Expression of allergenic protein and polycyclic aromatic hydrocarbons in the Platanus pollen grains collected from different area of Shanghai

Abstract

As one of biological particles, pollen grains could be suspended in air and cause health risks such as pollinosis and rhinitis. Air pollutants can be absorbed on the pollen grains which would increase allergenicity. However, few studies have been focused on characterization of polycyclic aromatic hydrocarbons (PAHs), one kind of toxic pollutants absorbed on pollen grains, and their relationships with the allergenic proteins. In this study, fresh Platanus pollen samples were collected in the central parking area and the outer ring area of Shanghai in the spring of 2023. Mass concentration of allergenic protein (Pla a3) released from the samples collected at the two sampling sites were investigated by using western blot assay and enzyme linked immunosorbent assay, while mass levels of PAHs absorbed on the surface of flower inflorescence and pollen grains were measured by using GC-MS. Our data showed that the mass level of Pla a3 released from the pollen grains collected in the parking area was significantly higher than that collected in the outer ring area. Mass level of PAHs on the flower inflorescence and pollen grains in the parking area was 2 times higher than that in the outer ring area. The molecular docking results indicated that four disulfide bonds (Cys4-Cys52, Cys14-Cys29, Cys30-Cys75, Cys50-Cys89) in the Pla a3 protein structure could interact with the PAHs by hydrogen bonds. This interaction could increase the structural stability of the protein and enhance the allergenicity.