Amaphrotheni: lokuphatselene nesakhiwo nemsebenti. izakhiwo amaprotheni

Njengoba yaziwa, amaprotheni - ngesisekelo umsuka eziphilayo eplanethini yethu. Ngokusho imfundiso yokuziphendukela Oparin-Haldane kwaba iconsi coacervate, ehlanganisa ama-molecule peptides, sesiye ngesisekelo imvelaphi yezinto eziphilayo. Akungabazeki ukuthi yilesi ngoba ukuhlaziya isakhiwo sangaphakathi noma yiliphi ilungu biomass ubonisa ukuthi la izinto konke: izitshalo, izilwane, izilokazane ezincane, isikhunta, amagciwane. Futhi zahlukahlukene kakhulu endalweni bese macromolecular.

Amagama la izakhiwo ezine, kuyahambisana:

• amaprotheni;
• amaprotheni;
• polypeptides;
• peptides.

molecule amaprotheni

Inombolo yabo mkhulu kakhulu ngempela. Kulokhu, zonke yezinhlayiya amaprotheni zingahlukaniswa ngamaqembu amabili amakhulu:

• Simple - aqukethe kuphela amino acid ukulandelanisa bajoyine peptide izibopho;
• eziyinkimbinkimbi - Sakhiwo isakhiwo iprotheni zinezikhathi ezengeziwe protolytic (wokufakelwa) amaqembu, obizwa nangokuthi cofactors.

Kulokhu, yezinhlayiya eziyinkimbinkimbi futhi babe ngezigaba zabo.

Ukushiyana kwezidalwa peptides eziyinkimbinkimbi

1. Glycoproteins - zisondelene kakhulu wamaprotheni ne-carbohydrate compounds. Isakhiwo engqamuzaneni nokwelukiweyo amaqembu wokufakelwa mucopolysaccharides.
2. Lipoproteins - ekhuthaza eziyinkimbinkimbi wamaprotheni ne lipid.
3. Metalloproteins - njengeqembu wokufakelwa kukhona ion metal (yensimbi, manganese, ithusi, futhi abanye).
4. Nucleoproteins - Impendulo protein ne acid nucleic (DNA, i-RNA).
5. Fosfoproteidy - conformation amaprotheni kanye ezisalayo of wali band acid.
6. Chromoproteids - okufana kakhulu metalloproteins, kodwa isici uba yingxenye yalelo qembu wokufakelwa kuyinto anemibala eziyinkimbinkimbi (obomvu - elithwala umoya-mpilo, oluhlaza - chlorophyll, nokunye).

Iqembu ngalinye waxoxa isakhiwo nezakhiwo amaprotheni zihlukile. Imisebenzi abawenza, futhi ngeke ifane kuye ngohlobo-molecule.

Isakhiwo amakhemikhali amaprotheni

Kule amaprotheni umbono - eside, uchungechunge omkhulu amino acid izinsalela oxhumene izibopho ezithile okuthiwa peptide. Kusukela side izakhiwo acid suka legatsha - ezizivelelayo. Lesi sakhiwo engqamuzaneni kwatholakala E. Fischer ekuqaleni ngekhulu xxi.

Kamuva, amaphrotheni, lokuphatselene nesakhiwo nemsebenti amaprotheni eziye zahlolisiswa kabanzi. Kwacaca ukuthi ama-amino acid akha isakhiwo peptide, abangu 20, kodwa Ngaleyo ndlela, kungaba ezihlangana ngezindlela ezihlukahlukene. Yingakho ukuhlukahluka polypeptide izakhiwo. Ngaphezu kwalokho, ngo-inqubo ukuphila kanye nokwenziwa kwemisebenzi yayo amaprotheni bayakwazi ibhekane uchungechunge kugucuka zamakhemikhali. Ngenxa yalokho, bayashintsha isakhiwo, futhi kukhona ngempela uhlobo olusha lwe-Inthanethi.

Ukuze aphule isibopho peptide, okungukuthi, ukuphazamisa amaprotheni isakhiwo ngamaketanga kufanele bakhethwe enemibandela kakhulu (okushisa aphakeme, acid noma ane-alikhali kulethe). Lokhu kungenxa amandla okusezingeni eliphezulu izibopho covalent e-molecule, okungukuthi, eqenjini peptide.

Ukuthola isakhiwo amaprotheni endaweni yokucwaninga Kwenziwa usebenzisa ukusabela biuret - nomthelela polypeptide asanda ukugqashuka hydroxide, ithusi (II). Isakhiwo se-peptide iqembu nethusi ion ihlinzeka elikhanyayo violet umbala.

