[12] Because of the vast variety of reactions catalyzed by CYPs, the activities and properties of the many CYPs differ in many aspects. Plant cytochrome P450s are involved in a wide range of biosynthetic reactions and target a diverse range of biomolecules. DNA Cell Biol . For example, if one drug inhibits the CYP-mediated metabolism of another drug, the second drug may accumulate within the body to toxic levels. 2004;5(9):735-740. doi: 10.1161/JAHA.118.009871. CYP105A1 from Streptomyces griseolus metabolizes sulfonylurea herbicides to less toxic derivatives,[45]) or are part of specialised metabolite biosynthetic pathways (e.g. [24] Because these drugs are metabolized by CYP3A4, the mean plasma levels of these drugs may increase because of enzyme inhibition or decrease because of enzyme induction. Bethesda, MD 20894, Copyright This interrupts the conversion of lanosterol to ergosterol, a component of the fungal cell membrane. Clipboard, Search History, and several other advanced features are temporarily unavailable. [3][5] As of 2018[update], more than 300,000 distinct CYP proteins are known.[6][7]. CYPs have been extensively examined in mice, rats, dogs, and less so in zebrafish, in order to facilitate use of these model organisms in drug discovery and toxicology. Glyphosate (Roundup) is an herbicide used extensively worldwide which acts as an inhibitor of 5′enolpyruvylshikimate-3-phosphate synthase and for which transgenic herbicide resistant plants have been developed.Here we report for the first time that glyphosate is an inhibitor of cytochrome P450 using a functional expression system forThlaspi arvensaeCYP71B1 inEscherichia coli. If no reducing equivalents are available, this complex may remain stable, allowing the degree of binding to be determined from absorbance measurements in vitro[18] Epub 2007 Sep 15. For example, CYP2E1 is the gene that encodes the enzyme CYP2E1—one of the enzymes involved in paracetamol (acetaminophen) metabolism. Alcoholic Liver Disease: Alcohol Metabolism, Cascade of Molecular Mechanisms, Cellular Targets, and Clinical Aspects. La súper família dels citocroms p450 forma part d'un gran i divers grup d'enzims. Cytochrome (CYP) P450 2E1 is clinically and toxicologically important and it is constitutively expressed in the liver and many other tissues. Some substrates cause an opposite change in spectral properties, a "reverse type I" spectrum, by processes that are as yet unclear. Unable to load your collection due to an error, Unable to load your delegates due to an error. High levels of CYP1A2 have been linked to an increased risk of colon cancer. In addition, chlorzoxazone and trimethadione metabolism are good CYP2E1 probes for liver disease in vivo and in vitro. Careers. Flies of this species have adapted an upregulation of this gene due to exposure of high levels of alkaloids in host plants. CYP 2C19 was the most important enzyme with regard to the demethylation of amitriptyline, the quantitatively … This page was last edited on 20 March 2021, at 04:40. ", "Inhibition of human liver cytochrome P450 by star fruit juice", "Tributyltin pollution on a global scale. A species of Sonoran Desert Drosophila that uses an upregulated expression of the CYP28A1 gene for detoxification of cacti rot is Drosophila mettleri. [citation needed]. Essi vedranno una diminuzione della loro concentrazione ematica e della loro durata d'azione ed effetto. eCollection 2019. I barbiturici inducono l'enzima glucuronosiltransferasi e il sistema Citocromo P450. 2019. For example, CYP6G1 is linked to insecticide resistance in DDT-resistant Drosophila melanogaster[41] and CYP6M2 in the mosquito malaria vector Anopheles gambiae is capable of directly metabolizing pyrethroids.[42]. This pathway entails oxidation of the ferric-substrate complex with oxygen-atom donors such as peroxides and hypochlorites. 8600 Rockville Pike Italian Heart Journal Supplement. Cytochrome P450 aromatic O-demethylase, which is made of two distinct promiscuous parts: a cytochrome P450 protein (GcoA) and three domain reductase, is significant for its ability to convert Lignin, the aromatic biopolymer common in plant cell walls, into renewable carbon chains in a catabolic set of reactions. Many substrates for CYP3A4 are drugs with a narrow therapeutic index, such as amiodarone[23] or carbamazepine. Significant research is ongoing into fungal P450s, as a number of fungi are pathogenic to humans (such as Candida yeast and Aspergillus) and to plants. Cytochrome P450 enzymes also function to metabolize potentially toxic compounds, including drugs and