Molecular Structure Explorer
ACE-031
Structure of the compound covered in this guide.
Verified structure pending review
Last reviewed: October 2026 · Cleared Peptides research team
Research use only. ACE-031: Research Guide to the ActRIIB-Fc Ligand Trap is supplied for laboratory research. It is not a drug, food, cosmetic, or dietary supplement. It is not FDA-approved. It is not for human or veterinary administration. This page does not give a dose or a method of administration. A study cited on this page describes that study’s own test article. It does not make this lot an approved medicine. To check a fact, open the PubMed or DOI link, confirm the authors and year, and match the paper’s compound name, CAS number, or sequence to the specification table. The full method is on the research desk page. Identity and purity for a lot are only what that lot’s certificate of analysis reports. An HPLC percentage is not a sterility result and not an endotoxin result unless the certificate prints those tests.
ACE-031 (ramatercept) is a recombinant fusion protein combining the extracellular ligand-binding domain of activin receptor type IIB (ActRIIB) with the Fc region of human IgG1. It acts as a soluble ligand trap for TGF-β superfamily members such as myostatin and activins.
ACE-031 Structure and Identifiers
| Name | ACE-031 |
|---|---|
| Synonyms | ActRIIB-Fc; ramatercept |
| CAS number | Not available. A single small-molecule CAS number is not assigned because this material is a recombinant protein preparation. |
| Structure | ActRIIB extracellular domain fused to IgG1 Fc |
| Form | Lyophilized powder |
Ligand Traps
Rather than blocking a receptor, a ligand trap binds circulating ligands so they cannot reach cell-surface receptors. Fc fusion dimerizes the construct and increases its stability.
Published In-Vitro Research Areas
- Ligand-binding and SMAD2/3 reporter assays
- Comparison with follistatin
This summary describes laboratory research only and makes no claim about effects in humans or animals.
Purity Testing and Storage
Every lot of ACE-031 supplied by Cleared Peptides is tested by an independent laboratory for identity and purity (or composition, for multi-component preparations), and the lot Certificate of Analysis is published on our COA page. Store lyophilized ACE-031 at −20 °C, sealed, dry and protected from light. Allow the vial to reach room temperature before opening and minimize freeze–thaw cycles. Handle according to your institution’s chemical-hygiene procedures.
Research materials referenced in this guide
Analytical testing notes for ACE-031
ACE-031 is identified in this guide as CAS Not available. A single small-molecule CAS number is not assigned because this material is a recombinant protein preparation.. An identity test compares a measurement with those values. A mass spectrum is the usual measurement for a peptide. FTIR, when a certificate uses it, is a supporting infrared fingerprint and is less specific for closely related sequences.
For ACE-031, routine chemical characterization is reversed-phase HPLC for area-percent purity and mass spectrometry for identity against the formula and mass in the table above. Oxidizable residues (cysteine, methionine, tryptophan) and deamidating residues (asparagine, glutamine), when the sequence contains them, are typical related-impurity questions for the chromatogram and the mass spectrum.
HPLC purity for this material is an area-percent result at the wavelength and gradient the laboratory states, commonly ultraviolet detection near 214 nm on a reversed-phase column. The instrument is a gradient pump, injector, column oven, and UV or diode-array detector. That percentage is not the number of milligrams in the vial. Water, acetate, trifluoroacetate, and other UV-silent material can dominate the gross weight while the purity figure stays high. Net peptide content, from an assay or amino-acid analysis, is the separate result to read when the certificate reports it.
A sterility test and an endotoxin test are not included in a chemical purity result. The compendial sterility test is a culture method (USP <71>): membrane filtration or direct inoculation into fluid thioglycollate medium and soybean-casein digest medium, incubated for 14 days. A PCR sterility screen uses a thermal cycler to detect microbial DNA and is a different method. The endotoxin test (USP <85> LAL, or USP <86> recombinant Factor C) reports endotoxin units with an incubating reader or a cartridge reader. Use a result only when that method is printed on the lot certificate. One published example in this catalog states that the report does not cover microbial contamination or endotoxins. The full description of equipment, standards, and how US laboratory accreditation works is in peptide analytical testing. Lot records are on the COA page.
Frequently Asked Questions
Is ACE-031 a peptide?
It is a recombinant fusion protein, much larger than a typical research peptide.
Is ACE-031 for human use?
No. Cleared Peptides supplies ACE-031 for laboratory research use only; it is not for human or veterinary use.
Selected References
Peer-reviewed literature on the compounds discussed in this guide, listed as scientific background for laboratory researchers. Citation does not imply endorsement by the authors or any use other than in-vitro research.
- George Carlson C, et al. Soluble activin receptor type IIB increases forward pulling tension in the mdx mouse. Muscle Nerve. 2011;43(5):694-9. PubMed 21462203 · DOI
Research Use Only Notice
This guide is provided for educational and laboratory reference purposes. It summarizes published, primarily in-vitro and structural research literature and does not describe, recommend or imply any use in humans or animals. Products sold by Cleared Peptides are for laboratory research use only; they are not drugs, foods, cosmetics or dietary supplements, are not FDA-approved, and are not intended to diagnose, treat, cure, mitigate or prevent any disease. No dosing, administration or therapeutic information is provided.
