B7-33 (6mg) Research Peptide: A Single‑Chain Relaxin Mimetic for Fibrosis, Cardiac & Vascular Studies

If your research investigates fibrosis, cardiac remodelling, or vascular dysfunction, B7-33 (6mg) research peptide offers a precisely defined and mechanistically distinct synthetic tool. B7-33 is a single‑chain peptide analogue derived from the B‑chain of human relaxin‑2 (H2 relaxin). Unlike the complex two‑chain, disulfide‑rich structure of native relaxin, B7-33 is a linear 27‑amino‑acid peptide that is far easier and cheaper to produce.

What makes B7-33 particularly valuable for research is its functional selectivity. While it binds to the relaxin family peptide receptor 1 (RXFP1)—the cognate receptor for relaxin‑2—it preferentially activates the pERK pathway over the cAMP pathway. This selective signalling profile is thought to preserve the potent anti‑fibrotic, cardioprotective, and vasoprotective effects of relaxin while avoiding pathways that have been associated with tumour‑promoting actions. This makes B7-33 (6mg) research peptide a valuable tool for laboratories investigating fibrosis, cardiac protection, vascular biology, and preeclampsia.

At Wuhan Top Miracle Peptides, we supply high‑purity B7-33 (6mg) research peptide to research institutions and wholesale buyers across the United Kingdom, France, Germany, Spain, Sweden, Italy, and the USA. Every batch is lyophilised, HPLC‑verified to ≥98% purity, and accompanied by a Certificate of Analysis (COA), ensuring your investigations into fibrosis, cardiac remodelling, and vascular biology begin with uncompromising quality.

What Is B7-33 and How Does It Work?

To fully appreciate the research potential of B7-33 (6mg) research peptide, it is essential to understand its biochemical design and the precise mechanism by which it exerts its effects.

The 27‑Amino‑Acid Single‑Chain Peptide

B7-33 is a synthetic linear peptide composed of 27 amino acids. Its sequence is H‑Val‑Ile‑Lys‑Leu‑Ser‑Gly‑Arg‑Glu‑Leu‑Val‑Arg‑Ala‑Gln‑Ile‑Ala‑Ile‑Ser‑Gly‑Met‑Ser‑Thr‑Trp‑Ser‑Lys‑Arg‑Ser‑Leu‑OH. Its molecular formula is C₁₃₁H₂₂₈N₄₀O₃₇S, and its molecular weight is approximately 2987.52 g/mol.

The peptide consists of residues 7‑29 of the B‑chain of H2 relaxin, with the addition of a KRSL sequence from positions 30‑33 of the B1‑33 isoform, which dramatically improves solubility. Unlike native relaxin, B7‑33 is a single‑chain linear peptide without the complex disulfide‑rich structure of the native hormone.

Mechanism of Action: Functional Selectivity at RXFP1

The biological activity of B7-33 (6mg) research peptide is mediated through its selective activation of the relaxin family peptide receptor 1 (RXFP1):

• RXFP1 Binding and Functional Selectivity: B7‑33 binds to RXFP1—the cognate receptor for relaxin‑2. However, unlike native relaxin, which strongly activates both the cAMP and pERK pathways, B7‑33 preferentially activates the pERK pathway over cAMP. This makes B7‑33 the first functionally selective agonist of the complex GPCR RXFP1.

• Anti‑Fibrotic Signalling via RXFP1‑AT₂R Heterodimers: The strong anti‑fibrotic actions of B7‑33 involve its activation of RXFP1‑angiotensin II type 2 receptor (AT₂R) heterodimers. This induces selective downstream signalling of pERK1/2 and the collagen‑degrading enzyme matrix metalloproteinase‑2 (MMP‑2).

• Inhibition of TGF‑β1 Signalling: B7‑33 inhibits excessive transforming growth factor β‑1 (TGF‑β1) signalling, thereby reducing pro‑fibrotic effects on myofibroblast differentiation and aberrant extracellular matrix production.

