Color tuning in short wavelength-sensitive human and mouse visual pigments: ab initio quantum mechanics/molecular mechanics studies.
Color tuning in short wavelength-sensitive human and mouse visual pigments: ab initio quantum mechanics/molecular mechanics studies.
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DOI：
10.1021/jp902754p
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发表时间：
2009-10-29
期刊：
影响因子：
--
通讯作者：
Morokuma K
中科院分区：
文献类型：
--
作者：
Altun A;Yokoyama S;Morokuma K
我们通过混合量子力学/分子力学（QM/MM）计算，研究了人蓝色视锥色素、小鼠紫外视锥色素以及牛视紫红质中席夫碱（SB）氮结合的11 - 顺式视黄醛的质子化状态和光吸收光谱。我们采用了多参考（MRCISD + Q、MR - SORCI + Q和MR - DDCI2 + Q）和单参考（TD - B3LYP和RI - CC2）量子力学方法。计算得到的基态和垂直激发能表明，紫外敏感色素的席夫碱氮是去质子化的，而 violet - sensitive（对紫光敏感的，此处可能是指对蓝光敏感的色素，因为前面提到人蓝色视锥色素，可能是作者笔误，正常应该是blue - sensitive）色素的席夫碱氮是质子化的，这与一些间接实验证据相符。相对于视紫红质，对紫光敏感的色素吸收峰的显著蓝移是由于这些色素的极化场导致11 - 顺式视黄醛多烯链的键长交替增加引起的。在对紫光敏感的脊椎动物色素和牛视紫红质中，主要的反离子都是Glu113。在席夫碱氮去质子化的紫外敏感色素中，Glu113和其余色素对11 - 顺式视黄醛的第一激发能都没有显著影响。在基态和第一激发态下，11 - 顺式视黄醛的席夫碱和β - 紫罗兰酮末端之间没有电荷转移。
We have investigated the protonation state and photoabsorption spectrum of Schiff-base (SB) nitrogen bound 11-cis-retinal in human blue and mouse UV cone visual pigments as well as in bovine rhodopsin by hybrid quantum mechanical/molecular mechanical (QM/MM) calculations. We have employed both multireference (MRCISD+Q, MR-SORCI+Q, and MR-DDCI2+Q) and single reference (TD-B3LYP and RI-CC2) QM methods. The calculated ground-state and vertical excitation energies show that UV-sensitive pigments have deprotonated SB nitrogen, while violet-sensitive pigments have protonated SB nitrogen, in agreement with some indirect experimental evidence. A significant blue shift of the absorption maxima of violet-sensitive pigments relative to rhodopsins arises from the increase in bond length alternation of the polyene chain of 11-cis-retinal induced by polarizing fields of these pigments. The main counterion is Glu113 in both violet-sensitive vertebrate pigments and bovine rhodopsin. Neither Glu113 nor the remaining pigment has a significant influence on the first excitation energy of 11-cis-retinal in the UV-sensitive pigments that have deprotonated SB nitrogen. There is no charge transfer between the SB and β-ionone terminals of 11-cis-retinal in the ground and first excited states.
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DOI：
10.1021/jp807172h
发表时间：
2008-12-25
期刊：
The journal of physical chemistry. B
影响因子：
--
作者：
Altun A;Yokoyama S;Morokuma K
通讯作者：
Morokuma K
影响因子：
2.8
作者：
Bauernschmitt, R;Ahlrichs, R
通讯作者：
Ahlrichs, R
影响因子：
2.9
作者：
Fasick, JI;Applebury, ML;Oprian, DD
通讯作者：
Oprian, DD
影响因子：
2.2
作者：
Geskin, VM;Bredas, JL
通讯作者：
Bredas, JL
影响因子：
4.4
作者：
BECKE, AD
通讯作者：
BECKE, AD