Solid Phase Synthesis And Bioactivity Of Biopeptide

The technology of solid phase peptide synthesis (SPPS) is attaching theC-terminal amino acid of peptide chain to the solid phase supports first, andadding amino acids from N-termina one by one. Since1963, the famousbiochemist Merrifield published his first article that synthesis four peptides withsolid resin as supporter, after about50years of development and improvement,solid phase peptide synthesis became the most popular of peptide synthesistechniques because its convenient, fast, and automation. However, there are manyissues, such as how to reduce the cost, the toxicity of solid phase synthesisreagents, interference of byproduct, and improve the efficiency and productivityof peptide synthesis.The research synthesized VR-6and LS-7series are bioactive peptide whichscreened by bioinformatics (the sequence were provided by tutor, and can’tpublic because patent application protection). VR-6and LS-7had inhibitoryeffect on cancer cells by bioinformatics prediction.The connection rate of resin and the first amino acid determined the finalyield of target peptide chain.Resins, amino acids, Dicyclohexylcarbodiimide(DCC), HOBt (Hydroxybenzotriazole) and DMAP (Dimethylaminopyridine) werethe key raw material for solid phase synthesis. The research divided them intothree factors, and designed orthogonal experiment to obtain the best mixture ratioof connection rate of resin and the first amino acid. In the orthogonal experiment,resin was fixed to1eq (0.2mmol, a unit of measurement), amino acids and DCCas factor one, HOBt as factor two, DMAP as factor three, and each factor hasthree levels(the levels of factor one and factor two are2eq,3eq,4eq, the levelsof factor three are0.3eq,0.4eq,0.5eq). Finally, the research analysised theorthogonal experiment data, obtein the best mixture ratio of connection rate,accounted the cost of each mixture ratio, compare and figure out the optimalconditions. Then, the research use the optimal conditions to synthesis thebioactive peptide (VR-6, LS-7), and verify its activity. Take synthetic VR-6for example, the results showed that the yield (80.58%)of optimum synthesis in this research increased about5points of percentagecompare with the common ways of high-yield (74.58%), and significantly reducethe cost of synthesis.MTT method was used to determine the activity of synthetic peptide, theresults showed that VR-6and LS-7had obvious inhibitory effect on hepatomacells HepG2and gastric cancer cell SGC7901. The hightest inhibition rate ofVR-6on hepatoma cells and gastric cancer cell were10μmol respectively. Thehightest inhibition rate of LS-7on hepatoma cells and gastric cancer cell were10μmol.