Institute of Physical and Theoretical Chemistry, University of Regensburg, Universitätsstraße 31, 93053 Regensburg, Germany.
Institut de Chimie Séparative de Marcoule (ICSM), UMR 5257 (CEA, CNRS, UM, ENSCM), BP 17171, 30207 Bagnols-sur-Cèze, France.
J Colloid Interface Sci. 2018 Apr 15;516:466-475. doi: 10.1016/j.jcis.2018.01.077. Epub 2018 Feb 6.
In the present contribution, we investigated the influence of the structuring of surfactant-free microemulsions (SFME) (water/1-propanol/limonene and water/tert-butanol/limonene) on the enzyme activity of horseradish peroxidase (HRP). To this purpose, the oxidation of 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) with hydrogen peroxide was chosen as a model reaction. Enzymatic activities in SFMEs of varying compositions were investigated by UV-Vis spectroscopy and compared to the enzyme activity in pure buffer solution. Dynamic light, small-angle-X-ray scattering and conductivity measurements were performed in order to obtain structural information on the used SFMEs. Findings presented in this study revealed that the ability of short-chain alcohols to form mesostructures (aqueous aggregates in oil) has a crucial effect on the enzyme activity in SFMEs. Mesoscale structuring with 1-propanol (NPA) was found to be more pronounced than for the more hydrophobic tert-butanol (TBA). It was concluded that the most pronounced mesoscale-structured SFMEs lead to the highest enzymatic activities.
在本研究中，我们研究了表面活性剂自由微乳液（SFME）（水/1-丙醇/柠檬烯和水/叔丁醇/柠檬烯）的结构对辣根过氧化物酶（HRP）酶活性的影响。为此，选择用过氧化氢氧化 2,2'-联氮双（3-乙基苯并噻唑啉-6-磺酸）二铵盐（ABTS）作为模型反应。通过紫外-可见光谱法研究了不同组成的 SFME 中的酶活性，并将其与纯缓冲溶液中的酶活性进行了比较。为了获得所使用的 SFME 的结构信息，进行了动态光散射、小角 X 射线散射和电导率测量。本研究的结果表明，短链醇形成介观结构（油中的水聚集）的能力对 SFME 中的酶活性有至关重要的影响。与疏水性更强的叔丁醇（TBA）相比，1-丙醇（NPA）形成的介观结构更为明显。得出的结论是，最显著的介观结构 SFME 导致最高的酶活性。
