Iprotheyini enzima: incazelo, ukwakhiwa, isakhiwo, isakhiwo, imisebenzi, ukuhlukaniswa kanye nezici. Uyini umehluko phakathi kwamaprotheni alula nezinkimbinkimbi?

Iprotheyini enzima, ngaphezu kwesakhi seprotheyini esifanele, iqukethe iqembu elengeziwe lezinto ezihlukile (isisu). Njengoba le nxenye i-carbohydrate, lipids, izinsimbi, i-phosphoric acid izinsalela, i-nucleic acid. Yini ehlukanisa amaprotheni alula ezivela eziyinkimbinkimbi, yiziphi izinhlobo zezinto lezi zinto ezihlukanisiwe, futhi yiziphi izici zazo, lesi sihloko sizokutshela. Umehluko omkhulu phakathi kwezinto ezicatshangelwe ukubunjwa kwawo.

Amaprotheni anamanzi: incazelo

Lawa yizinto ezimbili eziyingxenye, ezihlanganisa amaprotheni alula (amakhethini e-peptide) kanye ne-non-protein substance (i-prosthetic group). Inqubo ye-hydrolysis yabo, ama-amino acids, ingxenye engeyona amaprotheni nemikhiqizo yokubola. Uyini umehluko phakathi kwamaprotheni alula nezinkimbinkimbi? Okokuqala kuhlanganisa kuphela amino acid.

Ukuhlukaniswa nokuhlukaniswa kwamaprotheni anzima

Lezi zinto zihlukaniswe zibe yizinhlobo, kuye ngokuthi uhlobo lweqembu elixhasayo. Amaprotheni anamanzi afaka:

• Ama-glycoprotein amaprotheni awo ama-molecule anezinsalela ze-carbohydrate. Phakathi kwazo, ama-proteoglycans (izingxenye zesikhala se-intercellular) azihlukanisiwe, kuhlanganise nama-mucopolysaccharides esakhiweni sabo. I-glikoproteidam ihlanganisa i-immunoglobulins.
• I-lipoproteins ifaka ingxenye ye-lipid. Lezi zihlanganisa ama-apolipoproteins enza umsebenzi wokuhlinzeka nge-lipid transport.
• Ama-metalloproteins aqukethe ions zensimbi (ithusi, ama-manganese, insimbi, njll), ezixhunyaniswe ngokusebenzisana komnikeli-wamukeleki. Leli qembu alifaki amaprotheni e-heme, afaka izinhlanganisela zendandatho ye-profinine ene-iron kanye nama-compounds afana nesakhiwo (i-chlorophyll, ikakhulukazi).
• Ama-nucleoproteins amaprotheni anezibopho ezingekho-covalent ne-nucleic acid (i-DNA, i-RNA). Lezi zihlanganisa i-chromatin - ingxenye ye-chromosomes.
• 5. I-Phosphoproteins, ehlanganisa i-casein (iphrotheni eyinkimbinkimbi ye-cottage cheese), ifaka phakathi kwezinsalela ezihlanganisiwe zephosphoric acid.

• I-Chromoproteins ihlanganisa ukucweba kwesakhi se-prosthetic. Leli klasi lihlanganisa amaprotheni ama-heme, ama-chlorophyll nama-flavoprotein.

Izici ze-glycoproteins nama-proteoglycans

La maprotheni ayinto eyinkimbinkimbi. Ama-proteoglycans aqukethe isilinganiso esikhulu sama-carbohydrate (80-85%), kuma-glycoprotein ajwayelekile okuqukethwe okungu-15-20%. Ama-acids angenangqondo akhona kuphela emangqamuzaneni yama-proteoglycans, ama-carbohydrate awo ahlukile kwesakhiwo esivamile ngamayunithi aphindaphindiwe. Iyini isakhiwo nomsebenzi we-proteine eziyinkimbinkimbi zama-glycoprotein? Amaketanga abo e-carbohydrate ahlanganisa izixhumanisi ezingu-15 kuphela futhi abe nesakhiwo esingavamile. Ngokwakhiwa kwe-glycoprotein, isibopho se-carbohydrate engxenyeni yeprotheni ngokuvamile iqhutshwa ngokusebenzisa izinsalela zamamino acid ezifana ne-serine noma i-aspartic.

