Monitoring protein denaturation using thermal conductivity probe

Abstract

We propose a method for probing denaturation of proteins by measuring the thermal conductivity of the solution. We use the three-omega method with a microfabricated ac thermal sensor to measure the thermal conductivity of lysozyme, beta-lactoglobulin, and bovine serum albumin protein solutions over a range of temperature and pH. Results suggest that conformation transformation of the protein during denaturation changes the thermal network in protein solutions and thus changes the thermal conductivity for all the tested proteins. The proposed method of denaturation monitoring requires much simpler experimental setup than conventional methods such as differential scanning calorimetry and circular dichroism detection. We also demonstrate that the proposed analytical technique can detect the protein denaturation in real time. Consequently, it is expected to be useful in lab-on-a-chip (LoC) applications as the probe can be easily miniaturized for integration into LoC devices and allows real-time analysis. (C) 2012 Elsevier B.V. All rights reserved.