Linaclotide Research Peptide (GC-C Receptor Agonist) Supplier — UPOR Biotech
Linaclotide — a guanylate cyclase-C (GC-C) receptor agonist, a 14-amino-acid peptide locked into its bioactive conformation by three intramolecular disulfide bonds. Binds GC-C on intestinal epithelial cells to elevate cGMP, driving CFTR-mediated fluid secretion and colonic nociceptor inhibition (visceral analgesia). The active principle of the FDA-approved Linzess — supplied as research-grade lyophilized powder from UPOR Biotech.
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Linaclotide (CAS 851199-59-2, C₅₉H₇₉N₁₅O₂₁S₆, MW 1526.74 g/mol) is a 14-amino-acid synthetic peptide agonist of guanylate cyclase-C (GC-C). Its primary sequence — Cys-Cys-Glu-Tyr-Cys-Cys-Asn-Pro-Ala-Cys-Thr-Gly-Cys-Tyr — folds into a compact, cysteine-rich scaffold stabilized by three intramolecular disulfide bonds (Cys1-Cys6, Cys2-Cys10, Cys5-Cys13) that lock the peptide into its bioactive conformation. Linaclotide is structurally related to the heat-stable enterotoxin (ST) family of Escherichia coli, sharing the conserved disulfide framework that confers high-affinity GC-C binding. Mechanistically, linaclotide binds GC-C on the luminal surface of intestinal epithelial cells, elevating intracellular cGMP, which activates the CFTR chloride channel to drive chloride, bicarbonate, and fluid secretion into the intestinal lumen — accelerating transit — while elevated extracellular cGMP inhibits colonic nociceptors to reduce visceral pain. Administered orally, linaclotide acts locally within the gastrointestinal tract with minimal systemic absorption. UPOR Biotech supplies linaclotide as a white to off-white lyophilized powder, HPLC-purified to ≥98.0% and validated by ESI-MS.
Linaclotide occupies a central position in gastrointestinal and functional bowel disorder research, serving as the reference GC-C agonist for studies of IBS-C, chronic idiopathic constipation (CIC), and visceral pain. As the active principle of the FDA-approved Linzess, it is the benchmark compound against which novel GC-C agonists and laxative peptides are benchmarked in preclinical and translational assays. UPOR Biotech is a bulk supplier of research-grade linaclotide peptide, providing consistent lot-to-lot purity and full analytical documentation for academic, CRO, and pharmaceutical discovery programs. This material is Research Use Only (RUO) — not for human diagnostic or therapeutic use. Manufacturing is supported by ISO 9001 quality management, cGMP-compliant processes, and FDA facility registration, with lyophilized vials in 1, 5, 10, and 50 mg formats for flexible experimental dosing.
Linaclotide vs Plecanatide — 14-aa Triple-Disulfide GC-C Agonist vs 16-aa Uroguanylin Analog
Both linaclotide and plecanatide are GC-C receptor agonists indicated for IBS-C and chronic constipation, but they arise from distinct scaffolds. Linaclotide is a 14-amino-acid, triple-disulfide peptide derived from the E. coli heat-stable enterotoxin (ST) scaffold, whereas plecanatide is a 16-amino-acid uroguanylin analog with two disulfide bonds that more closely mirrors the endogenous ligand. Linaclotide’s three disulfide bonds (Cys1-Cys6, Cys2-Cys10, Cys5-Cys13) impose a rigid, high-affinity conformation that activates GC-C at low nanomolar concentrations, conferring greater potency than the uroguanylin-class peptide. For researchers, this structural distinction — ST-toxin-derived versus uroguanylin-derived — defines selectivity, potency, and off-target profiles, making linaclotide the reference compound for dissecting GC-C/cGMP/CFTR signaling and for benchmarking next-generation GC-C agonists. UPOR Biotech supplies both the linaclotide reference peptide and supporting analytical documentation to enable rigorous comparative pharmacology.
Technical Specifications
| Property | Specification |
|---|---|
| Product Name | Linaclotide Research Peptide (GC-C Receptor Agonist) — Research Grade (RUO) |
| CAS Number | 851199-59-2 |
| Molecular Formula | C₅₉H₇₉N₁₅O₂₁S₆ |
| Molecular Weight | 1526.74 g/mol |
| Amino Acid Sequence | Cys-Cys-Glu-Tyr-Cys-Cys-Asn-Pro-Ala-Cys-Thr-Gly-Cys-Tyr |
| Amino Acid Residues | 14 |
| Peptide Class | GC-C agonist — structurally related to E. coli heat-stable enterotoxin (ST) family |
| Disulfide Bonds | 3 intramolecular: Cys1-Cys6, Cys2-Cys10, Cys5-Cys13 |
| Mechanism of Action | GC-C activation → cGMP elevation → CFTR-mediated chloride/bicarbonate & fluid secretion |
| Purity (HPLC) | ≥98.0% |
| Peptide Content | ≥90% |
| Mass Spectrometry | ESI-MS, observed [M+H]⁺ consistent with C₅₉H₇₉N₁₅O₂₁S₆ |
| Appearance | White to off-white lyophilized powder |
| Solubility | Soluble in water and aqueous buffers (PBS, saline); sparingly soluble in organic solvents |
| Endotoxin | ≤1.0 EU/mg |
| Water Content | ≤5.0% |
| Counter-ion | Acetate |
| pH | 5.0 – 7.0 (1 mg/mL in water) |
| Heavy Metals | ≤10 ppm |
| Residual Solvents | Within ICH Q3C limits |
| Storage | -20°C, protected from light and moisture; avoid repeated freeze-thaw cycles |
| Grade | Research Grade (RUO) |
| Reference / Clinical Context | Active principle of FDA-approved Linzess (IBS-C / CIC) — supplied as research reference |
| Applications | IBS-C, CIC, GC-C pharmacology, cGMP/CFTR signaling, visceral pain research |
| Certifications | ISO 9001, cGMP-compliant manufacturing, FDA facility registration |
| Packaging | 1 mg / 5 mg / 10 mg / 50 mg lyophilized vials |
| Shelf Life | 2 years (stored at -20°C) |
| Disclaimer | Research Use Only (RUO) — not for human diagnostic or therapeutic use |
Key Benefits — Linaclotide Research Peptide
Potent GC-C Receptor Agonism
Linaclotide activates guanylate cyclase-C at low nanomolar concentrations, providing a high-affinity tool agonist for dissecting GC-C pharmacology and benchmarking next-generation GI peptides.
