Table 3.

Charge Difference (ΔZ) Among Various Metalation States of WT and ALS-Variant SOD1 as Measured by Capillary Electrophoresis at pH 7.4, 20°C

ΔZa	WTb	G85R	D90A	G93R	E100K
ΔZ 0(a)→1(b) Zn	4.01 ± 0.20	2.33 ± 0.01	3.18 ± 0.02	2.66 ± 0.03	2.94 ± 0.02
ΔZ 1(b)→2(e) Zn	−0.50 ± 0.27	−0.07 ± 0.10	−0.34 ± 0.08	0.16 ± 0.02	−0.39 ± 0.11
ΔZ 2(e)→3(i) Zn	0.07 ± 0.26	N/A	0.44 ± 0.07	−0.11 ± 0.01	−0.02 ± 0.11
ΔZ 3(i)→4(k) Zn	0.01 ± 0.12	N/A	−0.10 ± 0.02	0.06 ± 0.01	0.11 ± 0.03

^aThe labels “a”, “b”, “e”, etc., correspond to labels of electrophoretically unique states in Figure 2 and their values of net charge are obtained from Table 2.

^bValues for WT SOD1 are from a previous study.²¹