Interaction between human myelin basic protein and lipophilin.

The interaction of human myelin basic protein with lipophilin has been demonstrated by affinity chromatography. The interaction was specific since neither basic protein, nor albumin bound to an affinity column consisting of BP bound to agarose. Conversely an albumin affinity column failed to bind BP. The pH dependency of the interaction correlated with the known pK for histidine. By the use of large peptides formed by tryptophanyl cleavage by BNPS-skatole, peptide 1-117 bound to the BP affinity column while neither the smaller peptide, 118-170, nor the synthetic nonapeptide bound. The large fragment contains 9 of the 10 histidines in the molecule which may explain the binding of this fragment. The result of such protein-protein interactions makes available a large number of new antigenic sites and extends considerably the range of encephalitogens for disease induction.