1. Center for Blood Research; University of British Columbia; 2350 Health Sciences Mall Vancouver V6T 1Z3 Canada
2. Department of Chemistry; University of British Columbia; Vancouver V6T 1Z1 Canada
3. Institute of Chemistry and Biochemistry; Freie Universität Berlin; Takustrasse 3 14195 Berlin Germany
4. Department of Pathology and Laboratory Medicine; University of British Columbia; Vancouver V6T 2B5 Canada