Product details
B7-33 is a 27-amino-acid single-chain peptide analog of native relaxin-2 (H2-relaxin), engineered to retain the RXFP1 receptor agonism of the parent two-chain relaxin while being synthesizable as a simple single-chain peptide rather than the disulfide-bonded heterodimer of native relaxin. The molecule is a biased RXFP1 agonist, preferentially activating the ERK1/2 pathway downstream of RXFP1 while showing reduced activation of the cAMP pathway, a pharmacological profile that the developing group hypothesized would produce the anti-fibrotic and tissue-remodeling effects of relaxin without the dose-limiting cardiovascular effects associated with full-agonism dosing.
Peptuno supplies B7-33 as a lyophilized 27-residue peptide at ≥99.0% HPLC purity. As a single-chain linear peptide (no disulfide bridges), B7-33 is significantly easier to synthesize than the native disulfide-bonded relaxin heterodimer, this is the practical advantage of the biased-agonist design beyond the pharmacology. The analytical packet covers peak-integration HPLC, mass spec, and sequence verification on request. Two fill sizes (2 mg and 10 mg) cover typical research workflows in fibrosis, cardiovascular, and tissue-remodeling research models.
FAQ
- What does 'biased agonist' mean in the context of B7-33 and RXFP1 signaling?
- Receptor signaling biology in the last decade has recognized that G-protein-coupled receptors (GPCRs) can engage multiple downstream signaling cascades, primarily G-protein-pathway and β-arrestin-pathway routes, and that different ligands can preferentially activate one cascade over the other. A 'biased' agonist is one that activates one downstream pathway more strongly than others. B7-33 is described as a biased RXFP1 agonist because it preferentially activates the ERK1/2 phosphorylation cascade (the pathway hypothesized to drive the anti-fibrotic and tissue-remodeling effects of relaxin) while showing reduced activation of the cAMP pathway (which contributes to relaxin's cardiovascular effects). The biased-agonist design strategy is intended to dissociate the desired therapeutic effects from the dose-limiting side effects.
- How is B7-33 easier to synthesize than native two-chain relaxin?
- Native human relaxin-2 (H2-relaxin) is a 53-amino-acid heterodimer with two chains connected by two interchain disulfide bonds plus one intrachain disulfide on the A-chain. Synthesizing the native molecule by SPPS requires synthesizing each chain separately, then performing controlled oxidative folding to form the three disulfide bonds in the correct regiochemistry, a process that produces 5-15% yield of the correctly-folded product against a background of scrambled disulfide isomers. B7-33 is a single 27-residue linear peptide with no disulfide bonds, synthesizable by routine SPPS at 50-80% yield. The simplification makes B7-33 substantially more accessible at research and commercial scale than native relaxin while preserving the RXFP1-agonism that drives the biological readouts of interest.
Certificate of Analysis (COA)
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