A Selective, Protein-Based Fluorescent Sensor with Picomolar Affinity for Rare Earth Elements

Joseph A. Mattocks, Jackson V. Ho, Joseph A. Cotruvo

Research output: Contribution to journalArticlepeer-review

83 Scopus citations


Sensitive yet rapid methods for detection of rare earth elements (REEs), including lanthanides (Lns), would facilitate mining and recycling of these elements. Here we report a highly selective, genetically encoded fluorescent sensor for Lns, LaMP1, based on the recently characterized protein, lanmodulin. LaMP1 displays a 7-fold ratiometric response to all LnIIIs, with apparent Kds of 10-50 pM but only weak response to other common divalent and trivalent metal ions. We use LaMP1 to demonstrate for the first time that a Ln-utilizing bacterium, Methylobacterium extorquens, selectively transports early Lns (LaIII-NdIII) into its cytosol, a surprising observation as the only Ln-proteins identified to date are periplasmic. Finally, we apply LaMP1 to suggest the existence of a LnIII uptake system utilizing a secreted metal chelator, akin to siderophore-mediated FeIII acquisition. LaMP1 not only sheds light on Ln biology but also may be a useful technology for detecting and quantifying REEs in environmental and industrial samples.

Original languageEnglish (US)
Pages (from-to)2857-2861
Number of pages5
JournalJournal of the American Chemical Society
Issue number7
StatePublished - Feb 13 2019

All Science Journal Classification (ASJC) codes

  • Catalysis
  • General Chemistry
  • Biochemistry
  • Colloid and Surface Chemistry


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