Separation of the Enzymes present in the Mitochondrial Fraction from Apple Peel

Abstract

As a result of investigations of the respiration of disks of apple peel, it was suggested¹ that the extra carbon dioxide evolved during the period of the respiration climacteric in apple fruits may be due, at least in part, to the operation of a malic enzyme system. Dilley² has recently isolated a malic enzyme, dependent on TPN and Mn⁺⁺, from American apples. Using Dilley's method of isolation we have confirmed the existence of a similar enzyme in the pulp of the Cox's Orange Pippin apple. We have, however, also found a similar enzyme in mitochondria isolated from the peel of the same apples³. At this stage it should be emphasized that by ‘mitochondria’ is meant the centrifugate obtained under standard conditions and that, while all the evidence suggests³ that the preparation contains a high proportion of intact mitochondria, other particles and agglomerates having the same size/density characteristics could be present. For example, the preparations contain variable amounts of polyphenolic material⁴.