Table 2.

Bioactivity of hGH variants and PEGylated analogs

	pSTAT5	Proliferation
Variant	EC50, nM	EC50, nM
WHO hGH*	1.0	1.0
Y35pAcF	1.6 ± 0.4 (n = 2)	1.6 ± 0.8 (n = 3)
PEG-Y35pAcF	13.5 ± 4.9 (n = 2)	5.4 ± 2.8 (n = 4)
F92pAcF	1.3 ± 0.5 (n = 2)	1.4 ± 0.7 (n = 4)
PEG-F92pAcF	8.8 ± 3.0 (n = 6)	4.1 ± 0.9 (n = 3)
Q131pAcF	2.3 ± 1.8 (n = 2)	2.1 ± 1.1 (n = 3)
PEG-Q131pAcF	23.8 ± 1.7 (n = 2)	4.6 ± 2.4 (n = 3)
R134pAcF	1.1 ± 0.2 (n = 2)	1.7 ± 0.3 (n = 3)
PEG-R134pAcF	11.3 ± 1.1 (n = 2)	2.5 ± 0.7 (n = 4)
Y143pAcF	1.6 ± 0.1 (n = 2)	1.8 ± 0.6 (n = 2)
PEG-Y143pAcF	12.3 ± 0.9 (n = 2)	6.6 ± 2.7 (n = 3)
K145pAcF	2.3 ± 0.5 (n = 2)	3.0 ± 1.4 (n = 2)
PEG-K145pAcF	20.6 ± 9.8 (n = 2)	5.3 ± 3.5 (n = 3)

^*Expressed as unity for between-assay comparison.