Imisebenzi ye-glycoprotein:

• Ziyingxenye yodonga lwamangqamuzana e-bacterial, amathambo axhumene nezicubu ezinama-cartilaginous, ama-collagen fibers azungeze, i-elastin.
• Badlala indima yokuzivikela. Isibonelo, lesi sakhiwo sinama-antibodies, ama-interferons, izici zokuvala (prothrombin, fibrinogen).
• Ziyi-receptors ezithinta i-effector - i-molecule encane engeyona iphrotheni. Lezi zinsuku, ezijoyina amaprotheni, ziholela ekuguquleni ekuhambeni kwayo, okuholela ekuphenduleni okuqondile kwe-intracellular.
• Yenza umsebenzi we-hormonal. Ama-glycoprotein afaka i-gonadotropic, i-adrenocorticotropic ne-hormone ye-thyrotropic.
• Izinto zokuthutha egazini nasezintweni ngokusebenzisa i-membrane yeseli (transferrin, transcortin, albin, Na +, K + -ATPase).

Ama-enzyme we-glycoprotein afaka i-cholinesterase ne-nuclease.

Okuningi kuma-proteoglycans

Ngokuvamile, iproteoglycan iproteinyini eyinkimbinkimbi ifaka emaketangeni amakhulu ama-carbohydrate amaningi ngezinhlayiya eziphindaphindiwe ze-disaccharide eziqukethe ama-asidi angenangqondo namashukela e-amino. I-Oligo- noma i-polysaccharide ngamaketanga abizwa ngokuthi ama-glycans. I-former ejwayelekile iqukethe amayunithi angu-2-10 e-monomer.

Ngokuya ngesakhiwo samaketanga e-carbohydrate, izinhlobo ezihlukahlukene zihlukile, isibonelo, i-acid heteropolysaccharides nenani elikhulu lamaqembu ase-acid noma ama-glycosaminoglycans afaka amaqembu amino. Lokhu kuhlanganisa:

• I-Hyaluronic acid, esetshenziselwa ngokugcwele emkhatsini we-cosmetology.
• Heparin, ukuvimbela coagulability yegazi.
• I-Keratansulfates yizingxenye zezicubu zomzimba kanye ne-cornea.
• I-Chondroitin sulfates ziyingxenye ye-cartilage ne-synovial fluid.

Lezi polymers ziyingxenye yama-proteoglycans agcwalisa isikhala se-intercellular, agcina amanzi, agcoba izingxenye ezihambayo zamalungu, futhi yizingxenye zawo zesakhiwo. I-Hydrophilicity (ukutholakala kahle kwamanzi emanzini) ama-proteoglycans iwavumela esikhaleni se-intercellular ukudala isithiyo kuma-molecule amakhulu kanye nezinambuzane ezincane. Ngosizo lwabo, kudalwa i-matrix efana ne-jelly, lapho izintambo zamanye amaprotheni abalulekile, isibonelo, i-collagen, zibhapathizwa. Amathanga alo emvelweni we-proteoglycan anomumo ofana nomuthi.

Izici kanye nezinhlobo ze-lipoproteins

I-protein iphoprotein ephelele ihlukaniswa nomvelo owenziwe kahle we-hydrophilic kanye ne-hydrophobic. I-nucleus ye-molecule (ingxenye ye-hydrophobic) ihlanganisa ama-non-polar esters we-cholesterol ne-triacylglycerides.

Ngaphandle, indawo ye-hydrophilic iqukethe amaprotheni ingxenye, i-phospholipids, i-cholesterol. Kunezinhlobo eziningana ze-lipoprotein amaprotheni kuye ngokuthi isakhiwo saso.

Izigaba eziyinhloko zamapoprotein:

• Iprotheni eyinkimbinkimbi enkulu kakhulu (HDL, α-lipoproteins). Ihambisa i-cholesterol esibusweni sesibindi nesiphambano.
• Ubukhulu obuphansi (i-LDL, i-β-lipoproteins). Ngaphezu kwe-cholesterol, i-triacylglycerides ne-phospholipids ziyathuthwa.
• Ubuncane kakhulu (VLDL, pre-β-lipoproteins). Yenza umsebenzi ofanayo no-LDL.
• I-Chylomicrons (HM). Ama-acids amafutha kanye ne-cholesterol athuthwa emathunjini ngemuva kokondla kokudla.

I-pathology enjalo ye-vascular, njenge-atherosclerosis, ivela ngenxa yokulungiswa okungalungile kwezinhlobo ezahlukene ze-lipoproteins egazini. Izici zokwakheka zingabonisa ukuthambekela okumbalwa kwisakhiwo se-phospholipids (kusuka ku-HDL kuya kuma-chylomicrons): ukwehla kwenani lamaprotheni (kusuka kuma-80 kuya ku-10%) ne-phospholipids, ukwanda kwephesenti ye-triacylglycerides (20 kuya ku-90%).

