Transmembrane Domain-Mediated Colocalization of HLA-DM and HLA-DR Is Required for Optimal HLA-DM Catalytic Activity

摘要

HLA-DM catalyzes peptide loading and exchange reactions by MHC class II molecules. Soluble recombinant DM, lacking transmembrane and cytoplasmic domains, was observed to have 200- to 400-fold less activity compared with the full-length protein in assays measuring DM-catalyzed peptide dissociation from purified HLA-DR1 in detergent solutions.