Custom peptide synthesis

High-quality peptides at competitive prices are just one click away! Starting at €1.66 per amino acid, you can generate synthetic peptides up to 150 residues with an unlimited range of modifications and pay only if you’re satisfied with your order. In just a few clicks, fill out the form to receive an instant quote and order directly from our shop using the secure online payment system. Start your custom peptide synthesis now!

Why choose ProteoGenix' peptide
synthesis services?

Peptide synthesis price
1.66€/AA

The most competitive price for peptide synthesis on the market.

Cost effective peptides
Best price guaranteed

We guarantee to provide you with the most competitive price.

Buy custom peptide online
Instant quotation and online order

Save time and buy your peptides thanks to our online form. Delivery in 10 business days.

Custom peptide synthesis
Peptide synthesis up to 150 AA

ProteoGenix can synthesize peptides up to 150 AA.

Peptide modification
Unlimited range of modifications

ProteoGenix offers an unlimited range of peptide modifications.

Peptide synthesis
No win – no fee

Your project is our priority so we will start from the beginning until we get the right peptide or you won’t pay a thing.

Included in your custom peptide synthesis order

Peptide synthesis
method

  • Fmoc solid-phase synthesis (standard)

  • GMP peptide synthesis (upon request)

Quantity

  • From 1 mg to 1 kg

Purity

  • Crude to ≥ 98%

  • TFA removal upon request

Lead time

  • Starting from 10 business days

Shipping

  • Ambient temperature

Peptide order

  • Lyophilized peptide and corresponding QC report

Standard QC report

  • Amino acid sequence

  • Purity and quantity information

  • Modification and conjugation information

  • MS and HPLC profiles (except for crude/desalted peptides)

Additional analysis
(upon request)

  • Net peptide content analysis (N%)

  • Qualitative amino acid analysis (AAA)

  • Water content analysis

  • Ion chromatography analysis (TFA, HAC)

  • Solvent residue (DMF, ACN)

  • Endotoxin (<1EU/MG)

Solubility test
(upon request)

  • Request a solubility test to forgo the need to use part of your
    stock for testing. If you prefer to make it at your facilities,
    check our useful guidelines below.

Looking for custom-made recombinant peptides?

At ProteoGenix, we offer recombinant expression and semisynthesis
(ligation of synthetic and recombinant fragments) in addition to the
standard Fmoc solid-phase synthesis. If you are working with complex
structures, reach out to our team to learn how we can help.

Get the highest quality peptides in 3 simple steps

1. Keep the fundamental principles of peptide design in mind

Principle Description

Length

  • Keep the length between 6-20 amino acids (15 is the optimal)

  • Shorter peptides are easier to produce and purify, keeping the costs low

  • For longer peptides, fragment ligation or recombinant expression should be considered

Solubility

  • Most native proteins and derived peptides are highly hydrophobic, making them hard to produce and solubilize

  • Enhance solubility of native peptide sequences by:

    • Shortening the amino acid sequence

    • Replacingnon essential hydrophobic residues by aspartic acid, lysine, arginine, histidine, or glutamic acid

Crosslinking

  • Avoid peptide sequences rich in aspartic acid, glutamic acid, histidine, lysine, asparagine, glutamine, arginine, serine, threonine, or tyrosine

  • These amino acids are prone to establishing hydrogen bonds and forming gels in solution

  • If possible, replace these non-essential residues by others, less prone to crosslinking in solution

Stability

  • Examples of residues known to heavily reduce the stability of peptides:

    • Cysteine and methionine rich peptides are prone to oxidation – replace them with serine and norleucine, respectively

    • Avoid N-terminal glutamine residues as they cause undesirable cyclisation in acidic conditions Peptide bonds between aspartic acid and glycine, proline, or serine are prone to hydrolysis – replace them by aspartic acid

    • Avoid placing adjacent serine or proline residues as this increases the risk of deletion and thus reduces the purity of the final product

  • When these residues cannot be replaced, consider modifying the peptide backbone (acetylation, amidation, etc.) or conjugating your peptide to other molecules (PEG or BSA) to increase stability

2. Select a purity grade adapted to your intended application

Peptide purity grade Applications

Crude

  • Interaction studies (ligand-receptor, protein-protein…)

