基于肌红蛋白的氧激活蛋白的理性设计

Rational design of oxygen-activating protein based on myoglobin

金属酶催化了生命活动及工业催化中的很多重要反应。天然金属酶的研究往往受限于蛋白质本身结构复杂、表达纯化困难等问题。通过理性设计,可以在分子量小、结构简单、易于表达的骨架蛋白中模拟天然金属酶的结构、光谱和功能,构建人工金属酶。人工酶可以为天然酶的机制研究提供新的平台。本文中,笔者探讨以肌红蛋白为骨架蛋白,通过结构特征的模拟、非天然氨基酸的引入等手段,模拟氧激活蛋白,尤其是氧化酶。综述以对理性设计得到的人工氧化酶的反应中间体进行研究的进展,发现金属酶活性中心的酪氨酸作为催化反应的关键残基,对于氧化反应的调控非常重要;而在小分子量骨架蛋白中模拟天然金属酶是一种人工金属酶分子设计的方法,可以用于研究血红素酶外的其他金属酶。

Metalloenzyme catalyzes many important reactions in life processes and industrial catalysis.When we study native metalloenzymes,we encounter the complexity of the native proteins,difficulties in expression and purification,among others.It is possible to construct artificial metalloenzyme by mimicking the structure,spectroscopy and function of native protein in a small,simple and easy-to-express scaffold through rational design of metalloenzyme.The artificial enzyme provides unique opportunity for studying mechanism of the native metalloenzyme.We discuss mimicking of oxygen activating protein,especially oxidase using myoglobin as the scaffold protein,through rational design and unnatural amino acid incorporation.Reviewing the study on artificial oxidase,we could find the importance of a tyrosine residue at the active site for the regulation of oxidase activity.As an important method for artificial metalloenzyme design,mimicking native metalloenzyme in a low-molecular weight scaffold protein can be useful to study other metalloenzymes.