Table 1. Equilibrium constants, K = [Y]/[X], for the interconversion of the two conformations of I·II derived from subpopulation analysis.

	K
Monovalent cation	12°C	20°C	28°C	37°C
100 mM NaCl	0.63 ± 0.03	0.67 ± 0.03	0.51 ± 0.02	0.35 ± 0.02
100 mM KCl	0.34 ± 0.02	0.36 ± 0.03	0.46 ± 0.03	0.50 ± 0.03