Kupwanya Kwakaitwa Catalase Enzyme Hydrogen Peroxide
Hydrogen peroxide (H₂O₂) ikemikari inozivikanwa zvikuru muhupenyu hwezuva nezuva. Inowanzo shandiswa semushonga wekuuraya utachiona, bleach, uye kunyange sechishandiso chinotsigira mumabasa akasiyana-siyana emaindasitiri. Zvisinei, pasinei nemabhenefiti ayo, hydrogen peroxide imorekuru inoshandawo uye inogona kukuvadza masero mapenyu. Mumiviri yezvinhu zvipenyu—kusanganisira vanhu, mhuka, nemiti—H₂O₂ inogona kuumbwa semugumisiro wemetabolism. Kuti masero adzivirirwe, muviri une nzira yekudzivirira yakaoma. Mumwe we "vatambi vakakosha" muhurongwa uhwu hwekudzivirira ienzyme catalase, enzyme inokwanisa kupwanya hydrogen peroxide nekukurumidza uye zvinobudirira.
Hydrogen Peroxide: Molekyuli Diki, Rinochinja-chinja
Mumasero, hydrogen peroxide iri muboka re reactive oxygen species (ROS). ROS inoumbwa panguva yekufema kwemasero mu mitochondria , apo masero ekudzivirira muviri anorwisa utachiona, kana nekuda kwezvinokonzerwa nezvakatipoteredza zvakaita semwaranzi yeUV nekusvibiswa. Pamazinga akaderera, ROS inogona kuita basa mukutumira masaini mumasero. Zvisinei, kana iripo yakawanda, ROS inokonzera oxidative stress inokuvadza mapuroteni, membrane lipids, uye kunyange DNA.
Hydrogen peroxide pachayo haisi nguva dzose ine simba semafree radicals akaita se superoxide, asi inogona kushanduka kuita mamorekuru ane njodzi zvikuru. Semuenzaniso, kuburikidza neFenton reaction (nerubatsiro rwemaion esimbi akadai seFe²⁺), H₂O₂ inogona kugadzira hydroxyl radical (•OH) inokuvadza zvikuru uye inorwisa. Saka, H₂O₂ inofanira kubviswa nekukurumidza isati yaungana.
Catalase Enzyme: "Mudzimi wemoto" mumasero
Catalase ienzyme inowanikwa muzvinhu zvipenyu zvinenge zvese zvinogara munzvimbo dzine okisijeni. Mumasero evanhu, catalase inowanikwa zvakanyanya mu peroxisomes, ma organelles chaiwo anoita basa mu metabolism yemafuta uye kubvisa tsvina mumakemikari anokuvadza. Muzvirimwa, catalase inokoshawo pakubata neH₂O₂ inogadzirwa panguva ye photosynthesis nekufema.
Kusiyana kwe catalase kuri mukumhanya kwayo. Molekyuru imwe chete ye catalase inogona kupwanya mamiriyoni emamorekuru ehydrogen peroxide pasekondi. Izvi zvinoita kuti catalase ive imwe yema enzyme anoshanda zvakanyanya anozivikanwa mu biochemistry.
Maitiro Ekutanga: Kuchinja Chepfu Kuita Chinhu Chisina Kukuvadzwa
Muchidimbu, mhinduro inokonzereswa ne catalase ndeiyi:
2 H₂O₂ → 2 H₂O + O₂
Izvi zvinoreva kuti mamorekuru maviri ehydrogen peroxide anopatsanurwa kuita mamorekuru maviri emvura uye morekuru rimwe chete reokisijeni. Zvinozoitika hazvina njodzi: mvura inodiwa nemuviri, nepo okisijeni ichigona kuburitswa kana kushandiswazve.
Kana wakambodonhedza hydrogen peroxide paronda ukaona mabubbles, iwoyo muenzaniso wakapfava wekushanda kwecatalase. Enzyme catalase, iri muropa nematishu , inopwanya H₂O₂, ichiburitsa mweya weokisijeni, unoonekwa semabubbles.
Catalase Inoshanda Sei?
Kunyangwe maitiro ese achiita seari nyore, mashandiro ekuita kwecatalase anonakidza zvikuru. Catalase ienzyme inowanzova neboka rekugadzira rine heme (rine iron) panzvimbo yayo inoshanda. Heme iyi yakafanana neiri muhemoglobin, asi basa rayo rakasiyana: mucatalase, heme inobatsira kutamiswa kwemaerekitironi, zvichiita kuti H₂O₂ ishandurwe nekukurumidza.
Kazhinji, maitiro e catalase anoitika muzvikamu zviviri:
1. Danho rekutanga (kuumbwa kwemakemikari ari pakati):
Morekuru rimwe chete reH₂O₂ rinoshanda se "substrate" uye rinoputsika panzvimbo inoshanda yecatalase. Mukuita uku, H₂O₂ inopa okisijeni uye inoumba mvura, ukuwo enzyme ichishanduka kuita fomu yakasanganiswa inonzi Compound I (compound yepakati). Padanho iri, simbi iri muheme inenge iri muchimiro chepamusoro che oxidation.
2. Danho rechipiri (kuora kwemorekuru yechipiri yeH₂O₂):
Morekuru wechipiri weH₂O₂ anobva aita mubatanidzwa neCompound I. Morekuru uyu anopa maerekitironi kuti adzorere enzyme kuchimiro chayo chenguva dzose, uku achigadzira mvura uye achiburitsa okisijeni (O₂).
