Síntesis de péptidos a medida

Consulta en línea

Diseñado para investigación biológica y aplicaciones industriales; no destinado a fines clínicos o médicos individuales.

Síntesis de péptidos rápida y flexible, desde grado investigación hasta el desarrollo listo para GMP.

Discusión del proyecto

Comparta su secuencia objetivo, pureza, escala, modificación, formato de entrega y requisitos de documentación. Quantai evaluará la viabilidad y responderá con una vía de cotización práctica.

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Capacidades principales

Péptidos lineales, cíclicos, grapados y modificados

Linear sequences are built by solid-phase synthesis on a resin chosen for the required C-terminus: an acid for Wang or 2-chlorotrityl resin, an amide for Rink amide resin. Cyclic peptides are closed through a disulfide bridge, head-to-tail amide bond, or a side-chain lactam between glutamic acid and lysine. Stapled peptides use a hydrocarbon bridge installed by ring-closing metathesis between two olefinic residues, which locks a helical turn in place. Which route suits a sequence depends on where the constraint has to sit, so the ring strategy is confirmed together with the sequence before synthesis starts.

Secuencias difíciles y cadenas peptídicas largas

Sequences rich in beta-branched or hydrophobic residues tend to aggregate on the resin part-way through the chain, and coupling yields fall away. The usual counters are pseudoproline dipeptides that break up secondary structure, backbone amide protection, double couplings at the problem residue, and elevated-temperature or microwave-assisted coupling. Beyond roughly fifty residues, chemical ligation of purified fragments is generally more reliable than extending a single chain. A sequence is reviewed for these risks before quotation rather than after a failed run.

Planificación de escala de miligramos a kilogramos

Scale is not simply a larger version of the same run. Milligram quantities for screening tolerate a single preparative HPLC pass; gram quantities need the purification step designed around throughput and solvent recovery; larger campaigns need the route itself reconsidered, since reagent cost and waste handling start to dominate. Telling us the intended scale at the enquiry stage lets the route be chosen for the scale you actually need, instead of one that works only at the scale it was first developed for.

Purificación, análisis MS/HPLC y documentación

Crude peptide is purified by reversed-phase HPLC, most often on a C18 stationary phase with an acetonitrile and water gradient. Purity is then measured by analytical HPLC as an area percentage at a stated wavelength, and identity is confirmed by mass spectrometry against the calculated monoisotopic or average mass. The counter-ion left after purification matters for downstream work: trifluoroacetate is the default from TFA-based gradients, and an exchange to acetate or hydrochloride is a separate step that has to be requested.

Flujo de trabajo típico

1Revisión de requisitos

2Viabilidad técnica

3Cotización y cronograma

4Síntesis o ejecución del proceso

5Documentación de QC

6Envío y seguimiento

Etapa de desarrollo	Nuestro soporte en péptidos
Concepto y viabilidad	Estrategia de diseño peptídico, optimización de secuencia y evaluación de viabilidad
Investigación de descubrimiento	Síntesis peptídica a medida, diseño de péptidos de direccionamiento y apoyo al cribado funcional
Optimización de cabeza de serie	Modificación peptídica, estrategia de conjugación y optimización estructura-función
Desarrollo de procesos	Optimización de ruta, robustez del proceso y estrategia de control de impurezas
Fabricación GMP	Síntesis peptídica conforme a GMP, documentación de calidad y apoyo a la liberación de lotes

Notas técnicas

Fmoc and Boc strategies

Two protection strategies dominate solid-phase peptide synthesis. Fmoc chemistry removes the temporary alpha-amino protecting group with a mild base, usually piperidine, and cleaves the finished peptide from the resin with trifluoroacetic acid. Boc chemistry removes the temporary group with acid at each cycle and needs hydrogen fluoride for the final cleavage. Fmoc is the default for most sequences because it avoids repeated strong-acid treatment and handles acid-sensitive modifications better. Boc retains an advantage for strongly aggregating sequences and for some thioester chemistry used in ligation.

