Dissecting and Exploiting Lytic Polysaccharide Monooxygenases

在植物、昆虫和海洋生物的细胞壁中发现的被称为“多糖”的复合糖影响着我们所有人的日常生活。植物纤维素是这些糖中含量最多的，是纺织和造纸工业的基础（纸和棉花都是由纤维素制成的）。如果我们能够可持续地生产所谓的“第二代”生物燃料，如生物乙醇，植物细胞壁多糖，尤其是纤维素，也非常重要。纤维素在这方面非常重要的原因是它非常丰富（全球每年生产1000亿公斤），存在于所有植物中，并且是植物的主要成分，例如柳枝稷，可以在边缘土地上密集种植。然而，有一个主要问题是纤维素的化学惰性限制了生物乙醇的生产，目前纤维素不能以可持续的方式分解成糖。这是一个大问题。事实上，国际能源机构表示，只有克服纤维素顽固的关键技术障碍，生物乙醇才能在满足可持续能源需求方面发挥重要作用，这反映了所有能源当局的想法。这项BBSRC资助申请的目的是研究如何从真菌和细菌中分离出天然催化剂，称为“酶”，实际上可以用来消化和分解包括植物纤维素和昆虫/甲壳类动物甲壳素在内的多糖。这些催化剂是新兴工业的先锋，其目标是利用复杂的生物燃料来源。作为我们工作的一部分，我们将发现具有多种功能的新酶，研究它们的三维结构，并重点剖析它们对铜等金属的催化能力的高度不寻常的依赖。然后，我们将利用新兴的“合成生物学”领域来设计全新的催化剂，使用自然界中不存在的天然成分。我们的工作将使人们对这些催化剂的功能和作用有更深入的了解，并为其在生物燃料和其他行业的开发提供基础。

The complex sugars, termed "polysaccharides", that are found in the cell-walls of plants and in insects and marine organisms impact on the everyday lives of us all. Plant cellulose, the most abundant of these sugars, is the basis of the textile and paper industries (both paper and cotton are made of cellulose). Plant cell-wall polysaccharides, especially cellulose, are also very important if we are ever able to produce sustainably so-called "second-generation" biofuels such as bioethanol. The reason that cellulose is very important in this regard is that it is highly abundant (100 billion kilogrammes are produced globally every year), is present in all plants, and is the principal component of plants, such as switchgrass, that can be grown densely on marginal land. However, there is one major problem which is the production of bioethanol from cellulose is limited by the chemical inertness of cellulose, which cannot currently be broken down into sugars in a sustainable way. This is a major problem. Indeed, reflecting the thoughts of all authorities on energy, The International Energy Agency says that bioethanol will only play a major role in meeting sustainable energy demands if the key technological barrier of cellulose obduracy can be overcome. The aim of this BBSRC grant application is to study how natural catalysts which can be isolated from fungi and bacteria, termed "enzymes", can actually be used to digest and breakdown polysaccharides including cellulose from plants and chitin from insects/crustaceans. These catalysts are the vanguard of the industries that are springing-up which have the goal of harnessing complex as a biofuel source. As part of our work we will discover new enzymes with diverse functions, study their three-dimensional structures and crucially dissect their highly unusual dependence on metals such as copper for their catalytic ability. We will then use the emerging area of "synthetic biology" to design completely novel catalysts using components not found naturally in nature. Our work will provide the community with insight into the function and action of these catalysts and provide a foundation for their exploitation in the biofuel and other industries.