Lub enzyme catalase: lub ntsiab nta

Catalase - ib qho enzyme pom nyob rau hauv yuav luag tag nrho cov uas muaj sia nyob. Nws lub ntsiab muaj nuj nqi - mus catalyze lub decomposition ntawm hydrogen peroxide rau hauv txawm tshuaj rau tus kab mob. Catalase yog ntawm kuj zoo kawg tseem ceeb rau lub neej ntawm lub hlwb, raws li tiv thaiv lawv los ntawm kev puas tsuaj los ntawm reactive pa hom.

Txheej txheem cej luam

Lub enzyme catalase koom oxidoreductase - wide chav kawm ntawv ntawm enzymes uas catalyze cov kev hloov ntawm electrons los ntawm cov txo molecule (pub) mus rau lub oxidant molecule (acceptor).

Lub zoo pH rau catalase nyob rau hauv tib neeg lub cev yog hais txog 7, txawm li cas los, cov tshuaj tiv thaiv tus nqi tsis hloov ho ntawm qhov tseem ceeb ntawm lub hydrogen index los ntawm 6.8 mus 7.5. Lub pH zoo rau lwm catalases xws li ntawm 4 mus rau 11, nyob ntawm seb lub hom kab mob. Lub zoo kub yog kuj sib txawv rau ib tug neeg yog hais txog 37 ^° C

Catalase - ib qho ntawm tus ceev tshaj enzymes. Tsuas yog ib tug qauv yog muaj peev xwm hloov nws lab ntawm molecules ntawm hydrogen peroxide rau dej thiab cov pa ib ob. Nyob rau hauv cov nqe lus ntawm enzymology uas txhais tau tias ib tug loj tus naj npawb ntawm revolutions cov yam ntxwv ntawm cov enzyme catalase.

qauv enzyme

Catalase yog ib tug tetramer ntawm plaub polypeptide chains, txhua tus uas muaj ntau tshaj li 500 amino acids nyob rau hauv ntev. Lub enzyme yog muaj li ntawm plaub pab pawg txog heme porphyry, thiab los ntawm kev uas reacts nrog active oxygen hom. Lub oxidized heme prosthetic pab pawg neeg yog ib tug catalase.

Keeb kwm ntawm foundations

Catalase twb tsis paub mus zaum 1818 xyoo kom txog rau thaum Louis Jacques Thénard chemist sab nyob rau hauv nyob hlwb ntawm hydrogen peroxide yog tsis pom hais tias nws cov kev puas tsuaj vim qhov kev txiav txim ntawm ib tug tsis paub lom khoom.

Nyob rau hauv 1900, ib tug German chemist, Oskar Leo ua ntej nkag tau rau hauv lub "catalase" lub sij hawm mus rau xa mus rau ib tug mysterious tshuaj decomposing peroxide. Nws muaj peev xwm los teb rau lo lus nug, qhov twg lub enzyme catalase muaj. Raws li ib tug tshwm sim ntawm heev heev thwmsim Oskar Leo qhia hais tias qhov no enzyme yog cov yam ntxwv ntawm yuav luag tag nrho cov tsiaj thiab nroj tsuag. Nyob rau hauv nyob hlwb, raws li zoo li ntau lwm enzymes, catalase yog muaj nyob rau hauv peroxisomes.

Nyob rau hauv 1937 nws yog tus thawj rau crystallize catalase los ntawm nyuj lub siab. 250 KD - molecular ceeb thawj ntawm lub enzyme tau txiav txim nyob rau hauv 1938. Nyob rau hauv 1981 zaum tau txais dluab ntawm peb-dimensional qauv ntawm bovine catalase.

Lub catalysis ntawm hydrogen peroxide

Txawm tias muaj tseeb hais tias hydrogen peroxide - ib yam khoom uas muaj ntau cov qub metabolic dab, nws tsis yog txawm rau hauv lub cev.

Yuav kom tiv thaiv kev puas tsuaj rau lub hlwb thiab cov nqaij mos, hydrogen peroxide yuav tsum tau sai sai hloov dua siab tshiab rau hauv lwm yam, tsawg txaus ntshai rau lub cev. Nws yog no kev sib tw thiab copes enzyme catalase - nws decomposes lub peroxide rau ob molecules dej lwg me me thiab cov pa molecules.

