choline oxidase (chox) was chosen as a model enzyme for evaluating the performance of cnts’ functional groups for development of enzyme electrodes. cnts were functionalized with carboxylic acid, amine or amide groups. carboxylic acid, amine and amide functionalized cnts were obtained by acid treatment, ethylenediamine or tetraethylenepentamine chemically modification and ammonia plasma treatmen...

The construction and performance of an amperometric microbiosensor for the determination of choline chloride by immobilizing choline oxidase on a cellulose acetate membrane are described. The procedure of choline determination involved the electrochemical detection of enzymatically generated hydrogen peroxide. This microsensor has a linear response between 0.038-0.1 mM choline chloride. The...

the construction and performance of an amperometric microbiosensor for the determination of choline chloride by immobilizing choline oxidase on a cellulose acetate membrane are described. the procedure of choline determination involved the electrochemical detection of enzymatically generated hydrogen peroxide. this microsensor has a linear response between 0.038-0.1 mm choline chloride. the res...

Genetically modified crops have resistance to abiotic stress by introduction of choline oxidase protein. In the present study, the safety of choline oxidase protein derived from Arthrobacter globiformis was assessed for toxicity and allergenicity. The protein was stable at 90 degrees C for 1 h. Toxicity studies of choline oxidase in mice showed no significant difference (p > 0.05) from control ...

Choline oxidase catalyzes the oxidation of choline to glycine betaine. The reaction includes betaine aldehyde as an intermediate. FAD is reduced by the alcohol substrate, betaine aldehyde intermediate and oxidized by molecular oxygen to give hydrogen peroxide. In this study, the Ser101Ala variant of choline oxidase was prepared to elucidate the contribution of the hydroxyl group of Ser101 in th...

Choline oxidase catalyzes the two-step oxidation of choline to glycine betaine, one of limited osmoprotectants, with the formation of betaine aldehyde as an enzyme bound intermediate. Glycine betaine accumulates in the cytoplasm of plants and bacteria as a defensive mechanism to withstand hyperosmolarity and elevated temperatures. This makes the genetic engineering of relevant plants which lack...

Rat liver choline dehydrogenase has been known for many years to be one of the “cytochrome-reducing dehydrogenases” (1). Although it is functionally and structurally linked to the respiratory chain and acts without the mediation of readily dissociable coenzymes (2)) the cytochrome components linking choline dehydrogenase to oxygen have not been established. The purpose of this investigation was...

Rat liver choline dehydrogenase has been known for many years to be one of the “cytochrome-reducing dehydrogenases” (1). Although it is functionally and structurally linked to the respiratory chain and acts without the mediation of readily dissociable coenzymes (2)) the cytochrome components linking choline dehydrogenase to oxygen have not been established. The purpose of this investigation was...

The work of Moyer and du Vigneaud (1) has demonstrated that, of a considerable number of compounds related to choline, choline itself, betaine, its sulfur analogue dimethylthetin, and the dimethylethyl analogue of choline, i.e. dimethylethyl-P-hydroxyethylammonium chloride, are the only ones which will permit rat growth on a methionine-free homocystinecontaining diet. Subsequent work by Dubnoff...

Ethionine (S-ethylhomocysteine) has been shown to inhibit the growth of rats and of various microorganisms (2-7). In rats, this growth inhibition can be overcome by simultaneous administration of either methionine or choline, indicating that ethionine interferes in some manner with the metabolism of these compounds. Various hypotheses have been formulated in an effort to define more precisely t...