Description

B7-33 Peptide – Advanced Relaxin Mimetic for Cardiovascular & Anti-Fibrotic Research

B7-33 Peptide (Relaxin Mimetic) – RXFP1 Agonist Research Compound

B7-33 is a synthetic single-chain peptide analogue of human relaxin-2 (H2 relaxin), developed as a minimal potent derivative of the native peptide hormone . Unlike native H2 relaxin, which features a complex two-chain, three-disulfide-bond structure that is difficult and costly to synthesize, B7-33 maintains the organ-protective effects of relaxin in a simplified format . It functions as a selective agonist of the Relaxin Family Peptide Receptor 1 (RXFP1), preferentially activating the pERK signaling pathway over cAMP in cells natively expressing RXFP1 . This research-grade peptide is strictly for laboratory investigation and is not intended for human consumption.

Key Factual Details

Mechanism of Action & Research Applications

Selective RXFP1 Receptor Agonist: B7-33 binds to RXFP1, which is the primary receptor for human relaxin-2, and preferentially activates the pERK pathway without inducing significant cAMP signaling activation . This biased agonism replicates the beneficial effects of native relaxin while potentially avoiding pathways associated with tumorigenesis .

Anti-Fibrotic Activity: The peptide significantly modulates profibrotic gene expression, showing greater downregulation of Collagen Type I α-1 Chain (COL1A1) than reference anti-fibrotic agents, while maintaining biocompatibility with normal fibroblasts .

Cardioprotective Effects: B7-33 equivalently reduces left ventricular fibrosis, normalizes inflammation and cardiomyocyte hypertrophy, and restores blood vessel density and aortic contractility in experimental models of cardiomyopathy, matching the protective effects of native relaxin .

Research Applications:

• Cardiovascular Research: Investigating heart failure, myocardial infarction, and vascular dysfunction 

• Fibrosis Research: Exploring hypertrophic scar management, organ fibrosis, and TGF-β/Smad pathway modulation 

• Preeclampsia Models: Evaluating therapeutic potential in hypertensive pregnancy disorders 

• Drug Delivery Systems: Investigating electrospun peptide-based dressings and controlled release formulations 

Research Parameters

All dosages are for in-vitro and preclinical research use only and are not intended for human consumption.

In Vitro Research Concentrations :

• Fibroblast viability studies: 0.03–0.3 μg/mL (72-hour exposure) 

• Gene expression modulation: 298.7 ng/mL 

• Controlled release dressings: 1.5% w/w loading 

Preclinical Animal Dosing :

• Cardiomyopathy model (mouse): 0.25 mg/kg/day, subcutaneous 

• Preeclampsia model (rat): 35 μg, intraperitoneal biweekly from gestation day 10-20 

• RUPP model (rat): Twice weekly intravenous from gestation day 10-20 

Storage:

• Store lyophilized powder at -20°C

• Protect from light and moisture