B7-33 6mg

B7-33 is a synthetic peptide engineered from the H2-relaxin (relaxin-2) protein and designed to engage relaxin family receptor signaling, particularly via RXFP1. Relaxin-2 and its receptors are studied for roles in extracellular matrix remodeling, vascular signaling, and broader tissue homeostasis. B7-33 is described in the research literature as a functionally selective (biased) RXFP1 agonist, meaning it may preferentially activate certain downstream pathways relative to others under experimental conditions.

Most research involving B7-33 focuses on mechanistic questions related to fibrosis-associated signaling and extracellular matrix turnover. Studies frequently evaluate ERK1/2 pathway activation, matrix metalloproteinase regulation (such as MMP-2), and markers of collagen synthesis and degradation. Within laboratory settings, B7-33 is used as a tool to examine how RXFP1-mediated signaling influences fibroblast behavior, matrix organization, and vascular cell responses in controlled models.

Sequence: VIKLSGRELVRAQIAISGMSTWSKRSL
PubChem CID: 318164840
Synonyms: (B7-33)H2, GTPL9321

Source: Chemical Science

Research applications for B7-33 are conducted in vitro and in animal models to evaluate RXFP1-associated signaling and downstream extracellular matrix remodeling endpoints. Typical experimental designs compare B7-33–treated groups with vehicle controls and may include receptor antagonism, pathway inhibitors, or comparisons to full-length relaxin-2 to characterize pathway selectivity.

Commonly measured endpoints include fibroblast activation markers (e.g., α-SMA–associated signatures), collagen content or deposition metrics (histology-based scoring or biochemical collagen assays), and expression or activity of ECM remodeling enzymes such as MMPs (including MMP-2) and their regulators. In preclinical cardiac or pulmonary fibrosis models, investigators may quantify tissue collagen fraction, remodeling-associated gene expression panels, and structural or functional readouts relevant to the specific model, interpreted as changes relative to controls.

In vascular-focused studies, B7-33 is evaluated using endpoints such as endothelium-dependent relaxation responses in isolated vessel preparations, nitric oxide–linked signaling markers, and inflammatory or oxidative stress indicators in vascular tissues, measured relative to controls. In biomaterials research, B7-33 has been explored as a locally released factor from coatings, with endpoints including fibrotic capsule thickness, inflammatory cell infiltration, and collagen organization surrounding implanted materials under defined experimental conditions. Across applications, findings are interpreted as preclinical, mechanism-focused observations and do not imply therapeutic, preventive, or clinical use.

B7-33 demonstrates preferential activation of extracellular signal-regulated kinase (ERK1/2) signaling following RXFP1 receptor engagement, with minimal activation of cyclic AMP–dependent pathways. This signaling bias enables targeted examination of kinase-driven transcriptional and post-translational responses.

Mechanistic studies indicate that RXFP1 activation by B7-33 facilitates receptor interaction with angiotensin II type-2 receptors, contributing to downstream modulation of matrix-associated signaling networks. These interactions are assessed using phosphorylation assays, gene expression profiling, and extracellular matrix component analysis.

In preclinical animal and cellular studies, B7-33 has been investigated for its effects on extracellular matrix composition, metalloproteinase regulation, and vascular signaling endpoints. Experimental outcomes are measured using histological staining, biochemical quantification, and receptor signaling assays.

Additional research explores the incorporation of B7-33 into biomaterial coatings to evaluate cellular responses to implanted substrates, focusing on matrix deposition and capsule formation in controlled experimental systems.

B7-33 is supplied as a synthetic research peptide intended for laboratory use only. Identity and purity are verified using analytical techniques such as high-performance liquid chromatography (HPLC) and mass spectrometry (MS).

This material is not formulated for diagnostic, medical, veterinary, or clinical application.

The above literature was researched, edited and organized by Dr. E. Logan, M.D. Dr. E. Logan holds a doctorate degree from Case Western Reserve University School of Medicine and a B.S. in molecular biology.

Dr. Hossain is being referenced as one of the leading scientists involved in the research and development of B7-33. In no way is this doctor/scientist endorsing or advocating the purchase, sale, or use of this product for any reason. There is no affiliation or relationship, implied or otherwise, between Peptide Sciences and this doctor.

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4. “RXFP3 Gene – GeneCards | RL3R1 Protein | RL3R1 Antibody.” [Online]. Available: https://www.genecards.org/cgi-bin/carddisp.pl?gene=RXFP3. [Accessed: 18-Mar-2020].
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7. J. D. Silvertown, J. Ng, T. Sato, A. J. Summerlee, and J. A. Medin, “H2 relaxin overexpression increases in vivo prostate xenograft tumor growth and angiogenesis,” Int. J. Cancer, vol. 118, no. 1, pp. 62–73, Jan. 2006, doi: 10.1002/ijc.21288.
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9. S. A. Marshall et al., “B7-33 replicates the vasoprotective functions of human relaxin-2 (serelaxin),” Eur. J. Pharmacol., vol. 807, pp. 190–197, Jul. 2017, doi: 10.1016/j.ejphar.2017.05.005.
10. Afroze Syeda H et al., “Abstract P3042: Novel Peptide B7-33 and It’s Lipidated Derivative Protect Cytotrophoblasts From Preeclampsia Phenotype in a Cellular Model of the Syndrome,” Hypertension, vol. 74, no. Suppl_1, pp. AP3042–AP3042, Sep. 2019, doi: 10.1161/hyp.74.suppl_1.P3042.
11. “Coatings Releasing the Relaxin Peptide Analogue B7-33 Reduce Fibrotic Encapsulation | Request PDF.” [Online]. Available: https://www.researchgate.net/publication/337205944_Coatings_Releasing_the_Relaxin_Peptide_Analogue_B7-33_Reduce_Fibrotic_Encapsulation. [Accessed: 19-Mar-2020].

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The products offered on this website are furnished for in-vitro studies only. In-vitro studies (Latin: in glass) are performed outside of the body.  These products are not medicines or drugs and have not been approved by the FDA to prevent, treat or cure any medical condition, ailment or disease.  Bodily introduction of any kind into humans or animals is strictly forbidden by law.

For Laboratory Research Only. Not for human use, medical use, diagnostic use, or veterinary use.