B7-33

B7-33 is a 27-residue single-chain peptide derived from the B-chain of the relaxin-2 hormone. Native relaxin-2 is a two-chain (A+B chain, like insulin) heterodimer that activates the relaxin-family-receptor-1 (RXFP1, formerly LGR7) — a large G-protein-coupled receptor implicated in fibrosis, cardiovascular biology and pregnancy physiology. B7-33 was engineered as a single-chain analogue retaining functional RXFP1 agonism without the cyclic-disulfide-bridged structure of native relaxin.

ChEMBL ID CHEMBL5997095.

B7-33 binds and activates RXFP1, producing the anti-fibrotic and vasoactive effects associated with the relaxin pathway. The single-chain structure is more amenable to synthesis and storage than full relaxin-2 (which requires precise inter-chain disulfide bridging) while retaining the principal receptor-engagement properties.

Investigated in preclinical models of cardiac and pulmonary fibrosis, atrial fibrillation, and vascular remodelling. Relaxin-pathway agonism is an emerging research area; B7-33 provides a more tractable single-chain probe than native two-chain relaxin-2.

Supplied as a research-grade reference standard for laboratory use only. Not a licensed medicinal product in the United Kingdom and not approved by the MHRA for human or veterinary administration. Sale is restricted to researchers, institutions and laboratory professionals; the compound must be retained within research premises. End-user compliance with the Human Medicines Regulations 2012, the Misuse of Drugs Act 1971 (where applicable) and local institutional biosafety policy is the responsibility of the buyer.