, Volume 11, Issue 2, pp 81–86

Preliminary assessment of protein associated with airborne particles in Mexico City


  • Irma Rosas
    • Centro de Ciencias de la Atmósfera
  • Alma Yela
    • Centro de Ciencias de la Atmósfera
  • Eva Salinas
    • Centro de Ciencias de la Atmósfera
  • Roberto Arreguin
    • Instituto de QuimicaUniversidad Nacional Autónoma de México
  • Adela Rodriguez-Romero
    • Instituto de QuimicaUniversidad Nacional Autónoma de México

DOI: 10.1007/BF02738271

Cite this article as:
Rosas, I., Yela, A., Salinas, E. et al. Aerobiologia (1995) 11: 81. doi:10.1007/BF02738271


The protein associated with airborne particles was measured during 1991 as an indicator of airborne biological material in different outdoor urban environments. Fifty air samples were collected simultaneously at three sampling sites, located in the north, south and downtown Mexico City, using a PM10 high-volume sampler (particles<10 μm). The air filters were weighed and protein extracted using a phosphate buffer. Protein concentrations were determined by Lowry assay. The extracts were also analysed by SDS electrophoresis and IEF using a Phastsystem. High concentrations of airborne particles were recorded at the sampling sites with a geometric mean of 70.2 μg/m3 in the south (residential area), 95.5 μg/m3 in the center (urban-commercial area), and with the highest value of 108.9 μg/m3 in the north (urban-industrial area). No statistically significant difference (P>0.05) was observed among the protein concentrations from the sampling sites and the concentrations ranged from non-detectable to 2.54 μg/m3. However, the protein concentrations presented significant difference (P<0.05) with respect to rainy and dry seasons. The Spearman correlation coefficient between protein concentration and airborne particles concentration was statistically significant (r=0.50). The molecular weights (MW) and isoelectric points (pI) for the proteins present in some of the extracts were determined. The values ranged from approximately 8000 to 106 000 Da and the pI values from nearly 4.0 to 5.85. This is important because the major allergens from inhalants are mostly acidic proteins with molecular weights in the range of 20 000–40 000 Da.


Airborne particlesProteinAeroallergensMexico



isoeleetric focusing


sodium dodecyl sulfate


sodium dodecyl sulfate-polyacrylamide gel electrophoresis




molecular weight


isoelectric point

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© Elsevier Science Ireland Ltd 1995