Heat transfer in protein–water interfaces

Abstract

We investigate using transient non-equilibrum molecular dynamics simulation the temperature relaxation process of three structurally different proteins in water, namely; myoglobin, green fluorescence protein (GFP) and two conformations of the Ca 2+ -ATPase protein. By modeling the temperature relaxation process using the solution of the heat conduction equation we compute the thermal conductivity and thermal diffusivity of the proteins, as well as the thermal conductance of the protein-water interface. Our results indicate that the temperature relaxation of the protein can be described using a macroscopic approach. The protein-water interface has a thermal conductance of the order of 100-270 MW m −2 K −1 , characteristic of water-hydrophilic interfaces. The thermal conductivity of the proteins is of the order of 0.1-0.2 † Imperial College and NTNU ‡ Imperial College and CAS ¶ NTNU and CAS § UB and CAS 1 Anders Lervik et al.Heat transfer in protein-water interfaces W m −1 K −1 as compared with ≈ 0.6 W m −1 K −1 for water, suggesting that these proteins can develop temperature gradients within the biomolecular structures that are larger than those of aqueous solutions. We find that the thermal diffusivity of the transmembrane protein, Ca 2+ -ATPase is about three times larger than that of myoglobin or GFP. Our simulation shows that the Kapitza length of these structurally different proteins is of the order of 1 nm, showing that the protein-water interface should play a major role in defining the thermal relaxation of biomolecules.

Nonequilibrium molecular dynamics simulations of the thermal conductivity of water: A systematic investigation of the SPC/E and TIP4P/2005 models

“…It is then possible to rationalize the performance of fluid suspensions (nanofluids) in heat management problems [7][8][9] , or to quantify heat transfer in nanomaterials 10 and biological assemblies. The latter is a problem of particular significance in chemical physics and biophysics 11,12 .…”

Transition from Thermokinetic to Chemical Instabilities in a Modified Sal’nikov Model

“…Thus, instead of expecting ATP production to occur solely from a biochemical pathway tied to chemical instabilities, it could be the result of coupling thermal force and chemical machinery, as stated by non-equilibrium thermodynamics. 43 In fact, Lervik et al 44 used non-equilibrium molecular dynamics simulation to show that Ca 2+ -ATPase is able to sustain large thermal gradients across its structures.…”

Local heating of molecular motors using single carbon nanotubes

“…) (Lervik et al 2010). Thus, CNTs are an ideal candidate nanomaterial for exploring heat transfer at the level of individual biomolecules.…”

“…Assuming that the end point (length 2 μm) of the CNT works as a heat source by laser irradiation, these authors numerically determined the heat conduction from the end point into the rest of the CNT and the surrounding water using a boundary condition of constant temperature (20°C) at the 6 planes of the water cuboid. In this calculation, the thermal conductivity of both myosin and the actin filament was neglected due to the small size of these proteins and their similar thermal conductivity (0.12-0.23 Wm Lervik et al 2010) to water (~0.6 Wm…”

“…Since the minimal targeting size in the laser irradiation system is limited by the beam of the laser light, and 1480-nm light is relatively harmful to (Lervik et al 2010). …”