ACE-031
Stocked in 1mg vials at MontanaPep in Great Falls, Montana. Sold for laboratory research use only.
| Size | Catalog no. | Price per vial |
|---|---|---|
| 1mg vials | AE1 | $60 |
Classification
Recombinant Fc-fusion protein (NOT a peptide); human development halted for safety
Structure and chemistry
ACE-031, later renamed ramatercept, is a dimeric recombinant fusion protein: the extracellular domain of the human activin receptor type IIB (ActRIIB, gene ACVR2B) fused to the Fc portion of human immunoglobulin G1. It is roughly 110 kilodaltons and glycosylated, and it requires mammalian cell expression to produce. This is not a peptide and cannot be made by peptide synthesis — a distinction with direct practical consequences discussed under testing below.
What the published research shows
ACE-031 has real human clinical data, and the reason it matters is unusual: it worked, and was stopped anyway. Phase 1 studies in healthy volunteers showed increases in lean body mass and thigh muscle volume. A Phase 2 trial in ambulatory boys with Duchenne muscular dystrophy showed increased lean body mass and attenuated declines in thigh muscle volume and six-minute walk distance. Development was halted regardless, because of a vascular safety signal that the monitoring committee could not rule out worsening with continued exposure.
Mechanism of action
A soluble decoy receptor. ActRIIB is the docking site myostatin uses to initiate its growth-suppressing signal; ACE-031 presents a free-floating copy of that docking site, capturing myostatin in the circulation before it reaches muscle. The problem is that the receptor is not myostatin-specific: it also binds other TGF-beta superfamily ligands, and the vascular adverse events were attributed to off-target inhibition of BMP9 and BMP10, which are critical regulators of endothelial cell function and vascular development.
Development history
Developed by Acceleron Pharma, with Shire PLC as collaborator, as a treatment for muscle-wasting conditions with Duchenne muscular dystrophy as the primary clinical target. It was the first ActRIIB-Fc ligand trap to reach human trials in that indication.
Current regulatory status
ACE-031 is not approved by any regulator and its development was formally discontinued in May 2013 after the Phase 2 trial was halted. Note the related catalog entries: GDF-8 is myostatin itself, the target ACE-031 was built to intercept, and Follistatin acts on the same pathway by a different route.
Analytical testing
This deserves particular scrutiny. ACE-031 is a glycosylated dimeric fusion protein produced in mammalian cell culture; it cannot be manufactured by solid-phase peptide synthesis, and correct Fc fusion, dimerization and glycosylation are all required for the molecule to behave as the Acceleron biologic did. Material sold under this name should be assessed by methods appropriate to a recombinant protein — identity, molecular weight, dimer integrity, glycosylation profile, aggregate content and endotoxin. A COA reporting only HPLC peptide purity does not establish that the material is the fusion protein at all.
Ordering from Great Falls
MontanaPep, also known as Montana Peptides, is an independently owned supplier based at 715 13th Ave S, Great Falls, Montana. Local pickup is available by arrangement, and we ship to research addresses across Montana including Billings, Missoula, Bozeman, Helena, Butte, Kalispell and Havre. Call (406) 799-0812 or email customerservice@montanapep.com.