Terminal Oxidation in Cell-free Extracts of Fungii.

Dowler, William M. (University of Illinois, Urbana), Paul D. Shaw, and David Gottlieb. Terminal oxidation in cell-free extracts of fungi. J. Bacteriol. 86:9-17. 1963.-The terminal respiration in cell-free extracts of ten representative fungi is mediated by an electron transport system similar to that observed in animal tissue. Reduced nicotinamide adenine dinucleotide (NADH) and succinic cytochrome c reductases and NADH oxidase activity are contained in the extracts. An antimycin-sensitive site and cytochrome oxidase are present. Dehydrogenases including glucose-6-phosphate, triose phosphate, isocitric, glutamic, succinic, and malic dehydrogenase were found, but pyruvic and alpha-ketoglutaric dehydrogenases were absent. The soluble nature of the dehydrogenases indicates probable disruption of the mitochondria, since normally these enzymes are found within the mitochondria. Particles containing most of the terminal respiratory activity could be sedimented by centrifugation at 40,000 x g for 30 min. Oxygen was utilized by cell-free extracts with NADH, succinate, and isocitrate as substrates, but not with glucose.