Sökning: "protonation state"

Visar resultat 1 - 5 av 36 avhandlingar innehållade orden protonation state.

  1. 1. Quantum Chemical Interpretation of Protein Crystal Structure

    Författare :Kristina Nilsson; Beräkningskemi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; structure; Theoretical chemistry; quantum chemistry; Teoretisk kemi; kvantkemi; protein; ComQum-X; Hess2FF; QM MM; hetero-compound; metal; oxidation state; protonation; force field; quantum refinement; refinement;

    Sammanfattning : An initial model in the crystallographic structure determination process, usually contains many errors. To produce an accurate model, one must carry out several cycles of crystallographic refinement. LÄS MER

  3. 2. Computational Studies of Nitrogenase

    Författare :Lili Cao; Beräkningskemi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; nitrogenase; QM MM; quantum refinement; FeMo cluster; E4 state; N2 binding; V-nitrogenase; P-cluster; S2B dissociation; broken-symmetry state; homocitrate; DFT; protonation state; disorder; ComQumX-2QM;

    Sammanfattning : AbstractNitrogenase is the only enzyme that can convert the inert nitrogen molecule to ammonia, so that it can be used for biomass production and in biosynthetic pathways. It contains a complicated acitve site, composed of eight metal ions, nine sulfur ions and one carbide ion (the FeMo cluster). LÄS MER

  4. 3. The Oxygen Evolving cycle in Photosystem II studied with EPR Spectroscopy at different pH and Temperature

    Författare :Susan F Morvaridi; Biokemi och Strukturbiologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Kemi; Chemistry; Naturvetenskap; Temperature; Natural science; pH; EPR; S cycle; Photosystem II;

    Sammanfattning : PSII catalyses the light-induced water splitting process which leads to electron transfer through the thylakoid membrane and formation of energy rich molecules. Several redox components including a Mn4Ca, an amino acid residueYZ, two special Chl molecules P680, two Pheo and two quinone molecules participate in this process. LÄS MER

  5. 4. Trapping Tyrosine Z : Exploring the Relay between Photochemistry and Water Oxidation in Photosystem II

    Författare :Johannes Sjöholm; Stenbjörn Styring; Fikret Mamedov; A. William Rutherford; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Photosystem II; Tyrosine Z; EPR; proton-coupled electron transfer; hydrogen bond; pH;

    Sammanfattning : Photosystem II is unique! It remains the only enzyme that can oxidize water using light as energy input. Water oxidation in photosystem II is catalyzed by the CaMn4 cluster. The electrons extracted from the CaMn4 cluster are transferred to P680+ via the tyrosine residue D1-Tyr161 (YZ). LÄS MER

  7. 5. Analysis of Fluorescence Flicker as a Tool to Monitor Proton Transport and Biomolecular Interactions

    Författare :Tor Sandén; Jerker Widengren; Pär Nordlund; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Physics; Fysik;

    Sammanfattning : The overall focus of this thesis is on fluorescence flicker processes of fluorescent molecules, e.g. protonation-deprotonation or singlet-triplet electronic state transitions, intrinsic or generated by their interaction with their environment, monitored by fluorescence spectroscopy. LÄS MER