deBruyn Adrian M H, Gobas Frank A P C
School of Resource and Environmental Management, Simon Fraser Univesity, British Columbia. Canada.
Environ Toxicol Chem. 2007 Sep;26(9):1803-8. doi: 10.1897/07-016R.1.
Partition coefficients that are used to predict concentrations of hydrophobic organic chemicals in biota (e.g., the bioconcentration factor) often assume that the sorptive capacity of an organism or tissue is adequately represented by its lipid content. In lean organisms and tissues, however, theory suggests that partitioning may be strongly influenced by the sorptive capacity of nonlipid materials, such as protein. Little is known about the sorptive capacity of proteins for hydrophobic organic chemicals, and methods to include proteins in bioaccumulation models do not exist. Here, we present a compilation and meta-analysis of published data to estimate the relative sorptive capacities of animal proteins and lipids for neutral organic chemicals. We found that the estimated sorptive capacity of protein in solid animal tissues ranged from around 1 to 10% that of lipid for compounds with a log octanol/water partition coefficient (K(OW)) of greater than two. The sorptive capacity of blood protein (albumin) appeared to be substantially higher than this, especially for low-K(OW) chemicals. For modeling purposes, we recommend estimating the sorptive capacity of animal protein as 5% that of lipid. According to this estimate, the sorptive capacity of an animal or tissue will be dominated by the contribution from protein if the lipid content makes up less than 5% of the dry-weight organic content. In such situations, a consideration of the sorptive capacity of nonlipid constituents, such as protein, will permit more accurate predictions of chemical accumulation and distribution.
用于预测生物群中疏水性有机化学物质浓度的分配系数（例如生物富集因子）通常假定生物体或组织的吸附能力可以通过其脂质含量得到充分体现。然而，在瘦型生物体和组织中，理论表明分配可能会受到非脂质物质（如蛋白质）吸附能力的强烈影响。人们对蛋白质对疏水性有机化学物质的吸附能力知之甚少，且不存在将蛋白质纳入生物累积模型的方法。在此，我们对已发表的数据进行了汇编和荟萃分析，以估计动物蛋白质和脂质对中性有机化学物质的相对吸附能力。我们发现，对于辛醇/水分配系数（K(OW)）大于2的化合物，固体动物组织中蛋白质的估计吸附能力为脂质的1%至10%左右。血液蛋白（白蛋白）的吸附能力似乎远高于此，尤其是对于低K(OW)的化学物质。出于建模目的，我们建议将动物蛋白质的吸附能力估计为脂质的5%。根据这一估计，如果脂质含量占干重有机成分的比例小于5%，则动物或组织的吸附能力将主要由蛋白质的贡献决定。在这种情况下，考虑非脂质成分（如蛋白质）的吸附能力将能够更准确地预测化学物质的累积和分布。
