Programming A Molecular Relay for Ultrasensitive Biodetection through 129Xe NMR |
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Authors: | Yanfei Wang Benjamin W. Roose John P. Philbin Jordan L. Doman Prof. Ivan J. Dmochowski |
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Affiliation: | Department of Chemistry, University of Pennsylvania, Philadelphia, PA, USA |
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Abstract: | A supramolecular strategy for detecting specific proteins in complex media by using hyperpolarized 129Xe NMR is reported. A cucurbit[6]uril (CB[6])‐based molecular relay was programmed for three sequential equilibrium conditions by designing a two‐faced guest (TFG) that initially binds CB[6] and blocks the CB[6]–Xe interaction. The protein analyte recruits the TFG and frees CB[6] for Xe binding. TFGs containing CB[6]‐ and carbonic anhydrase II (CAII)‐binding domains were synthesized in one or two steps. X‐ray crystallography confirmed TFG binding to Zn2+ in the deep CAII active‐site cleft, which precludes simultaneous CB[6] binding. The molecular relay was reprogrammed to detect avidin by using a different TFG. Finally, Xe binding by CB[6] was detected in buffer and in E. coli cultures expressing CAII through ultrasensitive 129Xe NMR spectroscopy. |
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Keywords: | bioinorganic chemistry biosensors host– guest systems molecular recognition NMR spectroscopy |
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