Dusha sare, samaynta bonds peptide, soo saarida dipeptides, waa habka kiimikada fudud.Tani waxay ka dhigan tahay in labada qaybood ee amino acid ay ku xiran yihiin bond peptide, bond amide, halka fuuqbaxa.
Samaynta dammaanadda Peptide waa firfircoonida asiidhka amino-ka hoos yimaada xaaladaha falcelinta fudud.(A) moiety carboxyl, amino acid labaad (B) Nucleophilic activated carboxyl moiety ka dib waxay sameeyaan dipeptide (AB)."Haddii qaybta karboksylka (A) aan la ilaalin, samaynta curaarta peptide lama xakamayn karo."Alaabooyinka ay ka midka yihiin peptides linear iyo cyclic peptides waxaa lagu qasi karaa xeryahooda bartilmaameedka ah AB.Sidaa darteed, dhammaan kooxaha shaqeeya ee aan ku lug lahayn samaynta curaarta peptide waa in lagu ilaaliyaa si ku meel gaar ah loo rogi karo inta lagu jiro isku dhafka peptide.
Sidaa darteed, isku-dhafka peptide - samaynta curaarta peptide kasta - waxay ku lug leedahay saddex tallaabo oo isku-dar ah.
Tallaabada ugu horreysa waa in la diyaariyo qaar ka mid ah asiidhyada amino ee u baahan ilaalin, iyo qaabka zwitterionic ee acids amino hadda ma jiro.
Talaabada labaad waa falcelin laba-tallaabo ah si loo sameeyo bonds peptide, kaas oo kooxda karboxyl ee amino acid N-ilaalinta ayaa marka hore loo hawlgeliyay dhexdhexaadiyaha firfircoon ka dibna isku-dhafka peptide ayaa la sameeyay.Falcelintan la isku daray waxay u dhici kartaa mid hal-tallaabo ah ama laba falcelin oo xidhiidhsan.
Talaabada saddexaad waa ka saarista xulashada ama ka saarida dhamaystiran ee saldhiga ilaalinta.Inkasta oo dhammaan saarista ay dhici karto oo kaliya ka dib marka dhammaan silsiladaha peptide-ka la isku keeno, ka saarista xulashada kooxaha ilaalinta ayaa sidoo kale loo baahan yahay si loo sii wado isku-dhafka peptide.
Sababtoo ah 10 amino acids (Ser, Thr, Tyr, Asp, Glu, Lys, Arg, His, Sec iyo Cys) waxay ka kooban yihiin kooxo hawleed silsilad dhinac ah, kuwaas oo u baahan ilaalin doorasho ah, taasoo ka dhigaysa isku-dhafka peptide mid aad u adag.Saldhigyada ilaalinta ku meel gaadhka ah iyo kuwa badh-joogta ah waa in la kala saaraa sababtoo ah shuruudaha kala duwan ee xulashada.Kooxaha ilaalinta ku meel gaadhka ah ayaa loo isticmaalaa tallaabada xigta si ay u muujiyaan ilaalinta ku meel gaadhka ah ee amino acid ama kooxaha shaqaynaysa karboksyl.Kooxaha difaaca ee nus-joogta ah ayaa la saaraa iyada oo aan la faragelinin xidhmooyinka peptide-ka ee hore loo sameeyay ama silsiladaha dhinaca amino acid, mararka qaarkood inta lagu jiro isku-dhafka.
"Fikrad ahaan, kicinta qaybta karboksylka iyo samaynta soo socota ee bonds peptide (falcelinta isku-xidhka) waa inay ahaato mid degdeg ah, iyada oo aan la helin midab-jinsi ama wax-soo-saarka, iyo fal-celinta molar-ka waa in lagu dabaqaa si loo gaaro wax-soo-saar sare."Nasiib darro, mid ka mid ah hababka isku-xidhka kiimikada midkoodna ma qancin shuruudahan, qaar yarna waxay ku habboon yihiin isku-dubarid wax ku ool ah.
Inta lagu jiro isku-darka peptide, kooxaha shaqeynaya ee ku lug leh fal-celinno kala duwan ayaa inta badan ku xiran xarunta buug-gacmeedka, glycine waa ka kaliya ee ka reeban, waxaana jira khatar suurtagal ah oo wareeg ah.
Tallaabada ugu dambeysa ee wareegga isku-dhafka peptide waa ka saarida dhammaan kooxaha difaaca.Ka saarista xulashada kooxaha ilaalinta ayaa muhiim u ah kordhinta silsiladda peptide marka lagu daro shuruudaha si buuxda looga saaro ilaalinta isku-dhafka dipeptide.Xeeladaha synthetic waa in si taxadar leh loo qorsheeyo.Iyadoo ku xiran doorashada istaraatiijiga ah, N waxay si xushmad leh uga saari kartaa α-amino ama kooxaha ilaalinta karboksylka.Erayga “istaraatijiyad” waxa ay tilmaamaysaa isku xigxiga falcelinta uumiga ee amino acids-ka.Guud ahaan, waxaa jira farqi u dhexeeya isku-dhafka tartiib-tartiib ah iyo uumiga jajabka.Isku-dhafka Peptide (sidoo kale loo yaqaan "synthesis dhaqameed") ayaa ku dhaca xal.Inta badan, si tartiib tartiib ah u dheereynta silsiladda peptide-ka waxaa lagu soo saari karaa oo keliya iyadoo la isticmaalayo silsiladda peptide si loo soo saaro jajabyo gaaban.Si loo soo saaro peptides dheer, molecules bartilmaameedka waa in loo kala qaybiyaa jajabyo ku habboon oo la go'aamiyo inay yareyn karaan heerka kala duwanaanshaha C terminus.Ka dib markii jajabyada gaarka ah si tartiib tartiib ah la isu keeno, xarunta bartilmaameedka ayaa la isku dari doonaa.Istaraatiijiyada isku-dhafka peptide-ka waxaa ka mid ah xulashada qaybta ugu fiican ee ugu habboon ee ilaalinta, iyo istaraatiijiyada isku-dhafka peptide waxaa ka mid ah xulashada isku-dhafka ugu habboon ee saldhigyada ilaalinta iyo habka ugu wanaagsan ee isku-dhafka jajabka.
Waqtiga boostada: Jul-19-2023