Microsomal oxidation: ib tug txheej ntawm tshua

Lub luag hauj lwm ntawm microsomal oxidation nyob rau hauv lub neej ntawm tus kab mob yog ib qhov nyuaj rau overestimate los yog nco. Inactivation ntawm xenobiotic (tej yam tshuaj lom), lub cev qhuav dej thiab lub tsim ntawm adrenal cov tshuaj hormones muab kev koom tes nyob rau hauv lub metabolism ntawm cov nqaijrog thiab preservation ntawm kev tshuaj ntsuam genetic ntaub ntawv - tsuas yog ib tug me me feem ntawm lub npe hu teeb meem solved thanks rau microsomal oxidation. Nws yog ib qho yooj yim txheej txheem nyob rau hauv lub cev, uas yog khiav tom qab raug ntaus los ntawm ib tug txhais tshuaj thiab xaus nrog nws elliminatsiey.

txhais

Microsomal oxidation - ib tug cascade kev tshua muaj nyob rau hauv tus thawj hloov dua siab tshiab theem ntawm xenobiotics. Lub essence ntawm tus txheej txheem lus dag nyob rau hauv lub hydroxylation ntawm tshuaj nrog rau oxygen atoms thiab daim ntawv dej. Vim cov kev hloov nyob rau hauv cov qauv ntawm cov thawj cov khoom, thiab nws cov khoom yuav yog raug suppressed los yog amplified.

Microsomal oxidation yuav siv sij hawm koj mus rau qhov conjugation cov tshuaj tiv thaiv. Qhov thib ob theem transformations ntawm xenobiotics, qhov kawg ntawm uas ib tug uas twb muaj lawm haumxeeb pab pawg neeg yog txuas molecules ua nyob rau hauv lub cev. Tej zaum tsim ntawm intermediate tshuaj uas ua rau lub siab cell kev puas tsuaj, necrosis thiab cov nqaij mos degeneration ntawm Oncology.

Oxidation oxidase hom

Microsomal oxidation tshua tshwm sim nyob sab nraum ntawm mitochondria thiab yog li ntawd muaj noj kwv yees li kaum feem pua ntawm tag nrho cov pa nkag mus rau hauv lub cev. Ntsiab enzymes nyob rau hauv tus txheej txheem no - oxidase. Nyob rau hauv lawv cov qauv, cov hlau atoms yog tam sim no kuj tsis paub meej valence, xws li hlau, molybdenum, tooj liab, thiab lwm yam, thiab yog li ntawd lawv yog tau txais electrons. Nyob rau hauv lub cell oxidase nyob nyob rau hauv ib cov hlwv (peroxisomes) nyob rau lub txheej mitochondrial week thiab nyob rau hauv EPR (ntxhib endoplasmic reticulum). Substrate ntog rau peroxisome loses hydrogen molecules, uas yog txuas mus rau ib tug qauv ntawm cov dej mus rau daim ntawv peroxide.

Tsuas muaj tsib oxidases:

- monoaminooksigenaza (Mao) - yuav pab tau oxidize adrenaline thiab lwm yam biogenic amines ua los ntawm cov qog adrenal;

- diaminooksigenaza (DAO) - muab kev koom tes nyob rau hauv lub oxidation ntawm histamine (kho kom haum xeeb ntawm o thiab ua xua), polyamines thiab diamines;

- L-amino acid oxidase (ie, levorotatory molecules);

- D-amino acid oxidase (dextrorotatory molecules);

- xanthine - oxidize adenine thiab guanine (nitrogen bases muaj nyob rau hauv lub DNA molecule).

Tus nqi ntawm cov oxidase hom microsomal oxidation muaj nyob rau hauv lub tshem tawm ntawm xenobiotics thiab inactivate biologically active tshuaj. Kev Kawm Ntawv peroxide muaj ib tug bactericidal kev txiav txim thiab tus neeg kho tshuab ntxuav cov txhaum yog lub sab nyhuv uas occupies ib tug tseem ceeb qhov chaw ntawm cov lwm yam teebmeem.

Oxidation oxygenase hom

Oxygenase hom tshuaj tiv thaiv nyob rau hauv lub cell yog tseem noj qhov chaw nyob rau hauv lub ntxhib endoplasmic reticulum thiab mitochondria week vneschnih. Qhov no yuav tsum tau kev enzymes - oxygenase uas tsa lub oxygen molecule los ntawm lub substrate, thiab qhia nws mus rau hauv lub oxidizable substance. Yog hais tias siv ib cov pa atom, lub monooxygenase enzyme hu ua los yog hydroxylase. Nyob rau hauv cov ntaub ntawv ntawm qhia ob atoms (i.e., ib tug tag nrho molecule ntawm cov pa), cov enzyme hu ua diaksigenaza.

Oxygenase hom oxidation cov tshuaj tiv thaiv xws li ib tug ternary multienzyme complex uas koom nyob rau hauv cov kev hloov ntawm electrons thiab protons los ntawm lub substrate ua raws li los ntawm ua kom cov pa. Qhov no txoj kev muaj tshwm sim nrog kev koom tes los ntawm cytochrome P450, uas yuav tseem yuav tau piav nyob rau hauv kom meej.

