Cagrilintide Molecular Weight, Sequence & CAS Reference

Chemical Overview and Identifier Reference

Cagrilintide is a synthetic lipidated amylin analog engineered for preclinical investigation into dual amylin and calcitonin receptor signaling dynamics. As a research compound, it represents a modified peptide structure designed to exhibit extended plasma half-life in animal models compared to native human amylin. Understanding the exact molecular parameters—including formula, mass, and CAS registration—is essential for accurate quantitative assays and structural characterization.

Researchers evaluating cagrilintide must account for its structural modifications, specifically the introduction of a C18 or C20 fatty diacid moiety linked via a hydrophilic spacer. When sourcing from PX1 Research, laboratory personnel receive lot-specific analytical documentation validating identity via liquid chromatography-mass spectrometry (LC-MS) and high-performance liquid chromatography (HPLC). All reference materials are produced in GMP-compliant facilities and tested in ISO 17025 accredited laboratories.

Primary Chemical Data & Physical Properties

The fundamental chemical identity of cagrilintide is established through standardized analytical metrics. The primary keyword sequence and chemical data include assigned reference numbers, gross empirical formulas, and net target weights used during mass spectrometry verification.

• Chemical Name: Acylated human amylin analog (lipidated amylin receptor agonist) • IUPAC Name: Reference designation derived from 37-amino acid sequence with N-epsilon acylation • CAS Registry Number: 1415456-99-3 • Empirical Formula: C191H303N47O58 (varies depending on exact salt/hydration state) • Average Molecular Weight: Approx. 4409.8 g/mol • Monoisotopic Mass: ~4407.2 Da • Physical Form: Lyophilized white to off-white powder • Counterion: Trifluoroacetate (TFA) or Acetate salt form

Note: Molecular weight values reported on analytical certificates represent the free base peptide weight or the net salt-adjusted mass depending on the standard applied. Laboratory protocols must distinguish between gross mass (including counterion) and net peptide weight when preparing working molar concentrations. Additional catalog options can be explored across our complete index of all peptides.

Cagrilintide Amino Acid Sequence and Structural Modifications

The primary sequence of cagrilintide is derived from the 37-amino acid backbone of human amylin (islet amyloid polypeptide, or IAPP), containing selective substitutions to enhance solubility, prevent self-aggregation into amyloid fibrils, and permit side-chain acylation. Native amylin is prone to rapid biophysical precipitation in aqueous solution; thus, sequence modifications are critical for maintaining stability during in vitro assays.

The published sequence framework of cagrilintide incorporates an acylated lysine residue linked to a fatty acid diacid chain via a linker moiety (such as gamma-glutamyl and OEG units). This modification increases binding affinity to serum albumin in preclinical models, reducing renal clearance.

Sequence structure (backbone sequence notation): K-C-N-T-A-T-C-A-T-Q-R-L-A-N-F-L-V-H-S-S-N-N-F-G-P-I-L-P-P-T-N-V-G-S-N-T-Y-NH2 (incorporating specific side-chain acylation at designated lysine residues, such as 20-icosanedioyl-gGlu-2xOEG, and intra-molecular disulfide bridging between Cys2 and Cys7).

The presence of the intramolecular disulfide loop between Cys2 and Cys7 is essential for biological activity at the amylin receptor complex. Disruption of this disulfide bridge via reducing agents (e.g., DTT or BME) leads to loss of receptor activation in cell-based assays. Further structural details and background literature are accessible through the PX1 research hub.

Molecular Weight & Mass Spectrometry Verification

In analytical quality control, verifying the cagrilintide molecular weight sequence requires electrospray ionization mass spectrometry (ESI-MS) or matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) spectrometry. Due to the high molecular mass (~4.4 kDa), ESI-MS typically generates a distribution of multiply charged ions (e.g., [M+3H]3+, [M+4H]4+, and [M+5H]5+).

Deconvolution of the observed mass-to-charge (m/z) spectrum yields the neutral average molecular weight. A discrepancy between observed mass and theoretical mass greater than 1.0 Da may indicate oxidation (e.g., methionine or tryptophan oxidation, +16 Da), incomplete deprotection, or improper disulfide bond formation (-2 Da per disulfide pair). PX1 Research provides batch-specific spectra for every lot; researchers can review these metrics on our dedicated COA verification page.

Salt Form Dynamics: Counterion Impact on Net Peptide Content

Custom synthesis of cagrilintide utilizes solid-phase peptide synthesis (SPPS), where cleavage from the resin and final HPLC purification typically employ trifluoroacetic acid (TFA). Consequently, the raw synthesized material exists as a cagrilintide TFA salt, where basic residues (arginine, lysine, N-terminus) form ionic pairs with trifluoroacetate anions.

The presence of TFA counterions and residual hydration water means that the gross mass of a lyophilized vial is not 100% active peptide. Net Peptide Content (NPC) for research-grade peptides usually ranges between 70% and 90%. The remaining 10% to 30% consists of counterions (TFA or acetate) and bound water.

Calculation Example for Laboratory Dosing: If a vial contains 5.0 mg of gross lyophilized powder with a certified Net Peptide Content of 82.5%, the actual mass of cagrilintide peptide present is: 5.0 mg gross * 0.825 = 4.125 mg net cagrilintide peptide.

