Amazinga yenhlangano kwesakhiwo yezinhlayiya amaprotheni noma isakhiwo amaprotheni

Isakhiwo engqamuzaneni amaprotheni lafundvwako iminyaka engaphezu kuka-200. Yena waziwa amaprotheni amaningi. Ezinye zazo ziye kwemiqondo (isib insulini, RNase). Uhlelo oluyisisekelo oluthi iyunithi kwesakhiwo obusebenzayo amaprotheni molecule kusukela ama-amino acid. Ngaphezu kwalokho i-carboxyl nama-amino amaqembu namaprotheni aqukethe namanye amaqembu ukusebenza, okuyinto ukunquma nezici zabo. amaqembu okunjalo kuhlanganisa ibekwa lateral branchings amaprotheni-molecule: iqembu carboxy ka aspartic acid noma glutamic acid, acid iqembu lysine noma hydroxylysine, guanidine iqembu arginine, iqembu imidazole ka histidine, iqembu hydroxyl ka noSerine futhi threonine, iqembu phenol ka tyrosine, iqembu sulfhydryl ka cysteine, disulfide iqembu cystine, thioether iqembu methionine, phenylalanine benzelnoe core, amaketanga aliphatic ezinye amino acid.

Zikhona amazinga amane yenhlangano kwesakhiwo yezinhlayiya amaprotheni.

Isakhiwo eyinhloko amaprotheni. amino acid e-molecule amaprotheni nempumalanga kuhlangane ngu peptide izibopho, kanjalo zakha isakhiwo eyinhloko. It kuncike Ukwakheka qualitative we amino acid, inombolo yabo kanye ukulandelana phakathi compounds. Isakhiwo eyinhloko amaprotheni avame kunqunywa Sanger. I amaprotheni test iphathwa nge ditroftorbenzola isixazululo (DNP), ngaleyo ndlela ukwakha dinitrophenyl-amaprotheni (amaprotheni-DNP). amaprotheni Ngemva kwalokho DNP-hydrolyzed kwakhiwa ezisalayo amaprotheni-molecule futhi DNP-amino acid. DNP-amino acid is yasanguluka kulesi ngxube hydrolysis ezingalinganiseka. Imikhiqizo ka hydrolysis kuthiwa amino acid kanye dinitrobenzene. Okusele kwe-molecule amaprotheni ukuxubana izingxenye entsha DNP nje yonke i-molecule akusho sokudiliza ku-amino acid. Ngokwalolu cwaningo ambalwa amino acid akha isakhiwo eyinhloko ngabanye amaprotheni wesifunda. Akwaziwa isakhiwo eyinhloko amaprotheni-insulin, myoglobin, i-hemoglobin, glucagon nabanye abaningi).

Ngu indlela Edman amaprotheni ziphathwe phenyl isothiocyanate. Ngezinye izikhathi usebenzisa enzyme proteolytic - trypsin, pepsin, chymotrypsin, peptidase, njll

Isakhiwo yesibili amaprotheni. ososayensi American, usebenzisa-X-ray ukuhlaziywa, wathola ukuthi ngokuvamile amaketanga amaprotheni polypeptide khona ngesimo-alpha-helices futhi izakhiwo ngezinye izikhathi beta.

Alpha-Helix uqhathaniswa ezitebhisini Kuvunguza, okuyinto enze umsebenzi we-degree amino acid izinsalela. Ngo-molecule fibrillar amaprotheni (kasilika fibroin) polypeptide uchungechunge sisalokhu cishe ngokuphelele (i-beta-isakhiwo) futhi wahlela ngesimo sphere, Ukuzinziswa hydrogen izibopho.

zingase zimiswe Alpha-Helix angesabi ku polypeptides zokwenziwa (dederon, inayiloni), ezithinta isisindo yamangqamuzana kusuka 10 kuya kwezingu-20. Yebo. Ngezinye izingxenye ezithile namaprotheni-molecule (insulin, i-hemoglobin, RNAse) ephula alpha Helical ukucushwa kwe iketango peptide, futhi akhiwa isakhiwo Helical lomunye hlobo.

Isakhiwo ephakeme amaprotheni. izingxenye Kuvunguza yochungechunge polypeptide engqamuzaneni amaprotheni ku ubudlelwano ezahlukene enquma ephakeme (ngakuthathu) isakhiwo, ifomu ukuma ivolumu engqamuzaneni amaprotheni. Kukholakala ukuthi isakhiwo neliphezulu othomathikhi bese kwenzeka ngenxa ukusebenzisana acid acid izinsalela yezinhlayiya kuphela. ezizivelelayo Ngakho hydrophobic 'wawuthathelwe "engqamuzaneni amaprotheni, ukwakha indawo yabo yomile namaqembu hydrophilic kuthambekele ekwenzeni kuphela, okuholela kwetinhlavu bazisa evumayo iziqinisekiso-molecule. Le nqubo ibizwa ephelezelwa ukwakheka izibopho intramolecular. Isakhiwo ephakeme engqamuzaneni amaprotheni eloba ngoba RNAse, i-hemoglobin, lysozyme amaqanda inkukhu.

Isakhiwo quaternary amaprotheni. Lolu hlobo isakhiwo engqamuzaneni amaprotheni kwenzeka ngenxa yokuzihlanganisa nabanye subunits eziningana bafakwe ingqamuzana elilodwa. subunit ngalinye likwazi isakhiwo lokuqala, lesibili futhi ephakeme.