Sökning: "Sason Shaik"

Hittade 2 avhandlingar innehållade orden Sason Shaik.

1. 1. Theoretical studies of mononuclear non-heme iron active sites

   Författare :Arianna Bassan; Per E. M. Siegbahn; Sason Shaik; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; quantum chemistry; enzyme catalysis; iron enzymes; Quantum chemistry; Kvantkemi;

   Sammanfattning : The quantum chemical investigations presented in this thesis use hybrid density functional theory to shed light on the catalytic mechanisms of mononuclear non-heme iron oxygenases, accommodating a ferrous ion in their active sites. More specifically, the dioxygen activation process and the subsequent oxidative reactions in the following enzymes were studied: tetrahydrobiopterin-dependent hydroxylases, naphthalene 1,2-dioxygenase and α-ketoglutarate-dependent enzymes. LÄS MER

3. 2. Modeling DNA Damage

   Författare :Patric Schyman; Aatto Laaksonen; Sason Shaik; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; DNA; Ionizing radiation; DNA radicals; Strand break; Hydrogen abstraction; Density Functional Theory; Car-Parrinello Molecular Dynamics; QM MM; Physical chemistry; Fysikalisk kemi; Physical Chemistry; fysikalisk kemi;

   Sammanfattning : In this thesis methods of computational chemistry have been used to examine DNA damaging processes initiated by ionizing radiation, free radicals, or Low-Energy Electrons (LEE). The computational chemistry method based on quantum mechanics that has been mainly used here is the Density Functional Theory (DFT). LÄS MER