四种别藻蓝蛋白三聚体的时间分辨荧光光谱研究

Study on the Time resolved Fluorescence Spectroscopy of Four Kinds of Allophycocyanin Trimers

研究了从Ａｎａｂａｎａｖａｒｉｂｉｌｉｓ中提取的４种别藻蓝蛋白ＡＰＣＩ，ＡＰＣＩＩ，ＡＰＣＩＩ及ＡＰＣＢ三聚体的稳态光谱和皮秒荧光光谱。采用Ｍｏｎｔｅ－Ｃａｒｌｏ方法对瞬态荧光光谱进行拟合，实验结果表明：ＡＰＣＩ荧光有两个带，其中第一个带位于６６２ｎｍ，有两个时间组分：３５．８ｐｓ和１．６７ｎｓ；第二个带位于６８０ｎｍ，有两个时间组分：３４．２ｐｓ和１．６４ｎｓ；ＡＰＣＩＩ瞬态荧光位于６６０ｎｍ，有两个时间组分：２０．４ｐｓ和１．６４ｎｓ；ＡＰＣＩＩ瞬态荧光位于６６０ｎｍ，有两个时间组分：２３．８ｐｓ和１．７６ｎｓ；ＡＰＣＢ瞬态荧光有两个带，其中第一个带位于６６２ｎｍ，有两个时间组分：３６．６ｐｓ和１．４５ｎｓ；第二个带位于６８０ｎｍ，有两个时间组分：２５．８ｐｓ和１．６２ｎｓ。实验结果一方面说明了藻胆体核内４种别藻蓝蛋白形成能量传递的两条途径；另一方面瞬态荧光解叠结果揭示了ＡＰＣＩ和ＡＰＣＢ三聚体内能量传递的超快过程。

The time resolved fluorescence spectra and steady state spectra of four kinds of APCs have been studied. The data have been analyzed in terms of a sum of exponensials by Monte Carlo method. The results show that two bands appear in API and APB fluorescence spectra at 662 nm and 680 nm with different lifetimes (662 nm APCⅠ: 35.8 ps, 1.67 ns; APB: 36.6 ps, 1.45 ns; 680 nm APCⅠ: 34.2 ps, 1.64 ns, and APB: 25.8 ps, 1.62 ns); while for APCⅠⅠ and APCⅠⅠⅠ, only one peak exists at 660 nm with different lifetimes (APCII: 20.4 ps, 1.64 ns; APCⅠⅠⅠ: 23.8 ps, 1.76 ns). The results indicate that there are two paths of energy transfer in core of PBS and imply the ultrafast energy transfer processes of the APCI and APCB trimers.