AFP Peptide (FMNKFIYEI) – Catalog #B2026709

AFP Peptide FMNKFIYEI (Catalog #B2026709) is a synthetic 9-amino-acid peptide (Phe–Met–Asn–Lys–Phe–Ile–Tyr–Glu–Ile) derived from alpha-fetoprotein, a 70 kDa glycoprotein produced by the fetal liver and yolk sac during early development. In adults, AFP is a marker of hepatocellular carcinoma, hepatoblastoma, and certain germ cell tumors. The FMNKFIYEI sequence represents an immunogenic epitope recognized by helper T cells and used in cancer vaccine research to elicit or enhance anti-AFP immune responses. Supplied as 1 mg of lyophilized powder (MW 1204.45 Da), this peptide is suitable for immunization protocols, antibody generation, epitope mapping, and immunological assays.

Scientific Overview

Alpha-fetoprotein (AFP) is a 70 kDa glycoprotein synthesized during fetal development by the yolk sac and fetal liver. After birth, AFP production drops sharply; in adults, elevated serum AFP is associated with hepatocellular carcinoma (HCC), hepatoblastoma, and non-seminomatous germ cell tumors, making it a clinically important tumor marker. Beyond its diagnostic value, AFP is a target for cancer immunotherapy: T cell-based and peptide-based vaccines have been developed to elicit AFP-specific immune responses and reduce HCC recurrence.

The FMNKFIYEI sequence is an identified helper T cell epitope (MHC class II-restricted) derived from AFP. This peptide, and related AFP-derived epitope peptides, have been used in preclinical and clinical studies to induce anti-AFP immune responses, either alone or combined with other tumor antigens or immunostimulatory molecules (e.g., heat shock proteins, adjuvants, or immune-checkpoint inhibitors). The peptide's immunogenicity may vary depending on the MHC haplotype of the immunized host.

Key applications include:

• Peptide-based cancer vaccine research for hepatocellular carcinoma
• Induction of CD4+ helper T cell responses against AFP
• Epitope mapping and immunogenic site identification
• Generation of AFP-specific antibodies or T cell receptors
• Study of AFP-specific immune tolerance and anti-tumor immunity

Usage & Handling Guidance

Store at -20°C, protected from moisture. Reconstitute the lyophilized powder in sterile water or appropriate buffer immediately before use.

• Reconstitution: Dissolve in sterile water, PBS, or assay buffer. For immunization, peptide concentration should be optimized based on your immunization schedule and adjuvant choice.
• Immunization protocol: Typically, peptide is co-administered with an adjuvant (e.g., Freund's adjuvant, alum, or modern adjuvants) to enhance immunogenicity. Consult published vaccination protocols for dosing guidance.
• Stability: Lyophilized peptide is stable long-term at -20°C. In solution, stability depends on buffer and storage conditions; aliquot and store at -20°C to minimize freeze-thaw cycles.

What You Get

• 1 mg of FMNKFIYEI peptide (MW 1204.45 Da), supplied as lyophilized powder
• A defined, immunogenic AFP epitope for cancer vaccine research
• High purity suitable for immunological and immunochemical applications
• For research use only (RUO)

Why Researchers Choose It

• Defined helper T cell epitope with documented immunogenicity
• Suitable for peptide-based vaccine development against HCC
• Complements antibody-based AFP detection in dual diagnostic/therapeutic strategies
• Characterized sequence enables reproducible immunological studies

Frequently Asked Questions (FAQ)

• Is this peptide immunogenic on its own?
  AFP peptides are generally poorly immunogenic without an adjuvant. Co-administer with Freund's, alum, or modern adjuvants; follow published cancer vaccine protocols.
• What is the best immunization route?
  Subcutaneous, intradermal, or intramuscular routes are typical. Consult the literature on AFP vaccines for dosing and schedule recommendations for your experimental model.
• Can I use this peptide to generate antibodies?
  Yes. Conjugate this peptide to a carrier protein (e.g., KLH or BSA) before immunization to enhance antibody responses against the free peptide.
• Is this peptide specific to one MHC allele?
  The FMNKFIYEI epitope's presentation depends on MHC haplotype. Check published literature on MHC binding and T cell recognition for this sequence.
• Can I get documentation of purity or synthesis?
  Yes. Request a quote or contact us and we will provide available lot documentation including mass spectrometry or HPLC purity data.

References

• Hong Y, Peng Y, Guo ZS, Guevara-Patino J, Pang J, Butterfield LH, Mivechi NF, Munn DH, Bartlett DL, He Y. Epitope-optimized alpha-fetoprotein genetic vaccines prevent carcinogen-induced murine autochthonous hepatocellular carcinoma. Hepatology. 2014;59(4):1448-58.
• Tamai T, Mizukoshi E, Kumagai M, Terashima T, Iida N, Kitahara M, Shimakami T, Kitamura K, Arai K, Yamashita T, Sakai Y, Yamashita T, Honda M, Fushimi K, Kaneko S. A novel α-fetoprotein-derived helper T-lymphocyte epitope with strong immunogenicity in patients with hepatocellular carcinoma. Sci Rep. 2020;10(1):4021.
• Wang XP, Wang QX, Lin HP, Xu B, Zhao Q, Chen K. Recombinant heat shock protein 70 functional peptide and alpha-fetoprotein epitope peptide vaccine elicits specific anti-tumor immunity. Oncotarget. 2016;7(44):71274-71284.