ABSTRACTThe University of Manchester,School of Chemical Engineering and Analytical ScienceABSTRACT OF THESIS submitted by Mala Alhaji Sainna for the degree of Doctor of Philosophy (PhD) and entitled "Electronic and catalytic properties of iron porphyrin complexes: Trends and reaction mechanisms" The cytochrome P450s belong to the superfamily of proteins containing a heme cofactor and, thus, are termed hemoproteins. They perform important oxidation reactions in the body, and are, for instance, involved in the metabolism of drug molecules in the liver as well as the detoxification of xenobiotics and biosynthesis of hormones. The active species of these enzymes is identified as iron(IV)-oxo heme cation radical species (also known as Compound I), but it is short-lived and difficult to trap and characterize experimentally. Therefore, theoretical modelling as implemented in this thesis was instituted in order to give important answers to questions such as the mechanisms of substrate monoxygenation, the oxidant activity in enzymes and the effect of protein architecture on chemical catalysis. The present thesis focuses on addressing these issues using a combination of density functional theory and quantum mechanics/molecular mechanics studies. The work gives insight into the nature of heme, axial ligand bound to heme and the impact of substrate on oxidation reactions. We find trends in reaction mechanisms and rate constants and rationalize rate constants and reaction processes. The work has also given insight into the nature of high valent iron(IV)-oxo heme cation radical oxidants and their reactivity patterns with respect to a broad range of substrates. Hence, the offered studies have shown how small structural differences in the active site will result in dramatic differences in reactivity patterns and how nature approach and catalyzes vital reaction mechanisms.
Date of Award | 31 Dec 2015 |
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Original language | English |
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Awarding Institution | - The University of Manchester
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Supervisor | Samuel De Visser (Supervisor) |
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Electronic and catalytic properties of iron porphyrin complexes: Trends and reaction mechanisms.
Mala, A. (Author). 31 Dec 2015
Student thesis: Phd