Research Use Only — Not for Human Consumption. This article is written for laboratory research professionals. All compounds discussed are intended strictly for in vitro research use and are not for human or veterinary use, nor for diagnostic or therapeutic purposes.

SNAP-8, known by its INCI designation Acetyl Octapeptide-3, is a synthetic octapeptide encountered in the peptide research literature as a model compound for studying peptide–protein interactions associated with the SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) protein family. This article reviews its molecular identity, structural features, and how research laboratories employ it in in vitro study designs and analytical workflows.

Molecular Identity and Structural Features

SNAP-8 is an eight-residue synthetic peptide with an acetylated N-terminus and an amidated C-terminus. Its published amino acid sequence is Ac-Glu-Glu-Met-Gln-Arg-Arg-Ala-Asp-NH2, placing two acidic residues (glutamic acid), two basic residues (arginine), one aspartic acid, and one sulfur-containing methionine within a short backbone. These features give the molecule a distinctive charge profile that researchers consider when selecting aqueous buffer systems and chromatographic conditions for analysis.

Terminal modifications — N-terminal acetylation and C-terminal amidation — are common design elements in synthetic research peptides. In laboratory practice, such modifications are studied for their influence on peptide stability in solution and on behavior during reversed-phase chromatographic separation, making SNAP-8 a representative example for method-development exercises in peptide characterization.

Relationship to SNAP-25 and the SNARE Protein Family

SNAP-8 is described in the literature as a peptide fragment related to the N-terminal region of SNAP-25 (synaptosome-associated protein of 25 kDa), a core component of the neuronal SNARE complex involved in membrane fusion events. In vitro, fragments of this type are used as model systems for investigating how short peptides interact with larger protein assemblies, providing a simplified experimental window into protein–protein interaction chemistry without the complexity of full-length proteins.

Structural and sequence information for SNAP-25 is catalogued in public protein databases such as UniProt, which research teams consult when designing fragment-based interaction studies.

In Vitro Study Applications

Research laboratories employ SNAP-8 in several non-clinical contexts:

• Protein-interaction model studies: cell-free assays examining how synthetic fragments associate with SNARE-related protein targets.
• Analytical method development: a representative acetylated/amidated octapeptide for validating reversed-phase HPLC and LC-MS methods applied to short synthetic peptides.
• Reference material in characterization workflows: used alongside calibration standards when comparing chromatographic retention behavior of modified peptides.
• Stability-indicating studies: monitoring degradation products such as methionine oxidation species under controlled laboratory conditions.

Analytical Considerations for Research Laboratories

Identity and purity assessment of SNAP-8 in a research setting typically relies on orthogonal techniques. Reversed-phase HPLC with UV detection is used to evaluate chromatographic purity, while mass spectrometry confirms molecular identity. Because the sequence contains methionine, analysts watch for oxidation-related impurities that can arise during storage or handling, and laboratories document all handling steps according to internal standard operating procedures. General chemical identity information for the compound is indexed in PubChem, and related primary literature can be located through PubMed.

Research-Use Compliance Note

SNAP-8 (Acetyl Octapeptide-3) supplied for laboratory work is a research chemical. It is not approved for human or veterinary use, and no medical, therapeutic, or cosmetic efficacy claims are made or implied in this article. Research teams should consult institutional biosafety guidance and maintain complete analytical records for all materials used in vitro.

References and Further Reading

• PubChem — Acetyl Octapeptide-3: https://pubchem.ncbi.nlm.nih.gov/
• PubMed — literature search for acetyl octapeptide-3: https://pubmed.ncbi.nlm.nih.gov/
• UniProt — SNAP-25 protein entries: https://www.uniprot.org/