Maps强力黏附单元DOPA二联体与HClO反应的理论研究

Theoretical studies on the oxidizing mechanism for the reaction of HClO and adhesive unit DOPA-DOPA in the mussel

应用量子化学从头算HF/3-21G方法,在全局优化中确定贻贝黏附蛋白的强力粘附单元DOPA二联体的几何构型、各原子电荷分布及热力学参数.计算表明:DOPA二联体易与HClO发生亲电取代反应生成2-氯-4-酮-5羟基-苯丙氨酸,破坏了贻贝内超强黏附单元DOPA二联体的结构,降低粘附蛋白内粘性;热力学性质的ΔH放热为88.712 kJ/mol,吉布斯自由能变ΔG恒小于0,较易自发正向进行.

By using ab initio molecular orbital HF/3-21G method, the structure of DOPA-DOPA were obtained in the global optimization, and properties were theoretically studied. The atomic electric charges, activation of reaction and thermodynamics parameters were obtained. The results show that benzene rings in DOPA-DOPA favor for electrophonic attacking substitution reaction with HClO, and the structure of DOPA-DOPA is destroyed which＇s the superstrongly adhesive unit in mussels, and then the stickiness among mussel adhesive proteins reduced. The calculation of thermodynamics properties indicates that the reaction heat（△H）is 88. 712 kJ/mol, and the △G is always less than 0, the reaction is easily occurred spontaneously.