Studies on the Respiratory System of the Poky Strain of Neurospora

Authors

Alfred Tissieres, Molteno Institute, University of Cambridge, Cambridge, England
Herschel Mitchell, Kerckhoff Laboratories of Biology, California Institute o j Technology, Pasadena, California
Francis A. Haskins, University of Nebraska-LincolnFollow

Date of this Version

1953

Comments

Published in JOURNAL OF BIOLOGICAL CHEMISTRY 205:1 (1953), pp. 423-433.

Abstract

It was shown recently that the poky strain of Neurospora accumulates large amounts of cytochrome c, but is deficient in cytochromes a and b and thus in cytochrome oxidase and succinic acid oxidase activities (1). These findings, which suggest that respiration in poky does not utilize the cytochrome system, led to a study of the respiratory system of poky compared with that of wild type. The experiments reported here are concerned with the effects of the inhibitors cyanide and azide on the respiration of intact mycelium of poky and wild type, the oxygen uptake of cell-free extracts in the oxidation of their endogenous substrates, the cofactor requirement for this oxidation, and the effects of azide and of oxygen tension. Evidence presented confirms that, in poky, respiration does not depend upon the cytochromes, but upon another terminal oxidase system in which flavin- adenine dinucleotide (FAD) enzymes appear to be concerned.