Inhlangano isakhi amaprotheni amazinga-molecule: isakhiwo yesibili iprotheni

Ngesisekelo isakhiwo amaprotheni proteids yochungechunge polypeptide, futhi i-molecule ye-protein kungase kuhilele izifunda eyodwa, ezimbili noma ngaphezulu. Noma kunjalo, izakhiwo ngokomzimba, begazi futhi amakhemikhali biopolymers zibangelwa jikelele hhayi kuphela isakhiwo sazo sekhemikhali okungase kube "lutho", kodwa futhi ezinye amazinga lenhlangano yezinhlayiya amaprotheni.

Isakhiwo eyinhloko iprotheni kunqunywa qualitative ambalwa acid acid kwengoma. izibopho Peptide ziyisisekelo isakhiwo eyinhloko. Ngokokuqala ngqá lo mbono liphakamisa 1888 A. Ya. Danilevsky, futhi kamuva izinsolo zakhe zazinqamukile kuqinisekiswa synthesis peptides okuyinto eyenziwa E. Fischer. Isakhiwo amaprotheni molecule ngokuningiliziwe uphenyo A. Ya. Danilevskim no E. Fischer. Ngokwalo mbono, amangqamuzana amaprotheni aqukethe inani elikhulu acid acid izinsalela zazo zixhunywe peptide izibopho. amaprotheni-molecule angase abe munye noma ngaphezulu amaketanga polypeptide.

Lapho izakhiwo eyinhloko amaprotheni osetshenziselwa ejenti test chemical kanye enzyme proteolytic. Ngakho, usebenzisa indlela Edman esivumelana kakhulu ukuhlonza acid esibulalayo acid.

Isakhiwo yesibili amaprotheni sikhombisa ukucushwa kwezendawo engqamuzaneni amaprotheni. Kukhona secondary isakhiwo zinhlobo ezilandelayo: i-alpha-Helix, beta-Kuvunguza, collagen Helix. Ososayensi bathole ukuthi isici kakhulu isakhiwo alpha-Helix we peptides.

Isakhiwo yesibili namaprotheni uhlaliseke esebenzisa hydrogen izibopho. Lesi sakamuva kuphakama phakathi ama-athomu ye-hydrogen banamathele i electronegative nitrogen athomu eyodwa peptide isibopho, kanye athomu carbonyl-mpilo kweyesine amino yayo acid, nama-baqondiselwa eduze Kuvunguza. Amandla izibalo zibonisa ukuthi polymerization yalezi amino acid esebenza kahle kakhulu ilungelo-alpha-Helix, okuyinto ekhona amaprotheni bomdabu.

Isakhiwo yesibili iprotheni: beta-ishidi isakhiwo

amaketanga Polypeptide beta-emphethweni kudluliselwa ngokugcwele. Beta-emphethweni akhiwa nokuxhumana izibopho ezimbili peptide. Lesi sakhiwo sici amaprotheni fibrous (yi-keratin, fibroin, njll). Ikakhulukazi, i-beta-yi-keratin elinesimo ilungiselelo okucishe kufane nalokhu polypeptide amaketanga zibuye Ukuzinziswa interchain disulfide izibopho. I usilika fibroin engumakhelwane polypeptide amaketanga kukhona antiparallel.

Isakhiwo yesibili amaprotheni: Helix collagen

Ukwakheka lakhiwe ngemalunga lamatsatfu spiralized tropocollagen amaketanga, okuyinto has simise induku. Spiralized uchungechunge zinyakaze bese bakha superhelix. Helix Ukuzinziswa hydrogen isibopho phakathi hydrogen we peptide okwenzeka amino acid acid ezisalayo kwelinye iketango oxygen leqembu carbonyl ka okuseleyo acid acid lomunye chain. Kwethulwa i-collagen isakhiwo unika amandla okusezingeni eliphezulu futhi kuyaqina.

Isakhiwo ephakeme amaprotheni

amaprotheni kakhulu e isimo bomdabu kukhona isakhiwo icwecwe kakhulu, okuyinto kunqunywa ijamo, ubungako, futhi polarity we ezizivelelayo acid acid, nama-amino acid ukulandelana.

A elikhulu kumiswa bomdabu amaprotheni conformation, noma izakhiwo ephakeme kufanele ekusebenzisaneni hydrophobic futhi ionic, i-hydrogen amabhondi, njll .. Ngaphansi isenzo awo acekela kufinyelelwa conformation thermodynamically kunilungele engqamuzaneni protein ne kuqiniswa yayo.

Isakhiwo quaternary

Lolu hlobo isakhiwo engqamuzaneni kuwumphumela inhlangano subunits eziningana endaweni eyodwa molecule eyinkimbinkimbi. Ukwakheka subunit ngamunye kuhlanganisa izakhiwo lokuqala, lesibili futhi ephakeme.