The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Tranquillizing drugs of the phenothiazine class form charge-transfer complexes with a ceruloplasmin-Cu(II) ion [De Mol NJ. 1985 Biochim Pharmacol34, 2605–2609], the interaction resulting in a stimulatory effect on the ceruloplasmin catalyzed oxidation of catecholamines and NADH; the latter used as substrate in the present study. A good correlation between stability of the enzyme–drug complex and...
Lactoperoxidase, which is produced in mammary glands, is proposed to be involved in carcinogenesis, because of its ability to react with estrogenic molecules, oxidizing them to free radicals. In the present study the reactivity towards six species (estradiol, ethynylestradiol, estriol, estrone, pregnenolone and mestranol) was investigated by means of a NADH-coupled system. The enzyme activity towards...
Serum albumin (human, bovine) has a specific Cu(II)-ion binding site, and is proposed to act as a copper transport protein in blood plasma. Human transferrin, normally about 30% saturated with iron in vivo, has two sites/molecule capable of complexing Cu(II); one more strongly than the other (Hirose et al. 1996). The present study shows that this binding site has a slightly stronger affinity for Cu(II)...
Lactoperoxidase is an iron containing enzyme, which is an essential component of the defense system of mammalian secretary fluids. The enzyme readily oxidizes adrenaline and other catecholamines to coloured aminochrome products. A Km-value of 1.21 mM and a catalytic constant (k = V\max/[Enz]) of 15.5 × 103 min−1 characterized the reaction between lactoperoxidase and adrenaline at pH 7.4. Urate was...
Xanthine oxidase reduces molecular oxygen to H2O2 and superoxide radicals during its catalytic action on xanthine, hypoxanthine or acetaldehyde. Ascorbate is catalytically oxidized by the superoxide radicals generated, when present in the reaction solution (Nishikimi 1975). The present study shows that iron ions markedly stimulate the enzyme dependent ascorbate oxidation, by acting as a red/ox-cycling...
Serum albumin can specifically bind one Cu(II)-ion, and is proposed to function as a copper transport protein in vivo. Cu(II)-albumin is rapidly reduced by ascorbate. A second order rate constant of 0.54 mM−1 min−1 was estimated for the reaction. The oxidation process is catalytic, the Cu(I)-albumin molecule being reoxidized by molecular oxygen. The reaction was found to follow Michaelis-Menten kinetics,...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.