Cov kua protein ntau: txhais, composition, structure, structure, functions, classification thiab characteristics. Dab tsi yog qhov txawv ntawm cov nqaijrog yooj yim thiab cov tawv nqaij?

Cov kua protein muaj protein ntau, ntxiv nrog rau cov khoom noj kom zoo, muaj ib pawg ntxiv ntawm qhov sib txawv ntawm lub cev (hluavtaws). Raws li qhov no kev tivthaiv yog cov carbohydrates, lipids, hlau, seem ntawm phosphoric acid, nucleic acid. Dab tsi txawv qhov yooj yim proteins ntawm qhov sawv daws yuav, yam tshuaj dab tsi yog cov tshuaj no muab faib ua, thiab lawv yog dab tsi, cov tshooj no yuav qhia. Lub ntsiab qhov txawv ntawm cov tshuaj nyob rau hauv kev saib xyuas yog lawv muaj pes tsawg leeg.

Cov protein ntau: txhais

Cov no yog ob hom tshuaj, uas muaj cov protein ntau (peptide chains) thiab cov tshuaj tsis muaj protein (cov khoom nruab nrab). Nyob rau hauv tus txheej txheem ntawm lawv cov hydrolysis, amino acids, cov khoom tsis muaj protein thiab cov khoom lwj raug tsim. Dab tsi yog qhov txawv ntawm cov nqaijrog yooj yim thiab cov tawv nqaij? Thawj tshwm sim ntawm cov amino acids xwb.

Kev faib tawm thiab kev coj ntawm cov proteins uas ua haujlwm

Cov tshuaj no muab faib ua hom, nyob ntawm seb hom kev pab ntxiv. Cov protein ntau yog:

• Glycoproteins yog cov proteins uas nws cov khoom muaj roj muaj cov carbohydrate residue. Ntawm lawv, proteoglycans (Cheebtsam ntawm qhov chaw sib tshuam) raug cais, nrog rau mucopolysaccharides hauv lawv cov qauv. Glyoproteidam muaj immunoglobulins.
• Lipoproteins muaj xws li lipid tshuaj. Cov no muaj xws li apolipoproteins ua qhov kev ua haujlwm ntawm kev muab lipid thauj.
• Metalloproteins muaj hlau ions (tooj liab, manganese, hlau, thiab lwm yam.), Uas muaj kev sib txuas los ntawm kev pub dawb ntawm tus neeg tau txais txiaj ntsig. Cov pab pawg no tsis suav cov roj ntsha, uas muaj qhov sib txuas ntawm cov nplhaib uas muaj hlau nplaum nrog cov hlau thiab cov ntsiab lus sib xws hauv cov qauv (chlorophyll, hauv particular).
• Nucleoproteins yog cov proteins uas muaj cov kab uas tsis muaj cov qe nrog nucleic acids (DNA, RNA). Cov no muaj xws li chromatin - ib feem ntawm chromosomes.
• 5. Phosphoproteins, nrog rau casein (ib qho protein ntau ntawm tsev cheese), suav nrog cov khoom seem txuas uas phosphoric acid.

• Chromoproteins muab cov kev sib txuas ntawm cov khoom sib txuas. Chav kawm no muaj xws li cov roj ntsha proteins, chlorophylls thiab flavoproteins.

Cov nta ntawm glycoproteins thiab proteoglycans

Cov proteins uas yog cov tshuaj yeeb dej caw. Proteoglycans muaj ib feem ntawm cov carbohydrates loj (80-85%), hauv cov ntsiab lus glycoproteins uas yog 15-20%. Cov kua qaub no yog tam sim no nyob rau hauv lub molecule ntawm proteoglycans, lawv cov carbohydrates txawv cov qauv nrog rov ntsuas dua units. Tus qauv thiab kev ua haujlwm ntawm cov proteins uas muaj glycoproteins yog dab tsi? Lawv cov carbohydrate chains tsuas yog muaj 15 txuas thiab muaj cov qauv tsis zoo. Nyob rau hauv cov qauv ntawm glycoproteins, daim ntawv cog lus ntawm carbohydrate mus rau cov tshuaj protein feem ntau yog ua los ntawm qhov seem ntawm cov amino acids xws li serine los yog aspartic.

