SARS-CoV-2(55) COVID-19(22) variant(16) binding(15) SARS-CoV-2.(14) Protein(14) NMR spectroscopy(13) approach(13) protease(13) the SARS-CoV-2(13) Ligand(13) NMR(12) Aptamers(12) Vaccine(11) expressed(11) detection(11) reported(11) Infection(11) inhibitors(11) Interaction(11) Vaccines(10) SARS-CoV-2 variant(10) mechanism(10) aptamer(10) coronavirus(10) spike glycoprotein(10) FIVE(9) ACE2(9) variants of concern(9) Screening(9)