Gast Peter, Broeren Freek G J, Sottini Silvia, Aoki Risa, Takashina Akiko, Yamaguchi Takahide, Kohzuma Takamitsu, Groenen Edgar J J
Leiden University, Department of Physics, Huygens-Kamerlingh Onnes Laboratory, P.O. Box 9504, NL-2300 RA Leiden, The Netherlands.
Leiden University, Department of Physics, Huygens-Kamerlingh Onnes Laboratory, P.O. Box 9504, NL-2300 RA Leiden, The Netherlands.
J Inorg Biochem. 2014 Aug;137:57-63. doi: 10.1016/j.jinorgbio.2014.03.016. Epub 2014 Apr 12.
We report on a high-frequency electron-paramagnetic-resonance study of the type 1 copper site of pseudoazurin. The spectra fully resolve the contribution of a nearly axial spectrum besides the rhombic spectrum, which unequivocally proves the existence of two conformations of the copper site. Pseudoazurins have been considered from Achromobacter cycloclastes including eight mutants and from Alcaligenes faecalis. The two conformations are virtually the same for all pseudoazurins, but the rhombic/axial population varies largely, between 91/9 and 33/67. These observations are discussed in relation to optical absorption spectra and X-ray diffraction structures. A similar observation for fern plastocyanin from Dryopteris crassirhizoma suggests that dual conformations of type 1 copper sites are more common.
我们报告了对假单胞菌素1型铜位点的高频电子顺磁共振研究。光谱完全分辨出除菱形光谱外几乎轴向光谱的贡献，这明确证明了铜位点存在两种构象。已对包括8个突变体的环裂无色杆菌和粪产碱杆菌中的假单胞菌素进行了研究。所有假单胞菌素的两种构象实际上是相同的，但菱形/轴向比例变化很大，在91/9和33/67之间。结合光吸收光谱和X射线衍射结构对这些观察结果进行了讨论。对粗根茎鳞毛蕨的蕨类质体蓝素的类似观察表明，1型铜位点的双重构象更为常见。
