Molecular Design and Evolution Engineering for Compositc Biochatalysts

研究了复合生物催化剂的结构和功能，构建了新型复合生物催化剂。Toraya等人。基于钴胺依赖的二醇脱水酶的三维结构，建立了其精细催化机理，并通过理论计算论证了其能量可行性。利用蛋白质工程技术对该酶的活性进行了修饰。用几种脱氢酶模型构建了钴胺复合催化剂。Tanizawa等人。阐明了铜胺氧化酶中由特定酪氨酸残基产生的托喹酮辅因子的生物合成和催化功能的分子机制。此外，还鉴定了藜麦血蛋白胺脱氢酶中一种新的色氨酸衍生的苯醌辅因子--半胱氨酸色苯二酚。Miura等人。通过将人工黄素掺入黄素酶脱辅基蛋白获得具有新反应活性的黄素酶。Horiike等人。揭示了外源双加氧酶底物专一性的分子基础以及这些酶激活O2的分子基础。Hayashi等人。通过对质子转移过程的分析，阐明了吡哆醛酶的精细催化反应机理，从而展现了对“诱导FIT”和“多底物识别”的分子理解。Hirotsu等人。测定了各种天然复合生物催化剂的三维结构。Esaki等人。揭示了铁硫簇合物的生物合成机理，开发了一种利用新型复合生物催化剂制备手性化合物的新工艺。Shimada等人。结果表明，将化学修饰的血红素掺入到血红素蛋白中是制备高效蛋白质催化剂的有力工具。Kitazume等人。证明了催化抗体在离子液体中展示了一种新的功能。

Structures and functions of composite biocatalysts were studied, and novel composite biocatalysts were constructed. Toraya et al. established a refined catalytic mechanism for cobalamin-dependent diol dehydratase based on its three-dimensional structure and demonstrated its energetic feasibility by theoretical calculations. Reactivity of the enzyme was modified by protein engineering techniques. Cobalamin composite catalysts were constructed using several apoenzyme models. Tanizawa et al. elucidated the molecular mechanism of biosynthesis and catalytic function of the topaquinone cofactor that is contained in copper amine oxidase and produced from a specific tyrosine residue. Furthermore, a new tryptophan-derived quinone cofactor, cysteine tryptophylquinone, in quinohemoprotein amine dehydrogenase was identified. Miura et al. obtained flavoenzymes with novel reactivity by incorporating artificial flavins to flavoenzyme apoproteins. Horiike et al. revealed molecular bases for substrate specificity of extradiol dioxygenases and 0_2 activation by these enzymes. Hayashi et al. elucidated the refined catalytic reaction mechanisms of pyridoxal enzymes by analyzing the proton-transfer process, thereby presenting the molecular understanding of the "induced fit" and "multisubstrate recognition". Hirotsu et al. determined three-dimensional structures of various natural composite biocatalysts. Esaki et al. revealed the mechanism of biosynthesis of iron-sulfur clusters and developed a novel process for the production of chiral compounds by the use of novel composite biocatalysts. Shimada et al. showed that incorporation of a chemically modified heme into heme proteins is a powerful tool for the preparation of a highly efficient protein-based catalyst. Kitazume et al. demonstrated that catalytic antibodies exhibit a novel function in ionic liquids.