Publications

• The catalytic mechanism of 1-aminocyclopropane-1-carboxylic acid oxidase.

  Charng Y.Y., Chou S.J., Jiaang W.T., Chen S.T., Yang S.F.

  It has been proposed that 1-aminocyclopropane-1-carboxylic acid (ACC) oxidase catalyzes the oxidation of ACC to ethylene via N-hydroxyl-ACC as an intermediate. However, due to its chemical instability the putative intermediate has never been isolated. Here, we have shown that a purified recombinan ... >> More

  It has been proposed that 1-aminocyclopropane-1-carboxylic acid (ACC) oxidase catalyzes the oxidation of ACC to ethylene via N-hydroxyl-ACC as an intermediate. However, due to its chemical instability the putative intermediate has never been isolated. Here, we have shown that a purified recombinant ACC oxidase can utilize alpha-aminoisobutyric acid (AIB), an analog of ACC, as an alternative substrate, converting AIB into CO2, acetone, and ammonia. We chemically synthesized the putative intermediate compound, N-hydroxyl-AIB (HAIB), and tested whether it serves as an intermediate in the oxidation of AIB. When [1-(14)C]AIB was incubated with ACC oxidase in the presence of excess unlabeled HAIB as a trap, no labeled HAIB was detected. By comparing the acetone production rates employing HAIB and AIB as substrates, the conversion of HAIB to acetone was found to be much slower than that of using AIB as substrate. Based on these observations, we conclude that ACC oxidase does not catalyze via the N-hydroxylation of its amino acid substrate. ACC oxidase also catalyzes the oxidation of other amino acids, with preference for the D-enantiomers, indicating a stereoselectivity of the enzyme. << Less

  Arch Biochem Biophys 385:179-185(2001) [PubMed] [EuropePMC]

• Structure, catalytic activity and evolutionary relationships of 1-aminocyclopropane-1-carboxylate synthase, the key enzyme of ethylene synthesis in higher plants.

  Jakubowicz M.

  Both ethylene and the enzymes of ethylene synthesis are subjects of intensive scientific investigation. The present review discusses structure, catalytic activity and evolutionary relationships of 1-aminocyclopropane-1-carboxylate synthase, identified for the first time in ripening tomato in 1979. ... >> More

  Both ethylene and the enzymes of ethylene synthesis are subjects of intensive scientific investigation. The present review discusses structure, catalytic activity and evolutionary relationships of 1-aminocyclopropane-1-carboxylate synthase, identified for the first time in ripening tomato in 1979. This enzyme is responsible for the conversion of S-adenosyl-L-methionine to 1-aminocyclopropane-1-carboxylic acid, which is the key step of ethylene synthesis in higher plants. The role of this enzyme (especially in the fruit ripening) was demonstrated in 1991 in transgenic tomato plants, expressing 1-aminocyclopropane-1-carboxylate synthase antisense RNA. On the basis of mutagenesis and crystallization of the enzyme, new data were provided on the three-dimensional structure and amino-acid residues which are critical for catalysis. The control of ethylene production is of great interest for plant biotechnology because it can delay senescence and overmaturation. These processes are responsible for large loss of vegetables and fruit on storage. Detailed structural and biochemical data are necessary to help design 1-aminocyclopropane-1-carboxylate synthase inhibitors, whose application is expected to have immense agricultural effects. << Less

  Acta Biochim Pol 49:757-774(2002) [PubMed] [EuropePMC]

  This publication is cited by 1 other entry.