Figure 7.

The predicted histidine and asparagine residues are functional. A) Histidine and asparagine residues were alanine-substituted and confirmed by sequencing. Targeted amino acids were underlined in chromatogram. B) Both wild-type form of rPfcal-IIa (WT) and mutant form of rPfcal-IIa (MT) were expressed in the baculovirus system. Purified proteins were confirmed by Western blot using anti-PfCapnA antibody. C) The enzymatic activity was measured by fluorogenic substrate assay. The mutations in predicted histidine and asparagine residues completely disrupted enzymatic activity of rPfcal-IIa.