title: Not all empty MHC class I molecules are molten globules: tryptophan fluorescence reveals a two-step mechanism of thermal denaturation.
abstract: 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.
authors: Molecular Life Science, Jacobs University Bremen, Bremen, Germany.
authors: Sunil Kumar
authors: SK
authors: Saini
authors: Esam Tolba
authors: ET
authors: Abualrous
authors: Anca-Sarmiza
authors: AS
authors: Tigan
authors: Kathryn
authors: K
authors: Covella
authors: Ursula
authors: U
authors: Wellbrock
authors: Sebastian
authors: S
authors: Springer
mesh_terms: D000818:Animals; D005453:Fluorescence; D005805:Genes, MHC Class I; D006183:H-2 Antigens / Q000737:chemistry* / Q000378:metabolism; D064532:Histocompatibility Antigen H-2D; D051379:Mice; D010455:Peptides / Q000737:chemistry* / Q000378:metabolism; D011485:Protein Binding; D011489:Protein Denaturation; D017510:Protein Folding; D014364:Tryptophan / Q000737:chemistry*
chemical_list: D006183:H-2 Antigens; C032876:H-2Kb protein, mouse; D064532:Histocompatibility Antigen H-2D; D010455:Peptides; D014364:Tryptophan