4-CPI
4-CPI (4-(4-Chlorophenyl)imidazole) is a CYP2B4 inhibitor with an IC50 of 0.11 μM and a Kd of 0.043 μM. The Ks of 4-CPI for cytochrome P450eryF (S93C/C154S mutant) is 9.4 μM, with no allosteric cooperative effect of ligand binding. 4-CPI binds to CYP2B4 at a 1:1 ratio, which induces substantial conformational changes in the enzyme's active pocket to form a closed crystal conformation (PDB:1SUO). 4-CPI can be used to investigate the flexibility of P450 active pockets, protein-ligand binding thermodynamics, and the allosteric mechanisms of P450.
For research use only. We do not sell to patients.
- CAS No.: 35512-29-9
- Formula: C9H7ClN2
- Molecular Weight:178.62
-
Storage:Powder -20°C, 3 years , 4°C, 2 years ; In solvent -80°C, 6 months , -20°C, 1 month
Biological Activity
Description
IC50 & Target
[1]|
CYP2B4 0.11 μM (IC50) |
CYP2B4 0.043 μM (Kd) |
In Vitro
4-CPI (4-(4-Chlorophenyl)imidazole) (0-30 μM) inhibits the 7-ethoxy-4-trifluoromethylcoumarin oxidation activity of purified 2B4dH (H226Y) with an IC50 of 0.11 μM[1].
4-CPI (0-2.5 μM) binds to purified 2B4dH (H226Y) with a KD value of 0.043 μM, and induces type II heme spectral changes at 25 °C[1].
Binding of 4-CPI (10 μM; 1 hour) to purified 2B4dH (H226Y) reduces the accessibility of Trp121 to acrylamide by 2-fold, indicating that helix C containing Trp121 undergoes a conformational change and enters an environment with lower solvent exposure[1].
4-CPI docks into the experimentally observed binding pocket of the closed crystal structure of 2B4dH (H226Y)[1].
4-CPI (120 μM) induces dimerization of purified 2B4dH (H226Y) in the absence of CYMAL-5, whereas the protein remains in a monomeric state in the presence of 1 mM CYMAL-5[1].
4-CPI (0-12 μM) binds to the purified P450eryF (S93C/C154S) mutant at a 1:1 stoichiometric ratio, with a binding constant Ks of 9.4 μM, and induces type II spectral changes[2].
4-CPI binds to a single high-affinity site near the heme of the P450eryF (S93C/C154S) homology model, with no stable secondary high-affinity binding site, which is consistent with its non-cooperative 1:1 binding behavior[2].
MedChemExpress (MCE) has not independently confirmed the accuracy of these methods. They are for reference only. Further protocols information, click here.
Chemical Information
-
CAS No. 35512-29-9
-
Appearance Solid
-
Molecular Weight 178.62
-
Formula C9H7ClN2
-
SMILES
ClC=1C=CC(=CC1)C2=CN=CN2
-
Synonyms
4-(4-Chlorophenyl)imidazole
-
Shipping
Room temperature in continental US; may vary elsewhere.
-
Storage
Powder -20°C 3 years 4°C 2 years In solvent -80°C 6 months -20°C 1 month
Protocols
-
Cell Cytotoxicity Assay
Cytotoxicity assays are usually based on the assessment of cell membrane damage, which can also be indirectly detected by measuring cell viability. Detection methods include MTT assay, CKK-8 assay, LDH assay and ATP assay, etc.
Purity & Documentation
References
[1]. Muralidhara BK, et al. Conformational flexibility of mammalian cytochrome P450 2B4 in binding imidazole inhibitors with different ring chemistry and side chains. Solution thermodynamics and molecular modeling. J Biol Chem. 2006 Mar 24;281(12):8051-61. [Content Brief]
[2]. Muralidhara BK, et al. Dissecting the thermodynamics and cooperativity of ligand binding in cytochrome P450eryF. Journal of the American Chemical Society. 2007 Feb 21;129(7):2015-24. [Content Brief]
Calculators
Concentration (start) × Volume (start) = Concentration (final) × Volume (final)
Keywords
- 4-CPI
- 35512-29-9
- 4-(4-Chlorophenyl)imidazole
- Cytochrome P450
- CYP2B4 inhibitor
- P450eryF
- cytochrome P450
- type II ligand binding
- 1:1 binding stoichiometry
- ITC thermodynamics
- conformational flexibility
- closed P450 crystal form
- PDB 1SUO
- allosteric binding
- heme iron coordination
- imidazole P450 ligand
- 7-ethoxy-4-trifluoromethylcoumarin metabolism inhibitio
- Inhibitor
- inhibitor
- inhibit