B7‑33 99% pure peptide is a research probe which targeting the RXFP1 receptor, it mainly activates the ERK1/2 signaling pathway in cells. Once this pathway is switched on, it regulates MMP‑2 and changes the extracellular matrix around cells. It can also rely on RXFP1 and AT₂R to form a complex and send signals to ease tissue fibrosis. B7‑33 99% pure peptide can also trigger nitric oxide signaling in vascular cells. A notable trait of B7‑33 99% pure peptide is that it barely turns on the typical cAMP/PKA pathway. Therefore, most researchers use it as a tool to separate the functions driven by ERK signals from the classic cAMP‑related signals of the RXFP1 receptor.
In related research, the purity of this polypeptide is very important. Faithful Chemical can provide B7‑33 99% pure peptide, and we provide comprehensive testing certificates such as COA and MSDS. As a professional factory in bulk supplier manufacturer, we can guarantee the stability of each batch of products and provide different packages according to your needs.
Basic Introduction
B7‑33 99% pure peptide is a synthetic single-stranded polypeptide, a derivative of relaxin hormone and an agonist of selective relaxin receptor 1(RXFP1). It is composed of 27 amino acids and is a single-stranded version of relaxin B chain, which has no disulfide bond and stable structure. The molecular weight is about 2986.54, CAS 1818415-56-3. It is usually a white powder, which is easily soluble in water and PBS.
B7‑33 99% pure peptide can function by activating RxFP 1 receptor, which can phosphorylate ERK1/2, but does not induce the activation of cAMP signaling pathway, so it is a "functionally selective" agonist. Natural relaxin is a double-stranded structure, and B7-33 only keeps the core fragment of B chain, so the synthesis is simpler and the stability is better.
It is a truncated N-terminal and extended C-terminal fragment of human relaxin -2 B chain, which has anti-fibrosis effect similar to that of full-length peptide. The peptide has been used in the study involving excessive fibrosis, such as myocardial fibrosis and pulmonary fibrosis.
Action Principle
How does it work
It is a selective relaxin receptor 1(RXFP1) agonist. Its core function is to achieve anti-fibrosis and cardioprotection by activating RXFP1 receptor, and preferentially starting pERK signaling pathway.
Target binding
B7‑33 99% pure peptide is a single-stranded polypeptide designed and synthesized artificially, which mimics the B-chain structure of natural relaxin H2 and can specifically bind to RXFP1 receptor.
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Signal path selectivity
Different from natural relaxin, B7‑33 99% pure peptide does not activate the cAMP pathway first after binding to RXFP1, but preferentially activates the pERK1/2 pathway. This "functional selectivity" allows it to play an anti-fibrosis role while avoiding the side effects of promoting tumor caused by cAMP.
02
Anti-fibrosis effect
After activation of pERK pathway, B7‑33 99% pure peptide can promote the production of matrix metalloproteinases (MMP-2), degrade over-deposited collagen, inhibit TGF-β/Smad pathway and myofibroblast differentiation, reduce the deposition of type I/III collagen and fibronectin through these pathways, and finally control tissue fibrosis.
03
Cardioprotection
In the research model of myocardial infarction and acute myocardial injury, B7‑33 99% pure peptide can reduce myocardial cell death and endoplasmic reticulum stress, and researchers can improve cardiac function and inhibit bad cardiac remodeling through this mechanism.
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Faithful Chemical is your trusted partner for high-quality research peptides, delivering reliable products, consistent batches and thoughtful service to support your innovative biomedical exploration.
Comparison Of Similar Types
contrast
There are some substances that are very close to B7‑33 99% pure peptide. The following table is for comparison.
