“ Guanidine treatment at pH 4.5 decreased the reversible stabilities of Gly137- ->Ala , Gly139-->Ala and Gly137/Gly139-->Ala/Ala glucoamylases at infinite dilution while not changing those of Gly251-->Ala and Gly383-->Ala glucoamylases, which is, in general, opposite to what occurred with thermoinactivation.”