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646 result(s) for "CYPs"
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Sensing the Generation of Intracellular Free Electrons Using the Inactive Catalytic Subunit of Cytochrome P450s as a Sink
Cytochrome P450 reductase (CPR) abstracts electrons from Nicotinamide adenine dinucleotide phosphate H (NADPH), transferring them to an active Cytochrome P450 (CYP) site to provide a functional CYP. In the present study, a yeast strain was genetically engineered to delete the endogenous CPR gene. A human CYP expressed in a CPR-null (yRD−) strain was inactive. It was queried if Bax—which induces apoptosis in yeast and human cells by generating reactive oxygen species (ROS)—substituted for the absence of CPR. Since Bax-generated ROS stems from an initial release of electrons, is it possible for these released electrons to be captured by an inactive CYP to make it active once again? In this study, yeast cells that did not contain any CPR activity (i.e., because the yeasts’ CPR gene was completely deleted) were used to show that (a) human CYPs produced within CPR-null (yRD-) yeast cells were inactive and (b) low levels of the pro-apoptotic human Bax protein could activate inactive human CYPs within this yeast cells. Surprisingly, Bax activated three inactive CYP proteins, confirming that it could compensate for CPR’s absence within yeast cells. These findings could be useful in research, development of bioassays, bioreactors, biosensors, and disease diagnosis, among others.
Quinic acid from Annona muricata Fruit Inhibits Cyclophosphamide Metabolism through Modulation of Cytochrome P450: Implications for Herbal-Drug Interaction
The oxazaphosphorine alkylating drugs, cyclophosphamide and its structural isomer, ifosamide, are frequently employed in the field of oncology for cancer treatment and immunosuppression purposes. An effective treatment method against cyclophosphamide toxicity has been suggested using plant extracts with high levels of antioxidant constituents. This study evaluates in vitro anticancer activity and anticipates the potential of quinic acid from A. muricata fruit to impact cyclophosphamide metabolism using CYP 450 isoenzyme inhibition. The phytochemicals in the ethanolic extract of A. muricata fruit were initially identified and validated using Q-TOF LC-MS. The MTT assay, a widely used method in cancer research, was employed to assess the potential anticancer activity against MCF-7 cancer cell lines in an in vitro setting. In molecular docking, one of the isolated compounds, quinic acid, was therefore indented to be docked with CYP-450 proteins. In Q-TOF LC/MS analysis, the different peaks were obtained at different retention times, and the quinic acid was at the retention time of 3.1 minutes. The extract showed remarkable in vitro anticancer activity (IC50 value of 240.709 μg/mL) against MCF-7 cancer cell lines. The molecular docking study showed the most effective inhibition on CYP 3A4, CYP 2D6, CYP 2B6 and CYP 2C9 proteins, which indicated the interaction of quinic acid with CYP proteins and herbal drug interaction.
A Computational Pipeline Observes the Flexibility and Dynamics of Plant Cytochrome P450 Binding Sites
Binding site flexibility and dynamics strongly affect the ability of proteins to accommodate substrates and inhibitors. The significance of these properties is particularly pronounced for proteins that are inherently flexible, such as cytochrome P450 enzymes (CYPs). While the research on human CYPs provides detailed knowledge on both structural and functional level, such analyses are still lacking for their plant counterparts. This study aims to bridge this gap. We developed a novel computational pipeline consisting of two steps. Firstly, we use molecular dynamics (MD) simulations to capture the full conformational ensemble for a certain plant CYP. Subsequently, we developed and applied a comprehensive methodology to analyze a number of binding site properties—size, flexibility, shape, hydrophobicity, and accessibility—using the fpocket and mdpocket packages on MD-generated trajectories. The workflow was validated on human CYPs 1A2, 2A6, and 3A4, as their binding site characteristics are well known. Not only could we confirm known binding site properties, but we also identified and named previously unseen binding site channels for CYPs 1A2 and 2A6. The pipeline was then applied to plant CYPs, leading to the first categorization of 15 chosen plant CYPs based on their binding site’s (dis)similarities. This study provides a foundation for the largely uncharted fields of plant CYP substrate specificity and facilitates a more precise understanding of their largely unknown specific biological functions. It offers new insights into the structural and functional dynamics of plant CYPs, which may facilitate a more accurate understanding of the fate of agrochemicals or the biotechnological design and exploitation of enzymes with specific functions. Additionally, it serves as a reference for future structural–functional analyses of CYP enzymes across various biological kingdoms.
