新型光敏性表面活性剂对BSA的光控构象研究

The Optically Controlled Conformational Studies of BSA with Novel Photosensitive Surfactants

合成出一种新型光敏性表面活性剂-偶氮苯-4-氧己基三甲基溴化铵(AZO-OHTAB),通过核磁共振谱及质谱分析表征其结构,通过电导率法、表面张力法以及紫外可见分光光谱法探讨其光敏性能,并对比分析365nm紫外光与可见光下其结构及聚集状态的变化。研究结果表明,365nm光照射可使AZO-OHTAB发生反式向顺式结构转变,并明显增加其临界胶束浓度(cmc)值。进一步探索其与牛血清白蛋白(BSA)的相互作用,研究表明,反式AZOOHTAB与BSA相互作用明显强于顺式AZO-OHTAB与BSA的相互作用,通过冷冻蚀刻-透射电镜及流体力学半径的测定可以证明365nm紫外光对AZO-OHTAB与BSA的相互作用具有光控构象效应。

The novel photosensitive surfactant-azobenzene-4-oxohexyl trimethyl ammonium bromide （AZO- OHTAB） was synthesized. The product was characterized by 1H NMR, LC-MS, conductivity, surface tension and UV visible spectrophotometry, and then compared the change of structure and aggregation state in UV light at 365nm and visible light. The results showed that the structure of AZO-OHTAB changed from trans to cis structure and the critical micella concentration （cmc） values significantly in- creased at the 365nm light irradiation. The interaction mechanism between AZO-OHTAB with bovine ser- um albumin （BSA） was investigated by freeze etching-TEM and the measurement of hydrodynamic radius. Results showed that the interaction between the trans AZO-OHTAB with BSA was stronger than the cis AZO-OHTAB with BSA, and the UV light at 365nm could control the conformational change in the inter- action of BSA and AZO-OHTAB.