Microsomal igcwala: isethi reactions

Indima microsomal namachibi xa ibubomi kumzimba kunzima zazi okanye angaphosi. Inactivation of xenobiotic (izinto eziyityhefu), ekuweni kwaye ukuyilwa hormone adrenal ababandakanyekayo nethe kweziyi kunye nokulondolozwa kolwazi yemfuza - sibamba nje encane yeengxaki ezaziwayo sele microsomal igcwala. Le yinkqubo elizimeleyo emzimbeni, leyo iqhutywa emva kokuba watshayiswa into asibambe nesiphelo kunye elliminatsiey yakhe.

definition

Microsomal igcwala - ukuxubana reactions ziquka kwisigaba sokuqala ukuguquka xenobiotics. Undoqo wenkqubo bubonakala hydroxylation kwezinto kunye athom ioksijini kunye nefomu amanzi. Ngenxa utshintsho kwisakhiwo umbandela yokuqala, kunye neempawu zayo noba livunyelwe okanye wachaza.

Microsomal igcwala kuthatha ukuba indlela conjugation. Esi utshintshwano sesibini isigaba xenobiotics, ekupheleni apho iqela ezikhoyo ezisebenzayo iqhotyoshelwe iimolekyuli eveliswa ngaphakathi emzimbeni. Ngamanye amaxesha ukwakheka kwezinto eliphakathi ezibangela umonakalo iseli kwesibindi, necrosis kunye izicwili angakwazi Oncology.

uhlobo oxidase igcwala

reactions Microsomal igcwala lwenzeka ngaphandle kwe mitochondria kwaye ngoko ndibagqibele malunga neshumi ekhulwini ioksijini iyonke nghena umzimba. enzyme eziphambili kule nkqubo - oxidase. Kubume, i-atom etyhidiweyo akhoyo kunye Valence bume, ezifana nesinyithi, molybdenum, ikopolo, njalo njalo, kwaye ngoko ke bayakwazi ukwamkela electron. Xa oxidase iseli ibekwe vesicles ezithile (peroxisomes) ibekwe kwi inwebu zangaphandle ayo kwaye EPR (reticulum rough endoplasmic). Zeendawana uyakuwa peroxisome ulahlekelwa iimolekyuli hydrogen, leyo ziqhotyoshelwe zinemoletyhule yamanzi ukwakha peroxide.

Kukho ezintlanu kuphela oxidases:

- monoaminooksigenaza (Mao) - inceda oxidize iadrenaline kunye nezinye amine biogenic eveliswe adrenal;

- diaminooksigenaza (Dao) - inxaxheba igcwala of histamine (nomlamli ukudumba kunye nezidlo), polyamines kunye diamines;

- L-acid acid oxidase (oko kukuthi, iimolekyuli levorotatory);

- D-acid acid oxidase (molekyuli dextrorotatory);

- xanthine - oxidize adenine kunye guanine (neziseko nitrogen zibandakanyiwe kwemolekyuli DNA).

Ixabiso lohlobo oxidase microsomal igcwala iqulathe ephambili ekupheliseni xenobiotics kwaye okunqanda izinto eziphilayo esebenzayo. Imfundo peroxide na isenzo bactericidal kunye wokuhlanjululwa yokugaya isiphoso na isiphumo ongekhe libambe indawo ebalulekileyo phakathi kwezinye iziphumo.

uhlobo oxygenase igcwala

Oxygenase uhlobo ukusabela kwi iseli kwakhona othatha indawo kwi-reticulum rough endoplasmic kunye imifinya mitochondria vneschnih. Oku kufuna enzyme ezithile - oxygenase ezikhulisela kwemolekyuli oksijini evela zeendawana, nokusekwa kwindawo into oxidizable. Ukuba iphunyezwe neoksijini atom, i-enzayim monooxygenase ebizwa okanye hydroxylase. Kwimeko yokuqalisa athom ezimbini (ngamanye amazwi, yonke into molecule ye oksijini), i-enzyme ibizwa ngokuthi diaksigenaza.

Oxygenase uhlobo igcwala reaction iquka isakhiwo multienzyme izithathu ukuba lithathe inxaxheba ukutshintshwa elektroni kunye protons ukusuka zeendawana kulandele ukusebenza kwe-oksijini. Le nkqubo yonke lwenzeka kunye inxaxheba cytochrome P450, nto leyo eya kuba kuchazwe banzi.