CYPminer: an automated cytochrome P450 identification, classification, and data analysis tool for genome data sets across kingdoms
Background Cytochrome P450 monooxygenases (termed CYPs or P450s) are hemoproteins ubiquitously found across all kingdoms, playing a central role in intracellular metabolism, especially in metabolism of drugs and xenobiotics. The explosive growth of genome sequencing brings a new set of challenges and issues for researchers, such as a systematic investigation of CYPs across all kingdoms in terms of identification, classification, and pan-CYPome analyses. Such investigation requires an automated tool that can handle an enormous amount of sequencing data in a timely manner. Results CYPminer was developed in the Python language to facilitate rapid, comprehensive analysis of CYPs from genomes of all kingdoms. CYPminer consists of two procedures i) to generate the Genome-CYP Matrix (GCM) that lists all occurrences of CYPs across the genomes, and ii) to perform analyses and visualization of the GCM, including pan-CYPomes (pan- and core-CYPome), CYP co-occurrence networks, CYP clouds, and genome clustering data. The performance of CYPminer was evaluated with three datasets from fungal and bacterial genome sequences. Conclusions CYPminer completes CYP analyses for large-scale genomes from all kingdoms, which allows systematic genome annotation and comparative insights for CYPs. CYPminer also can be extended and adapted easily for broader usage.
The Central Role of Cytochrome P450 in Xenobiotic Metabolism—A Brief Review on a Fascinating Enzyme Family
Human Cytochrome P450 (CYP) enzymes constitute a superfamily of membrane-bound hemoproteins that are responsible for the metabolism of a wide variety of clinically, physiologically, and toxicologically important compounds. These heme-thiolate monooxygenases play a pivotal role in the detoxification of xenobiotics, participating in the metabolism of many structurally diverge compounds. This short-review is intended to provide a summary on the major roles of CYPs in Phase I xenobiotic metabolism. The manuscript is focused on eight main topics that include the most relevant aspects of past and current CYP research. Initially, (I) a general overview of the main aspects of absorption, distribution, metabolism, and excretion (ADME) of xenobiotics are presented. This is followed by (II) a background overview on major achievements in the past of the CYP research field. (III) Classification and nomenclature of CYPs is briefly reviewed, followed by (IV) a summary description on CYP’s location and function in mammals. Subsequently, (V) the physiological relevance of CYP as the cornerstone of Phase I xenobiotic metabolism is highlighted, followed by (VI) reviewing both genetic determinants and (VI) nongenetic factors in CYP function and activity. The last topic of the review (VIII) is focused on the current challenges of the CYP research field.
Human Cytochrome P450 Cancer-Related Metabolic Activities and Gene Polymorphisms: A Review
Background: Cytochromes P450 (CYPs) are heme-containing oxidoreductase enzymes with mono-oxygenase activity. Human CYPs catalyze the oxidation of a great variety of chemicals, including xenobiotics, steroid hormones, vitamins, bile acids, procarcinogens, and drugs. Findings: In our review article, we discuss recent data evidencing that the same CYP isoform can be involved in both bioactivation and detoxification reactions and convert the same substrate to different products. Conversely, different CYP isoforms can convert the same substrate, xenobiotic or procarcinogen, into either a more or less toxic product. These phenomena depend on the type of catalyzed reaction, substrate, tissue type, and biological species. Since the CYPs involved in bioactivation (CYP3A4, CYP1A1, CYP2D6, and CYP2C8) are primarily expressed in the liver, their metabolites can induce hepatotoxicity and hepatocarcinogenesis. Additionally, we discuss the role of drugs as CYP substrates, inducers, and inhibitors as well as the implication of nuclear receptors, efflux transporters, and drug–drug interactions in anticancer drug resistance. We highlight the molecular mechanisms underlying the development of hormone-sensitive cancers, including breast, ovarian, endometrial, and prostate cancers. Key players in these mechanisms are the 2,3- and 3,4-catechols of estrogens, which are formed by CYP1A1, CYP1A2, and CYP1B1. The catechols can also produce quinones, leading to the formation of toxic protein and DNA adducts that contribute to cancer progression. However, 2-hydroxy- and 4-hydroxy-estrogens and their O-methylated derivatives along with conjugated metabolites play cancer-protective roles. CYP17A1 and CYP11A1, which are involved in the biosynthesis of testosterone precursors, contribute to prostate cancer, whereas conversion of testosterone to 5α-dihydrotestosterone as well as sustained activation and mutation of the androgen receptor are implicated in metastatic castration-resistant prostate cancer (CRPC). CYP enzymatic activities are influenced by CYP gene polymorphisms, although a significant portion of them have no effects. However, CYP polymorphisms can determine poor, intermediate, rapid, and ultrarapid metabolizer genotypes, which can affect cancer and drug susceptibility. Despite limited statistically significant data, associations between CYP polymorphisms and cancer risk, tumor size, and metastatic status among various populations have been demonstrated. Conclusions: The metabolic diversity and dual character of biological effects of CYPs underlie their implications in, preliminarily, hormone-sensitive cancers. Variations in CYP activities and CYP gene polymorphisms are implicated in the interindividual variability in cancer and drug susceptibility. The development of CYP inhibitors provides options for personalized anticancer therapy.
