Coomassie brilliant blue stained sodium dodecyl sulphate polyacrylamide gel showing expression of AMYSBS gene: Lane 1, the soluble portion after lysis of BL21-CodonPlus (DE3) cells transformed with pET-21a without insert (negative control); Lane 2, the total cell protein after lysis of BL21-CodonPlus (DE3) cells transformed with pET-AMY; Lane 3, insoluble portion after lysis of sample in lane 2; Lane 4, soluble portion after lysis of sample in lane 2; Lane 5, purified AMYSBS after column chromatography.