Table 2. Class II MHC/peptide complexes

All complexes, both human and murine, are prepared with human β2 microglobulin unless listed otherwise.

Human MHC/peptide complexes

These reagents are suitable for research purposes.

^* Notes:

1. In covalent complexes, the peptide is tethered to the N-terminus of the MHC II β chain. In the case of HLA II complexes, the thrombin-sensitive linker SGGGGSLVPRGSGGGGS is used. In the case of H-2 II complexes, the GSGGSGGSG linker is used.
   Especially soluble mouse MHC II-peptide complexes can usually only be produced by covalently linking the peptide to the MHC II β chain.

2. Soluble HLA-DR molcules can be expressed “empty” (i.e. without peptide cargo) and can be subsequently loaded with the peptide of interest, provided that it binds avidly.

3. All soluble MHC II molecules are expressed in Drosophila cells and the sub-unit chains are held together by acidic (on the α chain) and basic leucine zippers (on the β chain).

4. The yield and stability of MHC II–peptide complexes depends strongly on the MHC allele and the peptide.

Murine MHC/peptide complexes

^* H-2IA^d and H-2IE^d constructs are also available.

^** Amino acid residues which have been modified with respect to the native sequence are shown in red in peptide analogs.

^*** The peptide has a S423Y mutation for optimized binding.