  • Mutation screening

  • Sequence optimization

>70%

  • Polyclonal antibody production

  • ELISA assays

>80%

  • Monoclonal antibody production

  • In vitro tests

  • In vivo studies

  • Quantitative inhibition studies

  • Quantitative interaction studies

  • NMR studies

>95%

  • Clinical trials

  • Crystallography

  • Quantitative studies

3. Consider conjugating or modifying your peptide

Type Available modifications, labels, or tags

N- C- Terminal
Modification

  • 3-(p-Hydroxyphenyl) propionic
    Acid

  • (Dnp, N-Terminal)

  • Acetylation (Lys)

  • Acetylation (N-Terminal)

  • Alloc (N-Terminal)

  • AMC (C-Terminal)

  • Amidation (C-Terminal)

  • Benzyloxycarbonylation (CBZ)

  • Br-Ac- ((N-Terminal))

  • CMK/FMK (C-Terminal)

  • DL-Lipoic acid (N-Terminal)

  • Fatty acid (N-Terminal)

  • Formylation (N-Terminal)

  • Lys(Pal) (middle, C-Terminal)

  • Maleimide (N-Terminal)

  • Myristic acid (N-Terminal)

  • NHEt (C-Terminal)

  • NHisopen (C-Terminal)

  • NHMe (C-Terminal)

  • OBzl (C-Terminal)

  • OEt (C-Terminal)

  • OMe (C-Terminal)

  • OtBu (C-terminal)

  • Palmitoyl (N-Terminal)

  • p-Nitroanilide (pNA, C-Terminal)

  • Succinylation (Suc, N-Terminal)

  • TBzl (C-Terminal)

Phosphorylation

  • (pSer)

  • (pTyr)

  • (pThr)

  • Di-sites in sequence

  • Tri-sites in sequence

Peptide
conjugation

  • KLH / OVA / BSA-Peptide
    (N-Terminal or Cysteine)

  • Horse Radish Peroxidase (HRP)

  • Ovalbumin

  • Myoglobin

Peptide
cyclization

  • Mono Disulfide bridge

  • Double Disulfide bridge

  • Triple Disulfide bridge

  • Amide cyclic (Side chain, end)

  • Intermolecular (Side chain, end)

Quenched
fluorescent
peptide

  • Abz/ Tyr (3-NO2)

  • EDANS or DABCYL

Isotope label

  • N15 Ala

  • N15 Gly

  • N15 Val

  • N15 Pro

  • N15 Leu

  • N15 Phe

  • N15 Lys

Fluorescent/Dye labels

  • (Lys(Dnp)) (middle)

  • (Lys(Maleimide)), (middle)

  • 3-Indolylacetic acid (N-Terminal)

  • 5-TAMRA (N-Terminal)

  • Biotin (N-Terminal, Y/N Ahx)

  • Biotin (Lys in sequence)

  • Biotin (without Lys in sequence)

  • Dansyl (N-Terminal, Y/N Ahx)

  • Dansyl (Lys in sequence)

  • DTPA (N-Terminal)

  • EDBiotin (C-Terminal)

  • EDDnp (C-Terminal)

  • FITC/5-FAM (N-Terminal, Y/N Ahx)

  • FITC/5-FAM (Lys in sequence)

  • HYNIC (N-Terminal)

  • Lys (Pen)

  • Lys(TMR) (C-Terminal)

  • Lys(TMR) (middle)

  • MCA (C-Terminal conjugated to the Lys side chain)

  • MCA (N-Terminal)

  • Palmitoylation (side chain of the Cys)

  • Rhodamine (N-Terminal)

  • Rhodamine (without Lys in sequence)

  • TMR (N-Terminal)

If you are looking for an expert’s advice to help you maximize the stability and yield of your synthetic peptide while keeping production costs low, reach out to our team for more information.