products of endogenous metabolism such as bilirubin, principally in the liver. CYPs are, in general, the terminal oxidase enzymes in electron transfer chains, broadly categorized as P450-containing systems. [36] This is a summary of the genes and of the proteins they encode. Cytochrome P450 enzymes are essential for the metabolism of many medications. An overview of relevant and recent research: impacts and issues", "Diagram of the pathways of human steroidogenesis", "The cytochrome P450 genesis locus: the origin and evolution of animal cytochrome P450s", "The chemical defensome: environmental sensing and response genes in the Strongylocentrotus purpuratus genome", "Dissecting the insecticide-resistance- associated cytochrome P450 gene Cyp6g1", "Pyrethroid activity-based probes for profiling cytochrome P450 activities associated with insecticide interactions", "Complete genome sequence and comparative analysis of the industrial microorganism Streptomyces avermitilis", "Investigating conservation of the albaflavenone biosynthetic pathway and CYP170 bifunctionality in streptomycetes", "CYP105-diverse structures, functions and roles in an intriguing family of enzymes in Streptomyces", "Characterization of a catalytically self-sufficient 119,000-dalton cytochrome P-450 monooxygenase induced by barbiturates in Bacillus megaterium", "Cloning of a potential cytochrome P450 from the archaeon Sulfolobus solfataricus", "Effects of tobacco smoking and nicotine on cancer treatment", "Inhibitory monoclonal antibodies to human cytochrome P450 enzymes: a new avenue for drug discovery", "Cytochrome P450 Mediated Drug and Carcinogen Metabolism using Monoclonal Antibodies", "Monoclonal antibodies specific and inhibitory to human cytochromes P450 2C8, 2C9, and 2C19", International Centre for Genetic Engineering and Biotechnology, Indiana University-Purdue University Indianapolis, "Human Cytochrome P450 (CYP) Allele Nomenclature Committee", disorders of globin and globulin proteins, https://en.wikipedia.org/w/index.php?title=Cytochrome_P450&oldid=1013127173, Short description is different from Wikidata, Articles containing potentially dated statements from 2018, All articles containing potentially dated statements, Articles with unsourced statements from April 2011, Articles needing cleanup from September 2016, Cleanup tagged articles with a reason field from September 2016, Wikipedia pages needing cleanup from September 2016, Creative Commons Attribution-ShareAlike License, 7-alpha hydroxylation of 24-hydroxycholesterol, Substrate binding induces electron transfer from NAD(P)H via, Molecular oxygen binds to the resulting ferrous heme center at the distal axial coordination position, initially giving a, A second electron is transferred, from either, The peroxo group formed in step 4 is rapidly protonated twice, releasing one molecule of water and forming the highly reactive species referred to as. [40], CYPs have also been heavily studied in insects, often to understand pesticide resistance. Biomedicines. Humans have 57 genes and more than 59 pseudogenes divided among 18 families of cytochrome P450 genes and 43 subfamilies. In this context, several phase I drug-metabolizing enzymes belonging to the CYP1, CYP2 and CYP3 families of the cytochrome P450 system have a central role, affecting the metabolism of several clinically used drugs. Susceptibilidad genética al desarrollo de hepatitis alcohólica aguda: papel de las mutaciones genéticas en alcohol deshidrogenasa, aldehído deshidrogenasa y citocromo P450 2E1 Genetic susceptibility to the develpment of acute alcoholic hepatitis: role of genetic mutations in dehydrogenae alcohol, aldehyde dehydrogenase and cytochrome P450 2E1 Would you like email updates of new search results? There are nomenclature committees that assign and track both base gene names (Cytochrome P450 Homepage) and allele names (CYP Allele Nomenclature Committee). Cytochrome P450 enzymes (CYPs) are essential components of cellular detoxification system. Gene and genome sequencing is far outpacing biochemical characterization of enzymatic function, though many genes with close homology to CYPs with known function have been found, giving clues to their functionality. In contrast to many other CYP isoenzymes, indisputable evidence for a functionally important polymorphism of CYP2E1 in the human population is lacking. This table is designed as a hypothesis testing, teaching and reference tool for physicians and researchers interested in drug interactions that are the result of competition for, or effects on the human cytochrome P450 system.The table contains lists of drugs in columns under the designation of specific cytochrome P450 isoforms. The P450 superfamily: update on new sequences, gene mapping, accession numbers, early trivial names of enzymes, and nomenclature. The number and diversity of P450 genes is responsible, in part, for the multitude of bioactive compounds.