Discovery and Engineering of Cytochrome P450s for Terpenoid Biosynthesis
Terpenoids represent 60% of known natural products, including many drugs and drug candidates, and their biosynthesis is attracting great interest. However, the unknown cytochrome P450s (CYPs) in terpenoid biosynthetic pathways make the heterologous production of related terpenoids impossible, while the slow kinetics of some known CYPs greatly limit the efficiency of terpenoid biosynthesis. Thus, there is a compelling need to discover and engineer CYPs for terpenoid biosynthesis to fully realize their great potential for industrial application. This review article summarizes the current state of CYP discovery and engineering in terpenoid biosynthesis, focusing on recent synthetic biology approaches toward prototyping CYPs in heterologous hosts. We also propose several strategies for further accelerating CYP discovery and engineering. CYP discovery and engineering are crucial for terpenoid biosynthesis, which has recently attracted great academic and industrial interest. Major obstacles to traditional CYP discovery methods are the inaccessibility of genetic tools in native hosts and the low activity of CYPs. Synthetic biology approaches based on multi-omics studies, heterologous CYP expression, and metabolic engineering of chassis cells have revolutionized CYP discovery platforms and significantly accelerated their discovery rate. Harnessing the great potential of genome engineering and robotic automation will further increase the likelihood of discovering or engineering CYP with desired activity as well as enhance the production of terpenoids with commercial value.
β-Naphthoflavone and Ethanol Reverse Mitochondrial Dysfunction in A Parkinsonian Model of Neurodegeneration
The 1-methyl-4-phenylpyridinium (MPP+) is a parkinsonian-inducing toxin that promotes neurodegeneration of dopaminergic cells by directly targeting complex I of mitochondria. Recently, it was reported that some Cytochrome P450 (CYP) isoforms, such as CYP 2D6 or 2E1, may be involved in the development of this neurodegenerative disease. In order to study a possible role for CYP induction in neurorepair, we designed an in vitro model where undifferentiated neuroblastoma SH-SY5Y cells were treated with the CYP inducers β-naphthoflavone (βNF) and ethanol (EtOH) before and during exposure to the parkinsonian neurotoxin, MPP+. The toxic effect of MPP+ in cell viability was rescued with both βNF and EtOH treatments. We also report that this was due to a decrease in reactive oxygen species (ROS) production, restoration of mitochondrial fusion kinetics, and mitochondrial membrane potential. These treatments also protected complex I activity against the inhibitory effects caused by MPP+, suggesting a possible neuroprotective role for CYP inducers. These results bring new insights into the possible role of CYP isoenzymes in xenobiotic clearance and central nervous system homeostasis.
Differences of Atomic-Level Interactions between Midazolam and Two CYP Isoforms 3A4 and 3A5
CYP 3A4 and CYP 3A5 are two important members of the human cytochrome P450 family. Although their overall structures are similar, the local structures of the active site are different, which directly leads to obvious individual differences in drug metabolic efficacy and toxicity. In this work, midazolam (MDZ) was selected as the probe substrate, and its interaction with two proteins, CYP 3A4 and CYP 3A5, was studied by molecular dynamics simulation (MD) along with the calculation of the binding free energy. The results show that two protein–substrate complexes have some similarities in enzyme–substrate binding; that is, in both complexes, Ser119 forms a high occupancy hydrogen bond with MDZ, which plays a key role in the stability of the interaction between MDZ and the enzymes. However, the complex formed by CYP 3A4 and MDZ is more stable, which may be attributed to the sandwich structure formed by the fluorophenyl group of the substrate with Leu216 and Leu482. Our study interprets the binding differences between two isoform–substrate complexes and reveals a structure–function relationship from the atomic perspective, which is expected to provide a theoretical basis for accurately measuring the effectiveness and toxicity of drugs for individuals in the era of precision medicine.
DEEPCYPs: A deep learning platform for enhanced cytochrome P450 activity prediction
Cytochrome P450 (CYP) is a superfamily of heme-containing oxidizing enzymes involved in the metabolism of a wide range of medicines, xenobiotics, and endogenous compounds. Five of the CYPs (1A2, 2C9, 2C19, 2D6, and 3A4) are responsible for metabolizing the vast majority of approved drugs. Adverse drug-drug interactions, many of which are mediated by CYPs, are one of the important causes for the premature termination of drug development and drug withdrawal from the market. In this work, we reported in silicon classification models to predict the inhibitory activity of molecules against these five CYP isoforms using our recently developed FP-GNN deep learning method. The evaluation results showed that, to the best of our knowledge, the multi-task FP-GNN model achieved the best predictive performance with the highest average AUC (0.905), F1 (0.779), BA (0.819), and MCC (0.647) values for the test sets, even compared to advanced machine learning, deep learning, and existing models. Y-scrambling testing confirmed that the results of the multi-task FP-GNN model were not attributed to chance correlation. Furthermore, the interpretability of the multi-task FP-GNN model enables the discovery of critical structural fragments associated with CYPs inhibition. Finally, an online webserver called DEEPCYPs and its local version software were created based on the optimal multi-task FP-GNN model to detect whether compounds bear potential inhibitory activity against CYPs, thereby promoting the prediction of drug-drug interactions in clinical practice and could be used to rule out inappropriate compounds in the early stages of drug discovery and/or identify new CYPs inhibitors.