A new T677C mutation of the aspartoacylase gene encodes for a protein with no enzymatic activity

Objective To verify the effect of and to date the unknown T677C mutation of the human N-acetylaspartoacylase (hASPA) gene on the function of the mutated enzyme. Design and methods Wild type and I226T-mutated proteins were expressed and purified from a transformed Escherichia coli colony. Enzymatic activities were measured in the presence of varying substrate concentrations. Results Whilst kinetic parameters of wild type hASPA were in line with data in literature, I226T-mutated hASPA showed no enzymatic activity. Conclusion Data indicated that this new mutation might be responsible in homozygosis for the phenotype corresponding to Canavan disease.