@article {2015|1677, title = {Recovering protein thermal stability using all-atom Hamiltonian replica-exchange simulations in explicit solvent}, journal = {J. Chem. Theo. Comput.}, volume = {11}, year = {2015}, pages = {5573{\textendash}5577}, abstract = {

The REST2 method is successfully applied to investigate the thermal stability of chignolin CLN025 and of Trp-cage. As opposed to temperature replica exchange, REST2 relies on the rescaling of the protein potential energy, which allows a smaller number of replicas. The shape of the stability curve reconstructed on the basis of the corresponding-state principle is in very good agreement with experimental data; for chignolin, the effect of mutations is also recovered.

}, issn = {15499626}, doi = {10.1021/acs.jctc.5b00954}, author = {Guillaume Stirnemann and Fabio Sterpone} } @article {2012|1753, title = {Rate limit of protein elastic response is tether dependent}, journal = {Proc. Natl. Acad. Sci. U.s.a.}, volume = {109}, year = {2012}, pages = {14416{\textendash}14421}, abstract = {

The elastic restoring force of tissues must be able to operate over the very wide range of loading rates experienced by living organisms. It is surprising that even the fastest events involving animal muscle tissues do not surpass a few hundred hertz. We propose that this limit is set in part by the elastic dynamics of tethered proteins extending and relaxing under a changing load. Here we study the elastic dynamics of tethered proteins using a fast force spectrometer with sub-millisecond time resolution, combined with Brownian and Molecular Dynamics simulations. We show that the act of tethering a polypeptide to an object, an inseparable part of protein elasticity in vivo and in experimental setups, greatly reduces the attempt frequency with which the protein samples its free energy. Indeed, our data shows that a tethered polypeptide can traverse its free-energy landscape with a surprisingly low effective diffusion coefficient D(eff) \~{} 1,200 nm(2)/s. By contrast, our Molecular Dynamics simulations show that diffusion of an isolated protein under force occurs at D(eff) \~{} 10(8) nm(2)/s. This discrepancy is attributed to the drag force caused by the tethering object. From the physiological time scales of tissue elasticity, we calculate that tethered elastic proteins equilibrate in vivo with D(eff) \~{} 10(4)-10(6) nm(2)/s which is two to four orders magnitude smaller than the values measured for untethered proteins in bulk.

}, issn = {0027-8424}, author = {Berkovich, R. and Hermans, R. I. and Popa, I. and Guillaume Stirnemann and Garcia-Manyes, S. and Berne, B. J. and Fernandez, J. M.} } @article {2011|1383, title = {Reorientation and Allied Dynamics in Water and Aqueous Solutions}, journal = {Annu. Rev. Phys. Chem.}, volume = {62}, year = {2011}, pages = {395{\textendash}416}, abstract = {

The reorientation of a water molecule is important for a host of phenomena, ranging over?in an only partial listing?the key dynamic hydrogen-bond network restructuring of water itself, aqueous solution chemical reaction mechanisms and rates, ion transport in aqueous solution and membranes, protein folding, and enzymatic activity. This review focuses on water reorientation and related dynamics in pure water, and for aqueous solutes with hydrophobic, hydrophilic, and amphiphilic character, ranging from tetramethylurea to halide ions and amino acids. Attention is given to the application of theory, simulation, and experiment in the probing of these dynamics, in usefully describing them, and in assessing the description. Special emphasis is placed on a novel sudden, large-amplitude jump mechanism for water reorientation, which contrasts with the commonly assumed Debye rotational diffusion mechanism, characterized by small-amplitude angular motion. Some open questions and directions for further research are also discussed. Expected final online publication date for the Annual Review of Physical Chemistry Volume 62 is March 31, 2011. Please see http://www.annualreviews.org/catalog/pubdates.aspx for revised estimates.

}, isbn = {0066-426X 1545-1593}, issn = {0066-426X}, doi = {doi: 10.1146/annurev.physchem.012809.103503}, url = {http://www.annualreviews.org/doi/abs/10.1146/annurev.physchem.012809.103503$\backslash$nhttp://www.annualreviews.org.login.ezproxy.lib.purdue.edu/doi/pdf/10.1146/annurev.physchem.012809.103503}, author = {Laage, Damien and Guillaume Stirnemann and Fabio Sterpone and Rey, Rossend and Hynes, James T.} } @article {2011|1691, title = {On the reorientation and hydrogen-bond dynamics of Alcohols}, journal = {J. Phys. Chem. B}, volume = {115}, year = {2011}, pages = {12173{\textendash}12178}, abstract = {

The mechanism of the OH bond reorientation in liquid methanol and ethanol is examined. It is found that the extended jump model, recently developed for water, describes the OH reorientation in these liquids. The slower reorientational dynamics in these alcohols compared to water can be explained by two key factors. The alkyl groups on the alcohol molecules exclude potential partners for hydrogen bonding exchanges, an effect that grows with the size of the alkyl chain. This increases the importance of the reorientation of intact hydrogen bonds, which also slows with increasing size of the alcohol and becomes the dominant reorientation pathway.

}, issn = {15206106}, author = {Vartia, Anthony A. and Mitchell-Koch, Katie R. and Guillaume Stirnemann and Laage, Damien and Thompson, Ward H.} }