Brown G S, Navon G, Shulman R G
Proc Natl Acad Sci U S A. 1977 May;74(5):1794-7. doi: 10.1073/pnas.74.5.1794.
X-ray absorption measurements of bovine carbonic anhydrase B have been made at the the Stanford Synchrotron Radiation Project with a spectrometer operating in the fluorescence mode. Differences in absorption at and beyond the zinc K-edge near 9664 ev have been observed upon the addition of bromide or iodide. The additional absorption in k space, out to k approximately 7 A-1, obtained upon the addition of iodide has been compared with the absorption in this region of a ZnI2 sample. The similarities between these absorptions lead to the conclusion that the zinc-iodide distance in the protein is 2.65 +/-0.06 A; it is known to be 2.62 A in ZnI2. This shows that the iodide binds directly to the zinc in the protein.
利用在荧光模式下运行的光谱仪，在斯坦福同步辐射项目中对牛碳酸酐酶B进行了X射线吸收测量。在添加溴化物或碘化物后，观察到在9664电子伏特附近锌K边及以外区域的吸收差异。将添加碘化物后在k空间中直至k约为7 Å⁻¹处获得的额外吸收与ZnI₂样品在该区域的吸收进行了比较。这些吸收之间的相似性得出结论，蛋白质中锌-碘的距离为2.65±0.06 Å；已知在ZnI₂中该距离为2.62 Å。这表明碘化物直接与蛋白质中的锌结合。
