Pamwamba, mapangidwe a peptide zomangira, kupereka dipeptides, ndi njira yosavuta mankhwala.Izi zikutanthauza kuti zigawo ziwiri za amino acid zimalumikizidwa ndi chomangira cha peptide, chomangira cha amide, pomwe chikusowa madzi.
Mapangidwe a Peptide ndi kuyambitsa kwa amino acid pansi pamikhalidwe yofatsa.(A) carboxyl moiety, second amino acid (B) nucleophilic activated carboxyl moiety ndiye amapanga dipeptide (AB)."Ngati gawo la carboxyl (A) silitetezedwa, mapangidwe a peptide sangawongoleredwe."Zogulitsa monga linear ndi cyclic peptides zitha kusakanikirana ndi chandamale AB.Chifukwa chake, magulu onse ogwira ntchito omwe satenga nawo gawo pakupanga ma peptide amayenera kutetezedwa mwanjira yosinthika kwakanthawi panthawi ya peptide synthesis.
Chifukwa chake, kaphatikizidwe ka peptide - kupangidwa kwa chomangira chilichonse cha peptide - kumaphatikizapo magawo atatu ophatikiza.
Gawo loyamba ndikukonzekera ma amino acid omwe amafunikira chitetezo, ndipo kapangidwe ka zwitterionic ka amino acid kulibenso.
Gawo lachiwiri ndikuchita kwa magawo awiri kuti apange zomangira za peptide, momwe gulu la carboxyl la N-protected amino acid limayamba kutsegulidwa kuti likhale lapakati ndiyeno mgwirizano wa peptide umapangidwa.Zophatikizidwira izi zitha kuchitika ngati njira imodzi kapena ziwiri zotsatizana.
Gawo lachitatu ndikuchotsa kosankha kapena kuchotsa kwathunthu maziko oteteza.Ngakhale kuchotsedwa konse kumatha kuchitika pambuyo poti maunyolo onse a peptide atasonkhanitsidwa, kusankha kosankha magulu oteteza kumafunikanso kuti apitilize kaphatikizidwe ka peptide.
Chifukwa ma amino acid 10 (Ser, Thr, Tyr, Asp, Glu, Lys, Arg, His, Sec ndi Cys) ali ndi magulu ogwirira ntchito am'mbali, omwe amafunikira chitetezo chosankhidwa, kupangitsa kaphatikizidwe ka peptide kukhala kovuta.Maziko osakhalitsa komanso osakhalitsa akuyenera kuzindikirika chifukwa cha zofunikira zosiyanasiyana pakusankha.Magulu oteteza kwakanthawi amagwiritsidwa ntchito mu gawo lotsatira kuwonetsa chitetezo kwakanthawi cha amino acid kapena magulu a carboxyl.Magulu oteteza osakhazikika amachotsedwa popanda kusokoneza zomangira za peptide zomwe zidapangidwa kale kapena unyolo wambali wa amino acid, nthawi zina pakuphatikiza.
"Choyenera, kutsegula kwa gawo la carboxyl ndikupangidwanso kwa ma peptide bond (kulumikizana kogwirizana) kuyenera kukhala kofulumira, popanda kupangika kapena kupangidwa ndi zinthu, ndipo ma molar reactants ayenera kugwiritsidwa ntchito kuti apeze zokolola zambiri."Tsoka ilo, palibe njira imodzi yolumikizira mankhwala yomwe imakwaniritsa zofunikirazi, ndipo zochepa ndizoyenera kuphatikizika kothandiza.
Pa kaphatikizidwe ka peptide, magulu ogwira ntchito omwe amakhudzidwa ndi machitidwe osiyanasiyana nthawi zambiri amalumikizidwa ndi malo opangira, glycine ndiye yekhayo, ndipo pali chiopsezo chozungulira.
Gawo lomaliza la peptide synthesis cycle ndikuchotsa magulu onse oteteza.Kuchotsa kosankhidwa kwa magulu oteteza ndikofunikira pakukulitsa unyolo wa peptide kuphatikiza pakufunika kochotsa kwathunthu chitetezo pamaphatikizidwe a dipeptide.Njira zopangira zimayenera kukonzedwa bwino.Kutengera kusankha kwanzeru, N imatha kusankha magulu oteteza α-amino kapena carboxyl.Mawu oti "ndondomeko" amatanthauza kutsatizana kwa ma condensation amino acid.Kawirikawiri, pali kusiyana pakati pa kaphatikizidwe pang'onopang'ono ndi fragment condensation.Peptide synthesis (yomwe imadziwikanso kuti "conventional synthesis") imachitika munjira.Nthawi zambiri, kutalika kwapang'onopang'ono kwa unyolo wa peptide kumatha kupangidwa pogwiritsa ntchito unyolo wa peptide kupanga zidutswa zazifupi.Kuti apange ma peptide ataliatali, mamolekyu omwe akuwatsata ayenera kugawidwa m'zidutswa zoyenera ndikutsimikiza kuti atha kuchepetsa kuchuluka kwa kusiyanitsa pa C terminus.Zidutswa zamtundu uliwonse zikasonkhanitsidwa pang'onopang'ono, gawo lomwe mukufuna lidzalumikizidwa.Njira ya kaphatikizidwe ka peptide imaphatikizapo kusankha kwachidutswa chabwino kwambiri komanso choyenera kwambiri chotetezera, ndipo njira ya kaphatikizidwe ka peptide imaphatikizapo kusankha koyenera kwambiri kwazitsulo zotetezera komanso njira yabwino kwambiri yolumikizira fragment.
Nthawi yotumiza: Jul-19-2023