全氟化合物及替代物与鱼类卵黄蛋白原及卵黄蛋白的结合特征与机制研究

Perfluorinated compounds (PFCs) and their substitutes have received growing attention as a group of persistent organic compound (POPs). Different from hydrophobic POPs which tend to accumulate in adipose tissue of biota, PFCs will bind to proteins. Current studies focus on the binding affinity of PFCs to serum albumin and fatty-acid binding proteins. Vitellogenin (Vg) and vitellin (Vn) are a group of proteins which play important roles in fish reproduction. They are produced in fish blood and ovum to provide nutrients to fish embryos. PFCs are more easier to accumulate in fish ovum and then be transferred to fish embryos, compared with the hydrophobic POPs due to the binding between PFCs and Vn、Vg. The project will study the characters and mechanisms of PFCs binding to Vn and Vg, including characters of PFCs distribution in ovum and their intergenerational transfer behavior, comparison between PFCs and hydrophobic POPs in intergenerational transfer tendency, binding affinity of PFCs to Vn and Vg、binding force、binding sites、structure change of proteins after the binding with PFCs. The project will benefit the intergenerational transfer study of PFCs and fish individuals and population risk assessment caused by water body PFCs pollution.

全氟化合物（perfluorinated compounds，PFCs）及替代物是一类受到广泛关注的持久性有机污染物（persistent organic compounds，POPs），与亲脂POPs易富集于脂肪中不同，PFCs倾向于与蛋白质结合，目前研究较多的是PFCs与血清白蛋白及脂肪酸结合蛋白的结合。卵黄蛋白原与卵黄蛋白是鱼类血液与卵细胞中为胚胎提供营养物质的一类重要蛋白质，PFCs与此类蛋白质的结合使PFCs较亲脂POPs更易富集于卵母细胞中进而实现代际传递。本项目将研究PFCs与卵黄蛋白原及卵黄蛋白的结合特征与机制，包括PFCs及替代物在卵母细胞中的分布及代际传递特征，PFCs与亲脂POPs代际传递特征的比较，PFCs与卵黄蛋白原及卵黄蛋白的结合强度、结合力类型、结合位点、结合体空间构象等。本研究将为全氟化合物及替代物的鱼类代际传递机制及鱼类个体及种群的风险评估提供理论基础。

全氟化合物及替代物因其毒性、高稳定性、普遍存在性而受到了广泛的关注，由于其易于与蛋白质结合，相比倾向于与脂质结合的疏水性持久性有机污染物，可通过与鱼类卵黄发生相关蛋白质结合而实现代际传递。本项目研究了全氟化合物及替代物与鱼类卵黄蛋白和卵黄蛋白原的结合特征与机制。研究结果发现相比疏水性持久性有机污染物，全氟化合物及替代物更易富集于鱼卵中，鱼卵中全氟化合物及替代物占鱼体总量比重可达53.3%，全氟化合物及替代物在鱼卵中的富集行为与其碳链长度和末端基团有关，部分替代物相比传统全氟化合物更易在鱼卵中富集。鱼类卵黄蛋白和卵黄蛋白原的主要组分在分子量、疏水性、带电量等方面存在差异，影响了与全氟化合物及替代物的结合。卵黄脂磷蛋白是结合全氟化合物及替代物的主要组分，主要结合位点位于其疏水性腔隙，作用力类型包括疏水作用力、氢键等。本研究为全/多氟化合物的鱼类代际传递行为提供了理论基础，为全/多氟化合物的生态风险研究提供了新的视角。