• Cardioprotection via ERK1/2‑Dependent Pathways: B7‑33 confers cardioprotection by attenuating cardiomyocyte death and endoplasmic reticulum stress through ERK1/2‑dependent mechanisms.

Research Note: Avoiding the Tumour‑Promoting Pathway

A key advantage of B7‑33 for research is that, in contrast to H2 relaxin, B7‑33 did not promote prostate tumour growth in vivo, likely because it does not strongly activate the cAMP pathway. This functional selectivity allows researchers to study the beneficial anti‑fibrotic and cardioprotective effects of relaxin receptor activation without the confounding variable of tumour‑promoting signalling.

Key Research Applications for B7-33 (6mg)

B7-33 (6mg) research peptide is a versatile tool with applications spanning several domains of biomedical research.

1. Fibrosis & Scarring Research

B7‑33 has demonstrated potent anti‑fibrotic effects in multiple preclinical models. Research applications include:

• Hypertrophic Scarring: B7‑33 modulates fibrotic signalling in human hypertrophic scar fibroblasts, inhibiting excessive TGF‑β1 signalling and reducing pro‑fibrotic effects. A 2026 study showed that B7‑33 significantly modulated profibrotic gene expression and downregulated Collagen Type I α‑1 Chain (COL1A1).

• Organ Fibrosis: B7‑33 has been shown to prevent or reverse organ fibrosis and dysfunction in three pre‑clinical rodent models of heart or lung disease. It reversed organ fibrosis in numerous pre‑clinical animal studies.

• Myocardial Infarction Scarring: B7‑33 significantly reduced infarct size (21.99% versus 45.32%; P=0.02) and preserved cardiac function in a mouse model of myocardial infarction.

• Surgical Mesh Fibrosis: B7‑33 is being investigated as an anti‑fibrotic coating for surgical meshes to mitigate fibrotic encapsulation.

2. Cardiovascular & Cardiac Research

B7‑33 has demonstrated significant cardioprotective effects. Research has shown:

• Cardioprotection Post‑Infarction: B7‑33 confers acute cardioprotection and limits myocardial infarction‑related adverse cardiac remodelling in mice. B7‑33 significantly reduced infarct size and preserved fractional shortening compared with vehicle.

• Reduction of Left Ventricular Fibrosis: In an isoprenaline‑induced cardiomyopathy model, B7‑33 reduced left ventricular fibrosis and normalised inflammation and cardiomyocyte hypertrophy. B7‑33 also reduced left ventricular fibrosis more rapidly than the ACE inhibitor perindopril.

• Vasoprotection: B7‑33 replicates the vasoprotective functions of human relaxin‑2 (serelaxin), preventing endothelial dysfunction induced by placental trophoblast‑conditioned media.

3. Preeclampsia & Vascular Research

B7‑33 has been studied for its effects in preeclampsia models:

• Preeclampsia Attenuation: Both B7‑33 and B7‑33 fusion proteins demonstrate efficacy in attenuating the symptoms of preeclampsia, including hypertension and inflammation, in the reduced uterine perfusion pressure (RUPP) rat model.

• Vascular Function: B7‑33 replicates the acute beneficial vascular effects of serelaxin in rat mesenteric arteries.

4. Drug Delivery & Biomaterial Research

B7‑33 is being investigated in advanced delivery systems:

• Controlled Release Dressings: Electrospun B7‑33‑loaded dressings enable controlled release over 72 hours, with the peptide retaining antifibrotic activity after incorporation.

• Biodegradable Coatings: Poly(lactic‑co‑glycolic) acid (PLGA) coatings releasing B7‑33 have been shown to reduce fibrotic encapsulation.

Chemical & Physical Specifications

Accurate characterisation of B7-33 (6mg) research peptide is essential for reproducible experimental design.

Note: The 6 mg mass refers to the weight of the peptide in its lyophilised form. B7‑33 is a single‑chain linear peptide, unlike the complex two‑chain, disulfide‑rich structure of native relaxin. This structural simplicity is a key advantage for research applications.

