The Chemistry of Lanthanides in Biology: Recent DiscoveriesEmerging Principles and Technological Applications

摘要

The essential biological role of rare earth elements lay hidden until the discovery in 2011 that lanthanides are specifically incorporated into a bacterial methanol dehydrogenase. Only recently has this observation gone from a curiosity to a major research area, with the appreciation for the widespread nature of lanthanide-utilizing organisms in the environment and the discovery of other lanthanide-binding proteins and systems for selective uptake. While seemingly exotic at first glance, biological utilization of lanthanides is very logical from a chemical perspective. The early lanthanides (La, Ce, Pr, Nd) primarily used by biology are abundant in the environment, perform similar chemistry to other biologically useful metals and do so more efficiently due to higher Lewis acidity, and possess sufficiently distinct coordination chemistry to allow for selective uptake, trafficking, and incorporation into enzymes. Indeed, recent advances in the field illustrate clear analogies with the biological coordination chemistry of other metals, particularlyCa^II and Fe^III, but with unique twists—includingcooperative metal binding to magnify the effects of small ionic radiusdifferences—enabling selectivity. This Outlook summarizes therecent developments in this young but rapidly expanding field andlooks forward to potential future discoveries, emphasizing continuitywith principles of bioinorganic chemistry established by studies ofother metals. We also highlight how a more thorough understandingof the central chemical question—selective lanthanide recognitionin biology—may impact the challenging problems of sensing,capture, recycling, and separations of rare earths.