From Molecule to Tissue: XIII European Conference on the Spectroscopy of Biological Molecules, Palermo, Italy, August 28–September 2, 2009, Part 2 of 2View this Special Issue
Gastric ATPase phosphorylation/dephosphorylation monitored by new FTIR-based BIA–ATR biosensors
Biosensors are composite devices suitable for the investigation of receptor–ligand interactions. In this paper we present the specific application to a membrane embedded protein of a new sensor device, so-called BIA–ATR, based on Attenuated Total Reflection–Fourier Transform Infrared (ATR–FTIR) spectroscopy. It consists in a functionalised ATR germanium crystal whose surface has been covalently modified to adsorb a biomembrane. Detection of the ligand–receptor interaction is achieved using FTIR spectroscopy. We report the specific detection of the phosphorylation/dephosphorylation of the H+/K+ gastric ATPase. The H+, K+-ATPase is a particularly large protein entity. This glycosylated protein contains more than 1300 residues and is embedded in a lipid membrane. Yet we demonstrate that the BIA–ATR sensor is capable of monitoring the binding of a single phosphate on such a large protein entity. Furthermore, we also demonstrate the potential of the approach to monitor the kinetics of binding and dissociation of the ligand.
Copyright © 2010 Hindawi Publishing Corporation. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.