Imizekelo oxygenase uhlobo ngayo

Njengoko kukhankanyiwe ngasentla, monooxygenase ukusetyenziswa igcwala enye kuphela oksijini atom ezimbini ezikhoyo. Okwesibini, ukuba incamathele iimolekyuli ezimbini hydrogen ukuze zenze amanzi. Omnye umzekelo yokusabela onjalo ukuyilwa collagen. oksijini zomzimba kulo mzekelo isebenza vitamin C. Prolingidroksilaza oxhaphaza yona le mpilo kwaye ulunika ukuba proline, nto leyo eyinxalenye molecule procollagen. Le nkqubo inika amandla kunye luthambe yethishyu nokuqina. Xa kukho ukuswela vitamin C, esi sifo asakhasayo. Kubonisa imposiso inyama nokuqina, ukopha, bazigruzule ilahleko amazinyo, oko kukuthi, umgangatho collagen kule umzimba ngezantsi.

Omnye umzekelo na hydroxylase ukuguqula cholesterol mpilo. Le yenye amanqanaba ukuyilwa iihomoni steroid, kuquka ngesondo.

ayikho hydroxylase ngqo

Le hydrolase ayimfuneko igcwala kwezinto amazwe, ezifana xenobiotics. Intsingiselo abasabela kukwenza loo izinto efanele ngakumbi ukususwa, enyibilikayo ngakumbi. Le nkqubo ibizwa ngokuba detoxification, yaye kwenzeka ubukhulu becala esibindini.

Ngokusebenzisa yonke molecule ye mpilo ekuveliseni umsantsa xenobiotics reactions Umjikelo nokucazululwa kuka-ubuncwane ezimbaxa zibe eziliqela lula kwaye ziyafumaneka ukwenzela iinkqubo metabolic.

uhlobo oxygen lovukelo

Oxygen into engathi ibe yingozi, kuba, enyanisweni, igcwala - inkqubo yokutsha. Xa uhlobo O _{iimolekyuli-2} okanye amanzi uzinzile yaye iikhemikhali egalelwe, kuba kumgangatho amandla zizalisiwe yaye electron ezintsha ayikwazi ukujoyina. Noko ke, iikhompawundi apho mpilo unotshe kukho iperi elektroni babe reactivity eliphezulu. Ngako oko ke kuthiwa esebenzayo.

iikhompawundi oxygen enjalo:

1. Xa reactions monooksidnyh zavelisa superoxide leyo siyahlukana le P450 cytochrome.
2. Ukusabela oxidase yi ukuyilwa anion yehidrojeni (hydrogen peroxide).
3. Ngexesha kwakhona oxygenation izicwili, leyo owayefumene ischemia.

Le oxidizer kakhulu ezinamandla yinto ezinkulu hydroxyl, ikhona ifomu free nje ezizigidi yomzuzwana, kodwa elo xesha nexesha iphumele eziliqela ngayo igcwala. msebenzi wayo kukuba ngokugqibeleleyo hydroxyl kuchaphazela iziyobisi kuphela kwindawo apho ezikhandelwa, njengoko awukwazi ukungena laphu.

anion Superoxide hydrogen peroxide

Ezi izinto bakhuthele hayi kuphela kummandla wemfundo, kodwa mgama abathile kubo, njengoko kusichukumisa ngokusebenzisa iseli ndizayo.

iqela Hydroxyl ebangela igcwala le iintsalela acid acid: histidine, cysteine kunye tryptophan. Oku kukhokelela inactivation lweenkqubo enzyme le, kwakunye ukuphazamiseka kwiiproteni zothutho. Ukongeza, microsomal igcwala ye asidi acid, esa entshabalalweni ngesakhiwo babangenagama acid nitrogen kwaye, ngenxa yoko, linyamezeleni izixhobo genetic esiseleni. Kwaye oxidized asidi olunamafutha ezibumba umaleko inwebu yeseli bilipidnogo. Oku kuchaphazela permeability, impompo yabo electrolyte umsebenzi inwebu kunye nendawo receptor.

