Ib qho protein ntau, ntxiv rau cov protein tivthaiv nws tus kheej, muaj ib pab pawg ntxiv ntawm qhov sib txawv (prosthetic). Carbohydrates, lipids, hlau, phosphoric acid residues, nucleic acids ua raws li cov khoom no. Kab lus no yuav qhia rau koj paub tias cov proteins yooj yim txawv li cas ntawm cov complex, hom tshuaj twg tau muab faib ua, thiab lawv cov yam ntxwv yog dab tsi. Qhov sib txawv tseem ceeb ntawm cov tshuaj suav hais tias yog lawv cov muaj pes tsawg leeg.
Complex Proteins: Txhais
Cov no yog ob yam khoom, uas suav nrog cov protein yooj yim (peptide chains) thiab cov khoom tsis muaj protein (prosthetic pawg). Nyob rau hauv cov txheej txheem ntawm lawv hydrolysis, amino acids, ib feem uas tsis yog-protein thiab cov khoom lwj yog tsim. Yuav ua li cas cov proteins yooj yim txawv ntawm cov complex? Cov qub tsuas muaj cov amino acids xwb.
Kev faib tawm thiab cov yam ntxwv ntawm cov proteins nyuaj
Cov tshuaj no tau muab faib ua hom nyob ntawm hom pab pawg ntxiv. Ua complexCov protein muaj xws li:
- Glycoproteins yog cov proteins uas nws cov molecules muaj cov carbohydrate residue. Ntawm lawv, proteoglycans (cov khoom ntawm qhov chaw intercellular) yog qhov txawv, uas suav nrog mucopolysaccharides hauv lawv cov qauv. Glycoproteins suav nrog immunoglobulins.
- Lipoproteins suav nrog cov lipid tivthaiv. Cov no suav nrog apolipoproteins, uas ua haujlwm ntawm kev thauj lipid.
- Metalloproteins muaj hlau ions (tooj liab, manganese, hlau, thiab lwm yam) khi los ntawm kev sib cuam tshuam ntawm tus neeg txais kev pab. Cov pab pawg no tsis suav nrog heme proteins, uas suav nrog cov ntsiab lus ntawm lub nplhaib prophyrin nrog hlau thiab cov khoom sib txuas zoo ib yam li lawv hauv cov qauv (chlorophyll, tshwj xeeb).
- Nucleoproteins yog cov proteins uas tsis muaj cov khoom sib txuas nrog nucleic acids (DNA, RNA). Cov no suav nrog chromatin, ib feem ntawm chromosomes.
- 5. Phosphoproteins, uas muaj xws li casein (ib qho nyuaj curd protein), suav nrog covalently txuas phosphoric acid residues.
Chromoproteins koom ua ke los ntawm cov xim ntawm cov khoom siv prosthetic. Cov chav kawm no suav nrog heme proteins, chlorophylls thiab flavoproteins
Cov yam ntxwv ntawm glycoproteins thiab proteoglycans
Cov proteins no yog cov tshuaj complex. Proteoglycans muaj ib tug loj feem ntawm carbohydrates (80-85%), nyob rau hauv cov pa glycoproteins, cov ntsiab lus yog 15-20%. Uronic acids yog tam sim no tsuas yog nyob rau hauv lub proteoglycan molecule; lawv cov carbohydrates yog yus muaj los ntawm ib tug tsis tu ncua qauv nrog rov qab units. Cov qauv thiab kev ua haujlwm ntawm complex glycoprotein proteins yog dab tsi? Lawv cov carbohydrate chains suav nrog tsuas yog 15 txuas thiab tsis sib xws.qauv. Hauv cov qauv ntawm glycoproteins, kev sib txuas ntawm carbohydrate nrog cov protein feem ntau yog ua los ntawm cov amino acid residues xws li serine lossis aspargine.
Kev ua haujlwm ntawm glycoproteins:
- Lawv yog ib feem ntawm cov kab mob ntawm cov phab ntsa, cov pob txha txuas thiab cov pob txha mos, ib puag ncig collagen thiab elastin fibers.
- Ua lub luag haujlwm tiv thaiv. Piv txwv li, cov tshuaj tiv thaiv, interferons, ntshav coagulation yam (prothrombin, fibrinogen) muaj cov qauv no.
- Yog cov receptors uas cuam tshuam nrog ib qho effector - ib qho me me uas tsis yog protein molecule. Qhov kawg, koom nrog cov protein, ua rau muaj kev hloov pauv hauv nws qhov kev sib haum xeeb, uas ua rau muaj qee qhov lus teb hauv lub cev.
