Isoprene monooxygenase: a missing link in the global isoprene cycle
Lead Research Organisation:
University of East Anglia
Department Name: Environmental Sciences
Abstract
Isoprene is a climate active gas which is produced by trees and is released into the atmosphere in huge amounts (the same amounts as methane; approximately 500Tg per year!). While we know a lot about biological oxidation of methane, virtually nothing is known about biological sinks of isoprene and the mechanisms by which bacteria oxidize isoprene and thus mitigate its effects on global warming and our climate. This project involves study of a novel diiron centre containing isoprene monooxygenase enzyme from the bacterium Rhodococcus. This enzyme will be purified and then characterized at the biochemical level. The biotechnological potential of the enzyme for the production of epoxides and chiral synthons will also be investigated.
Organisations
People |
ORCID iD |
| John Murrell (Primary Supervisor) | |
| Leanne Sims (Student) |
Studentship Projects
| Project Reference | Relationship | Related To | Start | End | Student Name |
|---|---|---|---|---|---|
| BB/M011216/1 | 01/10/2015 | 31/03/2024 | |||
| 1800133 | Studentship | BB/M011216/1 | 01/10/2016 | 30/09/2020 | Leanne Sims |
| Description | The substrate specificity, inhibition by alkynes and kinetics of the isoprene monooxygenase system from Rhodococcus sp. AD45 in the whole-cell system has been determined. This will allow a greater environmental understanding of the microbial oxidation of the climate-active gas isoprene. Three of the four components of the enzyme system have been purified; the oxygenase, Rieske protein and coupling protein. Attempts to purify the reductase have been unsuccessful due to instability, inclusion bodies and precipitation after affinity chromatography. Reconstitution of an active complex has not yet been achieved. The Rieske protein has been extensively characterised by spectroscopic techniques and mass spectrometry. I (Leanne) hope to complete this objective by the end of the funding period in October 2020. |
| Exploitation Route | The alkyne inhibition profile may be used to determine how much environmental isoprene oxidation is being performed by bacteria containing the isoprene monooxygenase, as opposed to cooxidation by alternative soluble diiron monooxygenases (SDIMOs). The substrate specificity will inform future research on SDIMOs as biocatalysts, and what SDIMO characteristics influence substrate specificity. A fully purified and reconstituted isoprene monooxygenase complex, if achieved, could be used to inform biocatalysis studies of SDIMOs and be used to understand the enzyme's vital role in biological degradation of isoprene. |
| Sectors | Environment,Manufacturing, including Industrial Biotechology |