期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1977
卷号：74
期号：5
页码：1794-1797
DOI：10.1073/pnas.74.5.1794
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：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.
