ALTERATION WITHIN A DISCRETE REGION OF THE H-2L(D)(ALPHA-1) HELIX UPON ASSOCIATION WITH HUMAN-BETA(2)MICROGLOBULIN

The utilization of the beta2-microglobulin (B2m) exchange assay allowe d for the association of H-2L(d) with human B2m. Upon association with H-2L(d), human B2m induces structural alterations in H-2L(d) that app ear dependent upon xenogeneic B2m amino acid sequence variability. In this regard, xenogeneic B2m exchange is used as a tool to induce struc tural alterations in class I as a means of analysing the structural-fu nctional relationship of B2m/class I association. Incorporating H-2L(d ) site-directed mutants into the experimental approach provided strong evidence that B2m makes indirect contact with discrete class I specif ic amino acid positions located in the helical region of the alpha1 do main.