PTD-DBM Research: The CXXC5–Dishevelled Competitor Peptide

What is PTD-DBM?

What is PTD-DBM? A synthetic peptide whose name is a description of its construction. PTD is a protein transduction domain — a delivery sequence that carries cargo across the cell membrane, the same class of tool as the penetratin leader described on our PNC-27 page. DBM is the Dishevelled-binding motif, the fragment that does the actual work: it mimics the region of CXXC5 that binds Dishevelled, and so competes with the full-length protein for that interface.

The 2015 Journal of Experimental Medicine paper that introduces it describes the construct as composed of a PTD for delivery, a linker for flexibility, the DBM itself, and — in the version used for imaging — a lysine conjugated with FITC for visualisation. That last element is worth registering, because it means the published peptide and a commercially supplied one may not be the same molecule; the fluorophore is a research addition, not part of the active design.

The mechanistic category matters. This is not a receptor agonist. It is a protein–protein interaction inhibitor, working by occupying a binding surface, and figures quoted for compounds of this class are not comparable with receptor affinities quoted elsewhere in this library.

Discovery and origin in the literature

CXXC5 as a brake

The peptide follows from a finding about a protein. In 2015 two papers from overlapping groups at Yonsei University characterised CXXC5 — a CXXC-type zinc finger protein — as a negative-feedback regulator of the Wnt/β-catenin pathway acting through Dishevelled. Kim and colleagues (Cell Death Differ, PMID 25633194) reported that role in the context of osteoblast differentiation. Lee and colleagues (J Exp Med, PMID 26056233) reported it in skin, finding CXXC5 protein reduced in epidermal keratinocytes and dermal fibroblasts of acute human wounds, and that CXXC5-knockout mice healed cutaneous wounds faster with enhanced keratin 14 and collagen synthesis.

If a protein is a brake, there are two ways to release it: remove the protein, or block the interaction through which it acts. The knockout mice did the first. PTD-DBM was built to do the second, and the 2015 paper reports it disrupting the negative-feedback loop and activating β-catenin and collagen production in cultured cells, with the peptide co-administered with valproic acid — a GSK3β inhibitor that activates the same pathway by a different route — accelerating wound healing in mice.

From wounds to hair

Lee and colleagues (2017, J Invest Dermatol, PMID 28595998) carried the same logic into hair biology. They reported CXXC5 upregulated in miniaturised hair follicles and arrector pili muscles in human balding scalp, inhibitory effects of CXXC5 on alkaline phosphatase activity and proliferation in human hair-follicle dermal papilla cells, accelerated hair regrowth in CXXC5-knockout mice, and that disrupting the CXXC5–Dishevelled interaction with a competitor peptide accelerated hair regrowth and wound-induced hair follicle neogenesis. A later paper from the same group (Ryu et al., 2023, Cells, PMID 36831222) reported that CXXC5 mediates dihydrotestosterone-induced hair loss via prostaglandin D2, and that the effect was overcome by PTD-DBM treatment or by Cxxc5 knockout in their models.

Reference data

The chemical record here is thin and its provenance should be stated. A PubChem entry exists (CID 176453931), but its listed synonyms are vendor catalogue identifiers rather than literature designations — meaning the record is supplier-derived rather than curated from the primary papers. The primary papers themselves give the peptide’s architecture in words and its sequence in a figure; no one-letter sequence appears in the abstracts or accessible text, so none is reproduced here rather than reconstructed.

The two sulfur atoms in that formula indicate two sulfur-containing residues — cysteine or methionine — which is a detail worth confirming against a supplier’s stated sequence, since two cysteines would raise a disulfide question and two methionines would not. No handling quantity, reconstitution procedure or route is given or implied on this page.

