1. Neurochemistry Section, Institute of Clinical Neuroscience, SU/Moelndal Hospital, Göteborg University, S-43180 Moelndal, Sweden, Protein Research Group, Department of Molecular Biology, University of Southern Denmark, Odense, Denmark, Bruker Daltonik, Bremen, Germany, and Protein Interaction Laboratory, Department of Molecular Biology, University of Southern Denmark, Odense, Denmark