1. Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
2. Centre for Blood Research, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
3. Institute of Pharmacy, Medicinal Chemistry, Freie Universität Berlin, Königin-Luise-Straße 2+4, 14195 Berlin, Germany
4. Institute for Physiological Chemistry, Martin-Luther-University Halle-Wittenberg, Hollystraße 1, D-06114 Halle (Saale), Germany