Mechanisms researchers have examined

• Competitive disruption of the CXXC5–Dvl interface — the central and essentially only mechanism. The peptide presents the Dishevelled-binding motif in isolation, occupying the site that full-length CXXC5 would otherwise use.
• Downstream β-catenin readouts — the 2015 paper reported increased nuclear translocation of β-catenin, Wnt reporter activity, Col1a2 promoter activity and collagen concentration in supernatants, in a dose-dependent manner in human dermal fibroblasts.
• Selective target-gene induction — the same paper reported that the peptide specifically increased endothelin-1 at both mRNA and protein level while not affecting c-Myc or cyclin D1. That selectivity within canonical Wnt targets is one of the more interesting observations in this literature and is not, so far as indexed sources show, explained.
• Fibroblast functional assays — collagen gel contraction and migration after monolayer scratching were both reported to increase.
• Combination with a GSK3β inhibitor — both the wound and hair work pair the peptide with valproic acid, which activates the same pathway by inhibiting GSK3β. That the strongest reported results come from a two-agent combination is a real qualifier on what the peptide alone is shown to do.

Research models and evidence status

The literature is one lineage

This is the most important thing to know about PTD-DBM and it belongs stated plainly. Kang-Yell Choi’s laboratory at Yonsei University, with Lee, Ryu, Kim, Seo and colleagues, is the source of essentially every paper in which this peptide appears. That is not a criticism — a group that identifies a target is naturally the group that builds the first tool against it. It does mean the peptide has not been through the process that actually validates a finding, which is somebody unaffiliated reproducing it.

The commercial interest is disclosed and should be read alongside that. The 2017 paper lists CK Biotechnology Inc. among an author’s affiliations; the 2023 Cells paper carries a conflict-of-interest statement recording that the corresponding author is chief executive of CK Regeon Inc., which holds a licence to develop the Wnt/β-catenin pathway activator disclosed in that publication. Disclosure is exactly what disclosure is for, and it is reported here for completeness.

An informative detail: the group moved to a small molecule

Ryu and colleagues (2021, Br J Pharmacol, PMID 33751552) reported KY19382, a small-molecule activator of Wnt/β-catenin signalling, for hair regrowth and follicle neogenesis; Kim and colleagues (2023, Exp Mol Med, PMID 37524876) reported small-molecule inhibition of the cytosolic function of CXXC5 in diabetic wound healing. The trajectory is worth noticing. Peptides of this kind are expensive to make, unstable in serum and hard to deliver; a small molecule against the same target is the natural next step, and it is where the effort went.

It is also where the only independent work went. Chen and colleagues (2025, Cell Commun Signal, PMID 40001144), at Nanjing University and collaborating institutions with no Yonsei author, reported CXXC5 function blockade promoting diabetic wound healing — using KY19382, not PTD-DBM. So the target has attracted genuine independent attention; the peptide has not.

What is not established

There are no registered clinical trials of PTD-DBM — a ClinicalTrials.gov search returns zero studies. There is no published human pharmacokinetic, safety or tolerability data of any kind. There is no independent replication of any reported result using this peptide. The strongest published effects come from combination with valproic acid rather than from the peptide alone. No pharmacokinetic characterisation of the peptide — serum stability, exposure, clearance — appears in the accessible literature, which for a peptide delivered by a transduction domain is a substantial gap. And the human observations in these papers are expression measurements in scalp tissue, not treatment results in people.

Nothing in this literature establishes any property of the supplied research material in a person. This page makes no efficacy, therapeutic, hair-growth, wound-healing or other use claim of any kind, and the material is supplied for laboratory research use only — not for human or veterinary use.

Why this page stops here

Because the peptide-specific evidence does. There is a larger and growing literature on CXXC5 as a target — in bone, in skin, in diabetic wound healing, in cancer — and it would be easy to write a long page by absorbing it. That would be borrowing: almost none of that work uses this peptide. The material above is what has actually been published about PTD-DBM itself, and when more appears, this page will grow.

How to verify this compound yourself

The provenance of the chemical record makes the certificate of analysis unusually load-bearing here rather than less so:

