Effects of Ca²⁺ on Refolding of the Recombinant Hemolytic Lectin CEL-III

Abstract

CEL-III is a hemolytic lectin isolated from Cucumaria echinata. Although recombinant CEL-III (rCEL-III) expressed in Escherichia coli showed very weak hemolytic activity compared with native protein, it was considerably enhanced by refolding in the presence of Ca²⁺. This suggests that Ca²⁺ supported correct folding of the carbohydrate-binding domains of rCEL-III, leading to effective binding to the cell surface and subsequent self-oligomerization.