ARSENIC SPECIES BINDING PROTEINS IN CARDIOVASCULAR TISSUES FROM CARDIAC PATIENTS OF CHILE

Abstract

The intracellular As-protein binding in cytosol and methanol–water extract of the auricle and saphene tissues of As impacted people was evaluated by bidimensional size exclusion FPLC-UV-ICP-MS. The fractionation of cytosol using Superdex, Phenomenex and MonoQ HR 5/5 columns, shows that As is distributed in a wide range of contiguous fractions of each column, being 8, 25, 50 % the percentages of As in the collected fractions, respectively. In the methanol: water extracts a similar study than performed with the cytosol using preparative gel chromatography on Sephadex G-75 and Shephadex G-100 columns and the MonoQ HR 5/5 anion protein exchange was carried out. A very low As (<1 % of total As) and protein contain were found in the different fractions of both SEC fractionating series. A similar As–protein association to that found in the cytosol after fractionating with MonoQ HR 5/5 was observed for auricle and saphene. Inorganic and methylated As speciation in the 20 – 26 cytosol fractions obtained within the Phenomenex column was performed by HPLC–ICP–MS using the Hamilton PRP-X100 column. Only As (III) and As (V) were present and the results obtained shows that the As (III)/As(V) ratio is constant in most cases. Direct evidence of the existence of As–binding peptides in auricle and saphene vein from arsenic impacted human beings has have been obtained which was previously reported by means of novo peptide synthesis.