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 1226T-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, 1226T-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.