What Is Snap-8? A Research Overview

What Is Snap-8?

Snap-8 (Acetyl Octapeptide-3, CAS: 868202-54-6) is a synthetic octapeptide with the sequence Ac-Glu-Glu-Met-Gln-Arg-Arg-Ala-Asp-NH2. It is an extended analog of the hexapeptide Argireline, designed to mimic the N-terminal domain of SNAP-25. In in vitro neuronal research models, Snap-8 has been studied for its interaction with SNARE complex formation and potential modulation of neurotransmitter release.

At a Glance

Property Value
Full Name Acetyl Octapeptide-3
CAS Number 868202-54-6
Sequence Ac-Glu-Glu-Met-Gln-Arg-Arg-Ala-Asp-NH2
Molecular Formula C42H72N16O15S
Molecular Weight 1073.2 g/mol
Appearance Lyophilized powder
Purity ≥99% (HPLC)
Storage -20°C, lyophilized, protect from light

What Is the Structure of Snap-8?

Snap-8 is an eight-amino-acid peptide bearing an N-terminal acetyl group and a C-terminal amide modification. Its full sequence — Ac-Glu-Glu-Met-Gln-Arg-Arg-Ala-Asp-NH2 — corresponds to an extended segment of the N-terminal domain of SNAP-25 (Synaptosomal-Associated Protein 25), a key t-SNARE protein involved in synaptic vesicle docking and membrane fusion.

The N-acetylation and C-amidation modifications enhance the peptide’s stability in in vitro assay conditions, protecting against exopeptidase degradation and improving resistance to terminal enzymatic cleavage. The sequence retains the glutamate-rich motif characteristic of the SNAP-25 N-terminal region, which is critical for its interaction with the SNARE complex.

Snap-8 Interaction with SNARE Complex Assembly

Plasma Membrane

Synaptic Vesicle

Synaptobrevin (v-SNARE)

Syntaxin (t-SNARE)

SNAP-25 (t-SNARE)

SNARE complex

Snap-8 (Ac-O8) Ac-EEMQRRAD-NH₂

competes with SNAP-25 binding

Figure: In vitro model of Snap-8 interfering with SNARE complex assembly by mimicking the SNAP-25 N-terminal domain.

Figure 1. Proposed in vitro mechanism: Snap-8 (Ac-EEMQRRAD-NH2) mimics the N-terminal region of SNAP-25, competing for the SNARE complex binding interface and disrupting the four-helix bundle assembly required for vesicle fusion.

How Does Snap-8 Interact with the SNARE Complex?

The SNARE complex is a four-helix bundle structure formed by three proteins: SNAP-25 (contributing two helices), syntaxin-1, and synaptobrevin (VAMP). This complex is essential for synaptic vesicle docking and subsequent membrane fusion in neuronal cells. Snap-8 is designed to mimic a segment of the N-terminal domain of SNAP-25, the region implicated in the initial stages of SNARE complex assembly.

In in vitro neuronal models, peptides patterned after the N-terminus of SNAP-25 have been shown to act as competitive inhibitors of SNARE complex formation. By occupying the binding interface normally engaged by SNAP-25’s N-terminal helix, Snap-8 may prevent the complete assembly of the functional four-helix bundle. Research suggests this interference could modulate the Ca2+-dependent exocytosis pathway, reducing neurotransmitter release from cultured neurons and chromaffin cells in laboratory settings.

Snap-8 is an extended analog of the hexapeptide Argireline (Acetyl Hexapeptide-8, sequence Ac-Glu-Glu-Met-Gln-Arg-NH2). The two additional residues (Arg-Ala) in Snap-8 provide an extended binding surface that may enhance the peptide’s affinity for the SNARE complex interface relative to the shorter hexapeptide. Published research on SNAP-25 N-terminal peptides indicates that longer sequences derived from this region can exhibit greater inhibitory potency in in vitro exocytosis assays.

Key Mechanistic Points

Reconstitution Protocol

  1. Allow the sealed vial to equilibrate to room temperature before opening to prevent condensation inside the vial.
  2. Briefly centrifuge the vial to collect the lyophilized powder at the bottom.
  3. Reconstitute with the appropriate volume of sterile research-grade solvent (e.g., sterile water, acetic acid solution, or PBS) to achieve the desired concentration.
  4. Gently swirl or invert — do not vortex or agitate vigorously, as this may denature the peptide.
  5. Allow the solution to stand for several minutes to ensure complete dissolution.
  6. Aliquot into sterile microcentrifuge tubes for storage.
Solvent Compatibility Note

Snap-8 is soluble in aqueous solvents including sterile water, dilute acetic acid (0.1–1%), and phosphate-buffered saline. For specific assay requirements, researchers should consult the Certificate of Analysis for batch-specific solubility data.

How Is Snap-8 Quality Verified?

PepperCo Research supplies Snap-8 as a lyophilized reagent with a minimum purity of 99%. Each production batch undergoes a multi-stage quality verification process to confirm identity, purity, and peptide content.

Test Method Specification
Purity HPLC (High-Performance Liquid Chromatography) ≥ 99%
Identity Mass Spectrometry (MS) Molecular weight confirmation
Peptide Content Amino Acid Analysis / Gravimetric Reported on COA
Residual Solvents GC (Gas Chromatography) Within ICH limits
Bacterial Endotoxins LAL (Limulus Amebocyte Lysate) Test Within specification

Every batch of Snap-8 is accompanied by a Certificate of Analysis (COA) documenting the results of all tests above, including lot number, test date, and specifications. PepperCo Research conducts third-party testing to independently verify purity and identity, ensuring that each vial meets the stated specifications for laboratory research applications.

For a detailed explanation of the analytical methods used in peptide quality verification, see our article on HPLC testing.

Frequently Asked Questions

What is the difference between Snap-8 and Argireline?

Snap-8 (Acetyl Octapeptide-3) is an eight-amino-acid peptide, while Argireline (Acetyl Hexapeptide-8) is a six-amino-acid peptide. Snap-8 is an extended analog of Argireline, with both designed to mimic the N-terminal domain of SNAP-25. In vitro research suggests Snap-8 may exhibit greater potency in modulating SNARE complex formation compared to the shorter hexapeptide, owing to its extended binding surface at the SNARE assembly interface.

How does Snap-8 interact with the SNARE complex?

Snap-8 mimics the N-terminal sequence of SNAP-25, a key component of the SNARE complex responsible for synaptic vesicle docking and fusion. In in vitro neuronal models, Snap-8 has been observed to interfere with SNARE complex assembly, potentially modulating neurotransmitter release at the cellular level. This mechanism has been characterized in permeabilized chromaffin cells and neuronal cell preparations.

What is the recommended storage temperature for Snap-8 reagent?

Snap-8 lyophilized reagent should be stored at −20 °C in its original sealed vial to maintain stability. Reconstituted solutions should be aliquoted and stored at −20 °C, with repeated freeze-thaw cycles avoided to preserve peptide integrity. Working solutions may be kept at 2–8 °C for up to 24 hours.

What purity grade is available for Snap-8 research reagent?

PepperCo Research supplies Snap-8 as a lyophilized reagent with a minimum purity of 99%, verified by HPLC analysis. Each batch includes a Certificate of Analysis documenting purity, peptide content, mass spectrometry confirmation, and endotoxin levels. Independent third-party testing is conducted to verify these results.

Research-Grade Peptides & Laboratory Reagents
For Research Use Only Not for human consumption, animal use, or diagnostic procedures.

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