采用吸收光谱法研究了十二烷基硫酸钠(SdS)诱导rHOdObACTEr AzOTOfOrMAnS外周捕光复合体lH2细菌叶绿素(bACTErIOCHlOrOPHyllS,bCHlS)的解离行为和规律.结果表明:室温下,在10MMOl？l-1TrIS-HCl(PH8.0)缓冲液中,低浓度SdS只诱导lH2中b800细菌叶绿素解离生成游离bCHlS,而b850不受影响;当浓度达到0.08%(W/V)时,能特异性地诱导b800缺失,其缺失过程和游离bCHlS的生成过程均符合单指数模型,且二者的速率常数近似相等.高浓度SdS能同时诱导b800和b850解离生成游离bCHlS,其中b800可发生缺失,而b850则不完全解离,解离过程均符合单指数模型;b800对SdS更敏感,其解离速率常数约是b850的4倍,游离bCHlS生成速率常数明显低于b800解离速率常数,而与b850解离速率常数相接近.The release behaviors of bacteriochlorophylls of peripheral light-harvesting complex LH2 from Rhodobacter azotoformans induced by sodium dodecyl sulfate (SDS) were investigated using absorption spectroscopy.The results indicated that bacteriochlorophylls of B800 band are released from their binding sites and transformed into free bacteriochlorophylls by incubating LH2 sample in 10 mmol?L-1 Tris-HCl (pH 8.0) buffer containing SDS of low concentration at room temperature.However, the bacteriochlorophylls of B850 band are not released.The dynamics of B800 release and free BChl formation induced by 0.08% (w/V) SDS can be well fitted by the monoexponential model.The rate constant of B800 release is nearly equal to that of free BChls formation.The release of both B800 and B850 of LH2 can be induced by high concentration SDS, simultaneously.The bacteriochlorophylls of B800 band can be completely transformed into free BChls, but not for B850.Although both of their release processes show monoexponential models in 1% SDS solution, the release rate constant of B850 is remarkably lower than that of B800 and close to that of free BChls formation.国家自然科学基金(No.30970068);国家科技基础条件平台建设(No.2005DKA21209);厦门大学近海海洋环境科学国家重点实验室高级访问学者基金(No.MELRS0907);山西省回国留学人员科研(No.200713)资助项
