normalized density profiles (ρ(z)/ρbulk) of TMAO nitrogen atoms at the vapor−liquid interfaces (dotted line) in 2.5 m TMAO aqueous solutions. Normalized water densities are shown in the same graph (continuous line). (D) Probability distribution (P(cos(θ)) of the cosine of the angle θ defined between ⎯⎯⎯→ the TMAO NO vector and the axis perpendicular to the liquid−vapor interfaces (z-axis, pointing toward the water phase) in 2.5 m TMAO aqueous solutions. In (C) and (D) z = 0 nm corresponds to the Gibbs dividing surface, which defines the surface at which water density is half of the water density in the bulk phase. © 2017 American Chemical Society
REFERENCES
(1) Rodríguez-Ropero, F.; Rötzscher, P.; van der Vegt, N. F. A. Comparison of Different TMAO Force Fields and Their Impact on the Folding Equilibrium of a Hydrophobic Polymer. J. Phys. Chem. B 2016, 120, 8757−8767. (2) Canchi, D. R.; Jayasimha, P.; Rau, D. C.; Makhatadze, G. I.; García, A. E. Molecular Mechanism for the Preferential Exclusion of TMAO from Protein Surfaces. J. Phys. Chem. B 2012, 116, 12095− 12104. (3) Kast, K. M.; Brickmann, J.; Kast, S. M.; Berry, R. S. Binary Phases of Aliphatic NOxides and Water: Force Field Development and Molecular Dynamics Simulation. J. Phys. Chem. A 2003, 107, 5342− 5351. (4) Schneck, E.; Horinek, D.; Netz, R. R. Insight into the Molecular Mechanisms of Protein Stabilizing Osmolytes from Global Force-Field Variations. J. Phys. Chem. B 2013, 117, 8310−8321.
Published: February 7, 2017 1455
DOI: 10.1021/acs.jpcb.7b00705 J. Phys. Chem. B 2017, 121, 1455−1455
