Kev cuam tshuam ntawm cov kuab tshuaj rau ntawm solubility ntawm peptides
Lub solubility ntawm peptides cuam tshuam los ntawm lawv cov amino acid muaj pes tsawg leeg. Hydrophobic amino acids xws li leucine (Leu), isoleucine (Ile), thiab valine (Val) ua peptides hydrophobic, thaum hydrophilic amino acids xws li lysine (Lys), histidine (Nws), arginine (Arg) ua peptides hydrophilic. Yog li, peptides sib txawv muaj qhov sib txawv ntawm qhov sib txawv vim lawv qhov sib txawv sib txawv.
Cov nyhuv ntawm cov kuab tshuaj ntawm peptide stability
Cov tshuaj tiv thaiv deamidation
Hauv cov tshuaj tiv thaiv deamidation, hydrolysis ntawm asparagine (Asn) thiab glutamine (Gln) residues tsim aspartic acid (Asp) thiab glutamic acid (Glu). Cov tshuaj tiv thaiv no tuaj yeem cuam tshuam rau kev ruaj ntseg ntawm peptides.
Oxidation
Peptide cov kev daws teeb meem yog oxidation, uas tej zaum yuav yog vim peroxide paug nyob rau hauv cov tshuaj los yog spontaneous oxidation ntawm peptide nws tus kheej. Oxidation tsis tsuas yog cuam tshuam rau cov qauv ntawm peptides, tab sis kuj tseem tuaj yeem ua rau lawv poob haujlwm.
Hydrolysis
Peptide bonds hauv peptides yooj yim hydrolyzed thiab tawg, tshwj xeeb tshaj yog cov tsim los ntawm Asp.
Disulfide daim ntawv cog lus yuam kev
Kev sib pauv ntawm disulfide bonds lossis nruab nrab ntawm disulfide bonds thiab thiol pawg yuav ua rau tsim cov disulfide bonds tsis raug, ua rau muaj kev hloov pauv hauv tertiary qauv thiab poob ntawm kev ua haujlwm.
Cov tshuaj tiv thaiv haiv neeg
Tsuas yog rau glycine (Gly), alpha carbon atoms ntawm tag nrho cov amino acid residues yog chiral thiab nquag muaj racemization tshwm sim nyob rau hauv alkaline catalysis. Ntawm lawv, aspartic acid (Asp) residues feem ntau ua rau muaj kev cuam tshuam racemization.
- tshem tawm
- Kev tshem tawm yog hais txog kev tshem tawm cov pab pawg ua haujlwm ntawm cov pa roj carbon atom hauv cov amino acid residues. Cov tshuaj tiv thaiv no feem ntau tshwm sim ntawm alkaline pH, thiab kub thiab hlau ions kuj muaj feem cuam tshuam rau nws.
Dissolve peptides hauv cov kuab tshuaj ib puag ncig
Thaum dissolving peptides, ib qho me me ntawm N-methylpyrrolidone (DMF) lossis dimethyl sulfoxide (DMSO) tuaj yeem siv los pab ua kom tawg. Ob cov kuab tshuaj no tuaj yeem txhawb kev sib cais los ntawm kev cuam tshuam cov qauv thib ob ntawm peptides. Txawm li cas los xij, nws yuav tsum raug sau tseg tias cov kuab tshuaj no tuaj yeem cuam tshuam rau kev ua haujlwm lom neeg ntawm peptides thiab kev tshawb fawb tom ntej, yog li yuav tsum tau ceev faj thaum siv lawv.
Xaus
Hauv cov ntsiab lus, cov kuab tshuaj zoo ib puag ncig xws li DMF thiab DMSO tuaj yeem pab yaj peptides los ntawm kev cuam tshuam lawv cov qauv theem nrab, tab sis lawv cov kev siv yuav muaj kev cuam tshuam rau cov qauv thiab kev ua haujlwm lom neeg ntawm peptides. Yog li ntawd, thaum xaiv thiab siv cov kuab tshuaj ib puag ncig, nws yog ib qho tsim nyog los ntsuas lawv qhov cuam tshuam ntawm peptide qauv thiab solubility kom ntseeg tau tias kev ruaj ntseg thiab kev ua haujlwm lom neeg ntawm peptides.