Solid Phase Peptide Synthesis of Same Amino Acid Based Sequence
Disciplines
Biochemistry | Organic Chemistry
Abstract (300 words maximum)
Solid phase peptide synthesis (SPSS) and Boc/Fmoc orthogonal protecting strategy promoted the rapid synthesis of larger and challenging peptides. Moreover, this method opened a new avenue for automation in peptide synthesis. To synthesize a peptide in SPPS, three key steps need to be fulfilled: i) resin swelling, (ii) deprotection of the protected group, and (iii) coupling reaction to form the amide bonds. Although SPPS is routinely used for various peptide sequences, synthesis of same amino acid-based sequence is quite challenging due to missed coupling reaction and low yield. In this study, we attempt to synthesize and characterize same amino acid-based sequence peptide. Initially two peptides including alanine based 7A (AAAAAAA) and tryptophan based 7W (WWWWWWW) were randomly selected. For synthesizing these peptides, rink amide resin with a loading power of 0.6 mmol/g was utilized. Fmoc amino acids, main solvent DMF, deprotection solution of piperidine, activator N,N’-diisiopropylcarbodiimide and activator base oxyma were used for all synthesises. After the synthesis, the peptide was dried with DCM to remove DMF and cleaved from the resin using a cleavage cocktail made up of 95% TFA, 2.5% H20 and 2.5% TIPS. Ether was added but yielded no precipitate, so chloroform was used instead. The peptide was then centrifuged, frozen, and lyophilized. Peptides were characterized by Liquid Chromatography and Mass Spectrometry. Alanine based peptides was eluted at 1.02 mins and the most intense peak detected at m/z 515.42 Da corresponds to [M+H]+. In addition, a peak for dimer is noticed at 1029.17 Da. Tryptophan based peptide was eluted at 6.53 mins and the most intense peak for this peptide was observed at m/z 661 Da corresponds to [M+H]+. In addition, a peak dimer is noticed at 1320.67 Da. LCMS results showed that both peptides was corrected synthesized although with low yield. Further research will be focused to increase the yield and explore potential applications for these peptides.
Academic department under which the project should be listed
CSM - Chemistry and Biochemistry
Primary Investigator (PI) Name
Mohammad A. Halim
Solid Phase Peptide Synthesis of Same Amino Acid Based Sequence
Solid phase peptide synthesis (SPSS) and Boc/Fmoc orthogonal protecting strategy promoted the rapid synthesis of larger and challenging peptides. Moreover, this method opened a new avenue for automation in peptide synthesis. To synthesize a peptide in SPPS, three key steps need to be fulfilled: i) resin swelling, (ii) deprotection of the protected group, and (iii) coupling reaction to form the amide bonds. Although SPPS is routinely used for various peptide sequences, synthesis of same amino acid-based sequence is quite challenging due to missed coupling reaction and low yield. In this study, we attempt to synthesize and characterize same amino acid-based sequence peptide. Initially two peptides including alanine based 7A (AAAAAAA) and tryptophan based 7W (WWWWWWW) were randomly selected. For synthesizing these peptides, rink amide resin with a loading power of 0.6 mmol/g was utilized. Fmoc amino acids, main solvent DMF, deprotection solution of piperidine, activator N,N’-diisiopropylcarbodiimide and activator base oxyma were used for all synthesises. After the synthesis, the peptide was dried with DCM to remove DMF and cleaved from the resin using a cleavage cocktail made up of 95% TFA, 2.5% H20 and 2.5% TIPS. Ether was added but yielded no precipitate, so chloroform was used instead. The peptide was then centrifuged, frozen, and lyophilized. Peptides were characterized by Liquid Chromatography and Mass Spectrometry. Alanine based peptides was eluted at 1.02 mins and the most intense peak detected at m/z 515.42 Da corresponds to [M+H]+. In addition, a peak for dimer is noticed at 1029.17 Da. Tryptophan based peptide was eluted at 6.53 mins and the most intense peak for this peptide was observed at m/z 661 Da corresponds to [M+H]+. In addition, a peak dimer is noticed at 1320.67 Da. LCMS results showed that both peptides was corrected synthesized although with low yield. Further research will be focused to increase the yield and explore potential applications for these peptides.