Table 1.

SPR-binding kinetics for the association of SDS22 with PP1 variants

PP1 variant	kon (M−1 s−1)*	koff (s−1)*	KD (nM)*	χ2*	n
No metal†
PP1α 7–330	1.98 × 104 ± 2.93 × 103	3.25 × 10−4 ± 7.0 × 10−5	16.9 ± 5.1	0.21 ± 0.11	6
PP1γ 7–323	1.74 × 104 ± 6.30 × 103	4.21 × 10−4 ± 8.2 × 10−5	25.2 ± 4.5	0.31 ± 0.34	3
PP1α 1–300	2.33 × 104 ± 4.13 × 103	7.15 × 10−4 ± 2.5 × 10−4	30.4 ± 9.6	0.16 ± 0.08	6
PP1α 7–300	2.03 × 104 ± 5.40 × 103	5.57 × 10−4 ± 1.5 × 10−4	29.6 ± 11.8	0.30 ± 0.20	4
PP1α 7–300 Y134A	No binding	—	—	—	4
PP1α 7–300 Y134F	2.13 × 104 ± 4.80 × 103	5.12 × 10−3 ± 8.3 × 10−4	257 ± 98	0.15 ± 0.07	5
PP1α 7–300 Y134K	No binding	—	—	—	4
PP1α 7–300: MC	No binding	—	—	—	4
PP1α 7–300 H66K	2.84 × 104 ± 1.99 × 103	6.12 × 10−4 ± 2.3 × 10−5	21.6 ± 1.3	0.53 ± 0.13	3
with Mn2+
PP1α 7–330	No binding	—	—	—	4
PP1γ 7–323	No binding	—	—	—	4
PP1α 7–300	No binding	—	—	—	4
PP1α 7–300 Y134A	No binding	—	—	—	4
PP1α 7–300 Y134F	No binding	—	—	—	5
PP1α 7–300 Y134K	No binding	—	—	—	4
PP1α 7–300 H66K	1.84 × 104 ± 9.5 × 102	1.07 × 10−3 ± 3.1 × 10−5	58.4 ± 4.0	0.22 ± 0.02	3
PP1α 7–330	No binding	—	—	—	4
with Zn2+
PP1α 7–330	No binding	—	—	—	3

^*Values are represented as the mean ± SD.

^†No metal included in the SPR ligand buffer.