- Ua haujlwm hormonal. Cov glycoproteins suav nrog gonadotropic, adrenocorticotropic thiab thyroid-stimulating hormones.
- Kev thauj khoom hauv cov ntshav thiab ions los ntawm cov cell membrane (transferrin, transcortin, albumin, Na +, K + -ATPase).
Glycoprotein enzymes suav nrog cholinesterase thiab nuclease.
Ntau txog proteoglycans
Feem ntau, cov txheej txheem protein ntau proteoglycan suav nrog hauv nws cov qauv loj carbohydrate chains nrog rov qab disaccharide residues, muaj qee yam uronic acid thiab amino qab zib. Oligo- lossis polysaccharide chains hu ua glycans. Cov qub feem ntau muaj 2-10 monomeric units.
Nyob ntawm cov qauv ntawm cov saw hlau carbohydrate, ntau hom ntawm lawv txawv, piv txwv li, qaubheteropolysaccharides nrog ntau pawg acidic los yog glycosaminoglycans, nrog rau cov amino pawg. Cov tom kawg suav nrog:
- Hyaluronic acid, uas nquag siv hauv cosmetology.
- Heparin, uas tiv thaiv cov ntshav txhaws.
- Chondroitin sulfates yog ib feem ntawm pob txha mos thiab cov kua dej synovial.
Keratan sulfates yog cov khoom ntawm pob txha mos thiab pob txha.
Cov polymers no yog cov khoom ntawm cov tshuaj tiv thaiv kab mob uas ua rau cov kab mob sib kis, khaws cov dej, lubricate qhov txav ntawm cov pob qij txha, thiab yog lawv cov khoom siv. Lub hydrophilicity (zoo solubility nyob rau hauv dej) ntawm proteoglycans tso cai rau lawv los tsim ib tug barrier rau loj molecules thiab microorganisms nyob rau hauv intercellular qhov chaw. Nrog lawv cov kev pab, ib tug jelly-zoo li matrix yog tsim, nyob rau hauv uas fibers ntawm lwm yam tseem ceeb proteins, xws li collagen, yog immersed. Nws cov strands hauv qhov nruab nrab proteoglycan muaj ib tsob ntoo zoo li.
Nta thiab hom lipoproteins
Cov protein lipoprotein complex muaj cov ntsiab lus zoo dual hydrophilic thiab hydrophobic xwm. Lub hauv paus ntawm cov molecule (hydrophobic part) yog tsim los ntawm cov roj cholesterol tsis-polar esters thiab triacylglycerides.
Sab nraud hauv thaj chaw hydrophilic yog cov protein, phospholipids, cholesterol. Muaj ntau ntau hom lipoprotein proteins nyob ntawm lawv cov qauv.
chav kawm tseem ceeb ntawm lipoproteins:
- High density complex protein (HDL, α-lipoproteins). Hloov cov roj cholesterol mus rau daim siab thiab cov ntaub so ntswg.
- Tsawg ntom (LDL, β-lipoproteins). Tsuas yogCov roj cholesterol yog thauj los ntawm triacylglycerides thiab phospholipids.
- Tsawg ntom ntom (VLDL, pre-β-lipoproteins). Ua haujlwm zoo ib yam li LDL.
- Chylomicrons (XM). thauj cov roj fatty acids thiab cov roj cholesterol los ntawm cov hnyuv tom qab noj mov.
Xws li cov kab mob vascular raws li atherosclerosis tshwm sim los ntawm qhov tsis raug ntawm qhov sib txawv ntawm lipoproteins hauv cov ntshav. Raws li cov yam ntxwv ntawm cov muaj pes tsawg leeg, ntau qhov kev hloov pauv hauv cov qauv ntawm phospholipids (los ntawm HDL mus rau chylomicrons) tuaj yeem txheeb xyuas: qhov txo qis ntawm cov protein (los ntawm 80 mus rau 10%) thiab phospholipids, nce hauv feem pua ntawm triacylglycerides (los ntawm 20 mus rau 90%).
Muaj ntau cov enzymes tseem ceeb ntawm cov metalloproteins
Metalloprotein tuaj yeem suav nrog ions ntawm ntau cov hlau. Lawv lub xub ntiag cuam tshuam rau kev taw qhia ntawm lub substrate nyob rau hauv lub active (catalytic) site ntawm lub enzyme. Cov hlau ions tau nyob hauv thaj chaw nquag thiab ua lub luag haujlwm tseem ceeb hauv cov tshuaj tiv thaiv catalytic. Feem ntau cov ion ua haujlwm ua tus txais hluav taws xob.
