• Folke Tjerneld

Proteomics is currently a focus of scientific attention both in basic bioscience and in drug development, following the huge advances in genome sequencing. Proteome analysis comprises identification of the proteins expressed in a cell or organism, and also quantification of the proteins, e.g. in studies of up- and down regulation of protein expression. The basic reason for problems with membrane proteomics is the hydrophobicity of the proteins. Membrane proteins need to be solubilized with detergents. Even when solubilized, integral membrane proteins still have a strong tendency to aggregate due to the dominating hydrophobic surface areas. Thus, proteome analysis is complicated; e.g. in the isoelectric focusing step in 2-D electrophoresis, many integral membrane proteins will form aggregates and cannot be analysed. In this project we are developing methods for membrane proteomics with a starting point in established methods for membrane vesicle isolation using aqueous two-phase systems which will be adopted to the studied organism of interest, and intergrating these methods with mass spectrometry (MALDI-TOF MS/MS) and bioinformatics for proteome analysis. Detergent/polymer two-phase systems and systems with amphiphilic polymers are being evaluated for membrane protein pre-fractionation prior to high resolution separation. Applications will be evaluated in proteome studies on plasma membranes from human white blood cells (membrane proteins connected to allergy) and on plasma membranes from blood platelets.