Kukhona inhlangano ezine eziyisisekelo kwesakhiwo, ngamunye ephethe izici zayo siqu isakhiwo amaprotheni.

Amazinga yenhlangano: isakhiwo eyinhloko

Njengoba kushiwo ngenhla, peptide - ukulandelana amino acid izinsalela nge inclusions, co-enzyme, noma ngaphandle kwazo. Ngakho shayela le isakhiwo eyinhloko molecule okwemvelo Yiqiniso, kuba amino acid kweqiniso bajoyine peptide izibopho, futhi akukho okunye. Okungukuthi, isakhiwo polypeptide komugqa. Kulendlela yokubhala ethile amaprotheni yalolu hlobo - kulelo le nhlanganisela acid kubalulekile ekwenzeni imisebenzi engqamuzaneni amaprotheni. Ngenxa yalezi zici kungenzeka hhayi kuphela ukubona peptide kodwa futhi ukubikezela izakhiwo kanye indima entsha ngokuphelele, njengoba okwamanje yokuzamazama. Izibonelo peptides kokuba isakhiwo yemvelo eyinhloko, - insulin, pepsin, chymotrypsin, nabanye.

conformation yesibili

Ukwakheka nezakhiwo amaprotheni kulesi sigaba kuyohlukahluka. isakhiwo esinjalo zingase zimiswe ekuqaleni ubunjalo noma lapho ngaphansi hydrolysis eyinhloko eqinile lokushisa noma ezinye izimo.

Lokhu conformation has izinhlobo ezintathu:

1. Smooth, njalo, ohlobo lwe stereoregular zakhiwa izinsalela acid acid ukuthi okokusonteka emhlabeni eksisi core uxhumano. labetibambile kuphela ndawonye ngu-hydrogen izibopho ezenzeka phakathi umoya-mpilo iqembu elilodwa peptide kanye nezinye hydrogen. Kulokhu-ke isakhiwo ilungile ngenxa yokuthi ematfuba ngokulinganayo kuphindwe njalo 4 ezingeni. isakhiwo esinjalo kungaba kokubili eyinxele futhi pravozakruchennoy. Kodwa amaprotheni owaziwayo kakhulu dextrorotatory evelele isomer. conformation okunjalo kwezinkolo kubizwa ngokuthi i-alpha-izakhiwo.
2. Ukwakheka kanye nesakhiwo uhlobo amaprotheni elandelayo ihlukile omunye yangaphambilini izibopho hydrogen abumane phakathi ecaleni ukuma eceleni ngakolunye uhlangothi lwale okusele engqamuzaneni kanye phakathi kakhulu zisuswe, lapho buqamama ngokwanele ezinkulu. Ngenxa yalesi sizathu, wonke isakhiwo iba inamagquma ngaphezulu, convoluted inyoka polypeptide ngamaketanga. Kukhona esinye isici okufanele abe amaprotheni. Isakhiwo amino acid amagatsha kufanele kube njengoba short njengoba lowo of glycine noma alanine, isibonelo. Lolu hlobo conformation yesibili ibizwa ngokuthi i-beta-amashidi ikhono lazo banamathelane uma kumiswa uhlaka.
3. Ukuba Ngowenkolo eyesithathu uhlobo amaprotheni isakhiwo njengoba biology lisho raznorazbrosannye eziyinkimbinkimbi, babutha izingcezwana eziyizinsalela unordered abangenalo stereoregularity futhi ukwazi ukuguqula isakhiwo ngaphansi kwethonya kwezimo zangaphandle.

Izibonelo amaprotheni kokuba isakhiwo yesibili ngokwemvelo, ayivezi.

zemfundo ephakeme

Lena conformation eyinkimbinkimbi, kokuba igama "globule". Kuyini iprotheni? Isakhiwo kusekelwe isakhiwo sesibili, kodwa wanezela izinhlobo ezintsha kokusebenzisana phakathi kwama-athomu amaqembu, futhi wonke-molecule emphethweni efana, eqondiswa ngakho, yokuthi amaqembu hydrophilic ziye iqondiswe ku globules kanye hydrophobic - out.

Lokhu kuchaza ukukhokhisa engqamuzaneni amaprotheni emanzini colloidal izixazululo. Yiziphi izinhlobo ekuxhumaneni khona

1. Hydrogen izibopho - zihlala zinjalo phakathi izingxenye efanayo e isakhiwo yesibili.
2. I hydrophobic (hydrophilic) nokuxhumana - ziphakame uma ziyoncibilika emanzini polypeptide.
3. Ionic Luhambo - raznozaryazhennymi obakhiwa acid acid izinsalela (olukhulu) amaqembu.
4. Covalent ekuhlanganyeleni - zingase zimiswe phakathi amasayithi athile esidi - molecule cysteine, noma kunalokho, imisila yawo.

