Crystal structure of the eosinophil major basic protein at 1.8 angstrom - An atypical lectin with a paradigm shift in specificity

The eosinophil major basic protein (EMBP) is the predominant constituent of the crystalline core of the eosinophil primary granule. EMBP is directly i mplicated in epithelial cell damage, exfoliation, and bronchospasm in aller gic diseases such as asthma, Here we report the crystal structure of EMBP a t 1.8 Angstrom resolution, and show that it is similar to that of members o f the C-type lectin superfamily with which it shares minimal amino acid seq uence identity (similar to 15-28%). However, this protein lacks a Ca2+/carb ohydrate-binding site. Our analysis suggests that EMBP specifically binds h eparin, Based on our results, we propose a possible new function for this p rotein, which is likely to have implications for EMBP function.