Combination therapy for treating disorders of protein deficiency

A method for improving stability in vitro or to increase lifespan in vitro of α-galactosidase A purified human recombinant wild type in a formulation having a pH between 7.0 and 7.5 for parenteral administration to be human, by contacting the α-galactosidase a in a pharmaceutically acceptable carrier with 1-deoxygalactonojirimycin in an effective amount for increased stability in vitro or to increase where the α-galactosidase life of the α-galactosidase a purified, a it is not a mutant α-galactosidase a that is misfolded in a biologically inactive conformation.