ACE-031, also known as ActRIIB-Fc, is a recombinant fusion protein consisting of the extracellular ligand-binding domain of human activin receptor type IIB (ActRIIB) fused to the Fc region of human IgG1. With an approximate molecular weight of 60,000 g/mol, ACE-031 is structurally classified as a soluble decoy receptor engineered to sequester multiple ligands within the TGF-beta superfamily, including Myostatin (GDF-8) and Activin A. Produced via recombinant expression, ActRIIB-Fc represents a distinct pharmacological approach, ligand trapping, that has generated significant research interest in preclinical musculoskeletal biology.

ACE-031 has been extensively investigated in preclinical research for its capacity to simultaneously antagonise multiple TGF-beta superfamily ligands through a single molecule. Unlike antibody-based approaches that target a single ligand, the soluble decoy receptor design of ActRIIB-Fc has been characterised in published studies as engaging Myostatin, Activin A, GDF-11, and other structurally related ligands through the ActRIIB ligand-binding domain. In vitro studies in cell-based signalling preparations have examined ActRIIB-Fc’s binding characteristics and ligand neutralisation across the ActRIIB ligand panel, documenting that GDF-8, GDF-11, and Activin A all signal through the ActRIIB receptor system and are susceptible to broad-spectrum neutralisation via soluble receptor-based trapping [1]. Preclinical studies have investigated body composition changes, skeletal muscle cross-sectional area, and contractile properties following administration of soluble ActRIIB constructs, documenting fibre type-independent increases in skeletal muscle mass and cross-sectional area under controlled experimental conditions [2], making ActRIIB-Fc a key reference compound in multi-ligand trapping research within the TGF-beta superfamily.

ACE-031 is manufactured in a cGMP compliant laboratory to a guaranteed purity of 98% or above. Every batch is independently tested using HPLC and MS-UPLC analysis before dispatch. Vials are vacuum sealed and stored in a temperature controlled, monitored cold storage system. Certificates of Analysis are available on request.

Sold strictly for in vitro research purposes only. Not for human consumption. Intended for use by qualified researchers in laboratory settings only.

Editorial Team

Dr. Martina Rossi, PhD

Scientific Contributor and Reviewer

Reviewed and approved 14 June 2026

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