Inhibitor of microsomal igcwala - are Antioxidants. Bona afumaneka ekutyeni kwaye ziveliswa ngaphakathi emzimbeni. Le antioxidant kakhulu ezaziwayo-kakuhle vitamin E. Ezi izinto kunganqanda microsomal igcwala. Eziphilayo ichaza intsebenziswano phakathi kwabo ngokusekelwe ingxelo. Oko kukuthi, oxidases ngakumbi, kokukhona zicinezelwa, kwaye vice versa. Oku kunceda ukuba kubekho ulungelelwano phakathi kweenkqubo kunye rhoqo kokusingqongileyo lwangaphakathi.

chain izithuthi electric

inkqubo Microsomal igcwala ayikho ezinyibilikayo kwi icytoplasm ngala macandelo ukuze zonke enqanda yayo eqokelelwa phezu komhlaba reticulum endoplasmic. Le nkqubo ibandakanya iiproteni eziliqela, ezenza wesiphaluka electrotransport:

- NADPH-P450 reductase kunye cytochrome P450;

- NGAPHA-tsitohromV5 reductase kunye cytochrome B5;

- steatorrhea-onx desaturase.

Electron abaxhasi kwi uninzi iimeko izenzo NADP (nicotinamide adenine dinucleotide phosphate). It yiluciferase NADPH-P450 reductase, eliquka coenzyme ezimbini (isininzi kunye FMN), kuba uthathe electron. Ekupheleni kwale chain FMN oxidized usebenzisa P450.

cytochrome P450

Le enzayim ye microsomal igcwala leeprothini heme-equlethe. Sibopha mpilo kunye zeendawana (idla a xenobiotic). igama layo linxulunyaniswa ukufunxeka ukukhanya kunye ngamaza 450 NM. Izazi baye bafumanisa ukuba kuzo zonke izinto eziphilayo. Okwangoku, ochazwe ngaphezulu kwe elinanye lamawaka kwiiproteni akwi kwinkqubo cytochrome P450. Ntsholongwane, iyeza unyityilikiswa ke kukho icytoplasm, yaye kukholelwa ukuba le fom yeyona evolutionarily yamandulo kweyabantu. Thina cytochrome P450 - iproteni udonga ligxile ndizayo cytoplasmic.

I-enzyme eli qela abandakanyeka nethe steroid kunye acids inyongo okunamafutha, phenols, lwaze iziyobisi, iityhefu okanye iziyobisi.

Iimpawu microsomal igcwala

Iinkqubo ze microsomal igcwala abe Okukodwa zeendawana ebanzi, kwaye oku, yena, ivumela ibhaqe ezahlukeneyo izinto. Elinanye lamawaka iiproteni P450 cytochrome nga agobe ngaphezu kwesinye anamanci mahlanu isoforms ze enzyme. Ngamnye kubo inani elikhulu substrates. Oku kwenza ukuba umzimba ukuphelisa phantse zonke izinto eziyingozi leyo akhiwa ngaphakathi okanye siwe ngaphandle. Umdali esibindini microsomal enzayim igcwala enze nakumazwe kude kakhulu emzimbeni.

Kulawulwe umsebenzi microsomal igcwala

Microsomal igcwala esibindini lilawulwa kwinqanaba mRNA, kodwa kunokuba umsebenzi wayo - tumbuluxiwa. Zonke zabo cytochrome P450, umzekelo, abhalwe kwi kwemolekyuli DNA, yaye kwabonakala kwi ESR eyimfuneko "uyibhale 'ulwazi ukusuka DNA isithunywa RNA. Ke mRNA sibhekiswe ribosome apho kwasekwa iimolekyuli protein. Inani ezi molekyuli lilawulwa evela ngaphandle kwaye kuxhomekeke kubungakanani kwezinto ekufuneka ingasebenzi, kwaye ukufumaneka asidi kubalulekile acid.

Okwangoku, ngaphezu kwamakhulu amabini, anamanci mahlanu kuchaziwe iikhemikali ukuba isebenze igcwala microsomal umzimba. Ezi ziquka barbiturates, hydrocarbon enuka kamnandi, alkoholi, ketones kunye iihomoni. Nangona kule yantlukwano ibonakale, zonke ezi izinto ezi lipophilic (enyibilikayo amafutha), kwaye ke ngoko bangenwe cytochrome P450.