Dechlorane Plus (DP) has been detected in human serum around the world. Determining how DP binds to human serum albumin (HSA) could improve our understanding of the effects of DP in humans. The results of a fluorescence titration experiment indicated that DP binds to HSA at the interface between domains IIA and IIB, and HSA has more affinity for anti-DP than syn-DP. The DP concentrations in serum from 33 people living in Wuxi City, China, were determined in five consecutive years (2012-2016). The total concentrations of the two DP isomers were 1.73-16.3 ng·g-1 lipid weight (mean 4.7 ng·g-1 lipid weight). No clear increasing or decreasing temporal trend was found in the DP concentrations in serum over the study period. The affinity between DP and HSA will increase as the amount of fatty acids combined with HSA increases. This explained the syn-DP and anti-DP concentrations in serum being higher for overweight people than for normal weight people. Ethanol can occupy the DP binding sites on HSA. This explained the syn-DP and anti-DP concentrations being lower for alcoholic people than for nonalcoholic people.
Keywords: Dechlorane Plus; binding site; ethanol; fatty acid; human serum albumin; temporal trend.