Isakhiwo sePrayimari

Isakhiwo seprotheni sinokumelwa ngenye yeendlela ezine. Ukuhlukahluka ngalunye kunokwakhe okukhethileyo. Ngoko ke, kukho isakhiwo seprotheni esine-quaternary, i-ternary, yesibini kunye nesiseko.

Inqanaba lokugqibela kuloluhlu luluhlu lwe-polypeptide eline-amino acid. Ama-acino amino axhunyelelana ngamabhondi e-peptide. Isakhiwo esiyinhloko seprotheni yinqanaba elilula kakhulu lombutho we-molecule. Ngokusetyenziswa kwee-peptide bonds phakathi kweqela le-alpha-amino kwelinye i-amino acid kunye neqela le-alpha-carboxyl kwelinye, ukuzinza okuphezulu kwemolekyu kunikezelwa.

Xa izibophelelo zeep peptide zenziwe kwiiseli, iqela le-carboxyl liqale lenziwe. Emva koko, kukho uqhagamshelo neqela le-amino. Ngokufanayo, i-polypeptide laboratory synthesis isenziwa.

Isibophelelo sep peptide, esiyiqhekeza esiphindayo sekholethi ye-polypeptide, sinempawu ezininzi. Ngaphantsi kweempembelelo zezi mpawu, kungekhona kuphela isakhiwo esiyinhloko seprotheni esakhiweyo. Ziyakuchaphazela amanqanaba aphakamileyo asemgangathweni yeketythi ye polypeptide. Phakathi kwezinto ezibalaseleyo ezibonakalayo yi-coplanarity (ubuchule bee-athomu zonke ezifaka iqela leep peptide ukuba liye kwindiza efanayo), ukuguqulwa kwamalungu athile ngokumalunga noxanduva lwe-C-N, ipropati ibekho kwiifom ze-resonance ezi-2. Iimpawu ezithile ze-peptide bonding ziquka ukukwazi ukwenza iimbophezelo ze-hydrogen. Kule meko, kwiqela ngalinye leep peptide, iimbumba ezimbini ze-hydrogen zingenziwa namanye amaqela (i-peptide equka). Nangona kunjalo, kukho ukungabikho. Ezi ziquka ama-peptide ngamaqela amino ama-hydroxyproline okanye i-proline. Bangakwazi ukudala kuphela isibophelelo esisodwa se-hydrogen. Oku kunempembelelo ekwakheni isakhiwo seprotheni yesibini. Ngoko, kwindawo apho i-hydroxyproline okanye i-proline itholakala khona, ikhonksi yep peptidi ilula, ngenxa yokuba akukho nxalenye yesibini ye-hydrogen eya kubamba (njengesiqhelo).

Igama lamapheptidi lenziwa ngamagama amino acids afakwe kuwo. I-dipeptide ivelisa ezimbini i-amino acid, i-tripeptide yintathu, i-tetrapeptide enye, njalo njalo. I-polypeptide chain (okanye peptide) nayiphi na ubude iqukethe i-N-terminal i-amino acid apho iqela le-amino likhululekile kunye ne-C-terminal i-amino acid apho iqela le-carboxyl likhulu.

Iipropati zeeprotheni.

Xa ufunda ezi zinto zenziwe, izazinzulu zazinomdla kwimibandela emininzi. Abaphandi, okokuqala, bafuna ukugqiba ubungakanani, bazimisele ukuma nomlinganiselo wee-molecule zamaphrotheni. Kufuneka kuqatshelwe ukuba ezi zinto zinzima kakhulu. Ubunzima bokuthi akunakwenzeka ukucacisa isisombululo sesilinganisi se- molecular ngokunyusa isiphumo sebhanti seeprotheni (njengoko kwenziwa ngezinye izinto), ekubeni izixazululo zeprotheni azikwazi ukupheka. Inkcazo yesalathisi ngokuhambelana nokunciphisa iphuzu lokuqandisa liphumela kwiziphumo ezingalunganga. Ukongezelela, iiprotheyini ngendlela engcolileyo ayikho. Nangona kunjalo, ngoncedo lweendlela eziphuhlisiwe zenziwe ukuba i- molecular molecular varies between 14 and 45 thousand and more.

Esinye seziganeko ezibalulekileyo ze-compounds yi-salting fractional out. Le nkqubo yodwa yodwa iiprotheni kwisisombululo emva kokufakelwa kwezisombululo ze-brine ngeengcamango ezahlukeneyo.

Olunye uphawu olubalulekileyo luyi-denaturation. Le nqubo iyenzeka xa iiprotheni zinyanzeliswa ngezinyithi ezinzima. I-Denaturation yilahleko yendalo. Le nqubo ibandakanya ukuguqulwa kohlu lwe-molecule, ngaphandle kwephulo le-polypeptide chain. Ngamanye amazwi, isakhiwo esiphambili seprotheni asiguqukanga ngexesha lokutshatyalaliswa.