1. Department of Biochemistry and Molecular Biology; University of British Columbia; Vancouver BC V6T 1Z3 Canada
2. Centre for Blood Research, University of British Columbia; Vancouver BC V6T 1Z3 Canada
3. Michael Smith Laboratories, University of British Columbia; Vancouver BC V6T 1Z4 Canada
4. Department of Chemistry; University of British Columbia; Vancouver BC V6T 1Z1 Canada