Piv txwv ntawm cov hlau muaj nyob rau hauv cov qauv ntawm enzymatic metalloproteins:
- tooj liab yog suav nrog hauv cov cytochrome oxidase, uas, nrog rau heme, muaj ib qho ion ntawm cov hlau no. Cov enzyme koom nrog tsim ATP thaum lub sijhawm ua haujlwm ntawm txoj hlab pa.
- Hlau muaj cov enzymes xws li ferritin, uas ua haujlwm ntawm kev tso cov hlau hauv lub cell; transferrin - ib tug cab ntawm hlau nyob rau hauv cov ntshav; catalase yog lub luag haujlwm rau cov tshuaj tiv thaiv hydrogen peroxide neutralization.
- Zinc yog cov yam ntxwv ntawm cov hlaucawv dehydrogenase koom nrog oxidation ntawm ethyl thiab zoo li cawv; lactate dehydrogenase - ib qho enzyme hauv cov metabolism hauv lactic acid; carbonic anhydrase catalyzing tsim carbonic acid los ntawm CO2 thiab H2O; alkaline phosphatase, uas ua rau hydrolytic cleavage ntawm phosphoric acid esters nrog ntau cov tebchaw; α2-macroglobulin yog cov tshuaj tiv thaiv cov ntshav protein.
- Selenium yog ib feem ntawm thyroperoxidase, uas koom nrog hauv kev tsim cov thyroid hormones; glutathione peroxidase, uas ua rau muaj kev ua haujlwm antioxidant.
- Calcium yog yam ntxwv ntawm cov qauv ntawm α-amylase, ib qho enzyme rau hydrolytic tawg ntawm starch.
phosphoproteins
Dab tsi suav nrog hauv cov protein ntau ntawm phosphoproteins? Cov pawg no yog tus cwj pwm los ntawm kev muaj cov phosphate pawg, uas yog txuam nrog cov protein ib feem los ntawm cov amino acids nrog hydroxyl (tyrosine, serine los yog threonine). Dab tsi yog qhov ua haujlwm ntawm phosphoric acid hauv cov qauv protein? Nws hloov cov qauv ntawm cov molecule, muab nws tus nqi, nce solubility, cuam tshuam cov khoom ntawm cov protein. Piv txwv ntawm phosphoproteins yog cov mis nyuj casein thiab qe albumin, tab sis cov enzymes feem ntau yog nyob rau hauv pawg no ntawm complex proteins.
Cov pab pawg phosphate plays lub luag haujlwm tseem ceeb, txij li ntau cov proteins tsis tau ua tiav rau nws. Phosphorylation thiab dephosphorylation txheej txheem yog tas li nyob rau hauv lub cell. Yog li ntawd, cov kev cai ntawm kev ua hauj lwm ntawm cov proteins yog ua. Piv txwv li, yog tias histones yog cov proteins txuas nrog nucleic acids, lawv dhaumus rau hauv lub xeev phosphorylated, ces cov kev ua ntawm genome (cov khoom siv caj ces) nce. Kev ua haujlwm ntawm cov enzymes xws li glycogen synthase thiab glycogen phosphorylase nyob ntawm phosphorylation.
Nucleoproteins
Nucleoproteins yog cov proteins txuas rau nucleic acids. Lawv yog ib feem tseem ceeb ntawm kev khaws cia thiab kev tswj hwm ntawm cov khoom siv caj ces, kev ua haujlwm ntawm ribosomes uas ua haujlwm ntawm cov protein synthesis. Lub neej yooj yim tshaj plaws ntawm cov kab mob tuaj yeem hu ua ribo- thiab deoxyribonucleoproteins, vim lawv muaj cov khoom siv caj ces thiab cov proteins.
Deoxyribonucleic acid (DNA) thiab histones cuam tshuam li cas? Hauv chromatin, 2 hom proteins cuam tshuam nrog DNA yog qhov txawv (histone thiab non-histone). Cov qub tau koom nrog hauv thawj theem ntawm DNA compaction. Lub nucleic acid molecule qhwv ib ncig ntawm cov proteins los tsim nucleosomes. Cov xov uas tshwm sim zoo ib yam li cov hlaws dai, lawv tsim cov qauv supercoiled (chromatin fibril) thiab supercoil (interphase chromonema). Vim qhov kev ua ntawm histone proteins thiab cov proteins ntawm cov qib siab dua, nws tau muab kev txo qis hauv DNA los ntawm ntau txhiab zaus. Nws yog txaus los sib piv qhov loj ntawm chromosomes thiab qhov ntev ntawm nucleic acid los ntsuas qhov tseem ceeb ntawm cov proteins (6-9 cm thiab 10-6 µm, ntsig txog).