[53]. Cytochromes P450 (CYPs) are a superfamily of enzymes containing heme as a cofactor that function as monooxygenases. Os substratos dos encimas CYP son intermediatos metabólicos como lípidos e hormonas esteroides, ou substancias xenobióticas como fármacos e compostos químicos tóxicos. InterPro provides functional analysis of proteins by classifying them into families and predicting domains and important sites. A subset of cytochrome P450 enzymes play important roles in the synthesis of steroid hormones (steroidogenesis) by the adrenals, gonads, and peripheral tissue: Certain cytochrome P450 enzymes are critical in metabolizing polyunsaturated fatty acids (PUFAs) to biologically active, intercellular cell signaling molecules (eicosanoids) and/or metabolize biologically active metabolites of the PUFA to less active or inactive products. Naturally occurring compounds may also induce or inhibit CYP activity. Abstract. [52] Plant genome annotations suggest that cytochrome P450 genes make up as much as 1% of the plant genes. Accessibility E.coli). Reported numbers range from 35 genes in the sponge Amphimedon queenslandica to 235 genes in the cephalochordate Branchiostoma floridae. Inducible and CYP1A2 5-10% deficient Although no P450 has yet been shown to be essential in a microbe, the CYP105 family is highly conserved with a representative in every streptomycete genome sequenced so far. Questo può determinare diminuzioni significative degli effetti di altri farmaci che dipendono dall'interazione con il citocromo P450 per il loro metabolismo. are inducible by some polycyclic hydrocarbons, some of which are found in cigarette smoke and charred food. Cytochrome P450 2E1 and its roles in disease. The Human Genome Project has identified 57 human genes coding for the various cytochrome P450 enzymes.[20]. [4] However, they are not omnipresent; for example, they have not been found in Escherichia coli. Neste estudo encontramos diferença significativa na trasncrição de genes de citocromo P450 (CYP356A2, CYP2AU2, CYP30C1, CYP3071A1 e CYP26F1) em amostras de glândula digestiva de ostras expostas por diferentes períodos a um local contaminado por esgoto sanitário. This can be measured by difference spectroscopies and is referred to as the "type I" difference spectrum (see inset graph in figure). Cytochromes P450 are a superfamily of enzymes containing heme as a cofactor that function as monooxygenases. The classes of CYPs most often investigated in non-human animals are those either involved in development (e.g., retinoic acid or hormone metabolism) or involved in the metabolism of toxic compounds (such as heterocyclic amines or polyaromatic hydrocarbons). Most CYP enzymes are presumed to have monooxygenase activity, as is the case for most mammalian CYPs that have been investigated (except for, e.g., CYP19 and CYP5). 2019 Aug 21;2019:1475163. doi: 10.1155/2019/1475163. In bacteria the distribution of P450s is very variable with many bacteria having no identified P450s (e.g. Biomedicines. 2020 May 1;322:109056. doi: 10.1016/j.cbi.2020.109056. Most CYPs require a protein partner to deliver one or more electrons to reduce the iron (and eventually molecular oxygen). National Library of Medicine O citocromo P450 é unha superfamilia de encimas monooxixenases constituída por un grupo grande e diverso de encimas que catalizan a oxidación de compostos orgánicos. This cysteine and several flanking residues are highly conserved in known CYPs and have the formal PROSITE signature consensus pattern [FW] - [SGNH] - x - [GD] - {F} - [RKHPT] - {P} - C - [LIVMFAP] - [GAD]. Evid Based Complement Alternat Med. These reactions lead to various fatty acid conjugates, plant hormones, secondary metabolites, lignins, and a variety of defensive compounds. Wang T, Du H, Ma J, Shen L, Wei M, Zhao X, Chen L, Li M, Li G, Xing Q, He L, Qin S. PeerJ. Hence, these drug interactions may necessitate dosage adjustments or choosing drugs that do not interact with the CYP system. The term cytochrome P450 stems from the fact that the proteins are members of the cytochrome (heme containing) family of proteins and that when the heme moiety is complexed with carbon monoxide the maximum absorption of light occurs at a wavelength of 450 nm. (This is useful only because humans' P450 have a different sensitivity; this is how this class of antifungals work.)