Exploring Adduct Formation between Human Serum Albumin and Eleven Organophosphate Ester Flame Retardants and Plasticizers Using MALDI-TOF/TOF and LC-Q/TOF

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• Alternative Title:
  Chemosphere
• Personal Author:
  Chu, Shaogang ; Baker, Margaret R. ; Leong, Gladys ; Letcher, Robert J. ; Gee, Shirley J. ; Hammock, Bruce D. ; Li, Qing X.
• Description:
  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.
• Keywords:
  Biomarker Biomarkers Chromatography, Liquid DNA Adducts Flame Retardant Flame Retardants Humans Human Serum Albumin Organophosphate Ester Organophosphates Organophosphorus Compounds Phosphorylation Plasticizer Plasticizers Protein Adduct Retrospective Studies Serum Albumin Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization Tyrosine

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• Source:
  Chemosphere. 180:169-177
• Pubmed ID:
  28407546
• Pubmed Central ID:
  PMC5494263
• Document Type:
  Journal Article
• Funding:
  G12 MD007601/MD/NIMHD NIH HHSUnited States/ ; R01 ES002710/ES/NIEHS NIH HHSUnited States/ ; U54 MD007601/MD/NIMHD NIH HHSUnited States/ ; U54 OH007550/OH/NIOSH CDC HHSUnited States/ ; U54OH007550/ACL/ACL HHSUnited States/
• Volume:
  180
• Collection(s):
  CDC Public Access
• Main Document Checksum:
  urn:sha-512:79fcf5173d5c07d8e284f7b419d041f99849ea4d14abd6a48c963de806a6cb599f5d121d11bd61877c26e310f2ac9a5d46e4792e3614fe74d577debbdc7769b4
• Download URL:
  https://stacks.cdc.gov/view/cdc/46662/cdc_46662_DS1.pdf
• File Type:
  [PDF - 730.31 KB ]