B7-33

B7-33 is a single-chain peptide analog of human H2 relaxin engineered to retain activity at the relaxin family peptide receptor 1 (RXFP1) while eliminating the native two-chain, disulfide-linked architecture. Its simplified linear design makes it a practical research tool for probing relaxin biology in controlled laboratory settings. Investigators use B7-33 to study receptor engagement and downstream signaling without the synthetic complexity of full-length H2 relaxin. The compound is supplied strictly for in-vitro and laboratory research use only.

B7-33 is investigated as a biased agonist at RXFP1 that preferentially engages pathways linked to extracellular-matrix regulation rather than the full spectrum of native relaxin signaling. In cell-based systems, receptor activation by B7-33 has been associated with modulation of cyclic AMP, nitric-oxide pathways, and downstream effectors that influence collagen synthesis and degradation. This biased profile allows researchers to dissect how selective RXFP1 engagement alters matrix metalloproteinase activity and fibrotic gene expression. Studies focus on molecular readouts in cultured fibroblasts and tissue explants.

Research with B7-33 centers on anti-fibrotic signaling and matrix remodeling in cardiac, renal, and pulmonary model systems. Investigators examine its effects on collagen turnover, fibroblast activation, and extracellular-matrix deposition in cell cultures and preclinical tissue models of fibrosis. The peptide is also employed to compare biased versus balanced RXFP1 agonism and to map structure–function relationships of relaxin-family ligands. These studies remain confined to laboratory and animal-model contexts for mechanistic insight.

Published laboratory work indicates that B7-33 can reduce markers of collagen accumulation and promote matrix-remodeling enzyme activity in fibrotic cell and tissue models. Comparative studies have shown that its simplified single-chain structure still supports RXFP1-dependent anti-fibrotic signaling while offering improved synthetic accessibility relative to native H2 relaxin. Findings are derived from controlled in-vitro assays and animal models of organ fibrosis and do not extend to clinical interpretation. Results continue to inform the design of next-generation relaxin-mimetic research probes.

B7-33 is typically handled as a lyophilized peptide and reconstituted under sterile laboratory conditions for use in cell-culture or biochemical assays. Stability, solubility, and receptor-binding characteristics should be verified for each experimental system. Researchers are advised to employ appropriate controls when comparing B7-33 with native H2 relaxin or other RXFP1 ligands. The material is intended solely for qualified laboratory investigation and is not for human or animal consumption.