Nenzira iyi, catalase inoshandisa mamorekuru maviri eH₂O₂: rimwe rekuita kuti enzyme ioxidize kwenguva pfupi, uye rimwe rekuita kuti idzoke pasi. Mugumisiro wacho imorekuru maviri emvura nemorekuru rimwe reokisijeni, zvichiita kuti enzyme iyi igadzirire kushandiswazve isina kushandiswa zvachose.
Sei Catalase Ichishanda Zvakadai?
Kubudirira kwe catalase kunokonzerwa nezvinhu zvakasiyana-siyana:
- Chimiro chepakati chinoshanda chakagadziridzwa zvakanyanya: Nzvimbo inoshanda ye catalase "yakagadzirwa" kuti isunge H₂O₂ nemazvo uye kukurumidzisa kupatsanuka kwebond ye O–O.
– Kuwanikwa kweheme nesimbi: Heme inobatsira mukufambisa maerekitironi zvakanyanya mukuita kwemaitiro.
– Nzvimbo yakakodzera: Nekuti inowanikwa muhuwandu hwakawanda mu peroxisomes, catalase inoiswa pedyo nenzvimbo dzeH₂O₂ idzo dzinowanzo bva mu fatty acid oxidation reactions uye mamwe ma metabolism.
– Kuchinja kukuru: Iyi enzyme inokwanisa kushanda nekumhanya kunoshamisa, nokudaro ichidzivirira H₂O₂ kusvika padanho rine njodzi.
Basa reCatalase muhutano nezvirwere
Catalase inoita basa rakakosha mukuchengetedza kuenzana kwe oxidative mumuviri. Kana basa re catalase rakaderera kana kuti risina kunaka, hydrogen peroxide inogona kuungana uye kuwedzera oxidative stress. Dambudziko iri rinobatanidzwa nematambudziko akasiyana-siyana ehutano, anosanganisira:
– Kukwegura nguva isati yakwana: Kushushikana kwe oxidative kunofungidzirwa kuti kunokonzera kukuvara kwemasero kunoungana nekufamba kwenguva.
– Kuzvimba kwenguva refu: ROS kusanganisira H₂O₂ inogona kuwedzera kuzvimba kana ikasadzorwa.
– Matambudziko emetabolism: Kusarongeka kweROS kunogona kukanganisa mashandiro emitochondrial uye metabolic yesimba.
– Dambudziko remajini risingawanzoitiki: Pane chirwere chisingawanzoitiki chinonzi acatalasia, chinoitika kana muviri usina enzyme inonzi catalase. Vanhu vane chirwere ichi vanonyanya kukuvadzwa nenyama, kusanganisira kukuvara kwemuromo.
Zvisinei, muviri une mamwe ma enzymes ekudzivirira muviri, akadai se superoxide dismutase (SOD) uye glutathione peroxidase, anoshanda pamwe chete ne catalase. Anoumba sisitimu yekudzivirira ine mativi akawanda kuti igadzire ROS zvishoma nezvishoma uye zvakachengeteka.
Catalase muhupenyu hwezuva nezuva uye basa rinoshanda
Enzayimu inonzi catalase haisi nyaya inongotaurwa mumabhuku ebhayoloji chete; zviri nyorewo kuratidzwa kuburikidza nekuyedza kuri nyore kuchikoro. Semuenzaniso, kana ukadonhedza hydrogen peroxide pachiropa chehuku, mbatatisi, kana shizha, mabubble eoxygen anowanzoonekwa. Izvi zvinodaro nekuti tissue yacho ine catalase. Kusimba kwemabubbles kunogona kuratidza huwandu hwebasa re catalase mumuenzaniso.
Zvisinei, zvakakosha kuyeuka kuti hydrogen peroxide kana yakanyanya kuwanda inogona kuva nengozi, saka kuyedza kunofanira kuitwa pasi pekutarisirwa, uchishandisa magirovhosi, uye uchitevera nzira dzekuchengetedza.
Mhedziso
Iyi enzyme inonzi catalase chinhu chakakosha pakudzivirira masero kubva mukushushikana kwe oxidative . Nekuita kuri nyore asi nekukurumidza zvikuru—kushandura hydrogen peroxide kuita mvura neokisijeni—catalase inodzivirira masero kubva mukukuvadzwa kunogona kuitika nekuda kwekuunganidzwa kweH₂O₂. Maitiro ayo anosanganisira nzvimbo inoshanda yeheme inobvumira kutamiswa kwemaerekitironi zvinobudirira, zvichibvumira enzyme kushanda mamiriyoni enguva pasekondi. Kuburikidza nebasa rayo mu peroxisomes nematishu akasiyana-siyana emuviri, catalase inobatsira kuchengetedza kuenzana kwemakemikari emukati, kutsigira hutano uye kugonesa zvipenyu kurarama munzvimbo dzakapfuma neokisijeni uye maitiro emetabolism.
Kana muchida, ndinogona kuwedzera chikamu chakakosha pamusoro pemaumbirwo emamorekuru e catalase (semuenzaniso chimiro chayo che tetramer), zvinhu zvinokanganisa mashandiro ayo (pH, tembiricha, zvinodzivisa), kana muenzaniso wakakwana werabhoritari une matanho nekuongorora data.
