Table 1. Apparent and real dissociation constants for PrP^57–91.

pH	Buffer	Number of sites	Kd (app)	Kd (real)
7.4	5 mM Tris	1	1.0±0.2 μM	3±2 nM
5.5	10 mM Acetate	1	13±2 μM	4±2 μM
7.4	50 mM Mops	2	6±2 μM	250±50 nM