Purification of mutant mPlg using Superdex-200 SEC column. Results of wild type and all 16 mutants are shown. Each mutant was expressed, refolded, and purified as described in the methods section. Non-reduced SDS-PAGE (4-12% polyacrylamide gradient gel) was used to access the folding. Each batch of refolding was performed with the wild-type enzyme as a positive control. On the SDS-PAGE, the lower major band in the second peak is the folded enzyme. In the SEC graph, the folded, active peak is indicated with red arrows.