| items |
B7‑33
|
B7‑27
|
B7‑30
|
B7‑35
|
| diagrammatic presentation |
 |
 |
 |
 |
| Target binding affinity | High, stable specific binding and lower KD value. | Medium affinity, easy to dissociate. | Affinity is slightly lower than B7‑33. | Weak affinity and unstable binding. |
| Off-target effect | Low off-target signal and less non-specific binding. | Moderate, easy to bind weakly to homologous receptors. | Small miss distance. | The miss distance is obvious. |
| Stability of aqueous solution | Good, short-term storage at 4℃ is not easy to be rapidly oxidized and degraded. | Poor stability, easy oxidation of aqueous solution. | Generally, the activity of repeated freezing and thawing decreases rapidly. | Poor stability and easy aggregation in solution. |
| Experimental repeatability | The difference between batches is very small, which is suitable for quantitative experiments and cell/animal function verification. | Batch fluctuation is obvious. | The batch fluctuates slightly. | Large batch difference and high repetition difficulty. |
| Applicable scientific research scenarios | Quantitative cell experiment, in vivo animal administration, mechanism research, drug effect screening, controlled experiment requiring high repeatability. | Only suitable for preliminary qualitative screening and pre-experiment. | Routine in vitro cell screening. | Only used for exploratory pre-experiment, not suitable for quantification. |
| Freeze-thaw tolerance | It can withstand 3-4 times of standard freeze-thaw and has good activity retention. | The activity of freezing and thawing twice decreased obviously. | Small loss of activity after freezing and thawing for three times. | Once freeze-thaw is easy to aggregate and inactivate. |
B7‑33 99% pure peptide Core Advantage Summary
More specificity and less off-target
It has better selectivity for the target, lower experimental background and more reliable results.
Better stability and freeze-thaw tolerance
It degrades slowly in solution, which is suitable for multiple sampling and drug administration experiments in animals, and its activity retention is better than other analogues.
Wider application scenarios
It can not only do simple in vitro screening, but also support in vivo function research and dose gradient quantitative test of animals.
Faithful Chemical is your trusted supplier of research-grade B7‑33 99% pure peptide. We maintain strict quality control to guarantee stable batches and smooth progress for your peptide exploration and biomedical research projects.
Research Applications
Popular Research Areas
Transforming the polypeptide itself
B7‑33 99% pure peptide is a synthetic short peptide molecule. Scientists will fine-tune its amino acid sequence, or attach different chemical groups to it to improve its stability and make it not easy to be decomposed. We are constantly optimizing the methods of synthesis and purification to obtain high-purity samples. At the same time, we will observe its performance in different liquid environments, see if peptide molecules will spontaneously aggregate, and study its own physical and chemical characteristics.
Study the interaction between peptides and receptors
B7‑33 99% pure peptide, like a special key, can be paired with a receptor named RXFP1 on the cell surface. Researchers will test how closely they combine and observe its unique pattern of activating signals inside cells. They will also use computer modeling to visually restore the way they fit together. This "key-lock" combination can also be used as a detection tool to find other molecules that can interact with this receptor.
Build an in vitro cell environment with biomaterials.
Many researches combine B7‑33 99% pure peptide with hydrogels, nanoparticles and other materials. Scientists fix peptides on the surface of materials in different ways, so that ordinary materials have new biological functions. Then, in the laboratory, these modified materials were used to build a simplified artificial cell growth environment to observe how cells interact with the surrounding matrix and explore the basic laws of cell activities.
Faithful Chemical provides B7‑33 99% pure peptide for your pioneering research journey.
Storage Recommendations
Storage method is important
Unresolved:
powder (priority)
Long-term storage:
At -20℃, the original bottle is sealed, protected from light and dried to avoid moisture, and the shelf life can generally reach about 2 years; In pursuit of higher stability, it can be put at -80℃.
Short-term temporary:
Refrigerated at 2-8℃ and protected from light (suitable for immediate use within 1-2 weeks).
Key points of opening the lid:
First put the bottle in a dry environment to return to room temperature, and then open the lid to prevent condensed water in the air from absorbing moisture and degrading; Minimize the number of times to open the lid.
Taboo:
Light, humidity, high temperature, strong oxidant/strong acid and alkali.
After redissolution:
solution
Recommended solvent:
Sterile water/bacteriostatic water.
Standard storage:
2-8℃ refrigerator should be protected from light, so do not freeze and thaw repeatedly; If it is necessary to store the solution for a long time in the experiment, it is recommended to store it at -80℃ after sub-packaging to avoid repeated freezing and thawing.
Note:
The stability of B7‑33 solution is much lower than that of dry powder, and it is easily degraded by bacteria and oxidation. Sterility of operation.
Faithful Chemical is your trusted supplier of research-grade B7‑33 99% pure peptide. We provide clear storage guidance alongside rigorous quality control to keep your samples stable and support your lab research smoothly.
Supplier Advantages
Why Choose Us
Reliable purification protocol
We apply a standardized purification protocol for B7‑33 99% pure peptide. Every production batch adheres to unified process specifications to cut down unexpected variation. Reliable raw material performance helps you steer clear of abnormal data and delivers repeatable experimental outcomes.
