Kamen M D, Kakuno T, Bartsch R G, Hannon S
Proc Natl Acad Sci U S A. 1973 Jun;70(6):1851-4. doi: 10.1073/pnas.70.6.1851.
Characteristic absorption spectra in the ultraviolet, visible, and near infrared regions are correlated with spin state in ferriheme proteins. Weak, diffuse bands in the near infrared exhibit maxima at about 1000-1100 nm (high spin) and at about 1450-1750 nm (low spin). In these and earlier studies such correlations have been established for several ferriheme proteins, but less extensively than in the more well-known cases of Soret and visible band maxima. We have strengthened the correlation in the near infrared by measurements of absorption spectra in Rhodospirillum rubrum cytochrome c', a variant c-type cytochrome that exhibits a pH-induced transition from high-spin to low-spin state as the pH varies from 6.3 to 13.1. Data are provided on extinction coefficients of characteristic absorption bands at various pH values, obtained by comparison with those measured under the same conditions for horse-heart ferricytochrome c. It is concluded that good correlations of spin state with absorption behavior exist over the entire spectroscopic range from 250 to 2500 nm and that the basic assignments of absorption bands to in-plane charge transfer processes are consistent with these correlations.
在紫外、可见和近红外区域的特征吸收光谱与高铁血红素蛋白中的自旋态相关。近红外区域的弱而弥散的谱带在约1000 - 1100 nm处出现最大值（高自旋），在约1450 - 1750 nm处出现最大值（低自旋）。在这些研究以及早期的研究中，已经为几种高铁血红素蛋白建立了这种相关性，但不如在更著名的Soret带和可见带最大值的情况那样广泛。我们通过测量红螺菌细胞色素c'的吸收光谱，加强了近红外区域的相关性，红螺菌细胞色素c'是一种变体c型细胞色素，随着pH值从6.3变化到13.1，它会表现出pH诱导的从高自旋态到低自旋态的转变。通过与在相同条件下测量的马心高铁细胞色素c的吸收光谱进行比较，给出了在不同pH值下特征吸收带的消光系数数据。得出的结论是，在250至2500 nm的整个光谱范围内，自旋态与吸收行为之间存在良好的相关性，并且吸收带对平面内电荷转移过程的基本归属与这些相关性是一致的。
