. 2007 Nov 19;18(2):732–737. doi: 10.1016/j.bmcl.2007.11.048

Table 1.

Inhibition of human ACE2, ACE, NEP, and CpA Inline graphic

#	R¹	R²	ACE2 K_{i App}^a (nM)	ACE K_{i App}^b (nM)	NEP K_{i App}^c (nM)	CpA K_{i App}^d (nM)
1a	CH₂Ph	H	86	30	1.1	1200
1b	H	CH₂Ph	1400	520	1.3	310
1c	H	H	320	16	13	1700
1d	Me	H	6.9	21	23	14,000
1e	Me	Me	2300	3400	730	>50,000
1f	Et	H	1.4	8.6	0.80	9,300
1g	n-Bu	H	1.8	9.3	1.2	8900
1h	i-Pr	H	1.5	200	13	17,000
1i	(R)-s-Bu	H	1.5	490	27	11,000
1j	(S)-s-Bu	H	1.6	200	2.4	15,000
1k	Cyb	H	2.4	620	5.4	12,000
1l	Cyp	H	1.8	700	38	12,000
1m	Cyh	H	65	13,000	1300	12,000
1n	Ph	H	84	>10,000	410	>50,000
1o	i-Bu	H	1.4	3.2	0.28	11,000
1p	CH₂t-Bu	H	7.1	2,700	2.6	22,000
1q	CH₂Cyh	H	420	840	130	17,000
1r	CH₂β-Np	H	550	210	140	32,000
1s	(CH₂)₂Ph	H	860	93	2.6	5,000

Inhibition of recombinant human ACE2 activity in a fluorescence assay using 0.4 nM ACE2, 30 μM MCA-Tyr-Val-Ala-Asp-Ala-Pro-Lys(DNP)-OH as substrate in 1 μM Zn(OAc)₂, 100 μM TCEP, 50 mM Hepes, 300 μM CHAPS, and 300 mM NaCl at pH = 7.5. The average percent coefficient of variance for the K_{i App} values was 45%.

Inhibition of recombinant human ACE activity in a fluorescence assay using 0.5 nM ACE, 10 μM MCA-Ala-Ser-Asp-Lys-Dap(DNP)-OH as substrate in 1 μM Zn(OAc)₂, 100 μM TCEP, 50 mM Hepes, 300 μM CHAPS, and 300 mM NaCl at pH = 7.5. The average percent coefficient of variance for the K_{i App} values was 58%.

Inhibition of recombinant human NEP activity in a fluorescence assay using 0.15 nM NEP, 2 μM FAM-Gly-Pro-Leu-Gly-Leu-Phe-Ala-Arg-Lys(TAMRA)-NH₂ as substrate in 1 μM Zn(OAc)₂, 100 μM TCEP, 50 mM Hepes, 300 μM CHAPS, and 300 mM NaCl at pH = 7.5. The average percent coefficient of variance for the K_{i App} values was 43%.

Inhibition of recombinant human CpA activity in a fluorescence assay using 37 nM CpA, 30 μM Abz-Gly-Gly-Nph-OH as substrate in 1 μM Zn(OAc)₂, 100 μM TCEP, 50 mM Hepes, 300 μM CHAPS, and 300 mM NaCl at pH = 7.5. The average percent coefficient of variance for the K_{i App} values was 38%.