Exploring cadmium-binding proteins in Japanese scallops Mizuhopecten yessoensis: isolation and characterization
Zehua Zheng1,2, Yuto Namikawa1, Yugo Kato1
1Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-Ku, Tokyo, 113-8657, Japan.
Abstract:
Scallops (Mizuhopecten yessoensis) accumulate abnormal levels of cadmium (Cd) in their bodies; however, the chemical form of Cd in vivo remains unclear. In this study, Cd concentrations in various scallop tissues were measured, revealing that Cd predominantly accumulated as a water-soluble component within the midgut gland. High-performance liquid chromatography combined with the post-column tetraphenylporphyrin tetrasulfonic acid (TPPS) experiment revealed that the molecular weight of the Cd-binding substances was approximately 44 kDa. Moreover, Cd-immobilized affinity chromatography and CdS precipitation identified M. yessoensis meprin A subunit alpha-like (myMEP1A) as a Cd-binding protein. The myMEP1A gene was specifically expressed in the midgut gland. TPPS measurements indicated that myMEP1A exhibited strong Cd-binding activity. These results suggested that myMEP1A is a protein responsible for Cd accumulation in the midgut gland.
