Screening of Hg-containing proteins in water hyacinth (Eichhornia crassipes) by LC-ICPMS and nanoLC-ESI- ITMS2

PABLO PACHECO; TRACI HANLEY; JULIO LANDERO; JOSEPH CARUSO

Tucson, Texas

Congreso; 2012 Winter Conference on Plasma Spectrochemistry; 2012

This study is based on the determination of Hg and its association to specific proteins in water hyacinth (Eichhornia crassipes). This plant is a floating macrophyte particularly useful in phytoremediation processes and monitoring heavy metals in aquatic environments due to its fast growth and large biomass. The plant was supplemented with 0.37 mM Hg2+ under green house conditions. After 1 week it was harvested and separated into roots, bains and leaves. The different organs were homogenized under liquid nitrogen, and treated with a Tris-HCl (pH 7.5) solution containing sodium dodecyl sulfate (SDS) and phenylmethanesulfonylfluoride (PMSF) to extract the protein fraction. Early studies with LC-ICPMS show the presence of high, medium and low molecular weight fractions. The medium molecular weight fraction corresponds to the protein fraction, indicating the association of Hg to proteins. Hg-protein complex concentrations between plant organs revealed a higher presence of these complexes in bains, followed by leaves and roots. Future studies will include fraction collection and ionic exchange separation prior to protein isolation, followed by identification with nanoLC-ESI-ITMS2.These studies will help to elucidate the Hg accumulation mechanism in water hyacinth, an important plant for bioremediation processes.