[51]. Ingelman-Sundberg M, Ronis MJ, Lindros KO, Eliasson E, Zhukov A. Chem Biol Interact. In short, it is a facilitator of a critical step in Lignin conversion. New Molecular Mechanism Underlying Myc-Mediated Cytochrome P450 2E1 Upregulation in Apoptosis and Energy Metabolism in the Myocardium. We combine protein signatures from a number of member databases into a single searchable resource, capitalising on their individual strengths to produce a powerful integrated database and diagnostic tool. Universidad de la SabanaFacultad de Enfermería y RehabilitaciónAsignatura: Farmacología I. El más conocido ha sido el sistema inmunológico, sin embargo existe otro poco menos conocido: El citocromo P450. However, some gene or enzyme names for CYPs may differ from this nomenclature, denoting the catalytic activity and the name of the compound used as substrate. Cytochrome P450 3A4 (abbreviated CYP3A4) (EC 1.14.13.97) is an important enzyme in the body, mainly found in the liver and in the intestine. Both of these characteristics account for their central importance in medicine. The remarkable reactivity and substrate promiscuity of P450s have long attracted the attention of chemists. These enzymes are of interest, because in assays, they can activate compounds to carcinogens. Depending on the substrate and enzyme involved, P450 enzymes can catalyze any of a wide variety of reactions. CITOCROMO P450
Es el principal catalizador de las reacciones de biotransformación de medicamentos. Human lymphocyte cytochrome P450 2E1, a putative marker for alcohol-mediated changes in hepatic chlorzoxazone activity. (the sequence identity of the members > 55%) ! doi: 10.7717/peerj.9628. (the sequence identity of the members > 40%) ! This site needs JavaScript to work properly. The superfamily of cytochrome P450 – over 7,000 cytochromes P450 have been identified. Clozapine, imipramine, paracetamol, phenacetin Heterocyclic aryl amines Most oxidations of chemicals are catalyzed by cytochrome P450 (P450, CYP) enzymes, which generally utilize mixed-function oxidase stoichiometry, utilizing pyridine nucleotides as electron donors: NAD(P)H + O2 + R → NAD(P)+ + RO + H2O (where R is a carbon substrate and RO is an oxidized product). ! FOIA In contrast to many other CYP isoenzymes, indisputable evidence for a functionally important polymorphism of CYP2E1 in the human population is lacking. The cytochrome P450 (P450 or CYP) isoenzymes are a group of heme-containing enzymes embedded primarily in the lipid bilayer of the endoplasmic reticulum of hepatocytes, it takes part in the metabolism of many drugs, steroids and carcinogens [].The most intensively studied route of drug metabolism is the P450-catalysed mixed-function oxidation reaction which conforms to the following … Zeaxanthin Dipalmitate in the Treatment of Liver Disease. 2020 Jul 31;8:e9628. En el hombre se estima que hay más de 40 enzimas y más de 150 isoformas diferentes de este complejo enzimático que han evolucionado desde hace más de un billón de años, encontrándose en todos los reinos biológicos incluyendo las bacterias y plantas, y actuando como The active site of cytochrome P450 contains a heme-iron center. 1998 Nov;28(11):1041-7. doi: 10.1080/004982598238930. La funció de la majoria dels enzims CYP consisteix a catalitzar les reaccions d'oxidació de les substàncies orgàniques. 1993;12:1–51. Learn about genetic conditions, genes, chromosomes, and more. This, combined with the remarkable chemistry they catalyse, has led to many studies using the heterologously expressed proteins in vitro. January 2005; Ciencias Marinas 31(1A) Authors: E.M. García. CYPs metabolize thousands of endogenous and exogenous chemicals.
Se encarga del metabolismo de toxinas en alimentos y fármacos.
Sus enzimas son proteínas de membrana con hem (hemo) localizadas en el REL de innumerables tejidos, las cuales estan en relación con la reductasa de NADPH-citocromo P450
