FIG. 6.

Purification of PrKX. cos cells were transfected with pSVPrKX, and His-tagged PrKX was isolated as described in Materials and Methods. Bacterially expressed His-PrKX (lane 2) and total protein from either pUC19 (lane 3)- or SVPrKX (lane 4)-electroporated cos cells was separated by SDS-polyacrylamide gel electrophoresis and compared with nickel affinity-purified cos His-PrKX (lanes 5). Duplicate gels were either stained with Coomassie brilliant blue (A) or Western blotted and probed with an antibody directed against the His tag (B). The eluted 42-kDa protein was found to be greater than 90% pure and was found only in the SVPrKX-electroporated cells when probed with the anti-His tag antibody.