Ngakho, ukwakheka kanye nesakhiwo amaprotheni kokuba isakhiwo ephakeme lingachazwa ngokuthi i usongwa ku globules polypeptide ngamaketanga, esaziwa neliqinisayo conformation yayo ngenxa izinhlobo ezahlukene ekuxhumaneni zamakhemikhali. Izibonelo peptides ezifana: fosfoglitseratkenaza, tRNA, alpha-yi-keratin, usilika fibroin, nabanye.

Isakhiwo quaternary

Lena enye yezinto ezinzima kakhulu globules, akha amaprotheni. Sakhiwo umsebenzi amaprotheni of plan onjalo uyazishintshashintsha kakhulu futhi eziqondile.

Kuyini lokhu conformation? Kuyinto ezimbalwa (kwesinye isikhathi eziningi) ka polypeptide ngamaketanga ezinkulu kanye nezincane, okuyinto akhiwa ngayodwana. Kodwa-ke, ngenxa ekusebenzisaneni efanayo esikuhlolile ngoba isakhiwo ephakeme yalezi peptides okokusonteka futhi munye. etholwe Ngakho globules eziyinkimbinkimbi conformational okungenzeka ukuthi aqukethe ama-athomu okusansimbi, amaqembu lipid, futhi ama-carbohydrate. Izibonelo namaprotheni anjenge: DNA polymerase, ugwayi igciwane imvilophi amaprotheni, i-hemoglobin, nabanye.

Zonke izakhiwo peptide esixoxe babe izindlela zabo siqu ukuhlonza endaweni yokucwaninga, esekelwe amathuba samanje usebenzisa chromatography, centrifugation, electron futhi microscopy optical futhi okusezingeni eliphezulu kwikhompyutha ubuchwepheshe.

imisebenzi

Sakhiwo umsebenzi amaprotheni eduze kwehlisa nomunye. Okungukuthi, peptide ngamunye ufeza indima ukuthi uhlukile futhi eziqondile. Kukhona futhi labo abakwaziyo ukwenza ngendlela kwengqamuzana ephilayo, ukuthengiselana eziningana abalulekile. Kodwa kungenziwa kanje ukuveza imisebenzi eyisisekelo yezinhlayiya amaprotheni ezindikimbeni izidalwa:

1. Ukunikeza traffic. eziphilayo elilodwa noma organelles, noma uhlobo oluthile amaseli labo abazokwazi ukunyakaza, ukusikeka, ukunyakaza. Lokhu amaprotheni inikezwa, eziyingxenye isakhiwo sabo apharathasi motor: cilia, flagella, ulwelwesi cytoplasmic. Uma sikhuluma ukungakwazi displacement we amaseli, amaphrotheyini kungase kube nomthelela ukunciphisa yabo (myosin kwemisipha).
2. umsebenzi lokudla okunempilo noma eyisipele. Kuyinto ekuqongeleleni amaprotheni-molecule e oocytes, zemibungu imbewu plant ukuze eminye ukugcwaliswa ulahlekile izakhamzimba. Lapho cleavage we peptides ukukhiqiza ama-amino acid kanye izinto eziphila abakhuthele, okuyizinto ezidingekayo ukuze zikhule kahle yezinto eziphilayo.
3. Umsebenzi amandla. Ngaphandle carbohydrate iphoqa umzimba angakhiqiza namaprotheni. Ngo ukubola 1 g peptide ezikhishwe 17.6 kJ amandla ewusizo ngesimo triphosphate adenosine (ATP), okuyinto esichithwa izinqubo ezibalulekile.
4. Esiginali futhi umsebenzi zokulawula. Siqukethe ekufezeni zokuqapha ngokucophelela izinqubo eziqhubekayo futhi ukudluliswa kwe-amasignali isitokisi izicubu, kuzo emagunyeni, kusukela zakamuva ohlelweni nokunye. Isibonelo esivamile se-insulin, okuyinto akuvunyelwe ilandisa inombolo kwegazi glucose.
5. Yokwamukela umsebenzi. Kwenzeka ngokushintsha conformation we peptide nomunye uhlangothi ulwelwesi nokwenza kube komunye umkhawulo ukwakha kabusha. Uma lokhu kwenzeka futhi ukudluliswa isignali futhi ulwazi oludingekayo. Eziningi zalezi amaprotheni obutholakala ulwelwesi cytoplasmic kwamangqamuzana futhi afeze control esiqinile phezu kwazo zonke izinto ezibonakalayo Ukudlula therethrough. Futhi ukukuxwayisa izinguquko zamakhemikhali ngokomzimba imvelo.
6. Ezokuthutha umsebenzi peptides. It wenziwa feeds amaprotheni Transporter amaprotheni. indima yabo isobala - ethutha molecule abafiselekayo amasayithi nge lokuhlushwa eliphansi ezingxenyeni okusezingeni eliphezulu. Isibonelo esivamile ukuthwala umoya-mpilo ne-carbon dioxide kusukela kwezitho nezicubu we-hemoglobin amaprotheni. Baye izuzwe ukulethwa compounds nge isisindo yamangqamuzana ongaphakeme ngokusebenzisa ulwelwesi esitokisini.
7. Ukwakheka umsebenzi. Enye yezindlela ezibaluleke kakhulu nalezo wenza amaprotheni. Isakhiwo amaseli bese organelles yabo inikezwa peptides. Bafana nama-uzimele ukuchaza ukuma nokwakheka. Ngaphezu kwalokho, nabo abasisekelayo, futhi ushintshe uma kunesidingo. Ngakho-ke, i-ukukhula nokuthuthuka sazo zonke izinto eziphilayo amaprotheni ebalulekile ekudleni. peptides ezinjalo zihlanganisa mithambo ine-elastin, tubulin, collagen actin, nezinye yi-keratin.
8. Umsebenzi okhanda amanye amathuba. Wakhe enza enzyme. Ziningi futhi zihlukahlukene, kodwa ukusheshisa lonke ukushintsha kwamakhemikhali kuhlanganise kwamakhemikhali emzimbeni. Ngaphandle iqhaza kwazo, apula abavamile esiswini bazokwazi inhlabamkhosi kuphela izinsuku ezimbili, kungenzeka bend ngesikhathi esifanayo. Ngaphansi isenzo catalase, peroxidase nezinye enzyme, le nqubo ithatha indawo ngamahora amabili. Ngokuvamile, kuba ngenxa le ndima, amaprotheni anabolism futhi catabolism Kwenziwa, okungukuthi, plastic kanye namandla umzimba.

