Table 1.

Inhibition Data and Selectivity of GlcNAcstatins C and F–H, PUGNAc, and Thiamet-G against Lysosomal hHexA/HexB, Human OGA and CpOGA-WT and V331C-CpOGA Mutant

	Ki (μM)	Ki (nM)	Selectivity	Ki (nM)	Ki (nM)
	hHex A/Ba	hOGAb	(hHexA/B/hOGA)	CpOGA-wild-type	V331C-CpOGA
GlcNAcstatin C	0.6 ± 0.1	3.2 ± 0.9	190	0.0046 ± 0.0002c	0.098 ± 0.006c
GlcNAcstatin F	11.0 ± 0.6d	11.2 ± 1.4	1,000	0.0032 ± 0.0002	0.005 ± 0.001
GlcNAcstatin G	>3,700d	4.1 ± 0.7	>900,000	0.0078 ± 0.0007	0.019 ± 0.002
GlcNAcstatin H	100 ± 30d	2.6 ± 0.3	35,000	nd	nd
PUGNAc	0.036e	50e	ns	5.4 ± 0.4	nd
Thiamet-G	750f	21f	35,000	nd	nd

nd, not determined; ns, no selectivity for hOGA.

^aThe Cheng-Prusoff equation (K_i = IC₅₀/(1 + [S]/K_m)) was used to convert the IC₅₀ values to an absolute inhibition constant (K_i).

^bAt physiological pH 7.3.

^cFrom Dorfmueller et al. (2009).

^dThese values are approximate IC₅₀s, obtained after including an artificial 100% inhibition point at an inhibitor concentration of 1000 M.

^eFrom Macauley et al. (2005).

^fFrom Yuzwa et al. (2008).