Useful guidelines for working
with synthetic peptides

How to test the solubility of your custom synthetic peptide

The most commonly used method to test solubility is based on charge determination. For small peptides with up to 5 amino-acids, distilled water remains the first option. For other cases, you can refer to this guide:

  1. Attribute -1 to each acidic residue (Asp / D, Glu / E) and to the terminal carboxylic acid. Then, assign +1 to each basic residues (Arg / R, Lys / K, His/h) and the terminal amine. Sum up both values to determine the overall charge of your peptide

  2. If the overall charge value is positive, try to dissolve your peptide in water. In case the peptide does not dissolve, acidify your solution with an acetic acid solution (10 to 30%). Add TFA if acetic acid does not allow peptide dilution du sufficient concentration

  3. In case the overall charge is negative and the peptide does not contain cysteine residues, try to dissolve your peptide in water. If the peptide does not dissolve, add ammonium hydroxide to obtain the desired concentration.

  4. 4.If the overall calculated charge is zero, the peptide can be diluted with organic solvents (methanol, ethanol, isopropanol or acetonitrile). A small amount of DMSO diluted with water can be used depending on final application. Specific care is requested for peptide containing cysteine, methionine or tryptophan residues as they are sensitive to oxidation. In these cases, replace DMSO by DMF.

How to design antigenic peptides for vaccines and antibody production

Synthetic antigenic peptides represent powerful tools for polyclonal or monoclonal antibody generation and as components of peptide vaccines. For these applications, peptides need to be designed with two properties in mind: antigenicity and immunogenicity.The first term is used to describe the ability of an antigen to interact with an antibody’s functional binding site, while the second term describes a peptide’s ability to elicit a humoral an/or cellular immune response. For effective vaccine and antibody production, peptides must have both properties.

Enhancing peptide antigenicity can be achieved by:

  • Choosing hydrophilic sequences: soluble regions have surface-exposed hydrophilic residues, more likely to elicit an immune response.

  • Ensuring high epitope accessibility: steric hindrance can hamper antibody-antigen interaction even in hydrophilic regions, it is essential to ensure the epitope can be easily accessed in the native protein.

  • Selecting epitopes according to secondary structure flexibility: flexible regions in a native protein make better targets for antibody generation.

  • Opting for an optimal peptide length: to maximize antigenicity, peptides should have between 10 and 20 AA residues. Short peptides (<10 AA) are unlikely to be bound by antibodies, while long peptides (>20 AA) are likely to adopt three-dimensional conformations that do not accurately mimic the structure of the native protein.

Peptide immunogenicity can be maximized by coupling synthetic peptides with carriers keeping the following recommendations in mind:

  • Peptide orientation: the peptide should always be presented in a similar manner than it would be presented in the native protein.

  • Nature of the carrier protein: the carrier protein often contains several epitopes able to elicit an immune response, thus, choosing the right carrier is of utmost importance to ensure the. KLH and BSA are the most used carrier proteins. KLH is the preferred molecule because of its large mass and complexity which elicit a much stronger immune response.

Major applications of synthetic peptides

Peptide drugs
Peptide drugs

Many peptide drugs are generated by chemical modification of natural molecules. These drugs remain invaluable for the treatment of multiple metabolic diseases.

Peptide vaccines
Peptide vaccines

Vaccines are considered one of the most successful strategies of modern medicine. Conventional vaccines have relied heavily in inactive pathogens to elicit an immune response, making them hard to produce. In contrast, peptide vaccines are increasingly considered as a cost-effective, safer, and highly specific alternative.

Peptides for tissue engineering
Peptides for tissue engineering

The discovery of cell adhesion and self-assembling peptides has opened up a new window of opportunity in tissue engineering applications. These peptides are increasingly used as bioactive molecules to support cellular growth and tissue regeneration.

Peptides for drug and gene delivery
Drug & Gene Delivery

Cell-penetrating peptides and self-assembling peptides are two increasingly important bioactive components of advanced gene and drug delivery applications . In comparison to conventional methods that make use of viral vectors, peptides are much easier to synthesize, thus, helping make the technology more accessible and widespread.

Cosmetic peptides
Cosmetic applications

Many personal care products harness the beneficial properties of cosmetic peptides . Small peptides able to cross the skin barrier are often incorporated in cosmetics due to their easy diffusion allied to their protective and regenerative properties. Peptides with antimicrobial properties are also often incorporated in creams to prevent and treat several well-known skin conditions.

