Mantle phenoloxidase activity and its role in sclerotization in a snail Achatina fulica

The precursors of sclerotin such as phenol and phenoloxidase have been localized in the mantle tissue of Achatina fulica based on incubation study. The phenolic compound exists as dopyl protein. The mantle shows both mono- and diphenoloxidase activity as evidenced by the effective oxidation of tyrosine and Dopa. The enzyme shows a pH optimum of 6.5. Chemicals acting on the mantle phenoloxidase reveal that it contains sulphydryl groups. Studies on the effect of temperature show that the heat inactivation of the enzyme is reversed at higher temperatures. Electrophoretic study indicates that the enzyme exists in multiple forms. Results are discussed in relation to sclerotization.