Antimicrobial · Disulphide-stabilised β-defensin
Human beta-defensin 4
Also known as hBD-4; HBD4; DEFB104A/DEFB104B
A 50-residue human β-defensin studied in microbial assays, with a gene identity distinct from the DEFB4-encoded hBD-2.
- Length
- 50 amino acids
- Half-life
- Not well characterised
- Mechanism
- The cationic mature peptide associates with microbial envelopes and exhibits antimicrobial activity in culture assays, consistent with membrane-directed effects. No single obligatory antimicrobial receptor is established, and receptor assignments from other β-defensins should not be assumed to apply to hBD-4.
- Studied in
- Bacterial cultures, epithelial expression systems and recombinant peptide assays study hBD-4 antimicrobial activity, salt sensitivity and structure–function relationships.
About Human beta-defensin 4
Human β-defensin 4 was identified through genomic searches and expression studies that expanded the known human β-defensin family. The canonical precursor contains 72 residues, including an N-terminal signal sequence, and the commonly studied mature peptide contains 50 amino acids. Its six conserved cysteines support the β-defensin disulphide pattern, linking cysteines I–V, II–IV and III–VI. The corresponding gene symbols are DEFB104A and DEFB104B; importantly, the gene symbol DEFB4 instead refers to β-defensin 2.
Research on hBD-4 includes recombinant production, chemical synthesis and antimicrobial testing against selected bacterial species. Its cationic surface favours association with negatively charged microbial components, but activity varies with organism, buffer composition and peptide preparation. Epithelial and tissue-expression studies provide context for its place within innate defence networks. Although several β-defensins have reported chemotactic or receptor-mediated effects, those findings require peptide-specific verification rather than automatic transfer to hBD-4 from another family member.
Laboratory notes
- Check the full sequence and gene annotation before ordering: hBD-4 and the DEFB4 gene product are different peptides.
- Verify terminal boundaries and disulphide pairing, particularly when comparing synthetic material with recombinant preparations.
- Include matched salt and medium controls in microbial assays, and test endotoxin contamination before interpreting cellular signalling readouts.
Storage and reconstitution basics: storage guide.
Questions about Human beta-defensin 4
Is human β-defensin 4 encoded by DEFB4?
No. Human β-defensin 4 corresponds to DEFB104A/DEFB104B, whereas DEFB4A/DEFB4B encode human β-defensin 2.
Which length does this entry describe?
It describes the commonly studied 50-residue mature hBD-4 peptide, not its 72-residue precursor. Construct boundaries should still be checked against the supplier's sequence.
Can receptor data for hBD-2 or hBD-3 be used to describe hBD-4?
Not without direct evidence. Closely related defensins can differ in receptor interactions, cellular responses and assay requirements.
Is Human beta-defensin 4 for human use?
No. It is supplied strictly for in-vitro laboratory research and is not for human or animal consumption.
Related research peptides
All products are sold for laboratory research use only. Not for human consumption, not a medicine, not for diagnosing, treating or preventing any condition.