Table 1. Binding of boundary- and surface-optimized CaM variants to smMLCK.

	Designed positions*
	11	12	14	55	76	83	84	87	91	109	114	116	120	123	127	145	Kd, nM
CaMwt	E	F	E	V	M	E	E	E	V	M	E	L	E	E	E	M	1.8 ± 1.3
CaMcore	L	Y	—	I	E	—	Y	—	I	L	—	—	—	—	—	I	1.3 ± 0.9
CaMboundary	L	Y	D	I	E	R	Y	L	I	L	I	E	—	—	Q	I	114 ± 83
CaMmodboundaryno-bias	L	Y	—	I	E	R	Y	K	I	L	I	E	—	K	—	I	6.1 ± 0.8
CaMmodboundarybias	L	Y	—	I	E	R	Y	K	I	L	I	E	—	Q	—	I	2.3 ± 0.7

^*Eight boundary and surface positions in the CaM—smMLCK binding interface were optimized. Dashes indicate sequence identity to CaM_wt. Eight core mutations, shown in bold, were carried over from CaM_core