Table 2.

Parameters of femtosecond dynamics decay for RNA aptamer constructs

Aptamer Constructs	Ligand	τ1 (ps)	A1 (%)	τ2 (ps)	A2 (%)	τ3 (ps)	A3 (%)	τ4 (ns)	A4 (%)
Theophylline-binding Aptamer
	none (and no Mg2+)	6.5	24	43	45	261	17	11.3	14
P27	none	6.8	22	37	41	169	27	11.3	10
	theophylline			18	9	471	21	11.3	70
	3MX			16	10	235	16	11.3	74
P27Z26	none	1.1	55	6	23	108	10	11.3	12
P27X28	none	3.7	47	21	33	145	12	11.3	8
P10	none	6	63	73	25			11.3	12
	theophylline	6	62	75	25			11.3	13
P10Z11	none	1.5	43	10	33	120	16	11.3	8
	theophylline	1.7	46	11	28	172	17	11.3	9
P10Z25	none	1.4	45	11	28	108	17	11.3	10
P10Z11Z25	none	1.3	54	11	19	137	17	11.3	10
3MX-binding Aptamer
P27	none	8	27	34	44	131	19	11.3	10
	3MX							11.3	100
P10	none	4.3	56	32	36			11.3	8
	3MX	4.3	60	36	27			11.3	13

Decay life times of amplitudes are represented by τ (ps) and A (%), respectively. Estimated errors are ~5%. All measurements were performed in a buffer of 100 mM HEPES, 100 mM NaCl, 5 mM MgCl, 0.1 mM EDTA, pH 7.5, and at 22 °C.