Whitten W B, Nairn J A, Pearlstein R M
Biochim Biophys Acta. 1978 Aug 8;503(2):251-62. doi: 10.1016/0005-2728(78)90186-x.
Absorption spectra of the bacteriochlorophyll a-protein from Prosthecochloris aesturaii were measured at temperatures from 2.9 to 300 K. Fourth and eight derivatives of the spectra were calculated from the digital data. From an analysis of 34 scans taken from 750 to 850 nm at 5 K, and 130 scans taken from 822 to 838 nm, we find evidence for nine peaks, six of which are probably 0--0 excitonic and three probably higher vibronic features. The major peaks are resolved in the derivative spectra to 300 K, and all shift with temperature by less than 1 nm compared to their 5 K positions, except for the 825 nm peak which shifts about 2 nm. The most prominent fourth derivative peak at 300 K shifts from 812.9 nm in the standard buffer solution to 814.1 nm in the cryogenic solution in which our low temperature measurements were made. We conclude that the conformation of the protein at 5 K is essentially the same as at 300 K.
测定了来自奥氏原绿球菌的细菌叶绿素a - 蛋白在2.9至300 K温度范围内的吸收光谱。从数字数据计算出光谱的四阶和八阶导数。通过对在5 K下从750至850 nm进行的34次扫描以及从822至838 nm进行的130次扫描的分析，我们发现了九个峰的证据，其中六个可能是0 - 0激子峰，三个可能是更高的振动特征峰。主要峰在导数光谱中可分辨至300 K，并且与它们在5 K时的位置相比，所有峰随温度的移动小于1 nm，但825 nm峰移动约2 nm。在300 K时最突出的四阶导数峰从标准缓冲溶液中的812.9 nm移动到我们进行低温测量的低温溶液中的814.1 nm。我们得出结论，该蛋白在5 K时的构象与在300 K时基本相同。
