Table 1. Summary of contribution of L223F mutation and N-terminal fusion of a polypeptide from Ci-VSP to enhancement of voltage-dependent enzyme activity of eVSP.

	Phosphatase activity (s-1)	Ratio	n	Phosphatase activity (s-1)	Ratio	n
	Kir2.1 (on cell)			KCNQ2/3
Dr-VSP WT	1.0 ± 0.8a	-	17	1.6 ± 1.1b	-	9
Dr-VSP L223F	1.7 ± 1.2a	1.7	22	5.5 ± 4.0b	3.4	9
	Phosphatase activity (s-1)	Ratio	n	Phosphatase activity (×102 ms)	Ratio	n
	Kir2.1 (whole cell)			TRPC6
Dr-VSPmChe WT	2.6 ± 2.6c,d,e	-	7
Dr-VSPmChe L223F	4.6 ± 1.6c,f	1.8	8
CiDr-VSPmChe WT	3.6 ± 2.2d,g	1.4	10	4.1 ± 1.7h	-	6
CiDr-VSPmChe L223F	7.3 ± 3.0e,f,g	2.8	11	2.0 ± 0.9h	2.1	3

Phosphatase activity is shown as the rate constant (s^-1) or time lag (ms) calculated from inward current decay of Kir2.1 or time-dependent change of TPRC6 current, respectively. Ratio is a comparison between the phosphatase activity of a target and WT. n is sample number. P values were calculated by two-tailed Student’s t test.

^aP = 0.03.

^bP = 0.03.

^cP = 0.13.

^dP = 0.46.

^eP = 0.005.

^fP = 0.03.

^gP = 0.007.

^hP = 0.04.