Enzyme structure-function studies towards novel spirotetronates and materials

Abstract

Biology generally performs chemistry using enzymes in a process termed biocatalysis. The natural products generated via biocatalysis represent a large source of chemical diversity and include compounds, such as antibiotics and materials, that are hugely beneficial to society. Even though pharmaceutical companies have moved away from natural products as a source of therapeutics over the past three to four decades, these compounds still represent a continuing source of novel drug leads with highly desirable characteristics. Abyssomicin C, a type 1 spirotetronate polyketide isolated from Micromonospora maris AB-18-032, is an example natural product antibiotic effective against clinically relevant Gram-positive and mycobacterial strains. Whilst an effective antimicrobial there are several issues that remain regarding the cytotoxicity profile of this compound. This thesis outlines efforts to further our understanding of how abyssomicin C inhibits its molecular target, aminodeoxychorismate synthase component 1 (PabB), and further elucidate the biosynthetic route to, and regulation of, this compound. As such, x-ray crystallographic and in silico docking experiments were performed for PabB from Gram-positive sources. Enzyme activity assays have been developed to enable rapid testing of functionally optimised abyssomicin C derivatives against PabB and related enzymes. Alongside the studies into PabB, attempts to exploit a separate biosynthetic pathway common to methanogenic archaea, towards an ambition of producing a suite of self-healing materials, are outlined. mfn genes, involved in the production of methanofuran in methanogenic archaea, have been cloned into synthetic operons to enable pathway reconstitution in a heterologous host, allowing subsequent production of non-natural products with self-healing capability based on the thermally reversible Diels-Alder reaction.

Date of Award	6 Dec 2022
Original language	English
Awarding Institution	University of Bristol
Supervisor	Paul R Race (Supervisor), Paul Curnow (Supervisor) & James E M Stach (Supervisor)