Peptide Synthesis

Solid Phase Peptide synthesis (SPPS), developed in the late 1950’s by Robert Bruce Merrifield, uses well established Fmoc/tbu chemistry to anchor successive amino acids onto a growing chain immobilised on a polymeric support. The synthesis utilises the coupling of N-α-amino and the carboxylic acid of amino acids to form an amide bond (Peptide bond) using coupling reagents or activators in a cyclical process until the target peptide is completed.

Peptide synthesis with Alta Bioscience

Alta Bioscience provides custom peptide synthesis with a flexible range of scales and purities. With more than 45 years’ experience, our peptide chemists will collaborate with you to create optimal solutions specifically for your synthesis project. Based in Worcestershire, UK, our experienced peptide team is able to provide custom peptides including peptide antigens for antibody production, KLH-Peptide conjugation, linear peptides, cyclic peptides and modified peptides with high purity and fast turnaround times.

Our custom peptide synthesis service offers peptide libraries, ideal for screening large proteins, generating overlapping peptides for epitope studies. We can also provide microarrays with individual peptides immobilised on a microscope slide, as well as offering a diverse spectrum of modifications, dyes and labels for incorporation into your peptide.

Stock peptides

We have a range of stock peptides which include:

• Individual histone peptides and histone sets for screening purposes
• Cell penetrating peptides for cellular studies
• Influenza virus peptides
• Epstein-Barr virus peptides

Quality and customer satisfaction focused, we deliver custom peptides according to stringent analytical specifications, with the purified peptides undergoing QC with HPLC and mass spectrometry.

We also offer additional options for peptide identification using amino acid analysis which will provide net peptide content and N-terminal protein sequencing providing the order of the amino acids in the peptide sequence.

Our highly skilled specialists will be able to offer you professional advice throughout the design and synthesis of the peptide sequence.

An introduction to peptide synthesis

Peptide synthesis involves the successive addition of amino acids covalently bonded via peptide bonds to build a stable peptide chain.

Solid phase peptide synthesis (SPPS) allows the assembly of amino acids in a controlled process keeping the growing chain immobilised on a solid support until the intact chain is finally released on cleavage. The amino acid building blocks often have side chain protection to ensure that reactions only occur between amino and carboxyl groups of the amino acids being coupled. These protective groups on the side chain are released on cleavage at the end of the peptide assembly.

At AltaBioscience, we also undertake some solution phase peptide synthesis for example when cyclising peptides or generating disulphide bridges using Cys residues.

Peptide synthesis applications

Peptides are used in a variety of applications and have distinct advantages over proteins in that they can be easily defined and synthesised quickly with consistency. Peptides as therapeutics is a fast growing area with more and more peptides being used in drug therapies, vaccines and cosmetics. Coupled to DNA, peptide cargo can be transported easily into cells (DNA-peptide conjugates)

Peptide applications and uses

• Peptides as antigens for polyclonal and monoclonal antibody generation
• Peptides are routinely used in contract manufacturing (LFD devices)
• ELISA assays for screening and enzyme immunological assays (inhibition and interaction studies
• Epitope studies when screening proteins
• Peptides can be developed as antimicrobial agents
• Synthetic peptides serve as probes of biological structure and function
• Interaction studies e.g. protein-protein or ligand-receptor.
• NMR studies
• For use in clinical trials

Peptide (epitope) tag sequences attached to proteins facilitate easy detection and purification of expressed proteins. In addition, they can also be used to identify potential binding partners for the protein of interest. Tags available can be incorporated at the N or C-Terminus of peptides. We can supply the peptide as lyophilized material as well as on solid phase.

What are peptides?

Peptides are comprised of short chains of amino acids, all of which are linked together by peptide bonds. Peptides are short fragments of proteins with the main difference between a peptide and protein being size. Typically peptides are much smaller than proteins containing less than 100 amino acids whereas proteins are longer and may have a more complex structure as they adopt secondary, tertiary and quaternary structures. This also means that peptides offer less variation in structure. Peptide synthesis uses the standard 20 amino acids or modified versions of these as building blocks when assembling the peptide.

Peptide synthesis methods

Fmoc chemistry is a well-defined method for peptide synthesis. It allows the deprotection of the amino end of the amino acid using a deprotection solvent whilst retaining the protective groups on the side chains of the amino acids. The first step is to remove the Fmoc from the amino acid immobilised on the resin to expose an amine. After washing, usually with DMF, the second step is coupling an activated amino acid to the exposed amine. This process is repeated until the chain is assembled. The final stage, cleavage, removes the intact peptide from the immobilised support (resin) and also the side protecting groups. The peptide is then freeze-dried ready for dispatch or further purification.

At AltaBioscience we incorporate additional steps such as double coupling and capping steps to further improve the synthesis and reduce prospects of deletions or poor coupling.

How long does peptide synthesis take?

Peptide synthesis turnaround is dependent on the number of peptides required, purification options as well as scale and complexity of each peptide.

AltaBioscience offers a fast turnaround for standard small scale peptides with completion generally in 7 – 10 working days. Large scale, complex, large numbers or highly purified peptides will extend the turnaround time.

Our Epitope peptide scale can synthesise up to 576 unpurified peptides in 6 – 8 working days per batch.

Our peptide chemists are happy to discuss turnaround times and how best we can help you meet your deadlines. Get in touch with us at info@altabioscience.com or call us on +44(0)1527 584495.

Peptide solubility: How do I dissolve my peptide?

Peptide solubility as a guide is determined by the overall charge of the peptide and the environment it exists in. Changing the pH can help in solubilising some peptides.

Care is needed when selecting your solvent and consideration should be given to the assay you intend to use it in, for instance, TFA may be toxic to cells in higher concentrations. DMSO is best avoided for peptides containing Cysteine, methionine and tryptophan as it may cause oxidation. As a general rule, where possible use volatile solvents, which can be removed by freeze drying to recover the peptide for further studies.

AltaBioscience offer a solubility test service which will provide information on the solubility of your peptide in 3 solvents. Due to the requirement to use additional peptide, this service is suitable for individual purified peptide orders of greater than 10mg amounts. Read more on peptide solubility and storage.

For more information on custom peptide synthesis with AltaBioscience, please email us at info@altabioscience.com or call us on +44(0)1527 584495 to speak to one of our experts.