Kev khiav dej num ntawm glycoproteins:

• Lawv yog ib feem ntawm cov kab mob ntawm cov kab mob ntawm tes, pob txha txuas thiab pob txha mos, pob zeb hluav taws xob, elastin.
• Lawv ua si txog kev tiv thaiv. Piv txwv, cov qauv no muaj tshuaj tua kab, interferons, clotting factors (prothrombin, fibrinogen).
• Lawv yog cov neeg tawm tswv yim uas cuam tshuam nrog ib qho kev cuam tshuam - ib qho khoom me me uas tsis muaj protein ntau. Lub tom kawg, pub ntxiv pub cov protein, ua rau muaj kev hloov hauv nws txoj kev sib nkag siab, uas ua rau cov lus teb sab nraud.
• Ua tus hormonal muaj nuj nqi. Glycoproteins muaj xws li gonadotropic, adrenocorticotropic thiab thyrotropic hormones.
• Thauj khoom nyob rau hauv cov ntshav thiab ions los ntawm cell membrane (transferrin, transcortin, albumin, Na +, K + -ATPase).

Glycoprotein enzymes xws li cholinesterase thiab nuclease.

Ntxiv rau proteoglycans

Feem ntau, proteinoglycan protein ntau nyob rau hauv nws cov qauv loj carbohydrate chains nrog rov qab disaccharide seem ntawm ib co uronic acid thiab amino suab thaj. Oligo- lossis polysaccharide chains hu ua glycans. Lub qub feem ntau muaj 2-10 hom monomer units.

Nyob ntawm tus qauv ntawm cov carbohydrate chains, ntau hom yog qhov txawv, piv txwv li, acid heteropolysaccharides nrog coob tus cov neeg mob cov kua qaub lossis glycosaminoglycans nrog rau cov amino pawg. Cov yav tas muaj xws li:

• Hyaluronic acid, uas yog nquag siv hauv cosmetology.
• Heparin, tiv thaiv kev coagulability ntawm cov ntshav.
• Keratansulfates yog cov khoom ntawm cartilaginous cov ntaub so ntswg thiab pob kws.
• Chondroitin sulfates yog ib feem ntawm cov pob txha mos thiab cov kua dej kua txob.

Cov polymers yog cov khoom ntawm cov roj proteoglycans uas ua rau thaj chaw intercellular, khaws dej, ntub cov txav ntawm cov pob qij txha, thiab yog lawv cov khoom ua. Hydrophilicity (zoo solubility hauv dej) ntawm proteoglycans pub rau lawv nyob rau hauv qhov chaw sib tshuam kom tsim tau ib qho chaw khuam khiab loj loj thiab kab mob. Nrog lawv cov kev pabcuam, muaj tus qauv zoo li jelly, uas cov fibers ntawm lwm cov proteins, piv txwv li, collagen, yog immersed. Nws strands nyob rau hauv ib puag ncig ntawm proteoglycan muaj ib tsob ntoo zoo li puab.

Nta thiab hom lipoproteins

Ua protein ntau lipoprotein yog qhov txawv ntawm ib qho kev qhia zoo txog hydrophilic thiab hydrophobic xwm. Lub nucleus ntawm molecule (hydrophobic part) cov qauv non-hnyuv ntxwm ntawm cov cholesterol thiab triacylglycerides.

Nyob sab nraum, thaj chaw hydrophilic muaj protein ntau, phospholipids, cholesterol. Muaj ntau ntau hom lipoprotein proteins nyob ntawm lawv cov qauv.

Cov ntsiab lus ntawm lipoproteins:

• High-density complex protein (HDL, α-lipoproteins). Tsom cov roj cholesterol mus rau daim siab thiab cov ntaub so ntswg peripheral.
• Tsis muaj qhov hnyav (LDL, β-lipoproteins). Ntxiv rau roj cholesterol, triacylglycerides thiab phospholipids yog thauj.
• Heev tsawg tsawg (VLDL, pre-β-lipoproteins). Ua haujlwm zoo ib yam li LDL.
• Chylomicrons (HM). Rog fatty acids thiab cov roj cholesterol raug thauj los ntawm cov hnyuv tom qab noj zaub mov.

Cov vascular pathology, xws li atherosclerosis, tshwm sim los ntawm qhov tsis muaj correlation ntawm ntau hom lipoproteins hauv cov ntshav. Tus cwj pwm ntawm cov kab lis kev cai muaj peev xwm nthuav tawm ntau yam hauv cov qauv ntawm phospholipids (ntawm HDL los chylomicrons): tus thawj txo ntawm cov protein (ntawm 80 rau 10%) thiab phospholipids, nce hauv feem pua ntawm triacylglycerides (20 mus rau 90%).

Cov metalloproteins muaj ntau yam tseem ceeb hauv cov enzymes

Lub metalloprotein muaj xws li ions ntawm ntau yam hlau. Lawv muaj feem xyuam rau cov kev taw qhia ntawm lub substrate nyob rau hauv lub active (catalytic) chaw ntawm enzyme. Hlau ions yog nyob hauv lub chaw ua haujlwm thiab ua si lub luag haujlwm tseem ceeb hauv catalytic cov tshuaj tiv thaiv. Feem ntau, cov ion ua hauj lwm raws li ib tug neeg txais electron.

