Dipartimento di Chimica e Tecnologie Chimiche, Università della Calabria, Via P. Bucci, 87036 Rende, Italy.
Inorg Chem. 2023 May 15;62(19):7461-7470. doi: 10.1021/acs.inorgchem.3c00754. Epub 2023 May 2.
Lanmodulin (LanM) is the first identified macrochelator that has naturally evolved to sequester ions of rare earth elements (REEs) such as Y and all lanthanides, reversibly. This natural protein showed a 10 times better affinity for lanthanide cations than for Ca, which is a naturally abundant and biologically relevant element. Recent experiments have shown that its metal ion binding activity can be further extended to some actinides, like Np, Pu, and Am. For this reason, it was thought that LanM could be adopted for the separation of REE ions and actinides, thus increasing the interest in its potential use for industry-oriented applications. In this work, a systematic study of the affinity of LanM for lanthanides and actinides has been carried out, taking into account all trivalent ions belonging to the 4f (from La to Lu) and 5f (from Ac to Lr) series, starting from their chemistry in solution. On the basis of a recently published nuclear magnetic resonance structure, a model of the LanM-binding site was built and a detailed structural and electronic description of initial aquo- and LanM-metal ion complexes was provided. The obtained binding energies are in agreement with the available experimental data. A possible reason that could explain the origin of the affinity of LanM for these metal ions is also discussed.
兰姆登蛋白（LanM）是第一个被发现的天然大环螯合剂，能够可逆地螯合镧系元素（REE）如 Y 和所有镧系元素的离子。这种天然蛋白质对镧系阳离子的亲和力比 Ca 高 10 倍，而 Ca 是一种自然丰富且具有生物学相关性的元素。最近的实验表明，其金属离子结合活性可以进一步扩展到一些锕系元素，如 Np、Pu 和 Am。出于这个原因，人们认为 LanM 可以用于分离 REE 离子和锕系元素，从而增加了人们对其潜在工业应用的兴趣。在这项工作中，从溶液化学的角度出发，对 LanM 与镧系元素和锕系元素的亲和力进行了系统研究，考虑了所有属于 4f（从 La 到 Lu）和 5f（从 Ac 到 Lr）系列的三价离子。基于最近发表的核磁共振结构，构建了 LanM 结合位点的模型，并提供了初始水合和 LanM-金属离子配合物的详细结构和电子描述。得到的结合能与可用的实验数据一致。还讨论了可能解释 LanM 对这些金属离子亲和力起源的原因。
