Cytochroma P450

Cytochromata p450 sunt superfamilia proteinorum cofactorem haemis continentium (haemoproteinorum) in bacteriis, archaeis, eukaryotis. Nomen de pigmento absorptionis 450 nm anno 1958 descripto derivatur^[1]. Cytochromata p450 enzyma metabolismos oxidativum et peroxidativum et reductivum substantiarum detrimentosarum diversarum supponunt^[2]. Cytochroma p450 magni momenti est ad substrata sua transformanda et hac re ad haec excretionis ex corpore vivo praeparanda. Enzymum expressa in formula generali hanc reactionem per oxidoreductionem catalizat:

RH + O₂ + 2H⁺ + 2e^- → ROH + H₂O.

Duae reactiones coram coenzymo addito evenient:

1. (Oxidatio): substratum organicum (RH) cum alio dimidio moleculae oxygenii (½O₂) ad -ROH (quam dicunt reactio "mono"-oxi-genasis igitur) et
2. (Reductio): Coenzymum instrumentum reductans electronem (2e^-) et Hydrogenium (2H⁺) reddens, ideo alium (½O₂) ad aquam (H₂O) coniungentur.

Substrata sunt per exemplum medicamenta sive hormones, coenzyma per exemplum NADH sive NADPH sive flavoproteina sive ferredoxinum. Plerumque quaeque cytochroma p450 coenzymo definitivo eget. Complures inhibitores cytochromatium notati sunt.

Nomina systematica

Magis quam unum et viginti milia^[3] cytochromatium nota sunt. Nomina systematica genorum Cytochromatium P450 singularium ex (1) signo superfamiliae CYP^[4] et (2) numero familiae genorum et (3) una littera maiuscula subfamiliae et (4) numero geni componuntur, per exemplum CYP2E1, scribens in modo currente^[5]. Anno 2009 circiter duodecim gena, mille familiae, duo milia quingenti subfamiliae nota sunt^[6].

Etymologia

Verbum Cytochroma p450 ex duobus verbis graecis (κύτος vasum, et χρώμα color) et abbbreviatione a verbo pigmenti et numero longitudinis undae compositum. Cytochroma proteinum cellulae coloratum describat, P pigmentum eius, quod lucem longitudinis undae 450 nm sub reductinone ferri et formatione carbonii monoxidi absorbet.

Structura

Cytochromata p450 ex volucro exteriore cum nucleo interiore componuntur:

Pars exterior, proteinum, cum circiter quingenti acidis aminicis exstructa.
Pars interior moleculum porphyrinorum et haem est. Centrum activum ionta electrice triplex oneratum ferri (Fe³⁺) est, cuius onus electricum interim mutabitur (Fe²⁺↔Fe³⁺↔Fe⁵⁺).

Effectus

In hominibus atque archaeis praesentibus cytochromatibus p450 munera perclara sunt, igitur cytochromata a millio milliones annis officia purgatoria perficere aestimatur. Exemplum gratia cum coenzymo NADPH:

RH + O₂ + NADPH + H⁺ → ROH + H₂O + NADP⁺

Divisio

Cytochromata in plures greges dividi possunt^[7]:

Systemata mitochondriorum (Systema NADPH)
Systemata microsomatum (Systema electron adrenodoxino committens)
Systemata bacteriorum (Systema electron ferredoxino committens)
Systemata cum Cytochromo b5 conexa (Systema CYB5R/cyb5/P450)
Systemata Rhodocci bacteriorum (Systema FMN continens reductasis)
P450 solum (Systema sine enzymo reductasis): CYP5 (Thromboxani synthasis), CYP8 (prostacyclini synthasis)

Cytochromata Corporis Humani

Corpori humano Cytochromum 18 familiae et 43 subfamiliae sunt.^[8]

Familia	Functio	Membra	Nomina
CYP1	Metabolismus substantiarum dependentiae et oestrogenorum	3 subfamiliae, 3 geni, 1 pseudogenum	CYP1A1, CYP1A2, CYP1B1
CYP2	Metabolismus substantiarum dependentiae et oestrogenorum	13 subfamiliae, 16 geni, 16 pseudogeni	CYP2A6, CYP2A7, CYP2A13, CYP2B6, CYP2C8, CYP2C9, CYP2C18, CYP2C19, CYP2D6, CYP2E1, CYP2F1, CYP2J2, CYP2R1, CYP2S1, CYP2U1, CYP2W1
CYP3	Metabolismus substantiarum dependentiae et oestrogenorum et testosteroni	1 subfamilia, 4 geni, 2 pseudogeni	CYP3A4, CYP3A5, CYP3A7, CYP3A43
CYP4	Metabolismus arachidonati	6 subfamiliae, 11 geni, 10 pseudogeni	CYP4A11, CYP4A22, CYP4B1, CYP4F2, CYP4F3, CYP4F8, CYP4F11, CYP4F12, CYP4F22, CYP4V2, CYP4X1, CYP4Z1
CYP5	Thromboxani A₂ synthetasis	1 subfamilia, 1 genum	CYP5A1
CYP19	Biosynthesis steroidorum	1 subfamilia, 1 genum	CYP19A1 (aromatasis)
CYP51	Biosynthesis cholesteroli	1 subfamilia, 1 genum, 3 pseudogena	CYP51A1 (lanosterolum 14-alpha demethylasis)

Notae

↑ Klingenberg M (1958). "Pigments of rat liver microsomes". Arch Biochem Biophys 75 (2): 376-86
↑ Danielson PB (2002). "The cytochrome P450 superfamily: biochemistry, evolution and drug metabolism in humans". Curr Drug Metab 3 (6): 561-97
↑ https://web.archive.org/web/20100627184446/http://drnelson.uthsc.edu/CytochromeP450.html Nelson, DR (2009): Cytochromatium p450 pagina interretialis
↑ CYP nomen officiale est, praeterea P450 vel CYP₄₅₀ utuntur.
↑ anglice: italic
↑ Nelson DR (2009). The cytochrome P450 homepage. Hum Genomics 4, 59-65
↑ Hanukoglu I (1996). Electron transfer Proteins of cytochrome p450 systems. Advances in Molecular and Cell Biology. 14: 29—56
↑ Nelson D (2003). Cytochrome P450s in humans.

Nexus externi

Nexus ad tabulam Flockhart (drogarum interactionum tabula) (Anglice)

[1] Klingenberg M (1958). "Pigments of rat liver microsomes". Arch Biochem Biophys 75 (2): 376-86

[2] Danielson PB (2002). "The cytochrome P450 superfamily: biochemistry, evolution and drug metabolism in humans". Curr Drug Metab 3 (6): 561-97

[3] ttps://web.archive.org/web/20100627184446/http://drnelson.uthsc.edu/CytochromeP450.html Nelson, DR (2009): Cytochromatium p450 pagina interretialis

[4] CYP nomen officiale est, praeterea P450 vel CYP₄₅₀ utuntur.

[5] : italic

[6] Nelson DR (2009). The cytochrome P450 homepage. Hum Genomics 4, 59-65

[Hanukoglu-7] Hanukoglu I (1996). Electron transfer Proteins of cytochrome p450 systems. Advances in Molecular and Cell Biology. 14: 29—56

[Nelson-8] Nelson D (2003). Cytochrome P450s in humans.

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