Piv txwv ntawm cov hlau uas muaj nyob hauv tus qauv ntawm cov tshuab pliaj hlau:

• Tooj tooj sib dhos muaj nyob rau hauv cov cytochrome oxidase, uas nrog rau heme muaj cov ion ntawm ib cov hlau. Lub enzyme tau txuam nrog kev tsim ntawm ATP thaum ua haujlwm ntawm txoj hlab pas.
• Hlau muaj cov enzymes xws li ferritin, uas ua tiav cov haujlwm ntawm kev xa cov hlau nyob hauv cell; Hloov siab - tus cab cov hlau hauv cov ntshav; Catalase yog lub luag haujlwm rau cov tshuaj tiv thaiv hydrogen peroxide.
• Zinc yog ib tus cwj pwm hlau ntawm cawv dehydrogenase, uas yog koom tes nrog oxidation ntawm ethyl thiab cov cawv zoo sib xws; Lactate dehydrogenase - ib qho enzyme hauv cov metabolism ntawm lactic acid; carbonic anhydrase uas catalyzes lub tsim ntawm carbonic acid los ntawm CO ₂ thiab H ₂ O; Alkaline phosphatase, uas ua haujlwm hydrolytic cleavage ntawm phosphoric acid esters nrog ntau lub tebchaw; Α2-macroglobulin yog tshuaj antiproteinic ntshav.
• Selenium yog ib feem ntawm thyreperoxidase, uas koom rau hauv tus txheej txheem ntawm tsim cov thyroid hormones; Glutathione peroxidase, uas ua tiav ib qho kev ua rau muaj antioxidant.
• Calcium yog tus cwj pwm ntawm cov qauv ntawm α-amylase, ib qho enzyme ntawm hydrolytic cleavage ntawm hmoov txhuv nplej siab.

Phosphoproteins

Dab tsi yog ib feem ntawm cov proteins uas muaj phosphoproteins? Pawg no yog tsi ntsees los ntawm muaj ib pawg phosphate, uas yog txuas rau cov protein ntau los ntawm cov amino acids nrog hydroxyl (tyrosine, serine los yog threonine). Yuav ua li cas puas phosphoric acid, thaum nyob rau hauv lub qauv ntawm ib tug protein? Nws hloov cov qauv ntawm molecule, muab nws them, nce solubility, cuam tshuam cov khoom ntawm cov protein. Piv txwv ntawm phosphoproteins yog mis nyuj casein thiab qe albumin, tab sis feem ntau cov khoom ntawm cov proteins uas muaj xws li enzymes.

Phosphate pawg plays lub luag haujlwm tseem ceeb, vim muaj ntau cov proteins uas tsis tas mus nrog nws. Nyob rau hauv lub xov tooj txhua lub sij hawm muaj cov txheej txheem ntawm phosphorylation thiab dephosphorylation. Yog li ntawd, kev cai ntawm cov proteins uas tau ua. Piv txwv, yog tias histones - cov proteins uas txuas nrog nucleic acids mus rau lub xeev phosphorylated, ces qhov kev ua ntawm genome (caj khoom) nce. Cov kev ua ntawm cov enzymes xws li glycogen synthase thiab glycogen phosphorylase nyob ntawm phosphorylation.

Nucleoproteins

Nucleoproteins yog cov proteins uas txuas nrog nucleic acids. Lawv yog cov - ib feem ntawm lub cia thiab kev tswj ntawm kev tshuaj ntsuam genetic khoom, cov ua hauj lwm ntawm ribosomes, ua cov kev ua ntawm cov protein ntau synthesis. Tej yam yooj yim ntawm lub neej ntawm cov kab mob hu ua ribo-thiab deoxyribonucleoproteins, vim lawv muaj cov khoom siv roj ntsha thiab cov roj ntsha.

Raws li cov kev sis raug zoo ntawm deoxyribonucleic acid (DNA) thiab histone? Nyob rau hauv chromatin cais ob hom ntawm cov nqaijrog uas txuam nrog DNA (histone thiab uas tsis yog-histone). Tus qub koom rau hauv thawj theem ntawm DNA compactification. Nucleic acid molecule wraps ncig lub proteins kom tsim nucleosomes. Lub txiaj ntsig ua tau zoo li cov hlaws dai, lawv tsim ib qho qauv siv rau supercoiled (chromatin fibril) thiab supercoiled (interphase chromone). Vim qhov kev txiav txim ntawm cov keeb proteins thiab cov proteins uas muaj ntau dua, cov DNA dimension yog txo los ntawm ntau txhiab zaus. Nws yog txaus los sib piv qhov loj ntawm chromosomes thiab qhov ntev ntawm lub nucleic acid nyob rau hauv thiaj li ntsuam xyuas qhov tseem ceeb ntawm cov proteins (6-9 cm thiab 10-6 μm, feem).