Reconstitution & Handling Protocol for B7-33 (6mg)

Proper reconstitution of B7-33 (6mg) research peptide is critical for maintaining its structural integrity and biological activity.

Step 1 – Preparation

• Bring the sealed B7‑33 vial and your chosen diluent (sterile bacteriostatic water or sterile PBS, pH 5‑7) to room temperature. Condensation can degrade the lyophilised powder.

• Clean your work surface with 70% ethanol and lay out sterile syringes, alcohol wipes and a clean work mat.

Step 2 – Vial Sanitisation

• Wipe the rubber stopper of the B7‑33 vial with a fresh 70% ethanol wipe. Allow the alcohol to evaporate completely before piercing.

Step 3 – Reconstitution

• Draw your desired volume of diluent into a sterile syringe. A common starting concentration for research applications is 6 mg per 0.6 mL of diluent, yielding a 10 mg/mL stock solution.

• Insert the needle and slowly inject the diluent against the inner glass wall. Do not spray directly onto the lyophilised powder.

• Gently swirl the vial until the solution is clear and fully dissolved. Do not shake vigorously, as shaking can cause denaturation.

Step 4 – Aliquoting & Storage

• Immediately after dissolution, aliquot the reconstituted B7‑33 into single‑use sterile vials.

• Store aliquots at –20°C. Avoid repeated freeze‑thaw cycles, as peptides are susceptible to degradation.

• Once thawed, store at 2‑8°C and use within a short period.

Concentration Reference Table

Adjust diluent volume based on your experimental requirements. For cell culture applications, typical working concentrations may range from 0.1‑10 µM.

Storage & Stability Guidelines

Why Choose Wuhan Top Miracle Peptides for B7-33 (6mg)?

As an authentic licensed peptide supplier based in the United Kingdom, we supply B7-33 (6mg) research peptide and a wide range of research‑grade compounds under rigorous quality assurance protocols, fully aligned with Google’s E‑E‑A‑T standards (Experience, Expertise, Authoritativeness, Trustworthiness).

• Verified Purity: Independent HPLC analysis with purity guaranteed ≥98% for every batch.

• GMP‑Compliant Manufacturing: All peptides are synthesised under strict quality control conditions.

• Full Traceability: Batch‑specific Certificates of Analysis (COA) are available for every order.

• Wholesale Supply: We serve research institutions, laboratories, and wholesale buyers across the UK, EU, and USA with flexible volume pricing and reliable logistics.

• UK‑Based Regulatory Compliance: All products are supplied strictly as research‑grade chemicals for laboratory use only (RUO).

Researchers across the United Kingdom—including those at leading institutions in London, Cambridge, Oxford, Manchester, and Edinburgh—trust us for fast domestic delivery, transparent documentation and professional technical support.

FAQ: B7-33 (6mg) Research Peptide

What is B7-33 (6mg) research peptide?
B7‑33 is a synthetic 27‑amino‑acid single‑chain peptide analogue derived from the B‑chain of human relaxin‑2 (H2 relaxin). It is a functionally selective agonist of the relaxin family peptide receptor 1 (RXFP1), preferentially activating the pERK pathway over cAMP.

What is the sequence and molecular weight of B7-33?
The sequence is VIKLSGRELVRAQIAISGMSTWSKRSL. Its molecular formula is C₁₃₁H₂₂₈N₄₀O₃₇S, and its molecular weight is approximately 2987.52 g/mol.

What are the primary research applications for B7-33?
B7‑33 is used in fibrosis and scarring research (hypertrophic scarring, organ fibrosis, myocardial infarction scarring), cardiovascular and cardiac research (cardioprotection, left ventricular fibrosis reduction, vasoprotection), preeclampsia and vascular research, and drug delivery and biomaterial research.

