Zhang Bin, Fang Chuan-Dong, Xu Jun-Hui, Cao Hui-Juan
Key Laboratory of Health Risk Factors for Seafood of Zhejiang Province, Zhejiang Ocean Univ., Zhoushan, Zhejiang, China.
School of Medicine, Ocean Univ. of China, No.1 Searoad, Marine building 214-1, Changzhi Island, Lincheng, Zhoushan, Zhejiang, China.
J Food Sci. 2017 Nov;82(11):2767-2773. doi: 10.1111/1750-3841.13939. Epub 2017 Oct 14.
Metallothionein (MT) plays a major role in the detoxification of toxic metal ions in mussel. This study served to investigate the effects of prepared protein hydrolysate-Fe (PH-Fe ) on depuration of cadmium salt (Cd ) from blue mussel (Mytilus edulis). The results indicated that Cd concentrations in control ranged from 46.1 to 47.1 μg/g during 15 d of depuration. While, 40 mg/L PH-Fe feed mussels exhibited obvious changes in Cd concentration variables, which decreased by 22.8 μg/g after 15 d of depuration, making them significantly lower than the values of the control. Our assumption was that Cd could be dissociated effectively from the complex of MT-Cd in mussels affected by the incorporation of PH-Fe during the feeding period. Further results of homology modeling and molecular dynamics (MD) confirmed that the combined power between MT and Cd weakened significantly by PH-Fe . This condition affected the charge density and/or the loop flexibility of MT and decreased the interaction energy within MT-Cd complex and resulted in the release of Cd from the complex, thereby exhibiting excretion detoxification. Finally, by comparing the experimental results to MD results, significant positive correlations were observed between PH-Fe and the depuration of Cd from MT-Cd complex. Overall, the findings of this study may help better understand the depuration mechanisms of Cd combined with MT, and the PH-Fe can be recommended as a depuration agent to decrease Cd concentrations in mussels.
Metallothionein (MT) is a low-molecular-weight protein with high metal-ion affinity. If the intracellular concentrations of metals are too high or if toxic metals are present within the cell, then the synthesis of MTs is induced and generated. In our previous work, it was found that the prepared hydrolysate-metal element complex showed obvious depuration activity of heavy metals (Cd ) from blue mussel (Mytilus edulis). This study provided further the depuration mechanisms of Cd from mussel (M. edulis), in particular to the role of MT and its chelate during the depuration process.
金属硫蛋白（MT）在贻贝对有毒金属离子的解毒过程中起主要作用。本研究旨在探究制备的蛋白水解物 - 铁（PH - Fe）对蓝贻贝（紫贻贝）中镉盐（Cd）净化的影响。结果表明，在净化的15天内，对照组中的镉浓度范围为46.1至47.1μg/g。而喂食40mg/L PH - Fe的贻贝镉浓度变量出现明显变化，净化15天后镉浓度降低了22.8μg/g，使其显著低于对照组的值。我们的假设是，在喂食期间，受PH - Fe掺入影响，贻贝中镉可从MT - Cd复合物中有效解离。同源建模和分子动力学（MD）的进一步结果证实，PH - Fe使MT与镉之间的结合力显著减弱。这种情况影响了MT的电荷密度和/或环柔韧性，降低了MT - Cd复合物内的相互作用能，导致镉从复合物中释放，从而表现出排泄解毒作用。最后，通过将实验结果与MD结果进行比较，观察到PH - Fe与MT - Cd复合物中镉的净化之间存在显著正相关。总体而言，本研究结果可能有助于更好地理解镉与MT结合的净化机制，并且PH - Fe可被推荐作为一种净化剂来降低贻贝中的镉浓度。
金属硫蛋白（MT）是一种对金属离子具有高亲和力的低分子量蛋白质。如果细胞内金属浓度过高或细胞内存在有毒金属，则会诱导并产生MT。在我们之前的工作中，发现制备的水解物 - 金属元素复合物对蓝贻贝（紫贻贝）中的重金属（Cd）具有明显的净化活性。本研究进一步提供了贻贝（紫贻贝）中镉的净化机制，特别是MT及其螯合物在净化过程中的作用。