Cov tshuaj tiv thaiv ntawm hydrogen peroxide decomposition nyob rau hauv nyob ntaub so ntswg:

2 H ₂ O ₂ → 2 H ₂ O + O ₂

Lub molecular mechanism ntawm lub cleavage enzyme ntawm hydrogen peroxide los ntawm catalase yog tseem tsis tau raws nraim to taub. Nws yog assumed tias cov tshuaj tiv thaiv yuav siv sij hawm qhov chaw nyob rau hauv ob ua sawv - tus thawj theem uas muaj hlau catalase prosthetic pab pawg neeg sib raug zoo rau ib tug oxygen atom ntawm lub peroxide, qhov no generates ib tug qauv ntawm cov dej. Nyob rau hauv lub kauj ruam thib ob lub oxidized heme interacting nrog lwm molecule ntawm hydrogen peroxide, li no txoj kev ua lwm molecule ntawm dej thiab ib tug qauv ntawm cov pa.

Los ntawm qhov kev txiav txim ntawm lub enzyme catalase rau lub hydrogen peroxide, lub xub ntiag ntawm lub active tshuaj nyob rau hauv cov ntaub so ntswg nrws yog yooj yim txiav txim. Yuav kom qhov no ntxiv kom ntau txaus rau cov kev kuaj sample ib tug me me npaum li cas ntawm hydrogen peroxide thiab soj ntsuam cov tshuaj tiv thaiv. Lub xub ntiag ntawm lub enzyme qhia rau tsim ntawm oxygen npuas. Qhov no cov tshuaj tiv thaiv no zoo vim nws tsis yuav tsum tau muaj kev tshwj xeeb cov cuab yeej los yog khoom - nws yuav pom nrog tus liab qab qhov muag.

Nws yog ib nqi sau cia hais tias ib tug ion ntawm tej hnyav hlau muaj peev xwm ua raws li ib tug noncompetitive inhibitor ntawm catalase. Tsis tas li ntawd, tag nrho cov paub cyanide behaves raws li ib tug kev sib tw inhibitor ntawm catalase, Yog hais tias nyob rau hauv ntau ntaub so ntswg ntawm hydrogen peroxide. Arsenates ua raws li activators.

daim ntawv thov

Kev txiav txim ntawm lub enzyme catalase decomposes hydrogen peroxide twb tau muab siv nyob rau hauv lub lag luam ua noj - siv no enzyme yog muab tshem tawm los ntawm cov mis nyuj H ₂ O ₂ mus rau qhov kev npaj ntawm cheese. Lwm daim ntawv thov - tshwj xeeb cov khoom noj ntim uas tiv thaiv cov khoom tiv thaiv oxidation. Catalase kuj yog siv nyob rau hauv lub textile kev lag luam rau qhov kev tshem tawm ntawm hydrogen peroxide los ntawm fabrics.

Nws yog siv nyob rau hauv kev tu cev ntawm kev sib cuag lo ntsiab muag nyob rau hauv me me qhov ntau. Ib txhia disinfectants yog muaj li ntawm hydrogen peroxide thiab catalase yog siv los phua qhov no kev tivthaiv ua ntej reusing lo ntsiab muag.

kev ua si

Kev ua ntawm catalase enzyme nyob rau hauv lub hnub nyoog ntawm tus kab mob. Cov tub hluas ntxhais ntaub so ntswg ntawm lub enzyme ua si yog ntau tshaj nyob rau hauv lub qub. Nrog lub hnub nyoog nyob rau hauv tib neeg thiab nyob rau hauv cov tsiaj catalase ua si maj txo raws li ib tug tshwm sim ntawm cov laus ntawm cov nqaij thiab kabmob.

Raws li ib tug tsis ntev los no txoj kev tshawv no, ib tug txo ntawm catalase kev ua si yog ib tug ntawm cov tau ua ntawm cov plaub hau graying. Hydrogen peroxide yog ua tsis tu ncua nyob rau hauv tib neeg lub cev, tab sis tsis muaj mob - catalase decomposes nws sai sai. Tab sis yog hais tias tus theem ntawm no enzyme yog txo, nws yog pom tseeb tias tsis yog txhua txhua lub hydrogen peroxide yog tshwmsim los ntawm lub enzyme. Yog li, nws discolors los ntawm sab hauv cov plaub hau los ntawm dissolving ntuj dyes. Qhov no npaj txhij txog foundations tam sim no yog soj ntsuam los ntawm kev soj ntsuam, thiab tej zaum yuav ua si ib lub luag hauj lwm nyob rau hauv txoj kev loj hlob ntawm cov tshuaj, suspending graying ntawm cov plaub hau.