Cyanide-resistant Mitochondria from the Spadix of an Arum

Abstract

HIGHLY active preparations of mitochondria have been obtained from the spadix of Arum maculatum ¹. These exhibited the ability to oxidize acids of the Krebs's cycle and pyruvic acid in their presence. No carrier needed to be added and the terminal oxidase responsible for the oxidations was not identified. The respiration of slices of spadix is not inhibited by cyanide², even though it is very rapid, with Q_{O 2} rising to 31.8. As mitochondria are generally supposed to promote respiratory oxidations through their contained cytochromes, the reaction of these aroid mitochondria to cyanide is of obvious interest.