Discovery and Exploitation of Novel Lytic Polysaccharide Monooxygenase Redox Partners.

点击翻译按钮获取中文摘要

Plants contain a vast amount of sugar. Sugar is important because it can be fermented by microorganisms into ethanol which can be used as a fuel - a commodity that we are running out of. The advantage of using fuels derived from plants is that this creates a carbon neutral cycle, where carbon dioxide released from fuel combustion is reabsorbed by photosynthesis during growth of new crops. Biofuels are already being produced, but they are largely derived from crops that could be better utilized as food sources. A significant challenge is, therefore, ensuring that we move towards a more sustainable solution by making use of the large amount of sugar that is found in the inedible parts of plants which currently goes to waste. These sugars are locked away in structures known as polysaccharides, which effectively act as the plants skeleton giving them rigidity. The most abundant polysaccharide is called cellulose, which is already utilized extensively in the paper and cotton industries, and is the main component of wood. The sugars in cellulose are all joined together in a highly ordered structure that is incredibly difficult to break down. The challenge then is to find an efficient means of deconstructing cellulose to release the sugars so that they can be used to generate bioethanol. Fungi and bacteria have evolved over millions of years to live in all sorts of environments. Some of these organisms are able to degrade and live off wood. In order to do this, they produce protein-based molecular machines known as enzymes. As a structural biologist I am able to study these enzymes and gain a fuller understanding of how they break down cellulose. Recently a new family of enzymes has been identified in this process known as LPMOs (lytic polysaccharide monooxygenases). LPMOs show great promise in enhancing the efficiency of biofuels production but our knowledge of how they function is limited.LPMOs require two things - oxygen and electrons. Oxygen is readily available from the air but electrons need to be supplied from some other source. In bacteria, this source of electrons has not yet been identified. The aim of this fellowship is to characterize a range of enzymes that are potential electron sources for LPMOs. By determining their three-dimensional structures and biochemical properties I aim to build up a thorough understanding of the interplay between these various enzymes at the molecular level. Modern enzyme engineering approaches will then be applied to make more efficient and novel enzymes for deployment in industry for biofuels production. Electron transport, and the so-called redox reactions which these processes support, are also of importance to other industries beyond the biofuels sector and so this fellowship also offers ample opportunities to explore the application of these proteins to solve other scientific problems. Having worked extensively on LPMOs this fellowship offers me the perfect opportunity to branch out into my own research area answering a fundamental question in the field and expanding my knowledge of new scientific approaches to tackle real world problems.