Zheng Zehua, Namikawa Yuto, Kato Yugo, Lu Peng, Negishi Lumi, Kurumizaka Hitoshi, Nagata Koji, Suzuki Michio
Department 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.
Bone Marrow Transplantation Center of the First Affiliated Hospital & Liangzhu Laboratory, Zhejiang University School of Medicine, Hangzhou, China.
Environ Sci Pollut Res Int. 2025 Jul;32(31):18961-18974. doi: 10.1007/s11356-025-36799-1. Epub 2025 Aug 5.
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.
扇贝（虾夷扇贝）体内会积累异常高水平的镉（Cd）；然而，体内镉的化学形态仍不清楚。在本研究中，对扇贝各组织中的镉浓度进行了测量，结果表明镉主要作为水溶性成分积累在中肠腺内。高效液相色谱结合柱后四苯基卟啉四磺酸（TPPS）实验表明，镉结合物质的分子量约为44 kDa。此外，镉固定亲和色谱法和硫化镉沉淀法鉴定出虾夷扇贝类金属蛋白酶A亚基α样蛋白（myMEP1A）为一种镉结合蛋白。myMEP1A基因在中肠腺中特异性表达。TPPS测量表明，myMEP1A表现出很强的镉结合活性。这些结果表明，myMEP1A是一种负责中肠腺中镉积累的蛋白质。
