Fig. 4 in Structural and functional features of a class VI chitinase from cashew (Anacardium occidentale L.) with antifungal properties

Fig. 4. Polyacrylamide gel electrophoresis (SDS-PAGE) of the purified recombinant chitinase from Anacardium occidentale, a member of class VI that has chitinolytic activity. (A) The recombinant chitinase (lane 1; 35 μg) was reduced with β-mercaptoethanol and subjected to denaturing gel electrophoresis (15% polyacrylamide), as described in the Methods section. Lane M: protein markers. (B) Representative fragmentation mass spectrum (LC-MS/MS) of a tryptic peptide, obtained from in gel-digestion of the 45 kDa protein band, that matched a segment of 17 residues of the primary structure of the recombinant product. (C) Colorimetric enzymatic assay, showing the ability of the recombinant cashew chitinase to degrade colloidal chitin. (D) Plot of initial reaction velocities vs substrate concentration. The enzymatic assays (panels C and D) were performed at pH 6.0 and 40 ◦C, and using colloidal chitin as substrate, as described in the Methods section.