Peptide synthesis

The peptide syntheses are realized with chemical approaches with automated peptide synthesizers. Two synthesizers are available, the A 433 (Applied Biosystems) and the Liberty Blue (CEM corporation). Peptides are purified by reverse phase HPLC.

The engineer is first establishing a quote according to the peptide sequence, the potential modifications and the quantity required.

After the validation of the quote by the user, he realizes the synthesis and the purification of the peptide. Peptides are delivered as a powder with 95% purity. A mass spectrum and a reverse phase HPLC profile are provided for each peptide.

Material
  • A 433 (Applied Biosystems)
    A first automated solid phase peptide synthesizer. It is compatible with Fmoc or Boc strategies and from 0.1 to 1 mmol of peptide can be produced.
  • Liberty Blue (CEM corporation)
    A second solid phase automated peptide synthesizer. This last generation instrument is using microwaves for every steps of the synthesis and allows much shorter reaction times (only 4 minutes per cycle). This synthesizer is only suitable for Fmoc strategy. Although it realizes one peptide synthesis at a time, it is possible to schedule up to 24 consecutive syntheses with the addition of two optional modules. From 0.025 to 5 mmol of peptide can be produced.
  • HPLC system (Goebel de BioServ)
    with different semi-preparative and analytical reverse phase columns to purify peptides or proteins.
  • A freeze-drying device
    It realizes the sublimation of the peptide solution with the help of a high vacuum and allows getting the product under a powder form, which is much, more stable.

Services

Peptide synthesis services:

- Typical turnaround time of 2-4 weeks per peptide.

- Flexible peptide quantities: from 1 to 100 mg.

- Synthesis upon request for quantities greater than 100 mg.

- Many possible modifications.

- Peptide purity guaranteed: ? 95%.

- Quality control: analytical HPLC chromatogram and MALDI-TOF MS spectrum.

- Peptide is supplied as lyophilized powder.

Peptide quality control:

- The reversed-phase HPLC chromatogram illustrates the peptide purity.

- The MALDI-TOF MS spectrum determines the peptide integrity.

- The peptide is lyophilized, weighted, then stored at -20°C.

Methodologies

Peptide synthesis methodology:

- Synthesis is performed using the 433A automated peptide synthesizer from Applied Biosystems or the Liberty Blue™ microwave peptide synthesizer from CEM Corporation.

- Peptides are synthesized on a solid support (polystyrene resin) from the C-terminus to the N-terminus of the sequence, using Fmoc chemistry.

- Synthesis is realized on a scale range of 0.025 to 5 mmol.

Purification:

- The crude peptide containing impurities (peptides with one or few amino acid deletions, chemical products) is purified by semi-preparative reversed-phase HPLC (C4 to C18 columns).

- After HPLC analysis of the crude peptide and determination of the optimal separation conditions, the different peaks are collected and the mass spectrum is determined in order to identify the peak corresponding to the expected molecular mass.

- The identified peptide of interest is then completely purified, lyophilized, weighted, and analyzed by analytical reversed-phase HPLC to assess its correct purity.

- The integrity of the peptide is determined by analyzing its mass spectrum.