Specially designed moisture-proof & light-proof packaging
We deploy tailored packaging for B7‑33 99% pure peptide. It effectively shields the product from light exposure and humidity ingress to retard degradation. It maintains peptide integrity throughout transit and routine lab storage, locking in its inherent performance before use.
Full traceable batch paperwork
Each order is accompanied by comprehensive batch records. Our COA includes all essential testing indicators required for laboratory filing. Documents are neatly organized for convenient filing and verification, complying with regular academic lab documentation norms.
Flexible supply for varied lab demands
We offer flexible supply schemes adapted to diverse research plans. Multiple package specifications are available to fit your research schedule. No matter you carry out preliminary screening or conduct successive serial tests, we can accommodate your dosage demand and keep your research on track.
FAQ
Conclusion and Reference
Conclusion
B7‑33 99% pure peptide is a functional selective RXFP1 agonist and a valuable scientific probe. It is a single-chain synthetic peptides derived from human relaxin 2b chain, with simple structure, good solubility and stable physical and chemical properties. Different from natural relaxin, B7‑33 99% pure peptide preferentially activates ERK1/2 signal pathway, but hardly activates cAMP/PKA signal pathway, which is an ideal tool to analyze the downstream signal of RXFP1 and study the mechanism of anti-fibrosis. Compared with B7‑27, B7‑30, B7‑35 and other homologous analogues, B7‑33 99% pure peptide has better target binding ability, lower off-target effect, good freeze-thaw tolerance and high experimental repeatability, which can support many research directions such as cell experiments in vitro, biomaterial construction and animal experiments in vivo. Its biological activity can be well preserved when stored according to the standard conditions. In a word, B7‑33 99% pure peptide is a reliable tool reagent for studying the biology, tissue fibrosis and related biomedical mechanisms of RXFP1.
Faithful Chemical, as a professional supplier of raw materials for research, can provide you with B7‑33 99% pure peptide. We are a supplier specially for B2B customers, and can provide complete COA documents and keep consistency among batches.
If you require B7‑33 99% pure peptide research or production
Please contact Faithful Chemical Click
Email: allen@faithfulbio.com
WhatsApp: +86 13137770562.
Reference
1.Hossain, M. A., Kocan, M., Yao, S. T., Royce, S. G., Nair, V. B., Siwek, C., Patil, N. A., Harrison, I. P., Rosengren, K. J., Selemidis, S., Summers, R. J., Wade, J. D., Bathgate, R. A. D., & Samuel, C. S. A single-chain derivative of the relaxin hormone is a functionally selective agonist of the G protein-coupled receptor, RXFP1. Chemical Science, 2016, 7(6): 3805–3819.
2.B7-33, a Functionally Selective Relaxin Receptor 1 Agonist, Attenuates Myocardial Infarction–Related Adverse Cardiac Remodeling in Mice. Journal of the American Heart Association, 2020, 9(8): e015748.
3.Alam, F., Gaspari, T. A., Kemp-Harper, B. K., Low, E., Aw, A., Ferens, D., Spizzo, I., Jefferis, A. M., Praveen, P., & Widdop, R. E. The single-chain relaxin mimetic, B7-33, maintains the cardioprotective effects of relaxin and more rapidly reduces left ventricular fibrosis compared to perindopril in an experimental model of cardiomyopathy. Biomedicine & Pharmacotherapy, 2023, 160: 114370.
4.Long-acting relaxin analogues: a novel tool in cardiology. Frontiers in Pharmacology, 2025, 16: 1626469.
5.Immune cell uptake of glycinated nanoparticles conjugated to anti-fibrotic peptides enables their prolonged activity and oral administration. Journal of Biomedical Science, 2025, 32(1).
6.Getchell, S., Zabbarova, I., Ikeda, Y., Kozlowski, M., Bircler, L., & Kanai, A. A Single-Chain Peptide Derived from Relaxin-2 is a Biased RXFP1 Agonist that Rescues Mouse Bladders with Irradiation-Induced Cystitis. International Continence Society (ICS) Annual Meeting Abstract, 2024.
7.Engineering and Characterization of a Long-Half-Life Relaxin Receptor RXFP1 Agonist. Molecular Pharmaceutics, 2024, 21(8).