... that the data weredescribed best by a two-binding site model. The IC50 (the concentration of the competing ligand that inhib-its 50% of the specific binding of [125I]TC-PCSK9) val-ues for the ... higher-affinity and lower-affinity binding sites are listed in Table 1. The high-affinity and the low-affinity sites accountedfor 25% and 75% of the total binding, respectively.These estimates of the relative ... PCSK9-S127R, only the upper and lower, respectively, halves of the ranges are shown, to avoidoverlap of the error bars. The results are expressed as percentage of control (c.p.m. in the absence of unlabeled...