Catalytic mechanism of fungal glucoamylase as defined by mutagenesis of Asp176, Glu179 and Glu180 in the enzyme from Aspergillus awamori.

Asp176, Glu179 and Glu180 of Aspergillus awamori glucoamylase appeared by differential labeling to be in the active site. To test their functions, they were replaced by mutagenesis with Asn, Gln and Gln respectively, and kinetic parameters and pH dependencies of all enzyme forms were determined. Glu179----Gln glucoamylase was not active on maltose or… CONTINUE READING