Parvez I. Haris
Department of Biological Sciences, De Montfort University,
The Gateway, Leicester, LE1 9BH, United Kingdom,
E-Mail: pharis@dmu.ac.uk
Components of biological membranes are being increasingly utilised for technological applications. For example, coating medical devices with phospholipid membranes led to the development of novel biocompatible materials [1]. More recently there is interest in utilising the protein component of biomembranes for developing biosensors and biomaterials. Advances in this field require a better understanding of the conformational properties of membrane proteins. We are characterising the folding of synthetic ion-channel peptides corresponding to functionally important domains of voltage-gated potassium channels using different biophysical techniques. Potassium channels are large transmembrane proteins that are responsible for diffusion of potassium ions across cell membranes. The lack of sufficient quantities of these proteins from natural sources, is a major barrier towards their structural characterisation using biophysical techniques such as X-ray crystallography and NMR spectroscopy. The crystal structure of a bacterial potassium channel has been recently reported, however the three-dimensional structure of the more complicated voltage-gated ion-channels remain unknown. Synthetic peptide fragments corresponding to functionally important domains of these proteins provide an attractive approach towards characterising the folding and structural organisation of these ion-channels. We are using a range of biophysical techniques including FTIR, NMR and CD spectroscopy to characterise the conformation of several ion-channel peptides in diverse media including phospholipid membranes [1-4]. The conformation of the ion-channel peptides are highly sensitive to the surrounding media. Here we will report on the environment dependent conformational switching in a number of synthetic ion-channel peptides.
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