Most widely used peptide synthesis methods

Chemical synthesis
Chemical peptide synthesis
  • Solid-phase synthesis
  • Liquid-phase synthesis
  • Native chemical ligation
Recombinant expression
Recombinant peptide synthesis
  • Bacterial systems ( coliand B. subtilis)
  • Yeast systems ( cerevisiaeand P. pastoris)
  • Mammalian or insect cell lines
Semisynthesis
Semisynthetic peptides
  • Combination of synthetic and recombinant fragments via chemical or enzymatic ligation

Solid-phase peptide synthesis  has dominated the market for custom production in the last couple of decades. The method, initially developed in the 1950s, has matured into a technology that remains unparalleled in terms of automation, cost-effectiveness, scalability, lead times, and yields.

This method is traditionally carried out on a solid support in a stepwise manner from the C to the N terminus. Nα-protected amino acids are used to control the direction of the synthesis process and thus minimize side reactions. Today, solid-phase synthesis makes use of two major N-terminus protective groups: Boc (t-butyloxycarbonyl) and Fmoc (9-fluorenylmethoxycarbonyl).

In addition to these protective groups, permanent protection groups are often attached to side chains. These groups prevent unwanted branching and can withstand several cycles of chemical treatment during the synthesis process. They are only removed in the final stage of the process using strong acids. Benzyl (Bzl) and tert-butyl (tBu) are two of the most widely used side chain protection groups.

The stepwise synthesis of peptides is carried out as follows:

  1. Deprotection: Nα-protective groups need to be removed to allow the addition of a new residue at the N-terminus. Deprotection agents used in this step depend on the nature of the protective groups. In this way, TFA (trifluoracetic acid) is used for Boc and piperidine for Fmoc-protected amino acids.

  2. Coupling: the addition of a new amino acid residue at the N-terminus of a polypeptide chain requires the activation of the C-terminal carboxylic acid. Carbodiimides such as dicyclohexylcarbodiimide (DCC) or diisopropylcarbodiimide (DIC) are widely used coupling reagents.

  3. Cleavage: after several cycles of deprotection and coupling, all remaining protective groups need to be cleaved from the new polypeptide chain. Strong acids such as hydrogen fluoride (HF), hydrogen bromide (HBr) or trifluoromethane sulfonic acid (TFMSA) are used to cleave Boc and Bzl groups, while a relatively milder acid such as TFA is sufficient to cleave Fmoc and tBut groups. During this stage, the peptide chain is also separated from the solid support in order to be further purified.

 

The use of strong chemicals to produce synthetic peptides may offer a challenge when it comes to purification. To overcome this limitation, liquid-phase synthesis is often employed to achieve GMP-grade peptide  production. Despite being significantly more time-consuming and leading to lower yields than solid-phase synthesis, liquid-phase methods are still sparingly used to produce highly pure short peptides (<10 AA) for some applications.

Both solid-phase and liquid-phase synthesis are chemical methods for linear peptide production. When large peptides with complex secondary or tertiary structures are required, recombinant expression is a much better alternative. However, despite being able a good method to produce long peptides, recombinant expression suffers from an important disadvantage – it is restricted to natural amino acids produced and processed by the host organism.

For this reason, when peptides with complex structures and unnatural amino acids need to be produced, a semisynthetic approach may be ideal.

Most efficient peptide purification methods

Despite the high efficiency of most peptide synthesis methods, many of these processes may still generate undesired impurities due to incomplete deprotection, unwanted reactions between free protecting groups, truncation and/or deletion of amino acids, isomers, and other side products.

Removal of these impurities is recurrently achieved by using one or several purification techniques:

  • Size-exclusion chromatography

  • Ion exchange chromatography (IEC)

  • High-performance liquid chromatography (HPLC)

  • Reverse-phase chromatography HPLC (RP-HPLC)

  • Gel-filtration HPLC

 

Among these, RP-HPLC is the most widely used process of purification. Unlike conventional HPLC that separates products according to the concentration of polar solvents on the mobile phase, RP-HPLC captures hydrophobic molecules from aqueous solutions and releases them in function of their hydrophobicity. This makes it easier to separate correctly synthesized peptides from undesired impurities.