University of Pittsburgh Peptide and Peptoid Synthesis Core

Liberty Blue Microwave Synthesizer

The Liberty Blue system's combination of microwave peptide synthesis along with rapid liquid handling offers several advantages over conventional synthesis conditions including:

  • Shorter reactions resulting in only 4-minute cycle times
  • Higher purity peptides than conventional synthesis
  • Synthesis of peptides impossible to synthesize under conventional conditions

Solid phase peptide synthesis involves the covalent attachment of a fully side chain protected N-terminal FMOC-amino acid derivative to an amine functionalized polyethyleneglycol based solid support by preactivation with TBTU/Hobt to form the corresponding active ester (below figure) Next, removal of the FMOC group with 20% piperidine exposes the pendent alpha amino group for addition of a second pre-activated FMOC-amino acid. This cyclic process is repeated until the desired length of peptide has been achieved. Treatment of the completed peptide resin with trifluoroacetic/scavengers detatches the peptide from the solid support while simultaneously removing all side chain protecting groups. The crude product is then characterized by analytical reversed phase HPLC (RP-HPLC) and MALDI-TOF prior to purification and lyophilization to a dry powder. 

The "submonomer method" of peptoid synthesis involves the covalent attachment of a bromoacetic acid linker to an amine functionalized polyethylene glycol based solid support via a carbodiimide based activation strategy (below figure). Next, a substitution type reaction step allows an amine containing monomer unit to covalently attach to the linker on the resin. These steps are repeated until the desired length of peptoid has been achieved after which the peptoids can remain attached to the solid support (on-bead technology) or detached from the resin and provided as a purified lyophilized powder. Additionally a "split and mix" method of synthesis allows for the production of "one bead one compound" (OBOC) combinatorial libraries with millions of potential epitopes available to researchers in support of high throughput screening assays.