KLOW is a research blend of four synthetic peptides: GHK-Cu, BPC-157, TB-500 and KPV. Each component acts on a different part of the machinery that fibroblasts, endothelial cells and epithelial cells use to build matrix, cross-link it, move and control cytokine transcription, which is why the four are studied together in cell culture. NuVion supplies KLOW as a laboratory chemical for in vitro research use only.
Key facts
| Type/class | Synthetic peptide blend, four components |
| Components | GHK-Cu (tripeptide copper(II) complex), BPC-157 (15 residues), TB-500 (thymosin beta-4 derived), KPV (tripeptide) |
| Component sequences | GHK: Gly-His-Lys; BPC-157: Gly-Glu-Pro-Pro-Pro-Gly-Lys-Pro-Ala-Asp-Asp-Ala-Gly-Leu-Val; KPV: Lys-Pro-Val; TB-500: thymosin beta-4 derived, carrying the Leu-Lys-Lys-Thr-Glu-Thr actin-binding motif |
| Component molecular weights | GHK 340.4 g/mol (free tripeptide); BPC-157 1419.5 g/mol; KPV 342.4 g/mol; TB-500 889 g/mol |
| Synonyms/other names | KLOW blend, GHK-Cu/BPC-157/TB-500/KPV blend |
| Supplied form | Lyophilised powder in a sealed vial |
Structure and chemistry
The four components are chemically unalike, and that is the first thing to plan around. GHK-Cu is a tripeptide (glycyl-L-histidyl-L-lysine) holding a Cu(II) ion through its glycine amine, the Gly-His amide nitrogen and the histidine imidazole. It is blue in solution and its copper can be stripped by EDTA or reduced by ascorbate and thiols. BPC-157 is a 15-residue linear peptide whose sequence derives from a protein found in gastric juice; it is proline-rich, carries a net negative charge from its glutamate and two aspartates, and contains no methionine, cysteine or tryptophan, so it is chemically stable in aqueous solution. TB-500 is derived from thymosin beta-4, the 43-residue N-acetylated actin-sequestering protein, and contains the Leu-Lys-Lys-Thr-Glu-Thr motif that binds monomeric actin. KPV is the C-terminal tripeptide (residues 11 to 13) of alpha-melanocyte-stimulating hormone (alpha-MSH), a small, basic and stable sequence.
All four dissolve readily in water. The mixture is analysed as four peaks: on a C18 gradient the components separate by hydrophobicity and size, and each is confirmed by its own molecular ion in mass spectrometry. Because the component masses range from about 340 to over 1,400 daltons, a single RP-HPLC method covering the whole gradient is needed to see all four in one run.
Mechanism of action
GHK-Cu acts through copper-dependent signalling. It carries copper into cells, where the metal is loaded onto lysyl oxidase, the enzyme that cross-links collagen and elastin, and onto Cu/Zn superoxide dismutase. In dermal fibroblast culture it increases collagen and glycosaminoglycan synthesis, shifts the balance of MMP-2 against TIMP-1 and TIMP-2, and reduces NF-kB p65 activity. Its contribution to the blend is the matrix side: what the cells deposit and how it is cross-linked.
TB-500 and BPC-157 both act on cell movement, by different routes. The thymosin beta-4 motif in TB-500 binds G-actin and holds it out of filaments, which changes the pool available for polymerisation at the leading edge and alters migration speed and spreading in scratch and transwell assays. BPC-157, in cultured fibroblasts and endothelial cells, increases phosphorylation of focal adhesion kinase and paxillin, reorganises the actin cytoskeleton toward a migratory phenotype, and activates VEGFR2 with downstream endothelial nitric oxide synthase signalling, measured as tube formation on basement membrane extract and nitric oxide production. One component sets the actin monomer supply and the other sets adhesion signalling, so their combination is a way to test whether migration readouts respond additively.
KPV brings melanocortin-derived control of transcription. It lacks the His-Phe-Arg-Trp core that alpha-MSH uses to activate melanocortin receptors, and its reported activity in epithelial and macrophage cell lines, a reduction in IkB-alpha degradation, p65 nuclear translocation and cytokine gene transcription, is largely independent of MC1R. In intestinal epithelial lines such as Caco-2 it is taken up by the PepT1 (SLC15A1) transporter, and in those cells it lowers NF-kB reporter output after cytokine or lipopolysaccharide stimulation. Alongside the GHK-Cu effect on p65, this gives the blend two independent inputs into the same transcription factor, which is the reason NF-kB reporter assays are a common readout for the mixture.
