适冷酶及其适冷机制

摘要

Compared with their mesophilic analogs, cold-adapted enzymes take on higher catalytic efficiency at low temperature, have lower optimal reaction temperature, and are more sensitive to heat. The high catalytic efficiency of cold-adapted enzymes at low temperature is associated with their loose and flexible structure. Such structure can achieve conformational change for catalysis with low energy, which is achieved by the weakening of the interaction between amino acid residues and the enzyme molecules as well as the enhancing of the interaction between enzyme and solvent molecules. Improvement of the interaction between the cold-adapted enzyme molecules and solvent molecules will reduce the internal tightness of the cold-adapted enzyme molecules, which may be one reason leading to the high sensitivity to heat and poor resistance to change of the cold-adapted enzymes.%与同类中温酶相比,适冷酶在较低的温度下具有较高的催化效率,最适反应温度较低,对热较敏感.适冷酶能够在较低的温度下保持较高的催化效率与其松散且更具柔性的蛋白结构相关联.这种蛋白质结构容许利用更少的能量产生具有催化效能的构象变化,它主要依赖于酶分子内氨基酸残基之间相互作用的减弱以及酶和溶剂分子相互作用的增强.适冷酶与溶剂相互作用的提高,会降低其分子内部的紧密度,这可能是适冷酶热敏感性高、抗变能力差的原因之一.