Phakathi kwama-metalloproteins kunezinhlobo eziningi ze-enzyme ezibalulekile

I-metalloprotein ingafaka ions yezinsimbi eziningana. Ukuba khona kwabo kuthinta ukuma kwe-substrate esikhungweni esisebenzayo (catalytic) se-enzyme. Ama-ioni we-Metal ahlala esikhungweni esisebenzayo futhi adlale indima ebalulekile ekuphenduleni okuthandayo. Ngokuvamile, ion isebenza njenge-acceptor electron.

Izibonelo zensimbi ziqukethe isakhiwo se-enzyme metalloproteins:

• I-Copper ifakwe ekubunjweni kwe-cytochrome oxidase, ehambisana ne-heme iqukethe i-metal enikeziwe. I-enzyme ihileleke ekubunjweni kwe-ATP ngesikhathi somsebenzi wezinketho zokuphefumula.
• I-Iron iqukethe ama-enzyme afana ne-ferritin, enza umsebenzi wokufaka insimbi; I-Transferrin - othwali wensimbi egazini; I-Catalase inesibopho se-hydrogen peroxide ekunqumeni ukuguquka komzimba.
• I-Zinc iyisici sensimbi yokuphuza utshwala dehydrogenase, okubandakanyeka ekuxhumeni kwe-ethyl kanye nokuphuza okufanayo; I-liquate dehydrogenase - i-enzyme ku-metabolism ye-lactic acid; I-carbonic anhydrase, eyenza ukwakhiwa kwe-carbonic acid kusuka ku-CO ₂ no-H ₂ O; I-alkaline phosphatase, eyenza i-hydrolytic cleavage ye-phosphoric acid esters enezinhlobo ezihlukahlukene; I-Α2-macroglobulin iyi-protein yamaprotheni e-antiproteinic.
• I-Selenium iyingxenye ye-thyreperoxidase, ehlanganyela ekusebenzeni kwamahomoni wegciwane; I-glutathione peroxidase, eyenza umsebenzi we-antioxidant.
• I-calcium iyisici sesakhiwo se-α-amylase, i-enzyme ye-hydrolytic cleavage yesitashi.

Phosphoproteins

Iyini ingxenye yamaprotheni amaningi ayenziwe ngama-phosphoprotein? Lesi sigaba sibonakala ngokuba khona kweqembu le-phosphate, elixhunyaniswa neprotheyini ingxenye nge-amino acid nge-hydroxyl (tyrosine, serine noma i-threonine). Iyini imisebenzi ye- phosphoric acid esakhiweni seprotheyini? Lishintsha isakhiwo se-molecule, linikeza inkokhelo, lwandisa ukuxazululwa kwemvelo, lithinta izakhiwo zeprotheni. Izibonelo ze-phosphoprotein ziyi-milk casein ne-albin i-albin, kodwa ngokuyinhloko lesi sigaba samaprotheni azintambo zihlanganisa ama-enzyme.

Iqembu le-phosphate lidlala indima ebalulekile yokusebenza, ngoba amaprotheni amaningi awahlanganiswa ngokuphelele. Esitokisini ngaso sonke isikhathi kunezinqubo ze-phosphorylation ne-dephosphorylation. Ngenxa yalokho, ukulawulwa kwamaprotheni kwenziwa. Isibonelo, uma i-histones - amaprotheni axhunyiwe ku-nucleic acid aya embusweni we-phosphorylated, khona-ke umsebenzi we-genome (izinto eziphathelene nezakhi zofuzo) ukwanda. Umsebenzi we-enzyme efana ne-glycogen synthase ne-glycogen phosphorylase incike ku-phosphorylation.

Nucleoproteins

I-nucleoproteins ngamaprotheni axhunyiwe ku-nucleic acid. Ziyingxenye ebalulekile yokugcinwa nokulawulwa kwezinto eziphilayo, ukusebenza kwama-ribosomes, okwenza umsebenzi weprotheyini synthesis. Izinhlobo ezilula kakhulu zokuphila kwamagciwane zingabizwa ngokuthi i-ribo-ne-deoxyribonucleoproteins, ngoba ziqukethe izinto eziphathelene nama-genetic namaprotheni.

I- deoxyribonucleic acid (i-DNA) ne-histones ixhumana kanjani? Ku-chromatin, izinhlobo ezimbili zama-protein zihlotshaniswa ne-DNA (histone non-histone). Abangaphambili babamba iqhaza esigabeni sokuqala se-DNA compactification. I-molecule ye-nucleic acid ihambela amaprotheni ukwenza ama-nucleosomes. I-filament ebangelwayo ifana nemigqa, yenza isakhiwo esine-supercoiled (i-chromatin fibril) futhi i-supercoiled (i-chromone ye-interphase). Ngenxa yesenzo se-histone amaprotheni namaphrotheni amazinga aphakeme, ubukhulu be-DNA buyancipha ngezikhathi eziningana. Kwanele ukuqhathanisa ubukhulu bama-chromosomes nobude be-nucleic acid ukuze kuhlolwe ukubaluleka kwamaprotheni (6-9 cm no-10-6 μm, ngokulandelana).

