Research use only · Lyophilised material · Not a medicine · Not for human or veterinary use · Disclaimer
Sable Peptides

Peptide Signalling Pathways in Laboratory Research: An Overview

Peptide Signalling Pathways in Laboratory Research: An Overview is supplied for laboratory research only. Key facts are below; stored as lyophilised powder.

Last verified 12 Oct 2026.

A CoA for every lot; each vial carries a printed lot number that matches it. Ask with the lot number and we send it.

The short answer

Most signalling peptides act through G protein-coupled receptors on the cell surface. Binding switches on G proteins, which change second-messenger levels such as cAMP and Ca²⁺. Laboratories measure these steps in cell-based assays.

Research use only. Sable Peptides supplies laboratory reagents for in vitro and laboratory research by qualified people. Not a medicine. Not for human or veterinary use.

The short answer

Most signalling peptides act through G protein-coupled receptors on the cell surface. Binding switches on G proteins, which change second-messenger levels such as cAMP and Ca²⁺. Laboratories measure these steps in cell-based assays.

GPCRs in brief

GPCRs share a seven-transmembrane architecture. Agonist binding shifts the receptor into active states that couple to Gs, Gi/o, Gq/11 or G12/13 proteins and to β-arrestins (Rosenbaum et al., 2009). Many families in Sable's catalogue act at such receptors, including ghrelin-receptor (GHSR), GHRH, GLP-1, melanocortin, oxytocin and kisspeptin receptors.

Common readouts

| Pathway | Typical assay | |---|---| | Gs / Gi → cAMP | cAMP accumulation (HTRF, luminescent reporters) | | Gq → Ca²⁺ / IP1 | Calcium flux, IP-One | | β-arrestin | Recruitment assays (BRET, enzyme complementation) | | Binding | Radioligand or fluorescent competition |

Design themes in analogues

Medicinal-chemistry work on peptides tunes affinity, selectivity, peptidase resistance and half-life in assay media, using D-residues, N-methylation, lipidation and cyclisation (Muttenthaler et al., 2021). Many of Sable's analogues are examples of these strategies.

Where to read more

See the topic index for families, and each compound's /learn brief for literature specific to that receptor.

- /learn/peptide-research-topics - /learn - /glossary

Sources

1. Rosenbaum DM et al.. The structure and function of G-protein-coupled receptors. *Nature* 2009;459:356-63. PMID 19458711. PMC3967846. doi:10.1038/nature08144 2. Muttenthaler M et al.. Trends in peptide drug discovery. *Nat Rev Drug Discov* 2021;20:309-325. PMID 33536635. doi:10.1038/s41573-020-00135-8

*Last reviewed: 2026-10-10. Original Sable content; sources verified via PubMed E-utilities / Crossref / live HTTP checks on 2026-10-10.*

Last reviewed: 2026-10-10

How much does Peptide Signalling Pathways in Laboratory Research: An Overview cost in the UK?

Frequently asked questions

How do most peptides signal?

By binding cell-surface receptors, most often G protein-coupled receptors (GPCRs), which trigger intracellular second messengers.

What are second messengers?

Small intracellular signals such as cAMP, Ca²⁺ and IP3 that relay and amplify receptor activation.

How is peptide signalling measured in vitro?

With receptor-binding assays, cAMP or calcium-flux reporter assays, and β-arrestin recruitment assays in cultured cells.

Why do analogues differ from natural peptides?

Substitutions can change receptor affinity, selectivity, stability against peptidases and duration of action in assays.

Does this page describe effects in organisms?

No. It covers receptor-level and cell-assay concepts only.