Immune · Acetylated annexin-derived signalling peptide
Annexin A1 peptide Ac2-26
Also known as Ac2-26; ANXA1(2–26)
An acetylated annexin A1 fragment used to investigate formyl peptide receptors, leukocyte migration and inflammatory signalling.
- Length
- 25 amino acids
- Half-life
- Not well characterised
- Mechanism
- Ac2-26 engages formyl peptide receptor signalling, including FPR1 and FPR2/ALX, with receptor contributions depending on the experimental system. It reproduces selected activities of the annexin A1 N-terminal domain rather than the full protein's calcium-dependent phospholipid-binding functions.
- Studied in
- Neutrophil migration assays, macrophage efferocytosis experiments and animal models of inflammation examine its effects on leukocyte trafficking and resolution-associated signalling.
About Annexin A1 peptide Ac2-26
Ac2-26 corresponds to residues 2–26 of annexin A1, a calcium-dependent phospholipid-binding protein historically studied under the name lipocortin I. Its sequence is Ac-AMVSEFLKQAWFIENEEQEYVQTVK, with an acetylated N-terminus. The fragment was developed to investigate activities associated with the exposed N-terminal region of annexin A1, separately from its much larger conserved core. It is therefore a signalling probe, not a structural substitute for the intact protein.
Experimental work links Ac2-26 to the formyl peptide receptor family, particularly FPR1 and FPR2/ALX. These G protein-coupled receptors participate in leukocyte sensing and migration, but peptide responses vary with receptor expression, species and assay conditions. Common readouts include calcium mobilisation, adhesion, chemotaxis and macrophage uptake of apoptotic cells. Interpretation requires care because receptor promiscuity and concentration-dependent responses can complicate attribution to a single signalling pathway.
Laboratory notes
- Confirm N-terminal acetylation and sequence identity by supplier documentation and mass spectrometry; terminal chemistry is part of the reagent's identity.
- Use receptor-selective controls or receptor-deficient cells to distinguish FPR1-dependent from FPR2-dependent responses.
- Assess endotoxin and peptide integrity when interpreting leukocyte activation assays; use single-use aliquots where stability testing supports this approach.
Storage and reconstitution basics: storage guide.
Questions about Annexin A1 peptide Ac2-26
Does Ac2-26 reproduce every function of annexin A1?
No. It represents an N-terminal signalling region and lacks the full protein's conserved calcium- and phospholipid-binding core.
Is Ac2-26 selective for FPR2/ALX?
It should not be treated as an exclusively FPR2-selective probe. FPR1 involvement has also been reported, and receptor dependence requires experimental confirmation.
Which cellular assays are commonly used?
Research-use assays include leukocyte chemotaxis, calcium mobilisation, adhesion and macrophage efferocytosis, ideally paired with receptor-specific controls.
Is Annexin A1 peptide Ac2-26 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.