Figure 2.

(a) Separation by cation-exchange chromatography. Peaks I and II contain MASP-1 CCP1-CCP2-SP, while the broad peak labelled ‘Bz’ is caused by benzamidine–HCl. The absorbance of benzamidine partially masks the protein peaks. The solid line is the absorbance at 280 nm, the dashed line is the absorbance at 254 nm and the dotted line is the conductivity. (b) Analysis of chromatographic fractions by native acidic PAGE. Peak I (lane 1) and peak II (lane 2) of the cation-exchange step are a mixture of two species each and three overall. Peak II was further purified by anion-exchange chromatography. The purest fractions contained a single species (lane 3) of MASP-1 CCP1-CCP2-SP.