(10 citocromo/1 … Els substrats que s'uneixen als enzims CYP inclou intermediaris metabòlics com per exemple els lípids i les hormones esteroides, i també xenobiòtics, tal com alguns fàrmacs s o altres substàncies químiques … Keywords Glyphosate .Roundup® .Chickembryo .Liver .Smallintestine .CytochromeP450 .Inovo Introduction In ovo injection is a … An alternative route for mono-oxygenation is via the "peroxide shunt" (path "S" in figure). [39] CYP1A5 and CYP3A37 in turkeys were found to be very similar to the human CYP1A2 and CYP3A4 respectively, in terms of their kinetic properties as well as in the metabolism of aflatoxin B1. Prevention and treatment information (HHS). El CYP450 se encarga de eliminar y neutralizar xenobióticos convirtiéndolos en compuestos más polares utilizando una serie de enzimas (Super familia de más de 40 enzimas), a este proceso se le llama biotransformación. [1][2][3] In mammals, these proteins oxidize steroids, fatty acids, and xenobiotics, and are important for the clearance of various compounds, as well as for hormone synthesis and breakdown. [37] Mice have genes for 101 CYPs, and sea urchins have even more (perhaps as many as 120 genes). In plants, these proteins are important for the biosynthesis of defensive compounds, fatty acids, and hormones. Alcoholic Liver Disease: Current Mechanistic Aspects with Focus on Their Clinical Relevance. The iron is tethered to the protein via a cysteine thiolate ligand. Many animals have as many or more CYP genes than humans do. Often there are differences in gene regulation or enzyme function of CYPs in related animals that explain observed differences in susceptibility to toxic compounds (ex. Genes encoding CYP enzymes, and the enzymes themselves, are designated with the root symbol CYP for the superfamily, followed by a number indicating the gene family, a capital letter indicating the subfamily, and another numeral for the individual gene. The active oxidants in P450s are thought to be iron(IV)−oxo porphyrin radical cations termed Compounds I, and these intermediates have been sought since the discovery of P450s 40 years ago. Presencia del citocromo P450 en las especies de coral Siderastrea siderea y Montastraea faveolata del Caribe. Ethanol-inducible cytochrome P4502E1: regulation, enzymology and molecular biology. Effects on CYP isozyme activity are a major source of adverse drug interactions, since changes in CYP enzyme activity may affect the metabolism and clearance of various drugs. It oxidizes small foreign organic molecules ( xenobiotics ), such as toxins or drugs, so that they can be removed from the body. As CYPs son os principais encimas implicados no metabolismo de fármacos e a bioactivación, e … Many drugs may increase or decrease the activity of various CYP isozymes either by inducing the biosynthesis of an isozyme (enzyme induction) or by directly inhibiting the activity of the CYP (enzyme inhibition). Cytochrome (CYP) P450 2E1 is clinically and toxicologically important and it is constitutively expressed in the liver and many other tissues. After the product has been released from the active site, the enzyme returns to its original state, with a water molecule returning to occupy the distal coordination position of the iron nucleus. A drug appears in a column if there is published evidence that it is metabolized, at least in part, via that isoform. [13] In general, the P450 catalytic cycle proceeds as follows: Binding of substrate is reflected in the spectral properties of the enzyme, with an increase in absorbance at 390 nm and a decrease at 420 nm. The commonly used azole class antifungal drugs work by inhibition of the fungal cytochrome P450 14α-demethylase. Please enable it to take advantage of the complete set of features! canines' inability to metabolize xanthines such as caffeine). Since the 1A2 enzyme can be induced by cigarette smoking, this links smoking with colon cancer. 2019 Jan 8;8(1):e009871. Those so far identified are generally involved in either biotransformation of xenobiotic compounds (e.g. Kurata N, Nishimura Y, Iwase M, Fischer NE, Tang BK, Inaba T, Yasuhara H. Xenobiotica. del citocromo P450 (CYP450) 2,3,4,5. Termenul de citocrom P450 face referire la o superafamilie de proteine enzime ce conțin hemul ca și cofactor (deci sunt hemoproteine). Evid Based Complement Alternat Med. Cytochrome P450 enzymes can be inhibited or induced by drugs, resulting in clinically significant drug-d… Each family is divided into subfamilies: CYP1A, CYP1B, CYP1C, etc. Such drug interactions are especially important to consider when using drugs of vital importance to the patient, drugs with significant side-effects, or drugs with a narrow therapeutic index, but any drug may be subject to an altered plasma concentration due to altered drug metabolism. The most common reaction catalyzed by cytochromes P450 is a monooxygenase reaction, e.g., insertion of one atom of oxygen into the aliphatic position of an organic substrate (RH) while the other oxygen atom is reduced to water: Many hydroxylation reactions (insertion of hydroxyl groups) use CYP enzymes. Introduction to Cytochrome