Figure 10.

Mab 55B20 is reactive against the mature 3CL protease (His-Prot), while Mab 55A10 is reactive against the N-terminus of 3DL. Total protein of induced cultures of E. coli transformed with plasmid pet11a-His-Prot-Pol* and pet11a-His-Prot (G₂₁₁₉-Q₂₃₉₃) were resolved in SDS-PAGE and analyzed via Western blot, side by side. (A) Mab 10B6 anti-His showed only the full-length His-Prot-Pol* (60 kDa) and the His-Prot (35 kDa). Note the weaker expression of His-Prot-Pol* in direct comparison to the His-Prot. Because of the shorter exposure time of this image, the cleavage product His-Prot is not visible in the case of pet11a-His-Prot-Pol*. (B) Mab 55A10 anti-Pol reacted with the 60 kDa Prot-Pol*-His and the smaller fragments of 26 and 28 kDa representing released Pol*-His. No reactivity of Mab 55A10 was seen against proteins in the culture expressing pet11a-His-Prot. (C) Mab 55B20 anti-Prot showed bands at 60 kDa in the case of His-Prot-Pol* and of 35 kDa for the mature protease in the case of His-Prot. Taken together, it can be clearly seen that Mab 55A10 targets the polymerase region and Mab 55B20 targets the protease region.