A-melanocyte stimulating hormone analogue (N-terminal)

The N-terminal α-MSH analogue is a synthetic peptide of the first 13 amino acids of α-MSH (Ac-Ser-Tyr-Ser-Met-Glu-His-Phe-Arg-Trp-Gly-Lys-Pro-Val-NH₂) with an N-terminal acetyl group and a C-terminal amide. This truncated sequence retains strong binding affinity for melanocortin receptors (MC1R, MC3R, MC4R, MC5R) and mimics hormone activities such as melanogenesis, anti-inflammatory effects, and energy homeostasis regulation. The N-terminal acetylation enhances stability and receptor affinity. Supplied as a white, lyophilized powder with high purity, it is widely used in research for melanocortin signaling, inflammation, and pigmentation studies.

Appearance

• White to off-white lyophilized powder

• Fine, free-flowing particles

• Odorless

• Hygroscopic, readily absorbs moisture from air

Source

• Synthesized via solid-phase peptide synthesis (SPPS) using Fmoc or Boc chemistry

• Commercially available from Bachem, Genscript, ProImmune, CPC Scientific

• Custom-synthesized for specific modifications or sequence variants

Molecular Weight and Structure

• Molecular formula: C₆₁H₈₇N₁₅O₁₉ (for Ac-SYSMEHFRWGKPV-NH₂)

• Molecular weight: ≈1664.06 g/mol

• IUPAC name: Acetyl-L-seryl-L-tyrosyl-L-seryl-L-methionyl-L-glutamyl-L-histidyl-L-phenylalanyl-L-arginyl-L-tryptophyl-glycyl-L-lysyl-L-prolyl-L-valinamide

• Structure: Ac-Ser-Tyr-Ser-Met-Glu-His-Phe-Arg-Trp-Gly-Lys-Pro-Val-NH₂ (Ac = acetyl, NH₂ = C-terminal amide)

• SMILES (truncated): CC(=O)NCC(=O)NC@@HC(=O)NC@@HC(=O)NC…

Biological Activity

• Agonist at melanocortin receptors MC1R, MC3R, MC4R, MC5R

• Stimulates melanogenesis (pigmentation) in melanocytes

• Exhibits anti-inflammatory effects

• Regulates energy homeostasis and appetite

• Immunomodulatory functions

Purity and Microbial Contamination

• Purity: > 95% by HPLC

• Peptide content: Confirmed by amino acid analysis

• Water content: Typically < 5% by Karl Fischer titration

• Microbial contamination: Controlled, < 100 CFU/g or per mg peptide

• Endotoxin levels: < 10 EU/mg peptide

Identity and Quality Control

Shelf Life and Storage

• Store at –20°C or below

• Protect from light and moisture

• Shelf life typically 2 years from manufacture

• Avoid repeated freeze-thaw cycles post reconstitution

Applications

• Melanocortin receptor signaling research

• Pigmentation studies

• Inflammation and immune modulation

• Energy homeostasis and appetite regulation

• Drug delivery system development

• Cosmetic formulations

Key Characteristics

• High affinity for melanocortin receptors

• N-terminal acetylation enhances peptide stability and receptor binding

• C-terminal amidation increases stability and reduces charge

• Lyophilized for long-term storage

• Soluble in aqueous buffers or DMSO

• Small size allows efficient cell penetration

Citation

• https://pubmed.ncbi.nlm.nih.gov/8863506/

• https://pubmed.ncbi.nlm.nih.gov/11198492/

• https://pubmed.ncbi.nlm.nih.gov/20620700/

• https://pubmed.ncbi.nlm.nih.gov/21884403/

• https://pubmed.ncbi.nlm.nih.gov/19500638/

• https://pubmed.ncbi.nlm.nih.gov/2585356/

• https://pubmed.ncbi.nlm.nih.gov/7644495/

• https://pubmed.ncbi.nlm.nih.gov/12388162/

• https://pubmed.ncbi.nlm.nih.gov/12825980/

• https://pubmed.ncbi.nlm.nih.gov/32432259/