Piv txwv oxygenase hom tshuaj

Raws li hais saum toj no, monooxygenase rau oxidation siv tsuas yog ib qho oxygen atom ntawm ob muaj. Ob, lawv yog txuas mus rau ob molecules ntawm hydrogen tsim dej. Ib tug piv txwv ntawm xws li ib tug tshuaj tiv thaiv yog lub tsim ntawm collagen. oxygen pub nyob rau hauv cov ntaub ntawv no ua raws li vitamin C. Prolingidroksilaza robs nws ntawm oxygen molecule thiab muab nws mus rau proline, uas nyob rau hauv lem yog ib feem ntawm lub procollagen molecule. Qhov no txoj kev muab lub dag lub zog thiab elasticity ntawm connective cov ntaub so ntswg. Thaum muaj ib tug tsis muaj peev xwm ntawm vitamin C, tus tsim gout. Nws manifests cov tsis muaj zog ntawm lub connective ntaub so ntswg, los ntshav, nqaij doog, tsis ntawm cov hniav, uas yog, qhov zoo ntawm collagen nyob rau hauv lub cev yog hauv qab no.

Lwm cov piv txwv yog lub hydroxylase uas hloov roj uas txhaws taus molecule. Qhov no yog ib tug ntawm cov theem ntawm tus tsim ntawm steroid cov tshuaj hormones, xws li kev sib deev.

yog tsis yog hais hydroxylase

Qhov no hydrolase tsim nyog rau cov oxidation ntawm txawv teb chaws tshuaj, xws li xenobiotics. Lub ntsiab lus ntawm lub tshua yog ua kom tej khoom ntau amenable mus tshem tawm, ntau soluble. Qhov no yog hu ua detoxification, thiab nws tshwm sim feem ntau nyob rau hauv lub siab.

Los ntawm kev siv tag nrho cov molecule ntawm oxygen yog ua nyob rau hauv cov kis xenobiotics voj voog tshua thiab decomposition ntawm lub complex tshuaj rau hauv ob peb yooj yim thiab muaj kev metabolic dab.

Reactive pa hom

Pa yog ib tug uas yus yam khoom uas, txij li thaum, nyob rau hauv qhov tseeb, lub oxidation - ib tug combustion txheej txheem. Nyob rau hauv daim ntawv ntawm O ₂ molecules los yog dej yog ruaj khov thiab sib inert, vim hais tias nws lub hwj chim theem tau sau thiab tshiab electrons yuav tsis tuaj koom nrog. Txawm li cas los, lub tebchaw nyob rau hauv uas cov pa yog tsis nyob rau hauv tag nrho cov muaj yog ib tug khub ntawm electrons muaj siab reactivity. Yog li ntawd lawv yog hu ua kom nquag plias.

Tej pa tebchaw:

1. Nyob rau hauv monooksidnyh tshua ua superoxide uas yog cais los ntawm lub cytochrome P450.
2. Lub oxidase tshua yog lub tsim ntawm peroxide anion (hydrogen peroxide).
3. Thaum lub sij hawm lub re-oxygenation ntawm ntaub so ntswg, uas underwent ischemia.

Tus haib tshaj oxidizer yog ib tug hydroxyl radical, nws tshwm sim nyob rau hauv ib tug dawb daim ntawv cia li ib tug millionth ntawm ib tug thib ob, tab sis nyob rau hauv hais tias lub sij hawm muaj lub sij hawm mus los ntawm ib tug xov tooj ntawm oxidation tshua. Nws feature yog hais tias lub hydroxyl radical muaj feem xyuam rau cov tshuaj yeeb dej caw tsuas yog nyob rau qhov chaw nyob rau hauv uas yog tsim, raws li nws muaj peev xwm tsis txeem tau cov ntaub.

Superoxide anion thiab hydrogen peroxide

Cov tshuaj yog active tsis tau tsuas yog nyob rau hauv lub cheeb tsam ntawm kev kawm ntawv, tab sis kuj nyob rau ntawm ib txhia nyob deb los ntawm lawv, raws li lawv muaj peev xwm txeem los ntawm tus xovtooj ntawm membrane.

Hydroxyl pab pawg neeg ua rau lub oxidation ntawm cov amino acid residues: histidine, cysteine thiab tryptophan. Qhov no ua rau cov inactivation ntawm cov enzyme systems, raws li zoo raws li lub cuam tshuam ntawm cov thauj proteins. Nyob rau hauv tas li ntawd, microsomal oxidation ntawm amino acids ua rau puas tsuaj ntawm cov qauv ntawm cov nucleic nitrogenous puag thiab, thiaj li, txom nyem lub caj apparatus ntawm lub cell. Thiab oxidized fatty acids uas ua tau lub cell week bilipidnogo txheej. Qhov no muaj feem xyuam rau lawv cov permeability, txoj hauj lwm ntsha membrane twj tso kua mis thiab qhov chaw ntawm lub receptor.

