Snap-8 (Acetyl Octapeptide-3)
Price
£45.00
With offer: £31.50
Snap-8 (Acetyl Octapeptide-3, also designated SNAP-8) is a synthetic octapeptide (Ac-Glu-Glu-Met-Gln-Arg-Arg-Ala-Asp-NH2) that is an extended analogue of the tetrapeptide Argireline (Acetyl Hexapeptide-3). Both peptides were designed to research the SNARE protein complex that mediates neurotransmitter vesicle fusion and exocytosis at the neuromuscular junction — the same molecular machinery targeted by botulinum toxin, but through a competitive peptide mechanism rather than enzymatic cleavage.
The SNARE complex that mediates acetylcholine release at the neuromuscular junction requires the N-terminal domain of SNAP-25 (synaptosomal-associated protein 25 kDa) for complex formation. SNAP-8 is designed to mimic this N-terminal SNAP-25 sequence, competitively occupying the SNAP-25 binding site on the SNARE complex components syntaxin and synaptobrevin (VAMP), reducing SNARE complex assembly efficiency and moderating vesicle fusion frequency.
Research applications for Snap-8 include: SNARE complex formation assays using recombinant SNAP-25, syntaxin-1a, and synaptobrevin-2 with competitive peptide inhibition measured by co-immunoprecipitation or FRET-based proximity assays; neurotransmitter release assays in PC12 or primary neuronal cultures measuring acetylcholine, dopamine, or glutamate release following stimulation with and without Snap-8 pre-treatment; and comparison with the shorter Argireline (hexapeptide) to characterise length-dependence of SNARE complex inhibition.
The distinction from botulinum toxin research is mechanistic: botulinum toxin cleaves SNAP-25 enzymatically (irreversible, zinc endopeptidase mechanism), while Snap-8 acts as a competitive peptide (reversible, concentration-dependent). Research comparing Snap-8 with botulinum toxin effects on the same SNARE complex endpoints characterises the mechanistic differences between competitive inhibition and proteolytic cleavage of the same molecular target.
MW: 1075.15 g/mol. CAS: 868844-74-0. Reconstitute in bacteriostatic water at 1mg/mL. Store lyophilised at -20°C. For laboratory and analytical research purposes only.
Snap-8 versus Argireline comparative research: the structural relationship between Snap-8 (Ac-Glu-Glu-Met-Gln-Arg-Arg-Ala-Asp-NH2, 8 residues) and Argireline (Ac-Glu-Glu-Met-Gln-Arg-Arg-NH2, 6 residues) provides a direct length-activity relationship study opportunity. Snap-8 adds Ala-Asp at the C-terminus of Argireline. In parallel SNARE complex inhibition assays using recombinant SNAP-25, syntaxin-1a, and VAMP2, comparing Snap-8 versus Argireline at matched molar concentrations quantifies the contribution of the C-terminal Ala-Asp extension to SNARE complex binding affinity and inhibition potency.
For neurotransmitter release assays: differentiated PC12 cells (NGF-differentiated, 7 days) release dopamine upon KCl depolarisation (50mM, 5 minutes). Pre-incubate with Snap-8 or Argireline (1nM-100µM) for 30 minutes before KCl stimulation. Collect conditioned medium and measure dopamine by HPLC-ECD or dopamine ELISA. Calculate percentage inhibition of KCl-stimulated dopamine release versus vehicle control. Include botulinum toxin type A (BoNT-A, 1nM) as a mechanistically distinct positive control for vesicle fusion inhibition — BoNT-A irreversibly cleaves SNAP-25, while Snap-8 competitively inhibits SNARE complex formation reversibly. Washout experiments (remove Snap-8, re-stimulate 24 hours later) confirm reversibility versus BoNT-A's persistent effect. MW: 1075.15 g/mol. CAS: 868844-74-0. Reconstitute in bacteriostatic water at 1mg/mL. Store lyophilised at -20°C. For laboratory and analytical research purposes only.
Snap-8 solubility and formulation notes: the octapeptide sequence Ac-Glu-Glu-Met-Gln-Arg-Arg-Ala-Asp-NH2 contains two glutamate residues at the N-terminus providing negative charges at neutral pH, and two arginine residues providing positive charges — making Snap-8 near charge-neutral at pH 7.4. Solubility in aqueous media is moderate — dissolve in sterile water or PBS at 1-5mg/mL with gentle warming if needed. For higher concentration stocks, DMSO at 10-50mg/mL provides reliable dissolution, diluted to less than 1% DMSO in aqueous working solutions. Contains methionine at position 3 — avoid strongly oxidising conditions and prolonged storage of reconstituted solutions. Prepare fresh working solutions daily for assays. For SNARE complex biochemistry research, recombinant SNARE proteins can be purchased commercially or expressed in E. coli: His-SNAP-25 (residues 1-206), GST-syntaxin-1a (residues 1-262), and His-synaptobrevin-2 (residues 1-96) are the standard recombinant SNARE complex components used in competitive peptide inhibition assays. Pull-down assays using GST-syntaxin as bait with His-SNAP-25 in the presence of increasing Snap-8 concentrations provide direct SNARE complex inhibition data. MW: 1075.15 g/mol. CAS: 868844-74-0. Store lyophilised at -20°C. For laboratory and analytical research purposes only.