Direct observation of the PH-dependent equilibrium between L-like and M intermediates of photoactive yellow protein
Direct observation of the PH-dependent equilibrium between L-like and M intermediates of photoactive yellow protein
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DOI：
10.1016/j.febslet.2004.09.065
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发表时间：
2004-11-05
期刊：
影响因子：
3.5
通讯作者：
Kataoka, M
中科院分区：
文献类型：
--
作者：
Imamoto, Y;Harigal, M;Kataoka, M
研究了以毫秒时间尺度存在的光活性黄色蛋白（PYP）的光产物之间的平衡。由于发色团的去质子化，PYP (PYPM) 的近紫外中间体因碱化而发生红移 (pK(a) = 10.2）。此外，少量红移中间体与PYPM共存。它在可见光区域的光谱形状与PYPL（PYPM 的前身）的光谱形状一致。 PYPL样产物的分数在pH 10时最大。它以与PYPM相同的速率常数衰减。这些结果表明 PYPL 样产物与 PYPM 和去质子化 PYPM 处于 pH 依赖性平衡。 (C) 2004 年欧洲生化学会联合会。由 Elsevier B.V. 出版。保留所有权利。
Equilibrium between the photoproducts of photoactive yellow protein (PYP), present in a millisecond time scale, was studied. The near-UV intermediate of PYP (PYPM) was red-shifted by alkalization due to the deprotonation of the chromophore (pK(a) = 10.2). In addition, a small amount of red-shifted intermediate coexisted with PYPM. Its spectral shape in the visible region agreed with that Of PYPL, the precursor of PYPM. The fraction Of PYPL-like product was maximal at pH 10. It decays with a rate constant identical to that of PYPM. These results indicate that PYPL-like product is in pH-dependent equilibrium with PYPM and deprotonated PYPM. (C) 2004 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.