Protein-enzyme: lub luag hauj lwm ntawm cov khoom, cov kev ua uas muaj protein ntau enzymes nyob rau hauv lub cev

Nyob rau hauv txhua txhua nyob cell muaj ib tug txheej ntawm tshuaj tshua. Enzymes (enzymes) - cov nqaijrog nrog kev thiab tseem ceeb heev functions. Lawv yog cov hu ua biocatalysts. Lub ntsiab muaj nuj nqi ntawm enzymes nyob rau hauv lub cev yog mus leeb biochemical kev tig cev. Cov pib cov ntaub ntawv, uas yog tshwmsim los ntawm tus sis ntawm cov molecules yog hu ua substrates, thiab qhov kawg compound - cov khoom.

Nyob rau hauv cov xwm, enzymes yog cov nqaijrog ua hauj lwm xwb nyob rau hauv nyob systems. Tab sis nyob rau hauv niaj hnub biotechnology, kev soj ntsuam diagnostics, pharmaceutics thiab tshuaj siv lim enzymes los yog lawv ceg, raws li zoo raws li ntxiv Cheebtsam tsim nyog rau cov lag luam ntawm lub system thiab cov ntaub ntawv visualization rau tus kws tshawb fawb.

Lub lom tseem ceeb thiab thaj chaw ntawm enzymes

Yog tsis muaj cov molecules nyob kab mob yuav tsis muaj nuj nqi. Tag nrho lub neej dab yog ua hauj lwm sib haum xeeb ua tsaug rau cov enzymes. Lub ntsiab muaj nuj nqi ntawm cov protein enzymes nyob rau hauv lub cev - cov kev cai ntawm cov metabolism hauv. Yog tsis muaj lawv, nws yuav tsis ua tau li qub metabolism. Cai ntawm cov kev ua ntawm molecules yuav siv sij hawm qhov chaw nyob rau hauv tus ntawm activators (inducers) los yog inhibitors. Control ua hauj lwm sib protein synthesis. Nws kuj "ua hauj lwm" nyob rau hauv kev sib hwm ntawm tas molecule.

Lub ntsiab thaj chaw ntawm cov protein ntau enzymes - tseem mus rau ib tug kev substrate. Thiab, raws li, muaj peev xwm catalyze lub tsuas yog ib qho los yog tsawg dua ib tug series ntawm kev tig cev. Feem ntau, cov dab yog reversible. Rau cov kev ua tau zoo ntawm ob zog lub luag hauj lwm yog ib tug enzyme. Tab sis hais tias yog tsis yog txhua txhua.

Lub luag hauj lwm ntawm enzymes yog qhov tseem ceeb. Yog tsis muaj lawv, tsis muaj biochemical kev tig cev coj qhov chaw. Los ntawm qhov kev txiav txim ntawm enzymes, reagents nws yog ua tau los mus kov yeej qhov ua kom barrier tsis tseem ceeb expenditure ntawm lub zog. Nyob rau hauv lub cev, muaj yog tsis muaj tau kom sov lub kub tshaj 100 ° C, los yog siv cov tshuaj txhoj puab heev tebchaw zoo li lab. Protein-enzyme uake mus rau lub substrate. Nyob rau hauv lub ua txhua yam lub xeev yog hloov, raws li los ntawm qhov kev tso tawm ntawm lub yav tas. Qhov no yog vim hais tias tag nrho cov catalysts yog siv nyob rau hauv cov tshuaj synthesis.

Yuav ua li cas ntau ntau cov koom haum ntawm lub molecule-enzyme protein?

Feem ntau, cov molecules muaj ib tug tertiary (globule) los yog quaternary (ob peb interconnected globules) protein cov qauv. Ua ntej, lawv yog tsim nyob rau hauv ib tug linear zam. Thiab ces quav mus rau hauv cov yam qauv. Yuav ua kom cov kev ua ntawm lub biocatalyst yuav tsum tau ib tug tej yam qauv.

Enzymes li zoo li lwm yam proteins uas muab los ntawm cov cua kub, huab tseem ceeb ntawm pH, txhoj puab heev tshuaj tebchaw.

