Biomarkers of organophosphorus (OP) exposures in humans

There are ongoing events where aircraft engine lubricant containing tricresyl phosphates (TCPs) contaminates aircraft cabins. Some individuals have experienced tremors or other neurological symptoms that may last for many months following exposures. Mass spectrometric (MS) protocols are being developed to determine the percentage of “biomarker proteins” that are modified by such exposures, specifically on active site serines. Both plasma butyrylcholinesterase (BChE) and red cell acylpeptide hydrolase (APH) are readily inhibited by 2-(ortho-cresyl)-4H-1,3,2-benzodioxaphosphoran-2-one (CBDP) or phenyl saligenin cyclic phosphate (PSP) and have the potential to provide information about the level of exposure of an individual. We have developed immunomagnetic bead-based single-step purification protocols for both BChE and APH and have characterized the active site serine adducts of BChE by MS.

► Tricresyl phosphate (TCP) can enter aircraft cabins and cause aerotoxic syndrome.
► Biomarkers of exposure: butyrylcholinesterase (BChE) and acylpeptide hydrolase (APH).
► One-step purification protocols for BChE and APH using immunomagnetic beads.
► Characterization of the active site serine adducts of BChE by mass spectrometry.
► Detection of cresyl phospho-serine and phospho-serine from in vitro inhibited BChE.