Effect of Temperature on the Structural and Hydrational Properties of Human Islet Amyloid Polypeptide in Water

Abstract

u sol describes the energy of H-bonds to solvent. These three model parameters are obtained by fitting to experimental C p curves. Best fits on 19 different lysozyme mutants under the same thermodynamic conditions (pH, ionic strength, etc.) reveals that u sol can be treated as constant. Moreover, u sol can be robustly parameterized with as few as five experimental mutants (the standard error of 100 random quintets is <12%). It was observed that a second degree of freedom could be removed due to a linear relationship (R¼0.86) between the remaining two parameters (d nat and v dha ) indicating that a global balance in enthalpy-entropy compensation must be maintained. Consequently, over a fairly wide range of d nat values {0.4, 1.6}, the correlation between the experimental and theoretical T m 's is nearly constant (ranging from 0.68 to 0.72). Using the best parameter set, T m can be predicted for new lysozyme mutants. Results on a validation set of an additional 81 lysozyme point mutations will be presented. This work is supported by NIH R01 GM073082.

Hydration Shells in Voronoi Tessellations

“…We estimated values of γ k solute for the molecular dynamics model of a polypeptide water solution simulated in [22]. We found the mean numbers n 1 solute = 332, n 2 solute = 513 and n 3 solute = 775.…”