PMID: 20444686 , Related PDB ids: 3LX9, 3LXA, 3LXB, 3LXC

Authors:

Tomasic IB, Metcalf MC, Guce AI, Clark NE, Garman SC

Title:

Interconversion of the specificities of human lysosomal enzymes associated with Fabry and Schindler diseases.

Journal:

J Biol Chem. 2010 Jul 9;285(28):21560-6. Epub 2010 May 5.

Abstract:

The human lysosomal enzymes alpha-galactosidase (alpha-GAL, EC 3.2.1.22) and alpha-N-acetylgalactosaminidase (alpha-NAGAL, EC 3.2.1.49) share 46% amino acid sequence identity and have similar folds. The active sites of the two enzymes share 11 of 13 amino acids, differing only where they interact with the 2-position of the substrates. Using a rational protein engineering approach, we interconverted the enzymatic specificity of alpha- GAL and alpha-NAGAL. The engineered alpha-GAL (which we call alpha-GAL(SA)) retains the antigenicity of alpha-GAL but has acquired the enzymatic specificity of alpha-NAGAL. Conversely, the engineered alpha-NAGAL (which we call alpha-NAGAL(EL)) retains the antigenicity of alpha-NAGAL but has acquired the enzymatic specificity of the alpha-GAL enzyme. Comparison of the crystal structures of the designed enzyme alpha-GAL(SA) to the wild-type enzymes shows that active sites of alpha-GAL(SA) and alpha-NAGAL superimpose well, indicating success of the rational design. The designed enzymes might be useful as non-immunogenic alternatives in enzyme replacement therapy for treatment of lysosomal storage disorders such as Fabry disease.