Abstract
CEL-III is a Ca2+-dependent hemolytic lectin isolated from the sea cucumber Cucumaria echinata. X-ray crystallographic analysis revealed that CEL-III is composed of two ricin-like carbohydrate-binding domains (domain 1/2) and an oligomerization domain (domain 3). After binding to the specific carbohydrate chains on erythrocyte membrane, CEL-III undergoes conformational change, which leads to formation of membrane pores composed of its oligomers. Carbohydrate-recognition mechanism of CEL-III and its relationship with self-oligomerization mediated by domain 3 are discussed.