Research applications
KLOW sits in the Cellular Ageing category and is used in the following kinds of work.
- Scratch and transwell migration assays with fibroblasts, keratinocytes or endothelial cells, comparing the blend with each component alone.
- Fibroblast matrix output by hydroxyproline, dye-binding collagen and glycosaminoglycan assays, with MMP-2, TIMP-1 and TIMP-2 by ELISA or zymography.
- Endothelial tube formation and VEGFR2 or eNOS phosphorylation by western blot.
- NF-kB reporter assays and cytokine transcript qPCR in epithelial or macrophage cell lines after stimulation.
- G-actin to F-actin ratio and focal adhesion imaging by phalloidin and paxillin staining.
- RP-HPLC and LC-MS method development for resolving and quantifying multi-peptide mixtures.
Handling in the laboratory
The lyophilised blend is reconstituted with bacteriostatic water added down the side of the vial and swirled until the solution is clear; a faint blue tint from the copper complex is expected. The reconstitution calculator gives the volume for a chosen total concentration from the vial content. Because GHK-Cu is present, buffers containing EDTA or citrate and reducing agents such as DTT or ascorbate are avoided if the copper complex is to stay intact, and phosphate is kept low to avoid copper precipitation. The thymosin beta-4-derived component and BPC-157 adsorb to untreated plastic at low concentration, so low-binding tubes are used and working dilutions are made fresh in medium.
Unopened vials are kept sealed, dry, away from light and refrigerated as described in the product documentation. Reconstituted solution is refrigerated and used within the period given in that documentation, with freeze-thaw cycles kept to a minimum. Each component is characterised by RP-HPLC for purity and by mass spectrometry for identity.
Testing and supply from NuVion
KLOW from NuVion is made by a GMP-audited manufacturer and supplied lyophilised in sealed vials. Most batches are independently tested by Janoshik Analytical for purity by RP-HPLC and identity by mass spectrometry, and the Certificate of Analysis for a tested batch is published on the product page and in the Certificates of Analysis library. Orders are dispatched from within Australia.
Related compounds
Each component has its own profile in the library: GHK-Cu for the copper and matrix arm, BPC-157 for the focal adhesion and VEGFR2 arm, TB-500 for actin sequestration, and KPV for the melanocortin-derived input into NF-kB transcription. All four are supplied separately as single-agent controls: GHK-Cu, BPC-157, TB-500 and KPV.
Frequently asked questions
What is KLOW peptide?
KLOW is a research blend of four synthetic peptides supplied together in one vial: GHK-Cu, BPC-157, TB-500 and KPV. The name refers to the mixture, and each component is a distinct molecule with its own profile. It is used in cell culture experiments where matrix synthesis, cell migration and NF-kB transcription are measured together, with the blend compared against each of its four components alone.
Which peptides are in KLOW?
Four. GHK-Cu, a copper-carrying tripeptide studied in collagen cross-linking and matrix output. BPC-157, a 15-residue peptide studied in focal adhesion and VEGFR2 signalling. TB-500, derived from thymosin beta-4 and carrying its actin-binding motif. KPV, the C-terminal tripeptide of alpha-MSH, studied in NF-kB transcription. Component molecular weights run from about 340 to over 1,400 daltons, which is why a single analytical method has to cover a wide gradient.
How is KLOW supplied and stored?
As a lyophilised powder in a sealed vial containing all four peptides, with purity determined by RP-HPLC and identity by mass spectrometry. Keep the sealed vial dry, away from light and refrigerated as set out in the product documentation. After reconstitution, keep the solution refrigerated in a low-binding tube, avoid chelating and reducing agents, and use it within the period stated in the documentation.
Is KLOW a therapeutic good in Australia?
No. KLOW from NuVion is a laboratory chemical for in vitro research. It is not included in the Australian Register of Therapeutic Goods and has not been assessed by the Therapeutic Goods Administration.
Research use only. This product is a laboratory chemical supplied for in vitro research. It is not included in the Australian Register of Therapeutic Goods and has not been assessed by the Therapeutic Goods Administration for quality, safety or efficacy. It is not for human or veterinary use, and nothing on this page is a representation about therapeutic use.
