Oxygen activation by mononuclear non-heme iron enzymes

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Abstract/Contents

Abstract
Non-heme iron (NHFe) enzymes are in critical in Nature, playing significant roles in bioremediation, the biosynthesis of natural products, DNA repair and human health. These metalloenzymes utilize an Fe cofactor to activate dioxygen for reaction with organic substrates in a wide variety of chemical transformations including: H-atom abstraction, hydroxylation, halogentation, aromatic ring cleavage, aliphatic ring expansion/formation, electrophilic aromatic substitution and sulfur oxygenation/oxidation. Elucidating the mechanisms of these diverse catalysts requires defining the geometric and electronic structure of key Fe-O2 intermediates along the reaction cycle. An ideal tool for the interrogation of these Fe-O2 intermediates is nuclear resonance vibrational spectroscopy (NRVS), a synchrotron-based technique that observes the vibrational side-bands of the Fe-57 Mossbauer transition, making it a site-selective probe of all normal modes containing Fe displacement. Interpretation and analysis of NRVS spectra by correlation to quantum mechanical simulations (via density functional theory), allows for assignment of Fe vibrations and crucially geometric structure. In this thesis, NRVS is applied to the Fe-O2 intermediates in the extradiol dioxygenase, homoprotocatechuate 2,3-dioxygenase (HPCD-HPCA-Int-1) and the intradiol dioxygenase, protocatechuate 3,4-dioxygenase (PCD-4FC-Int-1), the pre-Fe(IV)=O intermediate in the pterin-dependent hydroxylase, tryptophan hydroxylase, and intermediate Q in methane monooxygenase (included in the appendix), while the ETHE1 sulfur oxidase versus oxygenase and the alpha-KG-dependent DAOCS concerted versus sequential DAOCS mechanistic studies utilize a combination of spectroscopic methods.

Description

Type of resource text
Form electronic resource; remote; computer; online resource
Extent 1 online resource.
Place California
Place [Stanford, California]
Publisher [Stanford University]
Copyright date 2022; ©2022
Publication date 2022; 2022
Issuance monographic
Language English

Creators/Contributors

Author Babicz, Jeffrey T
Degree supervisor Solomon, Edward I
Thesis advisor Solomon, Edward I
Thesis advisor Fayer, Michael D
Thesis advisor Kanan, Matthew William, 1978-
Degree committee member Fayer, Michael D
Degree committee member Kanan, Matthew William, 1978-
Associated with Stanford University, Department of Chemistry

Subjects

Genre Theses
Genre Text

Bibliographic information

Statement of responsibility Jeffrey T Babicz.
Note Submitted to the Department of Chemistry.
Thesis Thesis Ph.D. Stanford University 2022.
Location https://purl.stanford.edu/hd667vm5656

Access conditions

Copyright
© 2022 by Jeffrey T Babicz
License
This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).

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