1.8.4.9 -20°C, 1 day, PpAPR is completely inactivated, plant APRs are very unstable enzymes because of the rapid loss of their iron-sulfur clusters 1.8.4.9 -20°C, 1 day, PpAPR-B retains 30% of its activity 1.8.4.9 4°C, PpAPR, completely stable for 48 h, inactivation after longer than 2 dayswith 15% remaining activity after 4-5 days 1.8.4.9 4°C, PpAPR-B is stable over 5 days