Contact lenses ntawm microsomal oxidation - yog antioxidants. Lawv muaj nyob rau hauv cov zaub mov thiab yog ua nyob rau hauv lub cev. Qhov tseem zoo-paub antioxidant yog vitamin E. Cov tshuaj yuav inhibit microsomal oxidation. Biochemistry qhia txog cov kev sis raug zoo ntawm lawv nyob rau hauv lub hauv paus ntawm lub tswv yim. Hais tias yog, qhov ntau oxidases, qhov ntau lawv yuav suppressed, thiab vice versa. Qhov no yuav pab kom muaj ib tug nqi koj tshuav ntawm lub tshuab thiab cov constancy ntawm lub sab hauv ib puag ncig.

hluav taws xob thauj saw

Microsomal oxidation system yog tsis soluble nyob rau hauv lub cytoplasm ntawm lub Cheebtsam yog li ntawd tag nrho nws cov enzymes yog sau rau ntawm qhov chaw ntawm lub endoplasmic reticulum. Qhov no system muaj xws li ob peb cov nqaijrog, uas tsim lub electrotransport Circuit Court:

- NADPH-P450 reductase thiab cytochrome P450;

- DUA-tsitohromV5 reductase thiab cytochrome B5;

- steatorrhea-CoA desaturase.

Lub electron pub nyob rau hauv feem ntau ntawm cov neeg mob cov kev ua ntawm NADP (nicotinamide adenine dinucleotide phosphate). Nws oxidizes NADPH-P450 reductase, uas muaj ob tug Coenzyme (fad thiab FMN), rau kev noj electrons. Thaum kawg ntawm lub saw FMN oxidized siv P450.

cytochrome P450

Qhov no enzyme ntawm lub microsomal oxidation ntawm heme-muaj protein. Nws uake oxygen thiab ib tug substrate (feem ntau yog ib tug xenobiotic). Nws lub npe yog txuam nrog tus haum ntawm lub teeb nrog ib tug wavelength ntawm 450 nm. Biologists muaj sab nws nyob rau hauv tag nrho cov uas muaj sia nyob. Thaum lub caij, piav ntau tshaj kaum ib txhiab cov nqaijrog teej tug mus rau lub cytochrome P450 system. Nyob rau hauv cov kab mob, lub yam khoom uas yog yaj nyob rau hauv lub cytoplasm, thiab nws yog ntseeg hais tias daim ntawv no yog cov feem ntau evolutionarily ancient dua cov tib neeg. Peb cytochrome P450 - ib tug mural protein tsau rau cov cytoplasmic membrane.

Cov enzymes ntawm no pab pawg neeg muab kev koom tes nyob rau hauv lub metabolism ntawm steriods kho thiab cov kua tsib fatty acids, phenols, neutralizing tshuaj, tshuaj lom los yog tshuaj.

Cov khoom ntawm microsomal oxidation

Cov kev ntawm microsomal oxidation muaj ib tug broad substrate tseem, thiab qhov no, nyob rau hauv lem, tso cai rau mus ntes ib tug ntau yam ntawm tshuaj. Kaum ib txhiab cov nqaijrog cytochrome P450 yuav daim ntau quav tso nyob rau hauv ntau tshaj ib puas thiab tsib caug isoforms ntawm lub enzyme. Txhua yam ntawm lawv muaj ib tug loj tus naj npawb ntawm substrates. Qhov no enables lub cev kom tshem tau ntawm yuav luag tag nrho cov ntawm teeb meem tshuaj uas yog tsim nyob rau hauv los yog lub caij nplooj zeeg sab nraum. Ua nyob rau hauv lub siab microsomal oxidation enzymes yuav ua ob zos thiab nyob ib tug txiav txim deb ntawm lub cev.

Cov kev cai ntawm cov kev ua ntawm microsomal oxidation

Microsomal oxidation nyob rau hauv lub siab yog tswj ntawm lub mRNA theem, tab sis, theej nws muaj nuj nqi - transcription. Tag nrho cov variants ntawm cytochrome P450, piv txwv li, muab sau tseg rau cov DNA molecule, thiab rau nws nyob rau hauv ESR tsim nyog los "sau dua tshiab" cov ntaub ntawv los ntawm DNA rau cov tub txib RNA. Ces mRNA yog raws kev coj kom ribosome qhov twg protein molecules raug tsim. Lub xov tooj ntawm no molecules yog tswj los ntawm sab nraum thiab yog nyob rau tus nqi ntawm cov tshuaj uas yuav tsum tau deactivated, thiab cov nyob rau ntawm qhov tseem ceeb cov amino acids.

Tam sim no, ntau tshaj ob puas tsib caug-piav tshuaj tebchaw uas qhib lub cev microsomal oxidation. Cov no muaj xws barbiturates, uas muaj ntxhiab hydrocarbons, alcohols, ketones thiab cov tshuaj hormones. Dua li no khees ntau haiv neeg, tag nrho cov tshuaj yog lipophilic (soluble nyob rau hauv cov rog), thiab yog li ntawd raug rau cytochrome P450.