物理化学学报2011，Vol.27Issue(12)：2907-2914,8.DOI:10.3866/PKU.WHXB20112907
不同类型表面活性剂与高铁肌红蛋白相互作用
Interactions between Different Classes of Surfactants and Metmyoglobin
摘要
Abstract
Complexes of horse metmyoglobin (metMb) with the anionic surfactants sodium bis(2-ethylhexyl) sulfosuccinate (AOT) and sodium dodecyl benzene sulfonate (SDBS), the cationic surfactants dodecyl trimethylammonium bromide (CTAB) and dodecyltrimethyl ammonium bromide (DTAB), and the zwitterionic surfactant 3-[(3-cholamidopropyl) dimethylammonio] propanesulfonate (CHAPS) were investigated by UV-Vis absorption, synchronous fluorescence emission, and circular dichroism (CD) spectroscopy. Experimental results show that the anionic and cationic surfactants can interact with metMb intensively depending on the surfactant concentration. The UV-Vis spectra indicate that AOT and SDBS interact with metMb at low concentrations. The addition of AOT (or SDBS) causes the formation of a six-coordinated low-spin heme (6-cLs) hemichrome as is evident from the red shift of the Soret band, theintensity decrease, concomitant appearance of two new Q bands, and the disappearance of ligand-to-metal charge transfer (LMCT). The surfactants disturb the Tyr and Trp microenvironment and change the second structure parameter of metMb while the or-helix content decreases. However, the interaction between metMb and CTAB (or DTAB) is different. They cannot disturb heme at very low concentrations but can disturb the Tyr and Trp microenvironment. CTAB and DTAB aggregates can convert metMb to a five-coordinated low-spin heme as shown by the blue shift of the Soret band and cause the heme monomer to leave the hydrophobic cavity of metMb through electrostatic attraction mainly. DTAB/metMb complexes behave in a slightly different way to CTAB/metMb because of their special structure. In contrast, no interaction is evident between the zwitterionic surfactant over a large range of concentrations because of the neutral charge of CHAPS, which precludes an effective electrostatic attraction between the ionic sites of CHAPS and a protein. The significant distance between the ionic sites with opposite charges in metMb precludes a double ionic interaction for each CHAPS surfactant molecule despite the presence of two oppositely charged ionic sites in the CHAPS molecule. Therefore, proteins interact with surfactants in multifarious ways and this depends on the surfactant species, concentration, and structure.关键词
阴离子型表面活性剂/阳离子型表面活性剂/两性表面活性剂/高铁肌红蛋白/光谱法Key words
Anionic surfactant/ Cationic surfactant/ Zwitterionic surfactant/ Metmyoglobin/ Spectrometry分类
化学化工引用本文复制引用
张莹莹,曹洪玉,唐乾,郑学仿..不同类型表面活性剂与高铁肌红蛋白相互作用[J].物理化学学报,2011,27(12):2907-2914,8.基金项目
国家自然科学基金(20871024),辽宁省高校创新团队(2006T002,2008T005,2009T003),辽宁省教育厅(2009A069,2009A071)和大连市科技计划(2008E11SF170)资助项目 （20871024）
