THE OXIDATION MECHANISM OF GLYCOLIC AND l-LACTIC ACIDS BY THE ENZYME FROM LEAVES
スポンサーリンク
概要
- 論文の詳細を見る
1. The amounts of O2 consumed and CO2 evolved in the oxidation of glycolic acid by the salt-precipitated enzyme were found to be dependent upon the amount of catalase contaminated in the enzyme sample. When catalase was practically absent, the amount of O2 consumed per mole of glycolic acid oxidized was one mole. When excess of catalase was present the O2-uptake was reduced to 1/2 of this value. 2. The addition of cyanide caused the accumulation of H2O2 together with the disappearance of CO2-formation without changing the amount of O2-uptake. The addition of azide, on the other hand, caused the increase in CO2-formation with no H2O2-accumulation, but the same O2-uptake was brought about as in the case of CN-addition. 3. The addition of peroxidase and its hydrogen donor (reduced Bindschedler's green) caused the disappearance of CO2-formation and of H2O2-accumulation without changing the amount of O2-uptake. 4. H2O2 was proved to react spontaneously with the intermediate as well as with synthetic glyoxylic acid to form CO2. Some additional evidence was aduced in support of the conclusion that glyoxylic acid is the intermediary product in the oxidation of glycolic acid. 5. Glycolic acid is oxidized by plant sap with an equivalent amount of O2-uptake but only with a little CO, -formation. When the sap was pretreated with H2O2, CO2-formation was remarkably increased. 6. The formation of H2O2 and accumulation of pyruvic acid were confirmed in the oxidation of lactic acid by the same enzyme in the presence of catalase in excess. 7. Based on these observations it was concluded that the oxidation of glycolic and lactic acids proceeds as follows: In the enzyme solution, Glycolic acid+O2→oxidaseglyoxylic acid+H2O2→spontaneousformic acid+CO2+H2O, Lactic acid+O2→oxidasepyruvic acid-+H2O2→spontaneousacetic acid+CO2+H2O. In plant sap, Glycolic acid+O2+AH2oxidase→peroxidaseglyoxylic acid+A+2H2O, Lactic acid+O2+AH2oxidase→peroxidasepyruvic+A+2H2O, where AH2 represents some unknown, presumably phenolic, substances present in the plant sap. The authors wish to thank Prof. Dr. Hiroshi Tamiya for his kind advice and interest in this work. The authors are also indebted to Dr. Yasuyuki Ogura for furnishing purified equine liver catalase used in this study, and to Dr. Takeshi Mori for his helpful suggestions in the purification of the enzyme. This work was aided by a Grant from the Scientific Research Fund of the Ministry of Education.
- 社団法人 日本生化学会の論文
社団法人 日本生化学会 | 論文
- Role of Histidine 46 in the Hydrolysis and the Reverse Transphosphorylation Reaction of RNase Rh from Rhizopus niveus.
- Inhibition of Aspartate Chemotaxis of Escherichia coli by Site-Directed Sulfhydryl Modification of the Receptor.
- Characterization and Primary Structure of a Base Non-Specific and Acid Ribonuclease from Dictyostelium discoideum.
- BIOCHEMICAL STUDIES ON CARBOHYDRATES:XXXV. Chondrosin
- THE INFLUENCE OF INORGANIC IONS ON THE ACTIVITY OF AMYLASES