阳离子Gemini型表面活性剂对α-糜蛋白酶超活性的诱导效应

Cationic Supreactivity of α-Chymotrypsin Induced and Regulated by Positive Charge of Gemini Surfactants

摘要: 本文主要研究了阳离子gemini型表面活性剂C₁₂C_sC₁₂Br₂ (s = 2、6和10)在稀溶液状态下对α-糜蛋白酶活性的影响。在稀溶液体系中我们选择了几种具有典型间隔链长度的gemini表面活性剂12-s-12 (s = 2、6和10)探究不同头基距离的表面活性剂与α-CT之间不同程度的相互作用，同时将传统单链阳离子表面活性剂DTAB作为对比研究。结果表明，12-s-12/α-CT体系在所研究的浓度范围内均出现“钟形”的超活性区域，催化效果比DTAB/α-CT要好。α-CT相对活性的大小与gemini型表面活性剂的间隔链长度也有关系，即spacer越长，头基的电荷密度相对越小，超活性出现的越早而且最大相对活性值也越高。

Abstract: In this work we studied the catalytic activity of α-chymotrypsin (α-CT) in gemini surfactants C₁₂C_sC₁₂Br₂ (s = 2, 6, 10) solution. We selected several cationic gemini surfactants (12-s-12, s = 2, 6, 10) to investigate the effects of different spacer lengths on the activity of α-chymotrypsin, meanwhile the conventional single-chain cationic surfactant DTAB was also used as a comparative study. In all cases, the superactivity of 12-s-12/α-CT system appears in a bell-shape in a concentration region below their respective critical micelle concentration and, the catalytic effect is better than that of DTAB/α-CT system. The relative activity of α-CT was related to the spacer chain length of the gemini surfactant, that is, the gemini surfactant with longer spacer might have a much stronger influence on the enzyme activity due to larger size and its stronger hydrophobicity of its head group.