The role of Ala134 in controlling substrate binding and reactivity in ascorbate peroxidase

The role of Ala134 in controlling substrate specificity in ascorbate peroxidase was explored. Replacement of Ala134 by proline has a small effect on oxidation of ascorbate or guaiacol. We conclude that the A134P mutation alone does not substantially affect the reactivity of towards aromatic substrates bound at the δ-heme edge.168