Effect of calcium and zinc ions on the sensitivity of peroxidase from mosses (Mniumsp.) and ferns (Polypodium vulgare) to high temperature

Abstract

Incubation of peroxidase from Mnium sp. and Polypodium vulgare with calcium or zinc ions caused an activation or inhibition. The enzyme was thermostabilized. The pronounced effect of calcium is interpreted as the result of its established structural role in the enzyme molecule and the hypothesis that calcium maintains the peptide bonds around the active site. The individual peroxidase isoenzymes reacted differently to metal ions added and to increased temperatures. These results are important for characterization of metabolic response to environmental stress and can be used in biological monitoring. Keywords: peroxidase, enzyme thermosensitivity, mosses, ferns, calcium, zinc.