TABLE 2

Effect of mutations of Arg^38(1.35) of the receptor to alanine and lysine on the GnRH peptide-stimulated IP responses

EC₅₀ and E_max values are presented as mean ± S.E. of three or more independent experiments. The fold-change was calculated as the ratio of the EC₅₀ values in the mutant and wild-type receptors. E_max is expressed relative to a wild-type control included in each transfection.

	Wild-Type			R38A
	EC₅₀	E_max	EC₅₀	EC₅₀ -Fold Increase	E_max	EC₅₀	EC₅₀ -Fold Increase	E_max
	nM	% wt	nM		% wt	nM		% wt
GnRH I	0.87 ± 0.06	100	5672 ± 302	6520	42 ± 4	129 ± 9	146	100 ± 9
[Pro⁹,NHEt]GnRH I	0.18 ± 0.01	100	433 ± 21	2405	56 ± 3	14 ± 2	77	91 ± 6
GnRH II	26 ± 3	100	17070 ± 690	656	41 ± 5	1978 ± 334	76	104 ± 7
[Pro⁹,NHEt]GnRH II	1.9 ± 0.15	100	711 ± 62	374	58 ± 3	125 ± 12	65	96 ± 4