Immobilized-Liposome Sensor System for Detection of Proteins under Stress Conditions

Abstract

An electrolyte-entrapping liposome was immobilized on an Au electrode to design and develop an immobilized-lipo-some sensor (ILS) system for the detection of the damage of proteins. Three kinds of proteins, such as bovine car-bonic anhydrase, lysozyme and chitosanase, were used as model analytes. The proteins treated by a denaturant (guanidium hydrochloride, GuHCl) were applied to the ILS analysis, resulting that the significant electrical signals could effectively be detected due to the interaction between the liposome and GuHCl-denatured protein. The diffu-sion currents normalized by protein concentrations were linearly correlated with local hydrophobicity of proteins evaluated by the conventional aqueous two-phase partitioning method. The ILS system can, therefore, be utilized as a useful tool for an on-line monitoring to conformational changes of proteins.