Empty Loadable MHC Tetramers: Know the Binding Rules for Success

🧬 Loadable MHC Tetramers: Know the Binding Rules for Success

Our Empty Loadable Tetramers (ELT) give you the flexibility to study T cell specificity by loading your peptide of interest directly into recombinant MHC molecules. To ensure reliable loading and robust staining of antigen-specific T cells, it’s critical that the peptide you use is compatible with the binding motif of the selected MHC allele.

Below, you’ll find a summary of the peptide binding preferences for each of our available ELT products. Following these rules helps ensure stable MHC–peptide complex formation and effective T cell staining.

Tip: Before use, always verify your peptide’s predicted binding affinity using NetMHC or other MHC-binding prediction tools.

🎯 Why Binding Rules Matter

Peptides must fit allele-specific structural pockets within the MHC molecule to be stably loaded. Mismatched peptides can:

  • Fail to bind

  • Displace easily

  • Lead to weak or no T cell staining with high background

By respecting each allele’s anchor residue requirements and peptide length preferences, you improve the likelihood of:

  • Efficient peptide exchange

  • Stable tetramer formation

  • Clear detection of antigen-specific T cells

📋 ELT Product Binding Rules by MHC Allele

🧪 Mouse MHC Class I Alleles

H-2Kb (Cat. No. MKb-016)

  • Optimal peptide length: 8-mers

  • Anchor residues:

    • Position 5 (P5): Proline or hydrophobic (Leu, Val)

    • Position 8 (PΩ): Tyrosine, Phenylalanine

  • Motif: X-X-X-X-[P/L/V]-X-X-[Y/F]

 

H-2Kd (Cat. No. MKd-009)

  • Optimal peptide length: 8-mers

  • Anchor residues:

    • Position 2 (P2): Hydrophobic (Leu, Ile, Val)

    • Position 8 (PΩ): Aliphatic (Leu, Ile)

  • Motif: X-[L/I/V]-X-X-X-X-X-[L/I]

🧪 Human MHC Class I Alleles

HLA-A*02:01 (Cat. No. HA02-070)

  • Optimal peptide length: 9-mers (8–10 tolerated)

  • Anchor residues:

    • P2: Hydrophobic (Leu, Met, Val, Ile)

    • P9: Hydrophobic (Leu, Val, Ile)

  • Motif: X-[L/M/V/I]-X-X-X-X-X-X-[L/V/I]

 

HLA-B*07:02 (Cat. No. HB07-017)

  • Optimal peptide length: 9-mers

  • Anchor residues:

    • P2: Proline (very specific)

    • P9: Leu or Met

  • Motif: X-[P]-X-X-X-X-X-X-[L/M]

 

HLA-A*11:01 (Cat. No. HA11-006)

  • Optimal peptide length: 9-mers

  • Anchor residues:

    • P2: Small/hydrophobic (Leu, Thr)

    • P9: Lysine, Val, or other aliphatic residues

  • Motif: X-[L/T/V]-X-X-X-X-X-X-[K/V]

 

HLA-A*24:02 (Cat. No. HA24-025)

  • Optimal peptide length: 9-mers

  • Anchor residues:

    • P2: Aromatic or hydrophobic (Tyr, Phe)

    • P9: Phe, Leu, Ile

  • Motif: X-[Y/F]-X-X-X-X-X-X-[F/L/I]

 

HLA-A*03:01 (Cat. No. HA03-001)

  • Optimal peptide length: 9-mers

  • Anchor residues:

    • P2: Small (Ala, Val)

    • P9: Lys or Arg (positively charged)

  • Motif: X-[A/V]-X-X-X-X-X-X-[K/R]

🧪 How to Check Peptide Compatibility

Before loading your peptide:

  1. Use NetMHC or IEDB to predict binding to your selected MHC allele.

  2. Aim for peptides with a predicted IC50 < 500 nM for strong binding (SB on NetMHC).

  3. Confirm the correct peptide length and anchor residues for the allele you’re using.

📦 Available ELT Products

Cat. No. MHC Type Format
MKb-016 H-2Kb Empty
MKd-009 H-2Kd Empty
HA02-070 HLA-A*02:01 Empty
HB07-017 HLA-B*07:02 Empty
HA11-006 HLA-A*11:01 Empty
HA24-025 HLA-A*24:02 Empty
HA03-001 HLA-A*03:01 Empty

✅ Questions?

If you’re unsure whether your peptide is a good fit for one of our ELT products, contact us — our team is happy to assist with peptide selection and prediction resources.