Iqhaza zokuzivikela

Kunezinhlobo eziningana izinsongo, okuyindawo amaprotheni zenzelwe ukuvikela umzimba.

Okokuqala, amakhemikhali kuhlasela kuhlasimulise reagents, amagesi, ama-molecule izinto spectrum ezahlukene isinyathelo. Peptides bayakwazi ukubandakanya nabo ukusabela zamakhemikhali, ukuguqulela kwifomu engeyona ingozi noma umane zokuyithena.

Okwesibili, usongo ngokomzimba kusuka isilonda - uma amaprotheni fibrinogen ngesikhathi akuyona siguqulelwa fibrin endaweni ukulimala, igazi akusho curdle, futhi kungakho ukuvaleka kuzokwenzeka. Khona-ke, ngokuphambene nalokho, kufanele plasmin peptide uyakwazi ihlule ukusivumela futhi ubuyisele patency bomkhumbi.

Okwesithathu, usongo amasosha omzimba. Sakhiwo ukubaluleka namaprotheni akha khona izivikelo mzimba, kubaluleke kakhulu. Amasosha Omzimba, immunoglobulin, ayisiza, interferon - kukhona zonke izakhi ezibalulekile futhi okuphawulekayo we lymph omzimba. Noma yimuphi izinhlayiya angaphandle, i-molecule enonya, amangqamuzana afile noma ingxenye isakhiwo sonke is phansi uphenyo ngokushesha by kwakwakhe peptide. Yingakho umuntu kungaba ngumnikazi, ngaphandle kokusebenzisa imithi nsuku zonke ukuze bazivikele ezifweni futhi amagciwane elula.

izakhiwo

Isakhiwo amaseli amaprotheni ethize kakhulu futhi kuncike umsebenzi. Kodwa Izakhiwo zanoma peptides zifana futhi zingancishiswa izici ezilandelayo.

1. Isisindo molecule - ukuze 1000000 Daltons.
2. Ngo isixazululo aqueous yakha uhlelo colloidal. Kube isakhiwo litholwa ukushaja uyakwazi iyashiyana asidi of the medium.
3. Lapho wadalula izimo ezinzima (kwemisebe, acid noma alikhali, izinga lokushisa, njll) ayakwazi ukuthuthela kwamanye amazinga conformations, isb denature. Inqubo e-90% amacala engelapheki. Nokho, kukhona shift reverse - renaturation.

Lokhu izakhiwo eziyisisekelo nezici zabo ezingokomzimba peptides.