Antimicrobial · Post-translationally modified, phenylalanine-rich antimicrobial peptide
Styelin D
Also known as —
A modified tunicate peptide studied for microbial membrane disruption and the contribution of unusual residues.
- Length
- 32 amino acids
- Half-life
- Not well characterised
- Mechanism
- Styelin D interacts with and disrupts microbial membranes, with its cationic and hydrophobic features contributing to membrane association. A specific protein receptor has not been established, and native post-translational modifications complicate comparison with unmodified synthetic sequences.
- Studied in
- Bacterial cultures, membrane-permeability assays and comparisons of native and synthetic analogues are used to study antimicrobial activity under different pH and salt conditions.
About Styelin D
Styelin D belongs to a group of antimicrobial peptides identified in haemocytes of the tunicate Styela clava. The mature peptide contains 32 amino acids and is C-terminally amidated. Native material is notable for extensive post-translational modification, including hydroxylated residues and a brominated tryptophan. These chemical features distinguish the isolated natural peptide from a synthetic product containing only standard amino acids, even when both share the same underlying sequence.
Research on styelin D explores microbial membrane disruption and the contribution of unusual residue chemistry to activity in challenging solution conditions. Bacterial growth measurements are often paired with permeability assays to separate growth inhibition from immediate membrane effects. Because native modifications alter molecular mass and side-chain properties, comparisons between preparations require explicit structural information. Neither a sequence label alone nor nominal peptide purity establishes equivalence between native styelin D and an unmodified analogue.
Laboratory notes
- Obtain an explicit modification map, terminal chemistry and expected molecular mass before comparing preparations.
- Report pH, salt composition and medium constituents, rather than describing assay conditions only as physiological or saline.
- Use orthogonal identity and purity measurements where possible; chromatographic purity alone does not confirm the native modification pattern.
Storage and reconstitution basics: storage guide.
Questions about Styelin D
Is an unmodified synthetic styelin D sequence equivalent to native styelin D?
No. Native styelin D contains unusual post-translational modifications, so an unmodified analogue differs in composition and may behave differently in assays.
Where was styelin D originally identified?
It was identified in haemocytes of Styela clava, a marine tunicate whose circulating cells contain several antimicrobial peptide families.
Which assays help investigate its membrane effects?
Dye-entry, membrane-potential and lipid-vesicle leakage assays can complement bacterial growth measurements, provided peptide–dye interference is controlled.
Is Styelin D 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.