PMX-53 is a synthetic peptidic research compound that functions as a potent, orally active antagonist of the complement C5a receptor (C5aR1/CD88). It selectively binds C5aR1, displays low-affinity agonism at MrgX2, and is used in preclinical studies of inflammation, nociception, cancer, and atherosclerosis.
- Potent complement C5a receptor antagonist (IC50 = 20 nM).
- Inhibits C5a-induced neutrophil myeloperoxidase release (IC50 = 22 nM).
- Inhibits C5a-induced neutrophil chemotaxis (IC50 = 75 nM).
- Low-affinity MrgX2 agonist that can induce mast cell degranulation.
- Peptidic sequence: Ac-Phe-{Orn}-Pro-{dCha}-Trp-Arg with Orn2-Arg6 lactam bridge.
- Molecular formula C47H65N11O7; molecular weight 896.09 g/mol.
- Available in small research pack sizes for in vitro and in vivo studies.