YDab tsi yog chromoproteins
Chromoproteins muaj ntau pawg neeg uas muaj tib yam nkaus xwb - muaj xim nyob rau hauv cov khoom siv prosthetic. Cov protein ntau ntawm pawg no tau muab faib ua: hemoproteins (muaj heme hauv cov qauv), retinal proteins (vitamin A), flavoproteins (vitamin B2),cobamide proteins (vitamin B12).
Hemoproteins raug cais raws li lawv txoj haujlwm ua tsis yog-enzymatic (hemoglobin thiab myoglobin protein) thiab enzymes (cytochromes, catalase, peroxidase).
Flavoproteins muaj raws li cov khoom siv prosthetic derivatives ntawm vitamin B2 flavin mononucleotide (FMN) los yog flavin adenine dinucleotide (FAD). Cov enzymes no kuj koom nrog hauv kev hloov pauv redox. Cov no suav nrog oxidoreductases.
Cytochromes yog dab tsi?
Raws li tau piav qhia saum toj no, heme yog tsim los ntawm porphyrin. Nws cov qauv muaj xws li 4 pyrrole rings thiab ferrous hlau. Ib pab pawg tshwj xeeb ntawm heme enzymes - cytochromes, sib txawv ntawm cov amino acids thiab cov xov tooj ntawm peptide chains, tshwj xeeb hauv kev ua cov tshuaj tiv thaiv redox, uas ua kom muaj kev hloov pauv ntawm cov hluav taws xob hauv cov hlab ntsws. Cov enzymes no koom nrog hauv microsomal oxidation - thawj qhov kev tshwm sim ntawm biotransformation ntawm xenobiotics, ua rau lawv cov neutralization, thiab kev sib pauv ntawm ntau yam exogenous thiab exogenous, piv txwv li, steroids, saturated fatty acids.
Kev cuam tshuam ntawm pab pawg prosthetic
Cov pab pawg prosthetic, uas yog ib feem ntawm cov proteins nyuaj, cuam tshuam rau nws cov khoom: hloov nws cov nqi, solubility, thermoplasticity. Piv txwv li, phosphoric acid residues los yog monosaccharides muaj xws li cov nyhuv. Cov carbohydrate ib feem muaj nyob rau hauv cov muaj pes tsawg leeg ntawm complex protein tiv thaiv nws los ntawm proteolysis (kev puas tsuaj raws li ib tug tshwm sim ntawm cov txheej txheem hydrolysis), cuam tshuam rau kev nkag mus ntawm molecules los ntawm lub cell.membrane, lawv secretion thiab sorting. Cov lipid fragment tso cai rau tsim cov protein raws rau kev thauj mus los ntawm cov dej tsis zoo-soluble (hydrophobic) compounds.
Cov qauv thiab kev ua haujlwm ntawm cov proteins nyuaj yog nyob ntawm cov pab pawg pob txha. Piv txwv li, hlau-muaj heme nyob rau hauv hemoglobin khi oxygen thiab carbon dioxide. Vim yog cov nucleoproteins tsim los ntawm kev sib cuam tshuam ntawm histones, protamines nrog DNA lossis RNA, cov khoom siv caj ces raug tiv thaiv, khaws cia compactly, thiab RNA yog khi thaum lub sij hawm tsim cov protein. Nucleoproteins yog cov complexes ntawm cov proteins thiab nucleic acids.
Zoo kawg
Yog li, cov proteins nyuaj ua haujlwm ntau hauv lub cev. Yog li, kev noj cov macro- thiab micronutrients tseem ceeb heev rau kev noj qab haus huv. Cov hlau yog ib feem ntawm ntau cov enzymes. Paub txog biochemistry, tus yam ntxwv ntawm koj txoj kev noj qab haus huv thiab lub xeev ecological ntawm qhov chaw nyob, koj tuaj yeem kho koj tus kheej noj. Piv txwv li, faib cov cheeb tsam uas yog tus cwj pwm los ntawm qhov tsis txaus ntawm txhua lub caij. Nws cov lus qhia ntxiv rau hauv kev noj zaub mov hauv daim ntawv ntawm cov tshuaj ntxiv tso cai rau koj los tsim kom muaj qhov tsis txaus.
