Franken E M, Neerken S, Louwe R J, Amesz J, Aartsma T J
Department of Biophysics, Leiden University, P.O. Box 9504, 2300 RA Leiden, The Netherlands.
Biochemistry. 1998 Apr 14;37(15):5046-51. doi: 10.1021/bi972264c.
A permanent hole burning study on the Fenna-Matthews-Olson, or FMO, antenna complex of the green sulfur bacterium Prosthecochloris aestuarii was carried out at 6 K. Excitation resulted not only in relatively sharp features resonant with the burn wavelength but also in broad absorbance changes in the wavelength region of 800-820 nm. The shape of the latter changes was almost independent of the wavelength of excitation. Evidence is given that they are induced by a different mechanism than that which causes the resonant holes and that they may be due to a conformational change of the protein. The original spectrum was restored upon warming to 60 K. The effective dephasing times T2, as obtained from the homogeneous line widths, increased from about 0.5 ps at 803 nm to >/=20 ps at 830 nm and are in good agreement with recent measurements of accumulated photon-echo and time-resolved absorbance changes.
在6K温度下对绿色硫细菌 aestuarii的Fenna-Matthews-Olson（FMO）天线复合体进行了永久烧孔研究。激发不仅导致了与烧孔波长共振的相对尖锐的特征，还导致了800-820nm波长区域的宽吸收变化。后者变化的形状几乎与激发波长无关。有证据表明，它们是由与导致共振孔不同的机制引起的，并且可能是由于蛋白质的构象变化。升温至60K时，原始光谱得以恢复。从均匀线宽获得的有效退相时间T2从803nm处的约0.5ps增加到830nm处的≥20ps，并且与最近积累的光子回波和时间分辨吸收变化的测量结果高度一致。
