Figure 1 - full size

Figure 1. TR-FRET analyses of the PCSK9-LDLR interaction and its inhibition. A, in a TR-FRET assay at neutral pH, EGF(A) and EGF(AB) compete with the LDLR ectodomain for binding to PCSK9 with low/submicromolar IC[50] values. B, in the TR-FRET assay, full-length WT PCSK9 and WT PCSK9ΔC are equipotent at disrupting the interaction of labeled WT PCSK9 with labeled LDLR, demonstrating that the C-terminal domain of PCSK9 is not required for binding. In contrast with WT PCSK9ΔC, an unprocessed form of PCSK9ΔC (S386A) was unable to disrupt the interaction.