The chaperone and potential mannan-binding lectin (MBL) co-receptor calreticulin interacts with MBL through the binding site for MBL-associated serine proteases.

The chaperone calreticulin has been suggested to function as a C1q and collectin receptor. The interaction of calreticulin with mannan-binding lectin (MBL) was investigated by solid-phase binding assays. Calreticulin showed saturable and time-dependent binding to recombinant MBL, provided that MBL was immobilized on a solid surface or bound to mannan on a surface.