Expression, Characterization, and Cellular Localization of Knowpains, Papain-Like Cysteine Proteases of the Plasmodium knowlesi Malaria Parasite
Knowpains were expressed in BL21(DE3) E. coli cells, purified from induced cells under denaturing conditions, refolded, and processed into mature proteases. For indicated knowpains (knowpain-2, KP2; knowpain-3, KP3; and knowpain-4, KP4) samples of the total lysates of uninduced (Un) and induced (In) cells, soluble (Sol) and insoluble (Ins) fractions of induced cells, Ni-NTA purified (Ni) and ion-exchange purified (IE) proteins, and refolded (Ref) and processed mature proteases (Pros) were resolved by 12% SDS-PAGE under reducing conditions. The gel was stained with coomassie blue. The same marker (M) was used in all cases, and molecular masses of markers are indicated in kDa; and the position of 29 kDa marker for the processed KP3 lane is indicated.