title: An N-acetylated natural ligand of human histocompatibility leukocyte antigen (HLA)-B39. Classical major histocompatibility complex class I proteins bind peptides with a blocked NH(2) terminus in vivo.
abstract: Sequence-independent interactions involving the free peptidic NH(2) terminus are thought to be an essential feature of peptide binding to classical major histocompatibility complex (MHC) class I proteins. Challenging this paradigm, a natural Nalpha-acetylated ligand of human histocompatibility leukocyte antigen (HLA)-B39 was identified in this study. It matched the NH(2)-terminal sequence of two human helicases, was resistant to aminopeptidase M, and was produced with high yield from a synthetic 30 mer with the sequence of the putative parental protein by the 20S proteasome. This is the first reported natural ligand of classical MHC class I antigens that has a blocked NH(2) terminus.
authors.affiliation: Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid, Facultad de Ciencias, 28049 Madrid, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Yagüe
authors.forename: I
authors.initials: I
authors.lastname: Alvarez
authors.forename: D
authors.initials: D
authors.lastname: Rognan
authors.forename: M
authors.initials: M
authors.lastname: Ramos
authors.forename: J
authors.initials: J
authors.lastname: Vázquez
authors.forename: J A
authors.initials: JA
authors.lastname: de Castro
mesh_terms: D000107:Acetylation; D000595:Amino Acid Sequence; D015235:HLA-B Antigens / Q000276:immunology* / Q000378:metabolism; D059946:HLA-B39 Antigen; D006801:Humans; D008024:Ligands; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry* / Q000276:immunology* / Q000378:metabolism; D011485:Protein Binding
chemical_list: D015235:HLA-B Antigens; D059946:HLA-B39 Antigen; D008024:Ligands; D010455:Peptides