Show simple item record

dc.contributor.authorZhang, Weiguo
dc.identifier.citationSource: Dissertation Abstracts International, Volume: 55-06, Section: B, page: 2150.;Advisors: Stanley G. Nathenson.
dc.description.abstractA key element in the cellular immune response resides in the ability of cytotoxic T cells to recognize MHC class I molecules with either foreign or self peptides bound in their antigen-binding grooves. Since it is extremely difficult to purify milligrams of class I from murine cells and class I molecules purified from murine cells have hundreds of different peptides bound, it was critical to establish an expression system in order to obtain sufficient amounts of class I proteins containing a single peptide to study the class I-peptide interactions at three dimensional level. This was accomplished by expressing class I heavy chain {dollar}\rm (K\sp{lcub}b{rcub},\ D\sp{lcub}b{rcub}){dollar} and light chain ({dollar}\beta{dollar}2-microglobulin) in E. coli. Although these proteins were expressed in large amounts in E. coli, they were insoluble in the form of inclusion bodies. These insoluble heavy and light chains were solubilized with 8 M urea and then refolded in the presence of a synthetic viral peptide. These refolded class I-peptide complexes were very successfully used to obtain protein crystals with good quality. The three-dimensional structures of H-2K{dollar}\sp{lcub}\rm b{rcub}{dollar} with the VSV N52-59 peptide and H-2D{dollar}\sp{lcub}\rm b{rcub}{dollar} with the influenza NP366-374 peptide were solved. The peptides bind to MHC class I in an extended {dollar}\beta{dollar}-conformation and the ends of the peptide are tethered in the groove by the conserved hydrogen-bonding network. Most hydrogen-bonds occur between the main chain atoms of the peptide and the side chains in the groove, a fact which allows class I molecules to bind a large number of peptides. Different architectures of the grooves of K{dollar}\sp{lcub}\rm b{rcub}{dollar} and D{dollar}\sp{lcub}\rm b{rcub}{dollar} determine the binding of peptides with allele-specific anchor motifs. While the side chains of anchor residues of the peptides are buried deeply inside of the groove, other residues are solvent-accessible and available for contact with the T cell receptor.
dc.publisherProQuest Dissertations & Theses
dc.titleOverexpression, in vitro reconstitution, and crystal structures of two murine MHC class I-antigenic peptide complexes (H-2K(b) and D(b))

Files in this item


There are no files associated with this item.

This item appears in the following Collection(s)

Show simple item record