Cov chromoproteins yog dab tsi?

Chromoproteins muaj ntau pawg neeg sib txawv, uas sib sau ua ke tsuas yog ib qho - muaj cov xim nyob rau hauv cov khoom sib txuas. Cov proteins uas muaj hauv pawg no tau muab faib ua ke: hemoproteins (muaj nyob hauv tus qauv ntawm heme), retinalproteins (vitamin A), flavoproteins (vitamin B2), cobamidproteins (vitamin B12).

Hemoproteins tau cais raws li cov kev ua haujlwm rau cov uas tsis yog-enzymatic (hemoglobin thiab myoglobin protein) thiab cov enzymes (cytochromes, catalases, peroxidases).

Flavoproteins muaj, raws li ib qho kev tivthaiv, vitamin B2 derivatives, flavin mononucleotide (FMN) lossis flavin adenine dinucleotide (FAD). Cov enzymes no kuj koom rau hauv kev hloov qis dua oxidation. Cov no muaj oxidoreductase.

Cytochrome yog dab tsi?

Raws li tau piav saum toj no, lub pov haum yog tsim los ntawm porphyrin. Nws cov qauv muaj xws li 4 pyrrole rings thiab ferrous hlau. Ib tug tshwj xeeb cov pab pawg neeg ntawm heme enzymes - cytochromes, differing nyob rau hauv amino acid muaj pes tsawg leeg thiab tus naj npawb ntawm peptide chains, tshwj xeeb nyob rau hauv nqa tawm lub redox cov tshuaj tiv thaiv, vim uas yog muab los ntawm electron hloov lwm lub tsev nyob rau hauv lub ua pa saw. Cov enzymes no muaj kev koom tes hauv microsomal oxidation - qhov pib ntawm biotransformation ntawm xenobiotics, ua rau lawv cov neutralization, thiab pauv ntau exogenous thiab exogenous, piv txwv li, steroids, saturated fatty acids.

Cov nyhuv ntawm pawg neeg sib koom tes

Pawg kws kho mob, uas yog ib feem ntawm txoj hauv cov protein, cuam tshuam nws cov khoom: nws hloov nws cov nqi, solubility, thermoplasticity. Piv txwv, residues ntawm phosphoric acid los yog monosaccharides muaj xws li kev ua. Lub carbohydrate ib sab, muaj nyob rau hauv cov protein ntau, tiv thaiv los ntawm proteolysis (kev puas tsuaj los ntawm qhov txheej txheem hydrolysis), muaj feem xyuam rau kev nkag mus ntawm cov khoom xiam hluav taws xob los ntawm cov cell membrane, lawv cov kua qaub thiab kev faib tawm. Lub lipid fragment pub rau kev tsim cov protein raws rau kev thauj cov dej tsis zoo-soluble (hydrophobic) sib txuas.

Tus qauv thiab kev ua haujlwm ntawm cov proteins uas ua tiav yog nyob ntawm seb pawg neeg sib koom ua ke. Piv txwv li, los ntawm cov hlau uas muaj hlau, hemoglobin khi rau cov pa oxygen thiab carbon dioxide. Vim cov nucleoproteins tsim los ntawm kev sib raug zoo ntawm histones, protamines nrog DNA los yog RNA, cov khoom siv tiv thaiv yog kev tiv thaiv, nws compact cia, qhov ruaj ntawm RNA thaum lub sij hawm synthesis ntawm proteins. Nucleoproteins hu ua cov kabmob ruaj khov thiab protein ntau.

Xaus

Yog li, ua cov proteins uas ua rau ntau lub zog hauv lub cev. Yog li ntawd, kev noj cov zaub mov thiab cov kab mob me me yog qhov tseem ceeb rau kev tswj hwm kev noj qab haus huv. Cov hlau yog ib feem ntawm ntau cov enzymes. Paub txog biochemistry, koj txoj kev noj qab haus huv thiab lub cev ntawm koj qhov chaw nyob, koj tuaj yeem kho koj cov khoom noj. Piv txwv, cim cov cheeb tsam uas tsis muaj txhij txhua nyob hauv ib qho twg. Nws ntxiv ntxiv nyob rau hauv kev noj haus nyob rau hauv daim ntawv ntawm additives ua rau nws muaj peev xwm los mus sau lub deficiency.