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. Author manuscript; available in PMC: 2012 Mar 1.
Published in final edited form as: Arch Biochem Biophys. 2010 Sep 15;507(1):135–143. doi: 10.1016/j.abb.2010.09.006

Table 1.

Summary of kinetic inactivation constants for acetylenic mechanism-based inhibitors of P450s.

MBIa CYPsb KI (μM) kinact (min-1) kinact/KI (min-1μM-1) Modified Sitec Ref.
2EN 2B1 0.08 0.83 10.4 Protein [28]
9EPh 2B1 0.14 0.45 3.2 Protein [31]
5-P1P 2B1 100 0.92 0.0092 Heme [33]
2E1 50 1.31 0.026 Heme [33]
Δ2E1 54 0.78 0.014 Heme [33]
4-P1B 2E1 (LM) ND 0.21 ND [33]
2E1 ND 0.55 ND [33]
2-P3B2 2E1 (LM) ND 0.04 ND [33]
2E1 ND 0.13 ND [33]
1-P2P1 2E1 (LM) ND 0.3 ND [33]
2E1 (LM) ND 0.16 ND [33]
17-EE 2B1 11 0.2 0.018 Protein [36]
2B6 0.8 0.03 0.038 Protein [36]
3A4 18 0.04 0.0022 Protein+Heme [35]
tBA 2B4 75 0.23 0.0031 Heme [42]
2E1 1000 0.2 2×10-4 Protein+Heme [41]
tBMP 2E1 100 0.12 1.2×10-4 Heme [41]
2B1 17 0.56 0.33 Heme [44]
tBPA 2B4 0.44 0.12 0.27 Protein [45]
2B1 0.7 1.64 2.3 Protein [44]
2B6 2.8 0.7 0.25 Protein+Heme unpublished data
DMPB 2B6 (LM) 5.1 0.09 0.018 Heme [54]
a

Abbreviations: 2EN, 2-ethynylnaphthalene; 9-EPh, 9-ethynylphenanthrene; 5-P1P, 5-phenyl-1-pentyne; 17EE, 17α-ethynylestradiol; tBA, tert-butyl acetylene; tBMP, tert-butyl-1-methyl-2-propynyl ether; tBPA, tert-butylphenylacetylene; 4-P1B, 4-phenyl-1-butyne; 2-P3B2, 2-phenyl-3-buty-2-ol; 1-P2P1, 1-phenyl-2-propyn-1-ol; DMPB, N-(3,5-Dichloro-4-pyridyl)-4-methoxy-3-(prop-2-ynyloxy)benzamide. The chemical structures of the listed MBIs are included in Table 1S in the Supplemental Materials.

b

LM, liver microsomes

c

ND, not determined.