# B7-33 (Relaxin-2 B-Chain Analog)

> Single-chain 27-residue relaxin-2 B-chain analogue researched as an RXFP1 agonist

All products are sold strictly for laboratory research use only. Not for human or veterinary use.

- Web page: https://peptidemedixeu.com/en/products/b7-33/
- Brand: Peptide Medix EU
- Category: [Tissue Repair & Healing Peptides](https://peptidemedixeu.com/en/collections/tissue-repair-peptides/)
- Purity: ≥99% by HPLC; mass-based identity confirmation; lot-matched COA available
- from €63 (EUR)

## Sizes and prices (EUR)

| Size | Price | SKU |
| --- | --- | --- |
| 6 mg | €63 | B7-33-6-MG |

_Catalog prices at build time; the web page and checkout are authoritative._

## Specifications

- **Amino acid sequence:** 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
- **Chain length:** 27 amino acids
- **Peptide class:** Linear human relaxin-2 B-chain analog
- **Form:** Lyophilized powder, sealed glass research vial
- **Purity:** ≥99% by HPLC; mass-based identity confirmation; lot-matched COA available
- **Solubility:** Water-soluble research peptide; buffer compatibility should be validated for the selected assay
- **Storage (lyophilized):** −20 °C, sealed and protected from light and moisture
- **Available size:** 6 mg
- **Primary research target:** Relaxin family peptide receptor 1 (RXFP1)
- **Research areas:** RXFP1 signaling bias, fibroblast biology, extracellular-matrix turnover, fibrosis and vascular-response models
- **Distinction:** Not native relaxin-2 or serelaxin; contains one engineered linear chain and no disulfide-linked A chain
- **Storage (in solution):** 2–8 °C for a defined study window; aliquot for longer holds

## Description

B7-33 is a synthetic single-chain peptide taken from the receptor-binding part of the human relaxin-2 B chain. Its 27 amino acids keep the arginine-rich motif that relaxin family peptide receptor 1 (RXFP1) recognises, but drop the native hormone's two chains and three disulfides. The name reflects the span covered — B-chain positions 7 to 33 — and since there is no cysteine in the sequence, no oxidative folding is required. The outcome is a linear analogue that is simpler to make and characterise than complete relaxin-2.

Its pharmacological appeal lies in how a single chain alters receptor signalling, not in copying relaxin. Studies at RXFP1 describe it as a biased agonist that favours one arm of the receptor's output rather than the cAMP-heavy profile seen with the native two-chain hormone — which is why researchers test it alongside relaxin-2 rather than as a substitute. Assay choice follows the fibrosis biology of the pathway: fibroblast and myofibroblast cultures, collagen and matrix metalloproteinase expression, and models of cardiac, renal and vascular remodelling. It is stocked as one 6 mg fill; keep it sealed at −20 °C, refrigerate working stocks for a set period, aliquot instead of refreezing, and confirm buffer compatibility for each assay.

## Frequently asked questions

### What is B7-33?

A synthetic 27-amino-acid analogue based on the B chain of human relaxin-2. It preserves the principal RXFP1-binding motif in a single linear chain, so it is structurally much simpler than native relaxin, whose A and B chains are linked by disulfide bonds.

### Which target does B7-33 act on in research?

Its main reported target is RXFP1, the natural receptor for relaxin-2. Studies look at receptor signalling, matrix production by fibroblasts, fibrotic remodelling and vascular readouts; outcomes vary with cell type, receptor density and study design.

### What purity records are provided?

The peptide is released at ≥99% purity by reversed-phase HPLC, with identity verified against the expected mass. A certificate of analysis bearing the vial's lot number is available for your study files.

### How is B7-33 stored?

Store the unopened lyophilised vial at −20 °C, dry and out of the light. Once prepared, refrigerate working stocks for short-term use and aliquot for longer studies so a single solution is not frozen and thawed over and over.

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All products offered on this website are intended solely for in-vitro laboratory research and development by qualified professionals. They are not drugs, foods, cosmetics or dietary supplements, and are not intended to diagnose, treat, cure or prevent any disease. Products must not be introduced into humans or animals in any manner. By purchasing, you confirm that you are a qualified researcher and accept full responsibility for handling and storage in accordance with applicable laws.

Peptide Medix EU · https://peptidemedixeu.com/en/products/b7-33/