Search for dissertations about: "amino-acid radicals"

Showing result 1 - 5 of 16 swedish dissertations containing the words amino-acid radicals.

2. 1. Exploring amino-acid radicals and quinone redox chemistry in model proteins

   Author : Kristina Westerlund; Cecilia Tommos; Astrid Gräslund; Sara Linse; Stockholms universitet; []
   Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; amino-acid radicals; quinone redox chemistry; model proteins; protein redesign; electrochemistry; Biochemistry; Biokemi; biokemi; Biochemistry;

   Abstract : 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. READ MORE

4. 2. Mechanistic Studies on Proton-Coupled Electron Transfer from Tyrosine and Tryptophan Derivatives

   Author : Astrid Nilsen-Moe; Leif Hammarström; Pia Ädelroth; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Proton-Coupled Electron Transfer; PCET; Tyrosine; Tryptophan; Amino Acid Radicals; Transient Absorption; Chemistry with specialization in Physical Chemistry; Kemi med inriktning mot fysikalisk kemi;

   Abstract : 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. READ MORE

5. 3. Using de novo design proteins to explore tyrosine radicals and cation-π interactions

   Author : Bruce W. Berry; Cecilia Tommos; Anders Hofer; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; tyrosine; radicals; cation-pi interactions; de novo designed proteins; biochemistry; biophysics; Biochemistry; biokemi;

   Abstract : 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. READ MORE

6. 4. Thiyl radicals, reaction kinetics and redox chemistry

   Author : Rong Zhao; KTH; []
   Keywords : ;

   Abstract : 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. READ MORE

7. 5. Quantum chemical calculations of electron paramagnetic resonance of biological radicals

   Author : Maria Engström; Shashi Karna; Linköpings universitet; []
   Keywords : ;

   Abstract : 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. READ MORE