Cov pab pawg tiv thaiv rau cov amino acid raw khoom rau polypeptide synthesis
amino acid tiv thaiv pawg
20 Cov amino acids feem ntau tuaj yeem muab faib ua ntau pawg raws li lawv cov saw saw: Aliphatic amino acids (Ala, Gly, Val, Leu, Ile), Aromatic amino acids (Phe, Tyr, Trp, His), Amide los yog carboxyl side chain amino acid (Asp, Glu, Asn, Gln), Basic side chain amino acids (Lysconsur) (Cys, Met), Cawv-muaj cov amino acids (Ser, Thr), Imino acid (Pro).
Kev tiv thaiv ntawm cov amino acids nyob rau hauv cov tshuaj synthesis ntawm peptides yog ib qho tseem ceeb heev thiab ncaj qha txiav txim qhov ua tau zoo ntawm cov synthesis. Vim hais tias ntau ntawm 20 hom amino acids muaj active sab chains thiab yuav tsum tau kev tiv thaiv, nws yog feem ntau yuav tsum tau kom cov pab pawg neeg tiv thaiv yog ruaj khov nyob rau hauv lub synthesis txheej txheem, tsis muaj ib tug sab kev xav, thiab yuav tsum tau tag nrho thiab ntau npaum li cas tom qab lub synthesis tiav. Amino acids uas xav tau kev tiv thaiv thaum lub sij hawm synthesis muaj xws li: Cys, Asp, Glu, Nws, Lys, Asn, Gln, Arg, Ser, Thr, Trp, Tyr. Cov pab pawg uas xav tau kev tiv thaiv: Hydroxyl, carboxyl, mercapto, amino, amide, guanidine, indole, imidazole, thiab lwm yam.
Hauv Trp Tsis tas yuav tiv thaiv nws vim tias indole yog qhov ruaj khov hauv qhov xwm txheej. Tau kawg, nyob rau hauv cov xwm txheej tshwj xeeb, qee cov amino acids yuav tsis tiv thaiv, xws li Asn, Gln, Thr, Tyr.
Table 1 Peb tej yam kev mob rau deamination ntawm cov amino pawg
| TFA | HBr/TFA | H2/Pd-C | Piperidine / DMF | |
| Boc | y | y | n | n |
| Z | n | y | y | n |
| Fmoc | n | y | n | y |
Daim duab 1 Peb hom amino tiv thaiv pawg qauv
Muaj ntau pab pawg tiv thaiv rau cov amino acid sab chains. Tib sab saw muaj ntau ntau pab pawg tiv thaiv, uas tuaj yeem xaiv tau tshem tawm raws li cov xwm txheej sib txawv. Qhov no yog qhov tseem ceeb hauv kev hloov pauv ntawm cyclic peptides thiab polypeptides. Ntxiv mus, sab saw tiv thaiv pab pawg yog ze ze rau txoj kev xaiv synthesis. Cov theem ua kua thiab cov theem khoom sib txawv. Hauv theem khoom BOC thiab FMOC Cov tswv yim kuj txawv. Hauv kev nkag siab, peptide chemistry yog kev siv tau yooj yim thiab ua ke ntawm cov amino acid tiv thaiv pawg. Hais txog kev siv cov saw tiv thaiv sab nraud, thov xa mus rau Wang Dexin's "Solid Phase Organic Synthesis" -- "Cov Ntsiab Cai thiab Daim Ntawv Thov" Tshooj 4, peb feem ntau qhia ntawm no Cys, Lys, Asp Ob peb pab pawg tiv thaiv thiab lawv txoj kev tshem tawm. Cys Muaj peb pawg tiv thaiv ntau tshaj plaws: Trt, Acm, Mob, Peb pawg tiv thaiv no tuaj yeem ua tiav cov synthesis ntawm polypeptides nrog ntau khub ntawm disulfide bonds.
Lys Cov pab pawg tiv thaiv feem ntau yog: Boc, Fmoc, Trt, Dde, Allyl, Qhov no muab ntau lub tswv yim tiv thaiv orthogonal rau cov khoom sib xyaw ua ke - theem ntawm cyclic peptides. Asp Cov pab pawg tiv thaiv feem ntau yog: Otbu, OBzl, OMe, OAll, OFm, Muaj ntau hom kev tiv thaiv orthogonal kuj tau muab.
Table 2 Cov pab pawg tiv thaiv feem ntau rau pawg thiol
| luv luv | qauv | Kev cais tawm |
| Trt |  |
TFA, HCl/HOAc, I2/MeOH |
| Acm |  |
I2/MeOH, Hg2+ |
| Mob |  |
HF, TFMSA, Hg2+ |
Table 3 Cov pab pawg tiv thaiv zoo rau cov amino pawg
| luv luv | qauv | Kev cais tawm |
| Trt |  |
TFA, HOAc, HCOOH |
| Boc |  |
HCl/HOAc, TFA/DCM |
| Fmoc |  |
Pip/DMF, NaOH/MeOH |
| Dde |  |
H2NNH2/DMF |
| Allyl |  |
Pd (Ph3P)4, Morpholine / THF |
Table 3 Cov pab pawg tiv thaiv feem ntau rau pawg carboxyl
| luv luv | qauv | Kev cais tawm |
| Otbu |  |
TFA, HOAc, HCOOH |
| OBzl |  |
H2/Pd, HF, TFMSA |
| OMe |  |
NaOH/MeOH |
| OAll |  |
Pd(Ph3P)4, Morpholine /THF |
| OFm |  |
Pip / DMF, DBU / DMF |