Figure 2. Functional analysis of laforin mutants.

(A) Recombinant proteins expressed in bacteria were purified using an amylose resin and used for in vitro phosphatase assays employing the artificial substrate OMFP. The mutant C266S was used as a negative control. (B) The same samples were used in phosphatase assays using different pH conditions and represented as % phosphatase activity compared to the pH of maximum activity of each mutant (pH = 8 in all cases). Error bars represent SD of three independent measurements; statistical significance refers to the activity of wt protein (*p<0.05, **p<0.01 and ***p<0.001).