Lub luag haujlwm ntawm kev tiv thaiv cov pab pawg yog qhov tseem ceeb hauv peptide thiab nucleic acid synthesis, tshwj xeeb tshaj yog nyob rau hauv synthesis ntawm complex molecules xws li peptide nucleic acids (PNA). PNA yog DNA analogue nrog peptide zoo li cov pob txha caj qaum, uas nws lub pob txha loj yog tsim los ntawm N (2-aminoethyl) - glycine thiab nucleic acid bases txuas nrog methylene carbonyl pawg. Hauv cov txheej txheem synthesis ntawm PNA, kev siv cov pab pawg tiv thaiv yog los tiv thaiv cov pab pawg ua haujlwm tshwj xeeb, tiv thaiv lawv los ntawm kev noj cov tshuaj tsis tsim nyog, thiab xyuas kom muaj txiaj ntsig zoo thiab ua kom huv ntawm lub hom phiaj molecules.
Kev xaiv thiab kev ua haujlwm ntawm Cov Kev Tiv Thaiv Kev Tiv Thaiv
Tiv thaiv cov amino acids: Hauv kev sib txuas ntawm PNA, cov pab pawg guanidine ntawm arginine muaj zog nucleophilicity thiab alkalinity, thiab yuav tsum tau tiv thaiv kom tsis txhob raug tshem tawm nyob rau hauv acidic thiab alkaline tej yam kev mob. Cov pab pawg tiv thaiv muaj xws li tert butoxycarbonyl, nitro, toluenesulfonyl, trifluoroacetyl, benzyloxyformyl, thiab lwm yam. Piv txwv li, pawg guanidine ntawm arginine tuaj yeem tiv thaiv nrog bis allyl carbonyl thiab thaum kawg tshem tawm siv palladium catalysis.
Tiv thaiv pawg carboxyl: Carboxyl pawg hauv peptide chains kuj yuav xav tau kev tiv thaiv los tiv thaiv lawv los ntawm kev koom tes hauv kev tsis txaus siab. Piv txwv li, nyob rau hauv synthesis ntawm ILE Glu (- pip), cov amino pawg ntawm ILE yog tiv thaiv los ntawm FMOC, thaum lub carboxyl pawg ntawm GLU yog tiv thaiv los ntawm TBU.
Tiv thaiv chromophore: p-nitroaniline (chromophore hauv PNA) muaj cov nucleophilicity tsis zoo vim muaj zog electron tshem tawm cov nyhuv ntawm nitro pawg, ua rau nws nyuaj rau kev txuas mus rau cov amino acids los ntawm txoj kev amide condensation. Hauv qhov kev tsim kho tam sim no, qhov teeb meem ntawm kev sib txuas p-nitroaniline yog daws los ntawm thawj zaug txuas p-phenylenediamine rau cov amino acid thiab tom qab ntawd oxidizing nws. Txoj kev no yog ib puag ncig zoo, nyab xeeb, thiab muaj txiaj ntsig ntau dua.