Low-nM GC-CTriple-Disulfide Bioactive Conformation
Three intramolecular disulfide bonds (Cys1-Cys6, Cys2-Cys10, Cys5-Cys13) lock the 14-aa peptide into its rigid, ST-toxin-derived bioactive fold required for receptor engagement.
3 DisulfidescGMP-Mediated Secretion + Analgesia
Elevates intracellular cGMP to drive CFTR chloride/bicarbonate secretion, while elevated extracellular cGMP inhibits colonic nociceptors — a dual secretory and visceral-analgesic mechanism.
Dual Mechanism≥98% HPLC Purity 14-aa Research Peptide
HPLC-purified to ≥98.0% with ESI-MS confirmation, full COA, and ≤1.0 EU/mg endotoxin — a reproducible, fully characterized reference for reproducible research results.
≥98% HPLCApplications
IBS-C & Functional GI Disorder Research
Reference GC-C agonist for modeling irritable bowel syndrome with constipation and functional bowel disorders in preclinical and translational studies.
Chronic Constipation & Transit Studies
Tool peptide for gastrointestinal transit, fluid secretion, and colonic motility assays in chronic constipation and CIC research.
Guanylate Cyclase-C Pharmacology
High-affinity agonist for receptor binding, potency, and selectivity profiling of GC-C and comparative evaluation against uroguanylin-class peptides.
cGMP/CFTR Signaling
Probe for cGMP elevation and CFTR-mediated chloride/bicarbonate secretion in intestinal epithelial cell models.
Visceral Pain Research
Model compound for studying cGMP-mediated colonic nociceptor inhibition and visceral analgesia mechanisms.
Peptide Reference Standard & Assay Development
Fully characterized reference standard for HPLC, MS, and bioanalytical assay development and method validation.
Frequently Asked Questions
Linaclotide (CAS 851199-59-2) is a 14-amino-acid synthetic peptide agonist of guanylate cyclase-C (GC-C). It contains three intramolecular disulfide bonds (Cys1-Cys6, Cys2-Cys10, Cys5-Cys13) that lock it into the bioactive conformation, and is structurally related to the heat-stable enterotoxin (ST) family of E. coli. Linaclotide binds GC-C on the luminal surface of intestinal epithelial cells, elevating intracellular cGMP and activating the cystic fibrosis transmembrane conductance regulator (CFTR) to drive chloride, bicarbonate, and fluid secretion into the lumen. Elevated extracellular cGMP simultaneously inhibits colonic nociceptors, producing visceral analgesia. It acts locally in the gastrointestinal tract with minimal systemic absorption.
Both linaclotide and plecanatide are GC-C agonists, but they arise from distinct scaffolds. Linaclotide is a 14-amino-acid, triple-disulfide peptide derived from the E. coli heat-stable enterotoxin (ST) scaffold, whereas plecanatide is a 16-amino-acid uroguanylin analog with two disulfide bonds. Linaclotide’s three disulfide bonds impose a rigid, high-affinity conformation that activates GC-C at low nanomolar concentrations, conferring greater potency than the uroguanylin-class peptide. This structural distinction is a key focus of comparative GC-C pharmacology research.
Linaclotide is used across gastrointestinal and functional bowel disorder research: irritable bowel syndrome with constipation (IBS-C), chronic idiopathic constipation (CIC), and functional GI disorders. Specific applications include guanylate cyclase-C pharmacology, cGMP/CFTR signaling studies, gastrointestinal transit and fluid secretion assays, visceral pain and nociceptor inhibition research, and use as a reference standard for peptide assay development. As the active principle of the FDA-approved Linzess, it is the benchmark compound for mechanism-of-action and comparative efficacy studies.
Linaclotide lyophilized powder should be stored at -20°C, protected from light and moisture. For reconstitution, dissolve in sterile water, PBS, or an appropriate aqueous buffer, taking care to preserve the three intramolecular disulfide bonds that maintain the bioactive conformation. Avoid repeated freeze-thaw cycles, which can promote aggregation and loss of activity — aliquot reconstituted peptide into single-use portions and store working solutions at -20°C for short-term use. Verify peptide content and integrity by HPLC and mass spectrometry before critical experiments.
Every linaclotide shipment includes: COA (HPLC purity ≥98.0%, peptide content, endotoxin, water content, heavy metals), MSDS, HPLC chromatogram, ESI-MS mass spectrum, and endotoxin certificate. UPOR Biotech operates under ISO 9001 quality management, cGMP-compliant manufacturing, and FDA facility registration. Linaclotide is supplied as Research Grade (RUO) material — Research Use Only, not for human diagnostic or therapeutic use.