Sökning: "tyrosyl radical"

Visar resultat 6 - 10 av 17 avhandlingar innehållade orden tyrosyl radical.

  1. 6. Manganese and Iron Heterodimers and Homodimers in Enzymes : Insights from Density Functional Theory

    Författare :Katarina Roos; Per Siegbahn; Margareta R. A. Blomberg; Frank Neese; Stockholms universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; NATURAL SCIENCES; Ribonucleotide reductase; manganese; iron; density functional theory; kemisk fysik; Chemical Physics;

    Sammanfattning : The enzyme ribonucleotide reductase (RNR) catalyzes the reduction of ribonucleotides to deoxyribonucleotides, the building blocks of DNA, and is essential for all organisms. Canonical class I RNR R2 proteins use a diiron cofactor to generate a tyrosyl radical, which is required for catalysis. LÄS MER

  2. 7. Biophysical investigations of ribonucleotide reductase : Activation and inhibition mechanisms

    Författare :Maria Öhrström; Astrid Gräslund; Anders Hofer; Stockholms universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Molecular biophysics; Molekylär biofysik; Biophysics; biofysik;

    Sammanfattning : Ribonucleotide reductase (RNR) is the enzyme responsible for de novo synthesis of deoxyribonucleotides, needed for both synthesis and repair of cellular DNA. The RNRs known so far are divided into three distinct classes; I, II and III. The conventional class I enzyme is composed of two separate subunits. LÄS MER

  3. 8. Structural basis for metalloprotein catalysis : Characterization of Mycobacterium tuberculosis phosphatidylinositol phosphate synthase PgsA1 and Bacillus anthracis ribonucleotide reductase R2

    Författare :Kristīne Grāve; Martin Högbom; Susanna Törnroth-Horsefield; Stockholms universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; biokemi; Biochemistry;

    Sammanfattning : About a third of all proteins need to associate with a particular metal ion or metallo-inorganic cofactor to function. This interplay expands the catalytic repertoire of enzymes and reflects the adaption of these catalytic macromolecules to the environments they have evolved in. LÄS MER

  4. 9. Quantum chemical calculations of electron paramagnetic resonance of biological radicals

    Författare :Maria Engström; Shashi Karna; Linköpings universitet; []
    Nyckelord :;

    Sammanfattning : The aim of this thesis was to use state-of-the-art quantum chemical calculations of electron paramagnetic resonance (EPR) with applications to radicals in biomolecular systems. Special emphasis has been devoted to investigations of structure-to-property relations of amino acid radicals and spin labels in proteins. LÄS MER

  5. 10. Paramagnetic states of diiron carboxylate proteins

    Författare :Nina Voevodskaya; Astrid Gräslund; Peter Brzezinski; Howard Dalton; Stockholms universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; electron paramagnetic resonance; diiron carboxilate proteins; ribonucleotide reductase; alternative oxidase; Biophysics; Biofysik;

    Sammanfattning : Diiron carboxylate proteins constitute an important class of metall-containing enzymes. These proteins perform a multitude of reactions in biological systems that normally involve activation of molecular oxygen at the diiron site. LÄS MER