Synthesis of Cysteine-containing Oligopeptides
Faculty Mentor Name
Jianhua Ren
Research or Creativity Area
Natural Sciences
Abstract
A peptide is a sequence of amino acids connected through peptide bonds. This project focuses on the synthesis of oligopeptides that contain a cysteine residue. These oligopeptides resemble the sequence motif of the active site of thioredoxin. Thioredoxin is an enzyme regulating the redox reaction in proteins. These oligopeptides will be used as a model to further study the biophysical properties within the active site of thioredoxin. The knowledge gained will help to create peptides for potential cancer treatment. The peptides are made using solid phase peptide synthesis (SPPS). In this method, Rink amide resin serves as a structural foundation to sequentially couple the amino acids. The first step is the initial deprotection using 20% piperidine in dimethylformamide (DMF) in order to remove the F-moc protecting group in the resin. Once removed, the resin is washed thoroughly with methanol (MeOH), dichloromethane (DCM), and DMF to remove residual reagents. The desired amino acid is then added into the vessel alongside Hexafluorophosphate Benzotriazole Tetramethyl Uronium (HBTU), DMF, and N,N'-Diisopropylethylamine (DIPEA). This constitutes the coupling step and is necessary for each addition of amino acids onto the resin. Once all desired amino acids are coupled, the peptide is cleaved from the resin and is placed through a purification process. The final step is to place the product into a lyophilizer in order to purify the peptide even further. The obtained peptide is analyzed using mass spectrometry where the amino acid sequence can be confirmed and the purity can be evaluated. We have successfully synthesized several oligopeptides, including Ac-Cys-Ala-Ala and Cys-Gly-Ala.
Synthesis of Cysteine-containing Oligopeptides
A peptide is a sequence of amino acids connected through peptide bonds. This project focuses on the synthesis of oligopeptides that contain a cysteine residue. These oligopeptides resemble the sequence motif of the active site of thioredoxin. Thioredoxin is an enzyme regulating the redox reaction in proteins. These oligopeptides will be used as a model to further study the biophysical properties within the active site of thioredoxin. The knowledge gained will help to create peptides for potential cancer treatment. The peptides are made using solid phase peptide synthesis (SPPS). In this method, Rink amide resin serves as a structural foundation to sequentially couple the amino acids. The first step is the initial deprotection using 20% piperidine in dimethylformamide (DMF) in order to remove the F-moc protecting group in the resin. Once removed, the resin is washed thoroughly with methanol (MeOH), dichloromethane (DCM), and DMF to remove residual reagents. The desired amino acid is then added into the vessel alongside Hexafluorophosphate Benzotriazole Tetramethyl Uronium (HBTU), DMF, and N,N'-Diisopropylethylamine (DIPEA). This constitutes the coupling step and is necessary for each addition of amino acids onto the resin. Once all desired amino acids are coupled, the peptide is cleaved from the resin and is placed through a purification process. The final step is to place the product into a lyophilizer in order to purify the peptide even further. The obtained peptide is analyzed using mass spectrometry where the amino acid sequence can be confirmed and the purity can be evaluated. We have successfully synthesized several oligopeptides, including Ac-Cys-Ala-Ala and Cys-Gly-Ala.