• Ask for the sequence, in writing. The primary papers give the peptide’s architecture but not a one-letter sequence in accessible text, and the PubChem record is supplier-derived. That means the sequence a supplier certifies is the definition of what is being bought, and it should be stated on the certificate rather than assumed from a product name.
• Mass-spec identity against the catalogued figure. A measured mass consistent with ≈3082.6 Da is the main independent check that the vial contains the construct named on the label rather than the DBM fragment alone or a differently linked variant — species that would differ substantially in mass and not at all in appearance.
• Establish whether there is a fluorophore. The published construct includes an FITC-conjugated lysine in the version used for imaging. A material carrying that label is a different molecule from one without it, with a different mass, and the distinction should be explicit rather than inferred.
• Two sulfur atoms mean a question to ask. If those are cysteines, the material has a disulfide or free-thiol state that a purity percentage does not report; if they are methionines, oxidation on storage adds 16 Da per residue. Either way it is worth knowing which.
• HPLC purity on a peptide of this length carries real information — deletion sequences accumulate during solid-phase synthesis, so the percentage means something here in a way it does not on a tripeptide.
• Counter-ion documentation — a transduction domain is typically arginine- and lysine-rich and therefore highly basic, so a substantial fraction of vial mass can be counter-ion, usually trifluoroacetate. A documentation question, not a purity failure.

See how to read a COA for what each certificate line means, and how to verify peptide purity for how the methods fit together. The exact batch received can be checked on the self-serve verify tool.

Research-grade sourcing and verification

PTD-DBM is not held in stock. It is listed on our sourcing catalogue as available to order — our supplier lists it, we have not bought it, and material of this kind typically takes about two to three weeks to reach us. For laboratory research use only, it is supplied with a per-batch Certificate of Analysis reporting HPLC purity (%) and mass-spec identity confirmation, verifiable at the lot level. For another compound in this library whose literature is similarly narrow and whose page says so, see PE-22-28 research; for another protein–protein interaction inhibitor peptide without human data, see FOXO4-DRI research. This is sourcing and quality-assurance framing only.

Frequently asked questions

Literature cited

1. Kim HY, Yoon JY, Yun JH, et al. “CXXC5 is a negative-feedback regulator of the Wnt/β-catenin pathway involved in osteoblast differentiation.” Cell Death Differ. 2015;22(6):912–920. PMID 25633194. pubmed.ncbi.nlm.nih.gov/25633194.
2. Lee SH, Kim MY, Kim HY, et al. “The Dishevelled-binding protein CXXC5 negatively regulates cutaneous wound healing.” J Exp Med. 2015;212(7):1061–1080. PMID 26056233. pubmed.ncbi.nlm.nih.gov/26056233. The paper that introduces PTD-DBM.
3. Lee SH, Seo SH, Lee DH, Pi LQ, Lee WS, Choi KY. “Targeting of CXXC5 by a Competing Peptide Stimulates Hair Regrowth and Wound-Induced Hair Neogenesis.” J Invest Dermatol. 2017;137(11):2260–2269. PMID 28595998. pubmed.ncbi.nlm.nih.gov/28595998.
4. Ryu YC, Lee DH, Shim J, et al. “KY19382, a novel activator of Wnt/β-catenin signalling, promotes hair regrowth and hair follicle neogenesis.” Br J Pharmacol. 2021;178(12):2533–2546. PMID 33751552. pubmed.ncbi.nlm.nih.gov/33751552 (the small molecule the same group moved to).
5. Ryu YC, Park J, Kim YR, et al. “CXXC5 Mediates DHT-Induced Androgenetic Alopecia via PGD₂.” Cells. 2023;12(4):555. PMID 36831222. pubmed.ncbi.nlm.nih.gov/36831222. Source of the CK Regeon conflict-of-interest disclosure.
6. Kim E, Seo SH, Hwang Y, et al. “Inhibiting the cytosolic function of CXXC5 accelerates diabetic wound healing by enhancing angiogenesis and skin repair.” Exp Mol Med. 2023;55(8):1770–1782. PMID 37524876. pubmed.ncbi.nlm.nih.gov/37524876.
7. Chen Y, Ding X, Ma Z, et al. “CXXC5 function blockade promotes diabetic wound healing through stimulating fibroblast and vascular endothelial cell activation.” Cell Commun Signal. 2025;23(1):108. PMID 40001144. pubmed.ncbi.nlm.nih.gov/40001144 (independent group, target not peptide).
8. National Center for Biotechnology Information. “PubChem Compound Summary for CID 176453931, PTD-DBM.” pubchem.ncbi.nlm.nih.gov/compound/176453931 (formula, mass, CAS 1609454-11-6; supplier-derived record).