. 2014 Sep 5;289(42):29014–29029. doi: 10.1074/jbc.M114.602474

TABLE 1.

In vitro and biochemical characteristics of type I IFNs used in this study

IFN	Anti-proliferation^a		Antiviral activity^a		BIAcore (SPR)^b
IFN	EC₅₀	Ratio^c	EC₅₀	Ratio^c	K_D	Ratio^c
	pm		pm		nm
IFNα2	3600^d	1×	0.6	1×	2.2^d	1×
IFNβ	30.6	120×	0.42	1.4×	0.4^d	5.5×
YNS	23^d	160×	0.2^d	3×	2.0^d	1.1×
YNSα8	6.6	540×	0.46	1.3×	0.4^d	5.5×
PAS-YNSα8	7.7	470×	0.50	1.2×	0.435	5.0×

^a Antiviral and antiproliferative potencies were determined in WISH cells as described. The experimental error (σ) for these biological assays was 35%. Therefore, a confidence level of 2× S.E. would suggest that differences smaller than 2-fold between interferons are within the experimental error.

^b K_D values against IFNAR2 were determined by SPR using either the ratio of k_a/k_d or mass action over five different concentrations of the analyte.

^c Ratios are relative to wild type IFNα2.

^d An error of 35% was calculated for the K_D measurements. The indicated values were determined as described elsewhere (21, 22).