Proteins and Amino Acids in Fine Particulate Matter in Rural Guangzhou, Southern China: Seasonal Cycles, Sources, and Atmospheric Processes

Abstract

Water-soluble proteinaceous matter including proteins and free amino acids (FAAs) as well as some other chemical components was analyzed in fine particulate matter (PM) samples collected over a period of one year in rural Guangzhou. Annual averaged protein and total FAAs concentrations were 0.79 ± 0.47 μg m and 0.13 ± 0.05 μg m, accounting for 1.9 ± 0.7% and 0.3 ± 0.1% of PM, respectively. Among FAAs, glycine was the most abundant species (19.9%), followed by valine (18.5%), methionine (16.1%), and phenylalanine (13.5%). Both proteins and FAAs exhibited distinct seasonal variations with higher concentrations in autumn and winter than those in spring and summer. Correlation analysis suggests that aerosol proteinaceous matter was mainly derived from intensive agricultural activities, biomass burning, and fugitive dust/soil resuspension. Significant correlations between proteins/FAAs and atmospheric oxidant (O) indicate that proteins/FAAs may be involved in O related atmospheric processes. Our observation confirms that ambient FAAs could be degraded from proteins under the influence of O, and the stoichiometric coefficients of the reactions were estimated for FAAs and glycine. This finding provides a possible pathway for the production of aerosol FAAs in the atmosphere, which will improve the current understanding on atmospheric processes of proteinaceous matter.

Sources and Transformation Processes of Proteinaceous Matter and Free Amino Acids in PM2.5

“…More recent studies suggested that FAAs in aerosols might be released by direct photolysis (UV radiation), photocatalytic hydrolysis, and enzyme‐based hydrolysis from proteins/peptides (CAAs). For instance, Song et al () found that both proteins and total FAAs showed significant correlations with O 3 in PM2.5. Similarly, a linear correlation is also observed for FAA concentrations with O 3 in Research Triangle Park, USA (Samy et al, ).…”

Association of airborne particles, protein, and endotoxin with emergency department visits for asthma in Kyoto, Japan

“…Asthma is an allergic disease, and there are several reports on allergic proteins originating from pollen and fungi in outdoor air [ 6 , 7 ]. In addition, various materials such as animal dander, as well as activities such as the combustion of organic materials, are also potential sources of protein in outdoor air [ 8 , 10 , 21 , 22 ]. Kang et al analyzed the protein and other constituents in airborne particles collected in Hefei, China, and concluded that anthropogenic activities and biomass combustion were the main sources of protein in the outdoor air in the study area [ 8 ].…”

Self-aligned 3D microlenses in a chip fabricated with two-photon stereolithography for highly sensitive absorbance measurement

“…The reference optical length of this cell was determined to be 6.2 mm according to the sample volume and the size of the well (internal diameter-6.40 mm). Based on the reference value, the EOL for the sample test in microfluidic chips could be calculated according to eqn (3). The EOL can also be used as an inspection indicator of stray light.…”

“…Absorbance measurement is a frequently used quantification method for various analysis applications such as immunoassays, 1,2 protein quantification, 3,4 detection of blood glucose, 5 assessment of environmental quality, [6][7][8] etc. Compared with absorbance analysis in 1 ml detection cells or 96-well plates, the microfluidic-based assay has attracted lots of attention due to the reduced sample consumption and the miniaturized system.…”