Ntxiv thaj chaw ntawm enzymes

Cov no nta yog cov nram qab no Cheebtsam:

1. Stereospecificity - lub tsim ntawm tsuas yog ib qho khoom.
2. Regioselectivity - txhaum lub tshuaj daim ntawv cog lus los yog pab pawg neeg kev hloov kho ntawm tsuas yog ib txoj hauj lwm.
3. Chemoselectivity - catalysis tsuas yog ib cov tshuaj tiv thaiv.

ua hauj lwm tshwj xeeb tshaj yog

Cov theem ntawm enzyme tseem txawv. Txawm li cas los, tej enzyme ib txwm nquag rau ib tug substrate los yog pab pawg neeg ntawm cov tebchaw xws li cov nyob rau hauv kev teeb tsa. Tsis-proteinaceous catalysts tsis muaj cuab yeej no. Tseem ntsuas losis tswvyim dabtsi qhov (mol / l), uas yuav ua tau mus txog rau 10 ^-10 mol / l. Ua hauj lwm active enzyme swift. Ib tug qauv catalyzes phav phav-lab ntawm cov lus qhia ib ob. Lub degree ntawm acceleration ntawm biochemical kev tig cev ho (1000-100,000 sij hawm) ntau dua li cov pa catalysts.

Qhov kev txiav txim ntawm enzymes yog ua nyob rau hauv ob peb mechanisms. Qhov yooj yim sis muaj tshwm sim nrog ib tug qauv ntawm substrate, ua raws li los ntawm tsim ntawm cov khoom. Feem ntau cov enzymes yuav khi 2-3 txawv molecules hnov mob. Piv txwv li, cov kev hloov ntawm ib tug atom los yog pab pawg neeg los ntawm ib tug compound mus rau lwm lub, los yog ib tug muab ob npaug rau hloov rau ib tug "ping-pong". Nyob rau hauv cov tshuaj feem ntau txuas ib substrate, thiab lub thib ob haumxeeb pab pawg neeg yog txuas los ntawm cov enzyme.

Txoj kev tshawb no ntawm lub enzyme mechanism ntawm qhov kev txiav txim yuav siv sij hawm qhov chaw nyob rau hauv ib tug raws:

1. Txiav txim intermediate thiab zaum kawg khoom.
2. Kev tshawb fawb ntawm cov qauv thiab cov geometry ntawm tej pab pawg uake mus rau lub substrate thiab muab ib tug siab cov tshuaj tiv thaiv tus nqi.
3. Change nyob rau hauv lub noob ntawm lub enzyme thiab kev txiav txim txog cov kev hloov nyob rau hauv nws cov synthesis thiab kev ua si.

Active thiab ruaj site

Substrate molecule npaum li cas me dua cov protein yog ib qho enzyme. Yog li ntawd, cov losis tswvyim dabtsi yog vim muaj ib tug me me muaj pes tsawg tus ntawm functional pawg ntawm cov biocatalyst. Lawv tsim lub active site, muaj raws ntawm ib qho ntawm cov amino acids. Nyob rau hauv txoj nqaijrog nyob rau hauv cov qauv ntawm cov prosthetic pab pawg neeg tam sim no nonprotein xwm, uas tej zaum yuav kuj yog ib feem ntawm lub active chaw.

Nws yuav tsum faib ib daim pab pawg neeg ntawm enzymes. Lawv muaj nyob rau hauv lub molecule muaj xws li cov Coenzyme mus tas li losis tswvyim dabtsi molecule thiab yog raug zam los ntawm nws. Nkaus tsim protein enzyme hu ua holoenzyme, thiab thaum twg tshem ib tug cofactor - apoenzyme. Raws li coenzymes feem ntau ua vitamins, hlau, derivatives ntawm nitrogenous bases (NAD - nicotinamide adenine dinucleotide, fad - flavin adenine dinucleotide, FMN - flavin mononucleotide).

Binding site muaj ib tug kev sib ze rau cov substrate. Vim nws tsim ib tug ruaj khov substrate-enzyme complex. Globule qauv ua lub tsev thiaj li mus yuav rau ntawm qhov chaw ntawm lub niche (txoj kab txiav los yog ua si nraum zoov) ntawm ib tug me me uas muab cov losis tswvyim dabtsi ntawm lub substrate. Qhov no cheeb tsam yog feem ntau nyob ze ntawm lub active site. Rau ib txhia enzymes, muaj cov chaw mus cuag nrog cofactors los yog hlau ions.

xaus

Protein-enzyme plays ib qho tseem ceeb luag hauj lwm nyob rau hauv lub cev. Tej tshuaj catalyze tshuaj tshua yog lub luag hauj lwm rau cov metabolism - metabolism. Nyob rau hauv txhua nyob ntawm tes lossi tshwm sim pua pua ntawm biochemical dab uas yuav txo tau kev tshua, cleavage thiab lub synthesis ntawm cov tebchaw. Ntxiv cov oxidation ntawm tshuaj nrog ib tug loj tso tawm ntawm lub zog. Nws, nyob rau hauv lem, yog siv rau cov tsim ntawm carbohydrates, cov nqaijrog, Sibhawm, thiab lawv ceg. Lub cleavage cov khoom uas ntxwv ntsiab yuav tsum tau rau lub synthesis ntawm cov organic sib txuas.