Title

Fluorogenic probes for monitoring peptide binding to class II MHC proteins in living cells

GSBS Program

Biochemistry & Molecular Pharmacology

UMMS Affiliation

Graduate School of Biomedical Sciences; Department of Pathology; Department of Biochemistry and Molecular Pharmacology

Date

3-14-2007

Document Type

Article

Medical Subject Headings

Animals; Antigen-Presenting Cells; Binding Sites; Cells, Cultured; Crystallography, X-Ray; Fluorescent Dyes; Histocompatibility Antigens Class II; Humans; Models, Molecular; Oligopeptides; Protein Binding

Disciplines

Life Sciences | Medicine and Health Sciences

Abstract

A crucial step in the immune response is the binding of antigenic peptides to major histocompatibility complex (MHC) proteins. Class II MHC proteins present their bound peptides to CD4(+) T cells, thereby helping to activate both the humoral and the cellular arms of the adaptive immune response. Peptide loading onto class II MHC proteins is regulated temporally, spatially and developmentally in antigen-presenting cells. To help visualize these processes, we have developed a series of novel fluorogenic probes that incorporate the environment-sensitive amino acid analogs 6-N,N-dimethylamino-2-3-naphthalimidoalanine and 4-N,N-dimethylaminophthalimidoalanine. Upon binding to class II MHC proteins these fluorophores show large changes in emission spectra, quantum yield and fluorescence lifetime. Peptides incorporating these fluorophores bind specifically to class II MHC proteins on antigen-presenting cells and can be used to follow peptide binding in vivo. Using these probes we have tracked a developmentally regulated cell-surface peptide-binding activity in primary human monocyte-derived dendritic cells.

Rights and Permissions

Citation: Nat Chem Biol. 2007 Apr;3(4):222-8. Epub 2007 Mar 11. Link to article on publisher's site

Related Resources

Link to Article in PubMed