Cytochromes P450 are a class of metalloproteins which are responsible for electron transfer in a wide spectrum of reactions including metabolic biotransformation of endogenous and exogenous substrates. The superfamily of cytochromes P450 consists of families and subfamilies which are characterized by a specific structure and substrate specificity. Cytochromes P450 family 1 (CYP1s) play a distinctive role in the metabolism of drugs and chemical procarcinogens. In recent decades, these hemoproteins have been intensively studied with the use of computational methods which have been recently developed remarkably to be used in the process of drug design by the virtual screening of compounds in order to find agents with desired properties. Moreover, the molecular modeling of proteins and ligand docking to their active sites provide an insight into the mechanism of enzyme action and enable us to predict the sites of drug metabolism. The review presents the current status of knowledge about the use of the computational approach in studies of ligand-enzyme interactions for CYP1s. Research on the metabolism of substrates and inhibitors of CYP1s and on the selectivity of their action is particularly valuable from the viewpoint of cancer chemoprevention, chemotherapy, and drug-drug interactions.
1 September 2012 in Bioorganic & Medicinal Chemistry
A novel series of methoxy-trans-stilbenes with 3,4-dimethoxy motifs was designed and synthesized. The inhibitory potency of 3,4-dimethoxystilbene derivatives against cytochrome P450 isozymes CYP1A1, CYP1B1 and CYP1A2 was evaluated. 3,4,2′-Trimethoxy-trans-stilbene (3,4,2′-TMS) exhibited extremely potent inhibitory action against CYP1B1 activity with an IC50 of 0.004 μM. 3,4,2′-TMS exhibited 90-fold selectivity for CYP1B1 over CYP1A1 and 830-fold selectivity for CYP1B1 over CYP1A2. However, 3,4,2′,4′-tetramethoxy-trans-stilbene appeared to be the most selective inhibitor of both CYP1B1 and CYP1A1 showing very low affinity toward CYP1A2. Complementary experimental studies and computational methods were used to explain what structural determinants decide the specific affinity of stilbene derivatives to CYP1A2 and CYP1B1 binding sites.
Human cytochrome P450 1B1 (CYP1B1) is an extrahepatic heme-containing monooxygenase. CYP1B1 contributes to the oxidative metabolism of xenobiotics, drugs, and endogenous substrates like melatonin, fatty acids, steroid hormones, and retinoids, which are involved in diverse critical cellular functions. CYP1B1 plays an important role in the pathogenesis of cardiovascular diseases, hormone-related cancers and is responsible for anti-cancer drug resistance. Inhibition of CYP1B1 activity is considered as an approach in cancer chemoprevention and cancer chemotherapy. CYP1B1 can activate anti-cancer prodrugs in tumor cells which display overexpression of CYP1B1 in comparison to normal cells. CYP1B1 involvement in carcinogenesis and cancer progression encourages investigation of CYP1B1 interactions with its ligands: substrates and inhibitors. Computational methods, with a simulation of molecular dynamics (MD), allow the observation of molecular interactions at the binding site of CYP1B1, which are essential in relation to the enzyme’s functions.
1 January 2018 in European Journal of Medicinal Chemistry
The self-assembly of 6,6′′′′-dimethyl-2,2′;6′,2′′;6′′,2′′′-quaterpyridine L with tetrahedral ions of silver(I) and copper(I) leads to the formation of dinuclear double stranded helicates 1–4. 1H NMR studies confirm the stability of each helicate both in 2% aqueous DMSO solution, which plays the role of a medium in biological studies, and in the cell extract solution. The cytotoxic properties of complexes were examined on two cancerous cell lines: HeLa and T-47D as well as on the non-neoplastic fibroblasts HaCaT by using the MTT assay method. The IC50 values of cisplatin towards cancerous cell lines are rather comparable. However, the trend of cancerous/healthy cell selectivity is not maintained. One may assume a different mechanism of action. Moreover, it is possible to distinguish the cell death pathway triggered by Ag(I) and Cu(I) helicates presented in this study. Flow cytometry, EtBr displacement titrations, CD titrations, DNA melting experiments and DFT calculations were used to characterize the type of interaction and the mechanism of cytotoxic action.