The Department of Biochemistry, The Ohio State University, 43210, Columbus, Ohio.
Photosynth Res. 1986 Jan;10(3):437-44. doi: 10.1007/BF00118310.
Reduction of plastocyanin (PC) caused a change in the electric field at the surface of the molecule which resulted in a 0.3 pH unit increase in the pKa of a nitrated derivative of Tyr 83. This change in electrical potential could alter the affinity for cytochrome f which is known to bind at this site. Conversely, properties of the copper center, including the pH dependence of the reduction potential, are regulated by the charge on the surface of the molecule. Both the reduction potential and conformation (as measured by near-UV circular dichroic spectra) were pH dependent. Thus the conformation and electrostatic behavior of PC are dependent on oxidiation state, pH and surface charge, raising the possibility that its redox activity is controlled by the pH gradient.
质体蓝素（PC）的还原导致分子表面电场发生变化，从而导致 Tyr83 的硝化衍生物的 pKa 值增加 0.3 pH 单位。这种电势变化可能会改变与该位点结合的细胞色素 f 的亲和力。相反，铜中心的性质，包括还原电势的 pH 依赖性，受分子表面电荷的调节。还原电势和构象（通过近紫外圆二色光谱测量）都依赖于 pH。因此，PC 的构象和静电行为取决于氧化状态、pH 和表面电荷，这增加了其氧化还原活性受 pH 梯度控制的可能性。
