Chu Shaogang, Baker Margaret R, Leong Gladys, Letcher Robert J, Gee Shirley J, Hammock Bruce D, Li Qing X
Department of Molecular Biosciences and Bioengineering, University of Hawaii at Manoa, 1955 East West Road, Honolulu, HI, 96822, USA; Ecotoxicology and Wildlife Health Division, Wildlife and Landscape Science Directorate, Science and Technology Branch, National Wildlife Research Centre, Environment and Climate Change Canada, 1125 Colonel Bay Dr., Ottawa, ON, K1A 0H3, Canada.
Department of Molecular Biosciences and Bioengineering, University of Hawaii at Manoa, 1955 East West Road, Honolulu, HI, 96822, USA.
Chemosphere. 2017 Aug;180:169-177. doi: 10.1016/j.chemosphere.2017.03.124. Epub 2017 Mar 31.
Organophosphate (OP) and organophosphate ester (OPE) adducts of albumin are valuable biomarkers for retrospective verification of exposure. In the present study, our goal was to determine whether OPE flame retardants (OPE FRs) and OPE plasticizers can covalently bind to human serum albumin (HSA), which would allow the resulting adducts to be used to evaluate exposure. Eleven OPE FRs and plasticizers were examined in a HSA-adduct in vitro assay. Pure HSA was incubated with the target OPEs, as well as with an OP insecticide (profenofos) positive control. After enzymatic cleavage with pepsin or Glu-C, the digested albumin was analyzed by matrix-assisted laser desorption ionization tandem time-of-flight mass spectrometry (MALDI-TOF/TOF-MS) and liquid chromatography-quadrupole time-of-flight mass spectrometry (LC-Q-ToF-MS). Under optimized HSA assay conditions, tyrosine adducts were formed at Y and Y/Y with a characteristic mass shift for phosphorylation (Δm/z 166) for the profenofos positive control. However, no such phosphorylated peptides were detected for the 11 target OPEs. This negative result suggests that these OPEs have very different affinities from the OP insecticide. They are less reactive or they may specifically interact with other proteins.
白蛋白的有机磷酸酯（OP）和有机磷酸酯（OPE）加合物是用于回顾性暴露验证的有价值的生物标志物。在本研究中，我们的目标是确定OPE阻燃剂（OPE FRs）和OPE增塑剂是否能与人类血清白蛋白（HSA）共价结合，从而使生成的加合物可用于评估暴露情况。在一项HSA加合物体外试验中检测了11种OPE FRs和增塑剂。将纯HSA与目标OPEs以及OP杀虫剂（丙溴磷）阳性对照一起孵育。用胃蛋白酶或Glu-C进行酶解后，通过基质辅助激光解吸电离串联飞行时间质谱（MALDI-TOF/TOF-MS）和液相色谱-四极杆飞行时间质谱（LC-Q-ToF-MS）分析消化后的白蛋白。在优化的HSA检测条件下，丙溴磷阳性对照在Y和Y/Y处形成了具有磷酸化特征质量位移（Δm/z 166）的酪氨酸加合物。然而，对于11种目标OPEs，未检测到此类磷酸化肽段。这一阴性结果表明，这些OPEs与OP杀虫剂的亲和力非常不同。它们的反应性较低，或者可能与其他蛋白质发生特异性相互作用。
