{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,23]],"date-time":"2026-10-23T20:08:17Z","timestamp":1792786097989,"version":"4.5.0"},"reference-count":44,"publisher":"Oxford University Press (OUP)","license":[{"start":{"date-parts":[[2026,9,17]],"date-time":"2026-09-17T00:00:00Z","timestamp":1789603200000},"content-version":"vor","delay-in-days":259,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100000015","name":"Department of Energy","doi-asserted-by":"publisher","award":["DOE DE-SC0022240"],"award-info":[{"award-number":["DOE DE-SC0022240"]}],"id":[{"id":"10.13039\/100000015","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100000001","name":"National Science Foundation","doi-asserted-by":"publisher","award":["NSF CBET 2402669"],"award-info":[{"award-number":["NSF CBET 2402669"]}],"id":[{"id":"10.13039\/100000001","id-type":"DOI","asserted-by":"publisher"}]},{"name":"GCE4All biomedical Technology Development and Dissemination Center"},{"name":"National Institute of General Medical Science","award":["RM1-GM144227"],"award-info":[{"award-number":["RM1-GM144227"]}],"id":[{"id":"https:\/\/ror.org\/04q48ey07","id-type":"ROR","asserted-by":"crossref"}]},{"name":"National Institutes of Health include MALDI MS","award":["NIH S10-OD030460"],"award-info":[{"award-number":["NIH S10-OD030460"]}],"id":[{"id":"https:\/\/ror.org\/01cwqze88","id-type":"ROR","asserted-by":"crossref"}]},{"DOI":"10.13039\/100017457","name":"Vagelos Institute for Energy Science and Technology","doi-asserted-by":"publisher","id":[{"id":"10.13039\/100017457","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2026,1,9]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:p>As demand for the rare earth elements (REEs) that power new and emerging technologies increases rapidly, there is a growing need for next-generation separations systems that can provide more selective isolation of these critical, but difficult-to-purify materials. Due to their evolvability and compatibility with existing separations platforms, polypeptides represent an ideal and environmentally-friendly chassis with which to meet this challenge; however, there exist no high-throughput approaches to selecting polypeptides with improved affinity and selectivity towards the various REEs, chiefly due to the difficulty of detecting a selectable phenotype. Here, we present work towards overcoming this obstacle by developing a bacterial display platform for the direct sensing of REE binding in living bacterial cells. Our approach exploits the antenna effect, which allows a sufficiently proximal fluorophore to sensitize a bound europium ion and stimulate emission through resonant energy transfer, and makes use of genetic code expansion to insert a fluorescent amino acid directly into the polypeptide backbone in cellulo. We find that targeting a model lanthanide-binding peptide to the periplasm enables the accumulation of sufficient concentrations of this binder in an easily accessible subcellular localization such that robust signal can be detected. Through optimization of encoding, sensitization, and handling, we further improve our signal up to &amp;gt;20-fold over control cells lacking binders and demonstrate facile differentiation and characterization of several variant peptides. Our work paves the way for high-throughput synthetic evolution of REE binding polypeptides with expanded functionality.<\/jats:p>","DOI":"10.1093\/protein\/gzag026","type":"journal-article","created":{"date-parts":[[2026,9,17]],"date-time":"2026-09-17T14:19:05Z","timestamp":1789654745000},"source":"Crossref","is-referenced-by-count":0,"title":["Towards directed evolution of rare earth element binding peptides using genetically encoded sensitizing amino acids"],"prefix":"10.1093","volume":"39","author":[{"given":"Riley M","family":"Bednar","sequence":"first","affiliation":[{"name":"Department of Chemistry, University of Pennsylvania , 231 S. 34 Street, Philadelphia, PA 19104 ,","place":["United States"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jason G","family":"Marmorstein","sequence":"additional","affiliation":[{"name":"Department of Chemistry, University of Pennsylvania , 231 S. 34 Street, Philadelphia, PA 19104 ,","place":["United States"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kathleen J","family":"Stebe","sequence":"additional","affiliation":[{"name":"Department of Chemical and Biomolecular Engineering, University of Pennsylvania , 220 South 33rd Street, Philadelphia, PA 19104 ,","place":["United States"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3854-9210","authenticated-orcid":false,"given":"E James","family":"Petersson","sequence":"additional","affiliation":[{"name":"Department of Chemistry, University of Pennsylvania , 231 S. 34 Street, Philadelphia, PA 19104 ,","place":["United States"]},{"name":"Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania , 421 Curie Boulevard, Philadelphia, PA 19104 ,","place":["United States"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"286","published-online":{"date-parts":[[2026,9,17]]},"reference":[{"key":"2026093010102398300_ref1","doi-asserted-by":"publisher","first-page":"1374","DOI":"10.1038\/s41596-025-01241-w","article-title":"Selecting aminoacyl-tRNA synthetase\/tRNA pairs for efficient genetic encoding of noncanonical amino acids into proteins","volume":"21","author":"Alexander","year":"2025","journal-title":"Nat Protoc"},{"key":"2026093010102398300_ref2","doi-asserted-by":"publisher","first-page":"3458","DOI":"10.1021\/acschembio.2c00639","article-title":"Generating efficient Methanomethylophilus Alvus Pyrrolysyl-tRNA synthetases for structurally diverse non-canonical amino acids","volume":"17","author":"Avila-Crump","year":"2022","journal-title":"ACS Chem Biol"},{"key":"2026093010102398300_ref3","doi-asserted-by":"publisher","first-page":"283","DOI":"10.1016\/j.jmb.2007.05.078","article-title":"Energetics of protein 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Energy Department Announces $134 Million in Funding to Strengthen Rare Earth Element Supply Chains, Advancing American Energy Independence"},{"key":"2026093010102398300_ref15","doi-asserted-by":"publisher","first-page":"1235","DOI":"10.3390\/pr12061235","article-title":"Review of methods for obtaining rare earth elements from recycling and their impact on the environment and human health","volume":"12","author":"Gkika","year":"2024","journal-title":"Processes"},{"key":"2026093010102398300_ref16","doi-asserted-by":"publisher","first-page":"3470","DOI":"10.1021\/acschembio.2c00640","article-title":"Structures of Methanomethylophilus Alvus Pyrrolysine tRNA-synthetases support the need for de novo selections when altering substrate specificity","volume":"17","author":"Gottfried-Lee","year":"2022","journal-title":"ACS Chem Biol"},{"key":"2026093010102398300_ref17","doi-asserted-by":"publisher","first-page":"328","DOI":"10.1016\/0968-0004(91)90135-i","article-title":"Periplasmic space and 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