Ziyini ama-chromoprotein

I-Chromoproteins iqukethe amaqembu ahlukahlukene kakhulu, ahlanganisa eyodwa kuphela - ubukhona bombala esiyingxenyeni sesisu. Amaprotheni anamandla alo mkhakha ahlukaniswe: ama-hemoproteins (aqukethe isakhiwo se-heme), ama-retinalproteins (i-vitamin A), i-flavoproteins (i-vitamin B2), i-cobamidproteins (i-vitamin B12).

Ama-hemoproteins ahlukaniswa kuye ngemisebenzi ye-non-enzymatic (i-hemoglobin ne-myoglobin amaprotheni) nama-enzyme (ama-cytochromes, ama-catalases, ama-peroxidases).

Ama-flavoprotein aqukethe, njengento eyisiqhwaga, i-vitamin B2 derivatives, i-flavin mononucleotide (FMN) noma i-flavin adenine dinucleotide (i-FAD). La ma-enzyme nawo ahlanganyela ekuguqulweni kwe-oxidation-ukunciphisa. Lokhu kuhlanganisa i-oxyidoreductase.

Kuyini i-cytochrome?

Njengoba kuchazwe ngenhla, i-gem iqukethe i-porphyrin. Isakhiwo saso sinezinsimbi ezine ze-pyrrole ne-ferrous iron. Iqembu elikhethekile lama-enzymes e-heme - ama-cytochromes, ahluke ekubunjweni kwama-amino acids kanye nenani lamaketanga e-peptide, akhethekile ekufezeni ukusikethwa kwe-oxidation-reduction, okuqinisekisa ukuthi ukudluliselwa kwama-electron kulayini lokuphefumula. Lezi zinkimbinkimbi zibandakanya ukuketshezi kwe-microsomal - ukusabela kokuqala kwe-biotransformation ye-xenobiotics, okuholela ekutheni i-neutralization yabo, kanye nokushintshaniswa kwezidakamizwa eziningi ezingenakuqhathaniswa nezokungafani, isibonelo, ama-steroid, amafutha amaningi agcwele amafutha.

Umphumela weqembu lezitho zomzimba

I-prosthetic group, engxenyeni ye-protini eyinkimbinkimbi, ithinta izakhiwo zayo: itshintsha ushintsho lwayo, isilubility, thermoplasticity. Ngokwesibonelo, izinsalela ze-phosphoric acid noma i-monosaccharides zinesenzo esinjalo. Ingxenye ye-carbohydrate, efakwe kuphrotheni eyinkimbinkimbi, iyayilondoloza kusuka ku-proteolysis (ukubhujiswa ngenxa yendlela yokwenza i-hydrolysis), ithinta ukungena kwamangqamuzana ngokusebenzisa i-membrane yeseli, ukufihla nokuhlunga kwazo. Isiqephu se-lipid sivumela ukudalwa kwamaprotheni amashaneli okuthuthwa kwamakhemikhali amancane angenawo amanzi (solphobic).

Isakhiwo nomsebenzi wama-proteine aqinile kuncike ngokuphelele eqenjini lezinyosi. Ngokwesibonelo, nge-heme ene-iron, i-hemoglobin ihlanganisa umoya-mpilo ne-carbon dioxide. Ngenxa ye-nucleoproteins eyakhiwe ngenxa yokusebenzisana kwama-histones, i-protamines ne-DNA noma i-RNA, izinto eziphathekayo ezivikelweyo zivikelwe, ukugcinwa kwayo okuhlangene, ukubopha i-RNA ngesikhathi sokuqala kwamaprotheni. I-nucleoproteins ibizwa ngokuthi izakhiwo eziqinile ezinamaprotheni nama-nucleic acids.

Isiphetho

Ngakho-ke, amaprotheni anamanzi enza imisebenzi eminingi emzimbeni. Ngakho-ke, ukusetshenziswa kwama-micro-microelements kubaluleke kakhulu ekugcineni impilo. Amakhombi ayingxenye yezinhlobo eziningi ze-enzyme. Ukwazi i-biochemistry, impilo yakho kanye nesimo sezemvelo endaweni yakho yokuhlala, ungalungisa ukudla kwakho. Isibonelo, thola izindawo ezingekho kunoma iyiphi into. Ukwengezwa kwalo okungeziwe ekudleni ngesimo sezithasiselo kwenza kube lula ukugcwalisa ukuntuleka.