Failing to adjust for salt content leads to systematic concentration errors in quantitative biochemical assays. Researchers performing high-precision binding or enzymatic studies can request conversion to acetate salt or verify exact TFA percentage via ion chromatography.

Comparative Structural Analysis: Cagrilintide vs. Related Metabolic Peptides

To contextualize the cagrilintide molecular weight sequence, analytical laboratories frequently compare its biophysical properties against other metabolic research peptides within the amylin and incretin classes. Structural variations in chain length, lipidation, and counterion mass directly influence solution behavior and receptor binding affinity.

Compared to pramlintide, an unlipidated 37-amino acid amylin analog (MW ~3949 g/mol), cagrilintide exhibits a significantly higher molecular weight (~4409.8 g/mol) due to its synthetic lipid diacid tail. In contrast, GLP-1 receptor agonists like semaglutide (MW ~4113.6 g/mol) and dual GIP/GLP-1 agonists like tirzepatide (MW ~4813.5 g/mol) feature distinct primary sequence backbones derived from glucagon-like peptide sequences rather than the calcitonin/amylin gene family.

Understanding these structural distinctions allows investigators to design orthogonal control assays when comparing selective amylin/calcitonin receptor co-agonism against classical incretin receptor pathways in vitro.

Reconstitution Parameters and In Vitro Solution Physics

Due to its hydrophobic lipid moiety and sequence composition, reconstituting cagrilintide requires careful consideration of pH, ionic strength, and solvent choice. Direct dissolution in neutral phosphate-buffered saline (PBS, pH 7.4) may lead to self-association or clear-to-cloudy phase transitions if concentration thresholds are exceeded.

Recommended Laboratory Protocol for Reconstitution: 1. Allow the vial to equilibrate to room temperature (20°C to 25°C) before opening to prevent atmospheric condensation inside the container. 2. Reconstitute initially in sterile dilute acetic acid (e.g., 10–50 mM, pH 4.0–5.0) or sterile bacteriostatic water, gently swirling without vigorous vortexing. 3. Dilute further into working buffer solutions (such as cell culture media or assay buffers containing 0.1% BSA) immediately prior to execution of assays.

To calculate precise volumetric dilutions based on net peptide mass and target micromolar concentrations, researchers should utilize our free digital tool: the PX1 reconstitution calculator.

Receptor Selectivity and Preclinical Assay Mechanisms

In vitro data indicate that cagrilintide functions as a potent, non-selective agonist at human amylin receptors (AMYR1, AMYR2, and AMYR3) as well as the human calcitonin receptor (CTR). The AMYR complexes consist of the calcitonin receptor core heterodimerized with receptor activity-modifying proteins (RAMP1, RAMP2, or RAMP3).

Preclinical studies suggest that dual activation of AMYR and CTR pathways induces intracellular cyclic AMP (cAMP) accumulation in transfected CHO or HEK293 cell lines expressing human RAMP/CTR complexes. Because cagrilintide maintains high potency across all three RAMP complexes, it serves as a valuable control compound for dissecting RAMP-dependent vs. RAMP-independent calcitonin receptor signaling cascade dynamics in vascular and metabolic tissue models.

All products supplied by PX1 Research are intended exclusively for in vitro functional assays, receptor binding studies, and physical chemistry research. They are not for human or veterinary administration.

Storage Stability, Handling, and Degradation Pathways

Lyophilized cagrilintide exhibits optimal long-term chemical stability when stored at -20°C to -80°C in a desiccated environment protected from light. Under these conditions, the solid peptide remains stable for up to 24 months without significant degradation.

Primary chemical degradation pathways for acylated amylin analogs include: • Oxidation: Oxidation of methionine or cystine residues if exposed to air or peroxides. • Deamidation: Conversion of asparagine (Asn) or glutamine (Gln) residues to aspartic/glutamic acid at alkaline pH. • Hydrolysis: Cleavage of peptide bonds under strongly acidic or basic conditions. • Aggregation: Non-covalent association driven by hydrophobic interaction of the lipid side chain at high concentrations.

Reconstituted liquid aliquots should be frozen at -80°C to minimize repeated freeze-thaw cycles, which accelerate physical precipitation. For institutional bulk requirements, lab managers can apply for structured purchasing via our wholesale portal.

PX1 Research Sourcing and Quality Assurance Standards

PX1 Research maintains rigorous quality control frameworks for all reference peptides. Cagrilintide supplied to research institutions undergoes multi-step verification to guarantee chemical fidelity and batch reproducibility.

Key quality standards include: • USA-Based Manufacturing: Synthesized under strict process controls. • High Purity: Guaranteed ≥98% purity verified by analytical RP-HPLC. • Mass Verification: High-resolution LC-MS sequence confirmation. • Endotoxin Testing: Validated by Chromogenic LAL assay (typically <0.05 EU/μg). • Logistics: Fast, reliable fulfillment shipped directly from facilities in California and Arizona.

Researchers requiring custom salt exchanges, specialized fill sizes, or comprehensive certificate documentation can rely on PX1 Research for fully transparent analytical data.