Dennison C, Berg A, Canters G W
Leiden Institute of Chemistry, Leiden University, The Netherlands.
Biochemistry. 1997 Mar 18;36(11):3262-9. doi: 10.1021/bi961960u.
The dinuclear paramagnetic center of the CuA variant of the cupredoxin amicyanin has been investigated using 1H NMR. The hyperfine-shifted resonances have been assigned using a combination of 1D NOE difference and 2D WEFT-NOESY spectroscopy. The shifts experienced by the assigned resonances have been used to calculate hyperfine coupling constants for these protons from which the spin density distribution on the ligands at the CuA center is obtained. A comparison with published data for the paramagnetic form of wild type amicyanin highlights a number of similarities and differences between these evolutionary related sites. In both cases 50-60% of the unpaired spin density is distributed on the ligands, which in the case of the CuA center involves two cysteine and two histidine ligands. The two weak axial interactions at the CuA center carry less than 1% spin density.
已使用1H NMR对蓝铜蛋白胺蓝蛋白的CuA变体的双核顺磁中心进行了研究。通过结合一维NOE差异和二维WEFT-NOESY光谱对超精细位移共振进行了归属。已将归属共振所经历的位移用于计算这些质子的超精细耦合常数，由此获得CuA中心配体上的自旋密度分布。与已发表的野生型胺蓝蛋白顺磁形式的数据进行比较，突出了这些进化相关位点之间的一些异同。在这两种情况下，50-60%的未成对自旋密度分布在配体上，在CuA中心的情况下，涉及两个半胱氨酸和两个组氨酸配体。CuA中心的两个弱轴向相互作用携带的自旋密度小于1%。
