Sökning: "Fahmi Himo"

Visar resultat 11 - 15 av 18 avhandlingar innehållade orden Fahmi Himo.

1. 11. Electron and Proton Transfer in Nitric Oxide Reductase : NO Binding, NO Reduction and no Pumping

   Författare :Peter Lachmann; Pia Ädelroth; Peter Brzezinski; Fahmi Himo; Stockholms universitet; []
   Nyckelord :Flow-Flash; Nitric Oxide Reductase; Heme Copper Oxidase;

   Sammanfattning : Nitric oxide reductase (NOR) from Paracoccus denitrificans catalyzes the two electronreduction of NO to N2O (2NO + 2H+ + 2e- → N2O + H2O) as part of the process ofdenitrification, the step-wise reduction of nitrate to dinitogen. The NOR-catalyzedreaction is central in the nitrogen cycle, since in this step the N=N double bond isformed. LÄS MER

3. 12. Quantum Chemical Cluster Modeling of Enzymatic Reactions

   Författare :Rongzhen Liao; Fahmi Himo; Robert Deeth; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; cluster approach; density functional theory; B3LYP; enzyme; mechanism; dinuclear; trinuclear; zinc; tungsten; hydrolysis; decarboxylation; formaldehyde oxidation; hydration; methyl transfer; Quantum chemistry; Kvantkemi; organisk kemi; Organic Chemistry;

   Sammanfattning : The Quantum chemical cluster approach has been shown to be quite powerful and efficient in the modeling of enzyme active sites and reaction mechanisms. In this thesis, the reaction mechanisms of several enzymes have been investigated using the hybrid density functional B3LYP. LÄS MER

4. 13. Quantum Chemical Modeling of Asymmetric Enzymatic Reactions

   Författare :Maria E. S. Lind; Fahmi Professor; Rajeev Prabhakar; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; biocatalysis; enantioselectivity; density functional theory; B3LYP; enzyme; hydrolysis; decarboxylation; Organic Chemistry; organisk kemi;

   Sammanfattning : Computational methods are very useful tools in the study of enzymatic reactions, as they can provide a detailed understanding of reaction mechanisms and the sources of various selectivities. In this thesis, density functional theory has been employed to examine four different enzymes of potential importance for biocatalytic applications. LÄS MER

5. 14. Quantum Chemical Studies of Enzymatic Reaction Mechanisms

   Författare :Bianca Manta; Fahmi Himo; Lubomir Rulisek; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; density functional theory; B3LYP; enzyme; cluster approach; mechanism; zinc; manganese; cytosine deaminase; ω-transaminase; dinitrogenase reductase-activating glycohydrolase; dual substrate recognition; organisk kemi; Organic Chemistry;

   Sammanfattning : Computer modeling of enzymes is a valuable complement to experiments. Quantum chemical studies of enzymatic reactions can provide a detailed description of the reaction mechanism and elucidate the roles of various residues in the active site. LÄS MER

7. 15. Quantum Chemical Modelling of Enzymatic and Organometallic Reactions

   Författare :Ferran Planas; Fahmi Himo; Edina Rosta; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; DFT; enzyme; organometallic; mechanisms; organisk kemi; Organic Chemistry;

   Sammanfattning : In this thesis, density functional theory (DFT) is employed in the study of two enzymes and two organometallic systems.First, the natural reaction mechanism, as well as the enantioselective formation of α-hydroxyketones catalysed by two thiamine diphosphate (ThDP)- dependent enzymes, namely benzoylformate decarboxylase (BFDC) and 2-succinyl-5-enolpyruvyl-6-hydroxy-3-cyclohexene-1-carboxylic-acid (SEPHCHC)- synthase (MenD), are investigated. LÄS MER