Figure 5.

Purification of RK from transfected COS-1 cells. (A) Chromatography on heparin–Sepharose. RK purification procedure from transiently transfected COS-1 cells was as in Methods. Elution profiles show absorption at 280 nm KCl, concentration and the RK activity. (B) Chromatography on mAb-6D8-protein A-Sepharose. Fractions 22–25 from A were pooled and applied to an immunoaffinity column as in Methods. Proteins from the loading sample (L), the flow-through (FL), the high-salt wash (wash 2–4), the low-salt wash (wash 5, 6, 8), and the elution fractions (elution 1–8) were analyzed by SDS/PAGE (Coomassie staining) (I). Selected fractions were analyzed by immunoblotting by using mAb-6D8 (II; M, molecular weight markers).