Table 2.

Determination of PBD Selectivity

		Kd (nM)a
Entry	Compd.b	PBD1	PBD2c	PBD3c
1	2a*	12	400 [33×]	306 [25×]
2	3c*	2	43 [21]	240 [120]
3	3m*	3	24 [8]	62 [20]

^aDetermined by fluorscence polarization assays using FITC-labeled ligands.

^bDesignation with an “*” indicates the presence of an N-terminal PEG-FITC group as described in Figure S5.

^cValues in brackets refer to the fold-change in binding affinity relative to PBD1. Binding curves are shown in Figure S6.