Date of Award

2017

Document Type

Open Access Dissertation

Department

Chemistry and Biochemistry

Sub-Department

College of Arts and Sciences

First Advisor

Thomas Makris

Abstract

Non-Ribosomal Peptide Synthetases (NRPSs) and their exogenous tailoring partners have been heavily studied but not in the context of non-cognate systems. Orf78, a dinuclear iron β-hydroxylase from the lysobacter pathway and homologous to CmlA from the chloramphenicol pathway, is used to test affinities for one native and two non-native T-domains. Results indicate that there is enough difference between Type I and Type II NRPS systems to disfavor common recognition motifs. Additionally, the β-hydroxylase P450sky, from the skyllamycin biosynthetic pathway, is used in conjunction with the NRPS ATdomain NikP1AT from the nikkomycin biosynthetic pathway, in lieu of the homolog P450nikQ. The second portion of the thesis will discuss the creation of a sustainable source of biodiesel products are currently a goal of ‘green’ programs. The fatty acid decarboxylase P450olet uses the cheaply obtainable hydrogen peroxide as the oxidant to achieve a high-valent iron species. Substitution of the iron for manganese in the porphyrin scaffold raises the redox potential and forms a Mn(IV)-oxo complex that is too weak to perform C-H bond abstractions. Alternatively, substitution of the iron-protoporphyrin IX with ironmesoporphyrin IX lowers the redox potential, increasing the amount of hydroxylated fatty acid at lower carbon chain lengths but also leads to a decrease in the efficiency in multiple turnover reactions.

Rights

© 2017, Steven Charles Ratigan

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