Sökning: "amino-acid radicals"
Visar resultat 1 - 5 av 16 avhandlingar innehållade orden amino-acid radicals.
1. Exploring amino-acid radicals and quinone redox chemistry in model proteins
Sammanfattning : Amino-acid radical enzymes have been studied extensively for 30 years but the experimental barriers to determine the thermodynamic properties of their key radical cofactors are so challenging that only a handful of reports exist in the literature. This is a major drawback when trying to understand the long-range radical transfer and/or catalytic mechanisms of this important family of enzymes. LÄS MER
2. Mechanistic Studies on Proton-Coupled Electron Transfer from Tyrosine and Tryptophan Derivatives
Sammanfattning : Proton-coupled electron transfer (PCET) from tyrosine (Y) and tryptophan (W) is vital to many redox reactions in Nature where PCET between several Ys, or Ws, or between a mix of Ys and Ws can be used to transfer electrons, or protons, or both over large distances of several Å. Studying the PCET reaction mechanisms of Y and W is important for fundamental knowledge, and can help researchers that wish to mimic redox reactions in Nature. LÄS MER
3. Using de novo design proteins to explore tyrosine radicals and cation-π interactions
Sammanfattning : Redox cofactors and amino-acid free radicals play important roles in biology. Although many of the same cofactors and amino acids that form these radicals are found across a broad range of biological systems, identical cofactors can have different reduction potentials. The local environment plays a role in defining these redox potentials. LÄS MER
4. Thiyl radicals, reaction kinetics and redox chemistry
Sammanfattning : In focusing on the free radical chemistry of thiyl radicals,two importantclasses are dealt with, namely, the amino acidalkylthiyl and the acylthiyl radicals, where pulse radiolysisand steady state γ-radiolysis are applied.Amino acid thiyl radicals (RS•), are important in manybiological systems,as intermediates in the repair reactions ofthiols towards targeted carbon-centeredradicals and ascatalytic centers in many enzymatic reactions. LÄS MER
5. Quantum chemical calculations of electron paramagnetic resonance of biological radicals
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