Chemical cross-linking of class I molecules on cells creates receptive peptide binding sites.
Class I heterodimers on the surface of cells are generally unreceptive to binding peptides in the absence of exogenous beta 2-microglobulin. Paraformaldehyde covalently cross-links beta 2-microglobulin to class I heavy chains in situ and stabilizes empty class I heterodimers. Functionally, this cross-linking creates receptive class I peptide binding sites by acting on beta 2-microglobulin-associated molecules. The presentation of preexisting peptide-class I complexes is also enhanced. These findings support a model whereby a structural alteration, the dissociation of beta 2-microglobulin, limits the existence of receptive class I molecules on normal cells and may control the half-life of active class I molecules.
Rock
K L
KL
Division of Lymphocyte Biology, Dana Farber Cancer Institute, Boston, MA 02115.
Rothstein
L
L
Gamble
S
S
Gramm
C
C
Benacerraf
B
B
D000818:Animals; D000938:Antigen-Presenting Cells / Q000502:physiology; D001665:Binding Sites; D005557:Formaldehyde / Q000494:pharmacology; D015395:Histocompatibility Antigens Class I / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D010446:Peptide Fragments / Q000276:immunology*; D011108:Polymers / Q000494:pharmacology; D001613:beta 2-Microglobulin / Q000494:pharmacology
D015395:Histocompatibility Antigens Class I; D010446:Peptide Fragments; D011108:Polymers; D001613:beta 2-Microglobulin; D005557:Formaldehyde; C003043:paraform