A study of succinic dehydrogenase, indole acetic acid oxidase, nitrate reductase and cytochrome c reductase in Hygrophorus Conicus
"The activity of the enzyme succinic dehydrogenase (succinate : phenazine methosulfate oxidoreductase, EC 1.3.99.1) of Hygrophorus conicus, a member of a class of fungi known as basidiomycetes, was found to be stimulated by nitrate. Two substances were tested as electron acceptors in the measurement of succinic dehydrogenase activity. Of the two substances tried, phenazine methosulfate and brilliant cresyl blue, the former was found to be the best. Nicotinamide adenine dinucleotide (NAD⁺) was a necessary cofactor for the enzyme and could be readily dissociated from the enzyme. The enzyme has the properties of a high molecular weight nucleo- or lipoprotein. The presence of two kinds of succinic dehydrogenase in H.conicus was demonstrated. One was precipitated at 10% ammonium sulfate saturation and the other at 40%... The oxidation of IAA by the enzyme IAA oxidase of H.conicus produces at least two more products besides oxindole acetic acid. Attempts to separate and characterize these products were unsuccessful. It is suggested that one of the products has a close structural relationship with o-formaminobenzoyl acetic acid while the other may be 5-hydroxy oxindole acetic acid. It was concluded that H.conicus has a great facility for detoxification of toxic substances present in the medium by either stimulating or inducing oxidative enzymes"--Abstract, page iii-iv.
Missouri University of Science and Technology
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