Sökning: "Oxygenases"

Visar resultat 1 - 5 av 9 avhandlingar innehållade ordet Oxygenases.

1. 1. Functional Models for Non-heme Mononuclear Iron Oxygenases

   Författare :Mainak Mitra; Kemisk fysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Bioinorganic chemistry; Iron; Oxygenases; Catalysis;

   Sammanfattning : Non-heme mononuclear iron oxygenases catalyze a large number of oxidation reactions in biological systems. The reactions are often proposed to proceed via the intermediacy of high valent Fe(IV) oxo (ferryl) or, Fe(V) oxo (perferryl) intermediates. LÄS MER

3. 2. Oxidation of Ketones: A (Chemo-) Enzymatic Approach Using Oxygenases and Hydrolases

   Författare :Georgina Chávez; Bioteknik; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; cross linked enzyme aggregates.; caprolactone; perhydrolase; Lipase B from Candida antarctica;

   Sammanfattning : Oxidation reactions are important in organic chemistry as well as in nature. In industry, oxidations are commonly used for the synthesis of chemicals and pharmaceuticals, however such processes have a number of limitations, they use chlorinated solvents, stoichiometric oxidation reagents, and in some cases the reagents that have risks of explosion during transportation and storage. LÄS MER

4. 3. Macrophages, Nitric oxide synthases and Heme oxygenases: possible roles during peripheral nerve regeneration

   Författare :Sofia Magnusson; Biologiska institutionen; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; satellite cells; peripheral ganglia; cell signalling; nerve regeneration; heme oxygenase; Macrophages; nitric oxide synthase; Animal physiology; Djurfysiologi;

   Sammanfattning : The purpose of this study was to investigate the suggestions that macrophages, and the systems generating nitric oxide (NO) and carbon monoxide (CO), i.e. nitric oxide synthases (NOS) and heme oxygenases (HO), could be important for peripheral nerve regeneration. LÄS MER

5. 4. Theoretical studies of mononuclear non-heme iron active sites

   Författare :Arianna Bassan; Per E. M. Siegbahn; Sason Shaik; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; quantum chemistry; enzyme catalysis; iron enzymes; Quantum chemistry; Kvantkemi;

   Sammanfattning : The quantum chemical investigations presented in this thesis use hybrid density functional theory to shed light on the catalytic mechanisms of mononuclear non-heme iron oxygenases, accommodating a ferrous ion in their active sites. More specifically, the dioxygen activation process and the subsequent oxidative reactions in the following enzymes were studied: tetrahydrobiopterin-dependent hydroxylases, naphthalene 1,2-dioxygenase and α-ketoglutarate-dependent enzymes. LÄS MER

7. 5. Enzymatic activation of oxygen in the biosynthesis of polyketide antibiotics

   Författare :Hanna Koskiniemi; Karolinska Institutet; Karolinska Institutet; []
   Nyckelord :;

   Sammanfattning : The electron structure of molecular oxygen (O2) is such that it cannot spontaneously react with organic molecules, a feature that protects organisms from oxidative stress. However, oxygenases can insert O2 in organic substrates. The enzymes do this after activating O2 for the reaction, most often with the aid of an organic or inorganic cofactor. LÄS MER