1. From the Department of Biochemistry (E.K.A., V.d.W., M.v.B., T.A.E.v.A., H.P., C.J.M.d.V.), Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands; Gaubius Laboratory (J.M.G.), Leiden, the Netherlands; and ULB-IBMM-IRIBHN (B.P.), Gosselies, Belgium.