. Author manuscript; available in PMC: 2012 Nov 18.

Published in final edited form as: ACS Chem Biol. 2011 Sep 26;6(11):1257–1264. doi: 10.1021/cb2002544

Table 3.

Inhibition (IC₅₀) values of wild-type α/β₁ and α/SalI proteasome complexes with various peptide-based inhibitors^a

Inhibitor	α/β₁ IC₅₀ (μM)	α/SalI IC₅₀ (μM)

Salinosporamide A	1.2 ± 0.1	36.8 ± 2.4
Salinosporamide B	19.2 ± 3.5	138.7 ± 27.3
Bortezomib	3.3 ± 0.2	42.7 ± 3.4
Antiprotealide	103.6 ± 7.2	>250
Salinosporamide X3	>250	>250
Salinosporamide X5	>250	>250
Salinosporamide X7	3.6 ± 0.2	>250

All assays were performed using the Z-VKM-amc substrate. Inhibitor insolubility prevented accurate IC₅₀ determination at concentrations exceeding 250 μM. Data shown is the mean ± standard deviation, N = 3.