What is the mechanism of action of B7-33?
B7‑33 binds to RXFP1 and preferentially activates the pERK pathway over cAMP. It activates RXFP1‑AT₂R heterodimers, inducing pERK1/2 and MMP‑2 signalling, inhibits TGF‑β1 signalling, and confers cardioprotection via ERK1/2‑dependent mechanisms.

How does B7-33 differ from relaxin-2 in research?
Unlike native relaxin, B7‑33 is a single‑chain linear peptide, making it easier and cheaper to produce. It preferentially activates pERK over cAMP, avoiding pathways associated with tumour promotion. Despite this, it retains the anti‑fibrotic and cardioprotective effects of relaxin.

What purity does your B7-33 (6mg) meet?
Our B7‑33 is tested to ≥98% purity by HPLC. A Certificate of Analysis (COA) is supplied with every order.

How should I reconstitute B7-33 (6mg)?
Reconstitute with sterile bacteriostatic water or sterile PBS (pH 5‑7). Allow the vial to reach room temperature, then slowly inject the diluent against the inner glass wall and swirl gently. Do not shake. A typical starting concentration is 10 mg/mL.

How should I store reconstituted B7-33?
Reconstituted B7‑33 should be stored at 2‑8°C for short‑term use. For longer storage, aliquot immediately into single‑use vials and store at –20°C for up to 3 months. Avoid repeated freeze‑thaw cycles.

Is B7-33 research peptide legal to purchase in the UK?
Yes. B7‑33 is a laboratory reagent sold for research use only (RUO). It is fully legal to purchase, possess, and use in the United Kingdom for legitimate in‑vitro or in‑vivo scientific research, provided it is not marketed with therapeutic claims.

Does Wuhan Top Miracle Peptides ship internationally?
Yes. We ship across the EU (France, Germany, Spain, Sweden, Italy) and to the USA from our UK warehouse. Wholesale pricing is available for bulk orders.

Wholesale B7-33 6mg Supply Across the UK and Europe

Wuhan Top Miracle Peptides supports wholesale peptide buyers in the United Kingdom and international markets.

We Support Enquiries From:

• United Kingdom
• France
• Germany
• Spain
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• Italy
• USA
• Wider Europe

For larger B7-33 6mg enquiries, contact our team before ordering. This helps confirm stock, documentation, shipping options, product identity, and buyer verification requirements.

Where to Source B7-33 6mg in the UK

If you are searching for where to source B7-33 6mg in the UK, Wuhan Top Miracle Peptides provides a simple professional enquiry process.

Professional Enquiry Process

1. Review the B7-33 6mg product details.
2. Check the current label and batch information.
3. Confirm whether the batch is listed as B7-33 or another verified identity.
4. Ask about COA and purity-related documentation.
5. Confirm the sequence and salt form where required.
6. Confirm CAS number and storage notes where required.
7. Confirm your shipping country.
8. Discuss wholesale quantity requirements.
9. Complete buyer verification where required.
10. Place a professional enquiry with support from our team.

 

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From its innovative design as a single‑chain relaxin mimetic to its well‑characterised role as a functionally selective RXFP1 agonist, B7-33 (6mg) research peptide provides a precisely defined and mechanistically distinct platform for advanced fibrosis, cardiac, and vascular research.

Its ability to preferentially activate the pERK pathway over cAMP, inhibit TGF‑β1 signalling, reduce infarct size, and attenuate left ventricular fibrosis—supported by peer‑reviewed research published in Chemical Science, the Journal of the American Heart Association, and other authoritative journals—makes it a valuable addition to any laboratory investigating fibrosis, cardiac remodelling, vascular dysfunction, or preeclampsia. By choosing high‑purity, lab‑verified B7-33 (6mg) research peptide from Wuhan Top Miracle Peptides, you ensure that your research is built on a foundation of quality, reproducibility, and scientific integrity.

Ready to advance your research with B7-33 (6mg)? Browse our product catalogue, request a wholesale quote, or contact our support team today to discuss your laboratory’s specific needs. Place your order now and receive GMP‑grade B7‑33 delivered directly to your facility in the UK, EU, or USA.