Full-length cDNA of enok was cloned into vector pBacPAK8 carrying a N-terminal His-Flag tag. Purification of the recombinant enok was performed essentially as described previously with minor modifications (Lin et al. 2008 (link)). Briefly, baculovirus-infected Sf9 insect cells were cultured at 27°C in the Sf-900 III SFM (Invitrogen) supplemented with 10% FBS and penicillin—streptomycin (Gibco). After lysis and centrifugation, clarified cell lysates were incubated with α-Flag (M2) agarose beads (Sigma) for 3 h at 4°C followed by washes and elution with triple Flag peptide.