Effect of introducing a disulphide bond between the A and C domains on the activity and stability of Saccharomycopsis fibuligera R64 α-amylase.

Native enzyme and a mutant containing an extra disulphide bridge of recombinant Saccharomycopsis fibuligera R64 α-amylase, designated as Sfamy01 and Sfamy02, respectively, have successfully been overexpressed in the yeast Pichia pastoris KM71H. The purified α-amylase variants demonstrated starch hydrolysis resulting in a mixture of maltose, maltotriose, and glucose, similar to the wild type enzyme. Introduction of the disulphide bridge shifted the melting temperature (TM) from 54.