Coupling and capping

Each residue is activated before it is added to the growing chain. Uronium and phosphonium reagents such as HBTU, HATU and PyBOP give fast couplings; carbodiimide with an additive such as Oxyma is a lower-cost alternative that also suppresses racemisation. Where a coupling is incomplete, unreacted amines are capped with acetic anhydride so that the resulting truncated chain stays short and separates cleanly during purification, rather than continuing to grow into a deletion sequence that co-elutes with the target.

Cleavage and scavengers

Final cleavage from the resin releases the peptide and removes side-chain protecting groups at the same time. The reactive cations generated in that step will attack sensitive residues unless they are intercepted, so the cleavage cocktail is matched to the sequence: triisopropylsilane and water for most peptides, with ethanedithiol or thioanisole added where cysteine, methionine, tryptophan or arginine are present. Getting this wrong shows up as a family of side products a few mass units away from the target.

Counter-ion and salt form

A peptide purified with TFA in the mobile phase is isolated as a trifluoroacetate salt. Because TFA absorbs in the region used for some cell assays and can affect biological readouts, an exchange to acetate, hydrochloride or a free base may be required. The salt form changes the peptide content of the powder, so quantities and any content specification should be discussed in the same conversation as purity.

Lyophilisation and final form

Purified fractions are pooled and freeze-dried to a lyophilised powder or cake. Fill weight, vial format and whether the material is aliquoted across several vials are all specified per project. Peptides intended for reconstitution in the laboratory are usually filled so that a full vial gives a convenient working concentration, which avoids repeated freeze-thaw of a single large vial.

Qué recibe

Purified peptide in the agreed salt form and fill format
Analytical HPLC chromatogram with purity stated as area percent
Mass spectrometry data confirming identity against calculated mass
Certificate of analysis listing appearance, purity, mass and net content
Sequence and modification summary as confirmed before synthesis

Aplicaciones habituales

Assay and screening peptides — Substrates, inhibitors and control peptides for enzyme and binding assays, usually at milligram scale with purity confirmed by HPLC and identity by MS.

Immunogens and antibody work — Epitope peptides for antibody generation, commonly supplied with a terminal cysteine for later conjugation to a carrier protein, or already conjugated.

Structure-activity studies — Sequence series in which single residues are substituted, including D-amino acids and unnatural residues, to map which positions carry the activity.

Formulation and stability work — Larger quantities of a single sequence where batch-to-batch consistency and a defined salt form matter more than turnaround on any one batch.

Preguntas frecuentes

What information do you need to quote a custom peptide?

The one-letter or three-letter sequence, the required purity, the quantity, any N-terminal or C-terminal modification, the salt form if it matters, and the intended use. Sequence and quantity alone are enough for a first feasibility view; the rest affects the route and therefore the price.

What purity should I ask for?

Purity is a cost driver, so it is worth matching it to the application rather than defaulting to the highest number. Crude or partially purified material is often adequate for initial screening. Binding and enzyme assays are commonly run at above 95 percent. Work where a small impurity could be mistaken for a real signal is where the highest grades earn their cost.

How is purity actually measured?

By analytical reversed-phase HPLC, reported as the area of the main peak as a percentage of total peak area at a stated detection wavelength. Because the number depends on the wavelength and the gradient, a purity figure should always be read together with the chromatogram it came from.

Can you synthesise sequences that other suppliers have declined?

Often, but the honest answer depends on why they declined. Aggregation-prone and highly hydrophobic sequences usually respond to pseudoproline dipeptides, backbone protection or a change of resin. Very long chains are better approached by ligating purified fragments. Send the sequence and we will say what the realistic route is, including when we think it is not worth attempting.

Is there a length limit?

There is no hard cut-off, but stepwise synthesis becomes progressively less efficient as the chain grows, because every cycle multiplies its yield into the total. Around fifty residues is the point where fragment ligation is usually the more reliable option, and that choice is made per sequence rather than by a fixed rule.

Do you supply peptides with a trifluoroacetate salt?

Yes, that is the default after purification with TFA in the mobile phase. If your work is sensitive to TFA, say so at the enquiry stage: exchange to acetate or hydrochloride is a separate processing step, and it changes the peptide content of the delivered powder.