Not all empty MHC class I molecules are molten globules: tryptophan fluorescence reveals a two-step mechanism of thermal denaturation

Mol Immunol. 2013 Jul;54(3-4):386-96. doi: 10.1016/j.molimm.2013.01.004. Epub 2013 Feb 4.


When major histocompatibility complex (MHC) class I molecules bind peptide, they change their conformation and their dynamics. The structure and properties of the peptide-empty class I are still largely unknown. We have investigated the thermal denaturation of the murine class I allotypes H-2D(b) and H-2K(b) through the fluorescence of their intrinsic tryptophans, and we find that it occurs via an empty form that can also be produced by folding denatured recombinant class I molecules. It rapidly binds exogenous peptides. Our data demonstrate that the empty form of class I is a distinct conformational state with at least transient stability.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Fluorescence
  • Genes, MHC Class I*
  • H-2 Antigens / chemistry*
  • H-2 Antigens / metabolism
  • Histocompatibility Antigen H-2D
  • Mice
  • Peptides / chemistry*
  • Peptides / metabolism
  • Protein Binding
  • Protein Denaturation
  • Protein Folding
  • Tryptophan / chemistry*


  • H-2 Antigens
  • H-2Kb protein, mouse
  • Histocompatibility Antigen H-2D
  • Peptides
  • Tryptophan