Table 3. Mutations at Tyr102, Tyr198, Tyr241, and Tyr247^a.

	Y102		Y198		Y241		Y247
residues	EC50 (μM)	nH	EC50 (μM)	nH	EC50 (μM)	nH	EC50 (μM)	nH
Y(wild type)	1.4 ± 0.2	1.6 ± 0.3	1.4 ± 0.2	1.6 ± 0.3	1.4 ± 0.2	1.6 ± 0.3	1.4 ± 0.2	1.6 ± 0.3
F	1.9 ± 0.6	1.1 ± 0.3	12 ± 1b	1.6 ± 0.1	21 ± 1b	1.3 ± 0.1	42 ± 4b	1.5 ± 0.2
A	110 ± 20b	1.2 ± 0.2	2000 ± 200b	1.1 ± 0.1	4900 ± 480b	1.1 ± 0.1	NR
S	135 ± 25b	1.3 ± 0.3	5600 ± 600b	1.6 ± 0.2	1500 ± 96b	1.2 ± 0.1	NR
W	860 ± 60b	1.4 ± 0.1	250 ± 30b	1.1 ± 0.1	8.2 ± 1.4b	1.3 ± 0.3	99 ± 8b	1.3 ± 0.1
4-F-Phe	3.1 ± 0.3	1.5 ± 0.2	34 ± 7c	1.9 ± 0.3	1100 ± 370b	0.6 ± 0.1b	90 ± 3b	1.9 ± 0.1
3,5-F2–Phe	6.1 ± 0.9b	1.6 ± 0.3	1700 ± 400c	1.4 ± 0.2	490 ± 190b	1.5 ± 0.3	NR
3,4,5-F3-Phe	3.4 ± 0.5	1.3 ± 0.2	8400 ± 1000c	1.5 ± 0.1	950 ± 140b	1.3 ± 0.3	NR
4-Br-Phe	1.6 ± 0.8	1.3 ± 0.4			620 ± 30b	1.8 ± 0.2	2900 ± 170b	1.1 ± 0.1
4-Me-Phe	4.6 ± 2.1	1.4 ± 0.3			140 ± 100b	1.4 ± 0.4	NR
4-MeO-Phe	180 ± 20b	1.4 ± 0.2	6.6 ± 2c	1.6 ± 0.2	530 ± 50b	1.7 ± 0.2	NR
3-OH-Phe	66 ± 9b	1.7 ± 0.3			350 ± 70b	1.5 ± 0.4	NR

^aData = mean ± SEM, n ≥ 3.

^bSignificantly different to wild type, p < 0.05.

^cPreviously published (ref (11)).