Table 1.

Inhibition of PP1 by Inh3 Mutants^a

Mutant		IC50 (nM)	$\frac{{\text{IC}}_{50}\text{Mutant}}{{\text{IC}}_{50}\text{WT}}$
WT	KKVEW	0.46	1
41AAA43	KKAAA	7,820	17,000
V41A	KKAEW	23	50
V41D	KKDEW	400	870
W43A	KKVEA	230	500
W43F	KKVEF	1.5	3
W43Y	KKVEY	1.5	3
E42A	KKVAW	1	2
E42C	KKVCW	2.3	5
E42T	KKVTW	0.5	1
42EW43/RF	KKVRF	0.7	2
42EW43/HY	KKVHY	1.4	3
39KK40/NN	NNVEW	22	47

^aThe IC₅₀’s were determined by inhibition of PP1 activity as described in Fig. 1. Mutated residues are shown in bold.