/. Biochem., 78, 1321-1329 (1975)
rubrum
Toichi EBISUNO,1 Katsuya SHIGESADA,2 and Hirohiko KATSUKI Department of Chemistry, Faculty of Science, Kyoto University, Sakyo-ku, Kyoto, Kyoto 606 Received for publication, May 12, 1975
D-a-Hydroxyglutarate dehydrogenase of R. rubrum grown anaerobically in the light was partially purified and some properties were investigated. 1. The enzyme catalyzes stoichiometrically the dehydrogenation reaction of D-ahydroxyglutarate into a-oxoglutarate, coupled with the reduction of 2,6-dichlorophenolindophenol. 2. Cytochrome c 2 , cytochrome c, and ferricyanide are effective as electron acceptors with the crude enzyme but not with the purified one, whereas NAD+ and NADP+ are completely ineffective. The enzyme is thought to play a role in the electron transport system of the organism. 3. D-a-Hydroxyglutarate is virtually the sole substrate for the enzyme. The apparent activity against L-a-hydroxyglutarate is presumed to be due to contamination of the L-isomer sample with the D-isomer. The enzyme shows barely detectable activity against both isomers of malate and virtually no activity against DL-lactate and glycolate. 4. Both isomers of malate and oxalate, which are presumably substrate analogues, inhibit the enzyme activity. 5. The enzyme is not an inducible enzyme but rather is a constitutive one for R. rubrum, unlike from the enzyme of Pseudomonas putida which is an inducible enzyme for the catabolism of lysine.
The metabolism of 5-aminolevulinate has been investigated mostly from the viewpoint of tetrapyrrole biosynthesis (1—4). With regard to the metabolic fate of 5-aminolevulinate, •Present address: the Department of Chemistry, Faculty of Science, Toho University, Funabashi,
Chiba 274 •Present address: the Institute of Virus Research, Kyoto University, Kyoto 606. Abbreviations used are: DCIP, 2,6-dichlorophenolindophenol; Tris, tris(hydroxymethyl)aminomethane; EDTA, ethylenediaminetetraacetic acid. Vol. 78, No. 6, 1975
Shemin and Russell ( 5 ) proposed the operation of a cyclic pathway starting from succinate and glycine through 5-aminolevulinate, y, 5dioxovalerate, and a-oxoglutarate for the supply of Ci compounds in animals. Subsequently, the involvement of various intermediates and , ,
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rubrum
Toichi EBISUNO,1 Katsuya SHIGESADA,2 and Hirohiko KATSUKI Department of Chemistry, Faculty of Science, Kyoto University, Sakyo-ku, Kyoto, Kyoto 606 Received for publication, May 12, 1975
D-a-Hydroxyglutarate dehydrogenase of R. rubrum grown anaerobically in the light was partially purified and some properties were investigated. 1. The enzyme catalyzes stoichiometrically the dehydrogenation reaction of D-ahydroxyglutarate into a-oxoglutarate, coupled with the reduction of 2,6-dichlorophenolindophenol. 2. Cytochrome c 2 , cytochrome c, and ferricyanide are effective as electron acceptors with the crude enzyme but not with the purified one, whereas NAD+ and NADP+ are completely ineffective. The enzyme is thought to play a role in the electron transport system of the organism. 3. D-a-Hydroxyglutarate is virtually the sole substrate for the enzyme. The apparent activity against L-a-hydroxyglutarate is presumed to be due to contamination of the L-isomer sample with the D-isomer. The enzyme shows barely detectable activity against both isomers of malate and virtually no activity against DL-lactate and glycolate. 4. Both isomers of malate and oxalate, which are presumably substrate analogues, inhibit the enzyme activity. 5. The enzyme is not an inducible enzyme but rather is a constitutive one for R. rubrum, unlike from the enzyme of Pseudomonas putida which is an inducible enzyme for the catabolism of lysine.
The metabolism of 5-aminolevulinate has been investigated mostly from the viewpoint of tetrapyrrole biosynthesis (1—4). With regard to the metabolic fate of 5-aminolevulinate, •Present address: the Department of Chemistry, Faculty of Science, Toho University, Funabashi,
Chiba 274 •Present address: the Institute of Virus Research, Kyoto University, Kyoto 606. Abbreviations used are: DCIP, 2,6-dichlorophenolindophenol; Tris, tris(hydroxymethyl)aminomethane; EDTA, ethylenediaminetetraacetic acid. Vol. 78, No. 6, 1975
Shemin and Russell ( 5 ) proposed the operation of a cyclic pathway starting from succinate and glycine through 5-aminolevulinate, y, 5dioxovalerate, and a-oxoglutarate for the supply of Ci compounds in animals. Subsequently, the involvement of various intermediates and , ,
.Q ^ ,
^
.
.
ft
w a s
.
, _ _.
dem