P450 (CYP) Enzymes. Functional characterization of the chlorzoxazone 6-hydroxylation activity of human cytochrome P450 2E1 allelic variants in Han Chinese. Examples include CYP5A1, thromboxane A2 synthase, abbreviated to TBXAS1 (ThromBoXane A2 Synthase 1), and CYP51A1, lanosterol 14-α-demethylase, sometimes unofficially abbreviated to LDM according to its substrate (Lanosterol) and activity (DeMethylation). A classical example includes anti-epileptic drugs, such as Phenytoin, which induces CYP1A2, CYP2C9, CYP2C19, and CYP3A4. Citocrom P450. Trimethadione metabolism by human liver cytochrome P450: evidence for the involvement of CYP2E1. Some CYPs metabolize only one (or a very few) substrates, such as CYP19 (aromatase), while others may metabolize multiple substrates. 1997 Dec;25(12):1429-35. Recently CYPs have also been discovered in avian species, in particular turkeys, that may turn out to be a useful model for cancer research in humans. For this reason, one species's reaction to a substance is not a reliable indication of the substance's effects in humans. 2018 Nov 12;6(4):106. doi: 10.3390/biomedicines6040106. Simon Bolívar University; The term "P450" is derived from the spectrophotometric peak at the wavelength of the absorption maximum of the enzyme (450 nm) when it is in the reduced state and complexed with carbon monoxide. title = "Citocromo P450: Polimorfismo genetico e vanabilit{\`a} farmacologica", abstract = "Pharmacogenetics deals with genetically determined variation in drug response. CYP170B1 catalyses production of the sesquiterpenoid albaflavenone in Streptomyces albus[46]). eCollection 2020. Privacy, Help Some bacteria, predominantly actinomycetes, have numerous P450s (e.g.,[43][44]). The metabolism of amitriptyline was studied in vitro using cDNA-expressed human cytochrome P450 (CYP) enzymes 1A2, 3A4, 2C9, 2C19, 2D6 and 2E1. CYPs are the major enzymes involved in drug metabolism, accounting for about 75% of the total metabolism. C: If carbon monoxide (CO) binds to reduced P450, the catalytic cycle is interrupted. [8], The current nomenclature guidelines suggest that members of new CYP families share at least 40% amino acid identity, while members of subfamilies must share at least 55% amino acid identity. Cunninghamella elegans is a candidate for use as a model for mammalian drug metabolism. These CYPs possess cytochrome P450 omega hydroxylase and/or epoxygenase enzyme activity. The superfamily is divided into families: CYP1, CYP2, CY3, etc. [54] Recent progress towards realizing the potential of using P450s towards difficult oxidations have included: (i) eliminating the need for natural co-factors by replacing them with inexpensive peroxide containing molecules,[55] (ii) exploring the compatibility of P450s with organic solvents,[56] and (iii) the use of small, non-chiral auxiliaries to predictably direct P450 oxidation. The CYP nomenclature is the official naming convention, although occasionally CYP450 or CYP450 is used synonymously. CYP2E1 metabolizes a wide variety of chemicals with different structures, in particular small and hydrophobic compounds, including potential cytotoxic and carcinogenic agents. In mammals, these proteins oxidize steroids, fatty acids, and xenobiotics, and are important for the clearance of various compounds, as well as for hormone synthesis and breakdown. Genetic variability (polymorphism) in these enzymes may influence a patient's response to commonly prescribed drug classes, including beta blockers and antidepressants. Functional characterization of human and cynomolgus monkey cytochrome P450 2E1 enzymes. 2019 Sep 5;7(3):68. doi: 10.3390/biomedicines7030068. Although this class has more than 50 enzymes, six of them metabolize 90 percent of drugs, with the two most significant enzymes being CYP3A4 and CYP2D6. [38] oxidize uroporphyrinogen to uroporphyrin (CYP1A2) in heme metabolism, but they may have additional undiscovered endogenous substrates. Few studies have investigated what P450s do in vivo, what the natural substrate(s) are and how P450s contribute to survival of the bacteria in the natural environment.Three examples that have contributed significantly to structural and mechanistic studies are listed here, but many different families exist. La famiglia del citocromo P450 (abbreviata come CYP, P450 e, molto frequentemente, CYP450) è una superfamiglia enzimatica di emoproteine presente in tutti i domini dei viventi (sono note più di 7.700 distinte macromolecole di tipo CYP), appartenente alla sottoclasse enzimatica delle ossidasi a funzione mista (o monoossigenasi).