Determination of the copper-binding site in amine oxidase by Fourier transform infrared spectroscopy.
FT-IR spectra in the region 3500-900 cm(-1) of 4-aminobutyric acid methyl ester, 3,3-dithiobis(2-nitrobenzoic acid), and a model compound, 3-nitro-1,2,4-triazol-5-one, were recorded and analyzed to determine the location of the copper(II) in the amine oxidase from Rhodospirillum rubrum. A combination of the second-derivative spectra in the region 1500-900 cm(-1) and the infrared difference spectra in the range 3500-2300 cm(-1) allowed us to identify the specific thiolate ligand of the copper(II) ion in the enzyme molecule. The results suggest that the histidine ligand of the enzyme molecule forms the Cu(II)-S coordination. The amino acid ligand is not involved in the coordination of the copper(II) ion.[Anticoagulants for the prevention and treatment of venous thromboembolism].
The treatment of choice for acute venous thromboembolism is anticoagulation with low-molecular-weight heparin (LMWH) or unfractionated heparin (UFH). The duration of treatment depends on the severity of the thromboembolic event, the initial INR value and risk factors associated with thrombosis. For low-risk patients, the risk of recurrence of thromboembolism must be balanced against the risk of bleeding during a short course of anticoagulant therapy, i.e. as low as possible but not zero. In these patients, the ideal treatment should be a short course of oral anticoagulant therapy, which in clinical practice can be provided with fondaparinux. However, in patients with an increased risk of thromboembolism (first-degree relatives with a history of venous thromboembolism or thrombophilia or more than one risk factor), the anticoagulant treatment should be uninterrupted for at least 3 months, with LMWH in most cases. The dose of LMWH should be fixed to 70 mg once a day or 60 mg twice a day. For the maintenance of anticoagulation, vitamin K antagonists
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