Carugo Oliviero
Department of Chemistry, University of Pavia, Italy; Department of Structural and Computational Biology, University of Vienna, Austria.
J Inorg Biochem. 2017 Oct;175:244-247. doi: 10.1016/j.jinorgbio.2017.07.031. Epub 2017 Jul 27.
The structural features of the silver and gold sites in protein crystal structures extracted from the Protein Data Bank have been investigated. It is observed that both cations have nearly always low oxidations states (+1) and low coordination numbers, adopt standard stereochemistries, and interact preferentially (particularly gold) with sulfur donor atoms of cysteine and methionine side-chains. Interestingly, gold cation have been very often refined with occupancy minor than 1.0 and are very often "naked", in the sense that no donor atoms are sufficiently close to the metal cation. This apparently strange observation points out towards the need to develop specific and efficient validation tools for these elements when they are coordinated to proteins.
对从蛋白质数据库中提取的蛋白质晶体结构中银和金位点的结构特征进行了研究。观察到这两种阳离子几乎总是处于低氧化态（+1）且配位数低，采用标准立体化学，并且优先（特别是金）与半胱氨酸和甲硫氨酸侧链的硫供体原子相互作用。有趣的是，金阳离子常常被精修占有率小于1.0，并且常常是“裸露的”，即没有供体原子足够靠近金属阳离子。这一明显奇怪的观察结果表明，当这些元素与蛋白质配位时，需要开发针对它们的特定且有效的验证工具。
