Table 3. Equilibrium dissociation constants (K_d, µM) for aminoglycosides to TAR-2′pyr(25) in the presence of nucleic acid competitors.

	Minimal conditionsa			‘Physiological’ conditionsb
	No competitor	+dsDNAc	+tRNAmixd	No competitor	+dsDNAc	+tRNAmixd
Neomycin B	5.8 ± 1	14 ± 3	94 ± 12	9.0 ± 1	15 ± 5	84 ± 18
Tobramycin	43.4 ± 4	44 ± 6	115 ± 7	22 ± 4	44 ± 2	137 ± 10
Kanamycin A	107 ± 13	142 ± 2	141 ± 2	84 ± 15	122 ± 13	157 ± 25

^a50 mM Tris pH 7.4, 100 mM NaCl, 1 mM MgCl₂.

^b30 mM HEPES pH 7.4, 100 mM KCl, 10 mM Na₂HPO₄, 20 mM guanidinium HCl, 2 mM MgCl₂, 20 mM NaCl, 0.5 mM EDTA, 0.001% non-ionic detergent P-40.

^cdsDNA competitor sequence: 5′-GCTGAATACATAAGACG-3′, and its complement.

^dIndicate apparent K_d (see text).