Contents lists available at ScienceDirect Food Chemistry journal homepage: www.elsevier.com/locate/foodchem Study of proteins with mercury in fsh from the Amazon region Bruna Cavecci-Mendonça a, ⁎ , José Cavalcante de Souza Vieira a , Paula Monteiro de Lima a , Aline Lima Leite b , Marília Afonso Rabelo Buzalaf b , Luiz Fabrício Zara c , Pedro de Magalhães Padilha a a São Paulo State University Julio de Mesquita Filho, Botucatu, Department of Chemistry and Biochemistry, Brazil b São Paulo University, Bauru Faculty of Dentistry, Brazil c University of Brasília, Brazil ARTICLE INFO Keywords: ESI-MS/MS Bioinformatics GFAAS ABSTRACT The high concentrations of mercury found in Amazon have been intensively studied by the scientifc community in the last decades. These mercurial species bind preferentially to proteins. Therefore, this work proposal sought to obtain the fractionation, identifcation and study of mercury – bound proteins present in samples of muscular and hepatic tissue from fsh collected in the reservoir of the Jirau Hydroelectric Power Plant – on the Madeira River. Two-dimensional electrophoresis (2D-PAGE) for protein fractionation, graphite furnace atomic absorption spectrometry (GFAAS) for the quantifcation of mercury and Mass Spectrometry (ESI-MS/MS) were used for the identifcation of proteins. Concluding the work with analysis of graphics from the Blast2go program. Two mercury – bound proteins were identifed as triosephosphate isomerase A and Protein FAM45A. The data generated by the bioinformatics programs confrm the tendency of these proteins to be linked to mercury and elucity the possibles existing physiological and cellular interactions. 1. Introduction The Amazon rainforest is known as the shelter of the world's greatest biodiversity and in it lies the largest hydrographic basin on the planet. Its main river is the Amazon (Lima, 2007). The Madeira River is the largest tributary of the Amazon River, with high sediment pro- ductivity, mainly in suspension (Bastos, Almeida, Dórea, & Barbosa, 2007; Latrubesse, Stevaux, & Sinha, 2005). Several studies have been carried out to understand the potential ecological impacts of mercury in the Amazon region (Martinelli, Ferreira, Forsberg, & Victoria, 1988). Most of these studies focus on mining sites and conclude that the concentrations of mercury in water, sediment and biota are above the world average and are related to the anthropogenic agent, such as mining, biomass burning (Meech, Veiga, & Tromans, 1997) and defor- estation, which causes soil erosion (Roulet & Lucotte, 1999). In Forsberg et al. (1999) argues that the presence of mercury in Amazo- nian soil occurs naturally due to erosion of rocky volcanoes (Andes and Amparo, Cotopaxi, Licancabur), which is the site of the source of the Madeira River, claiming that the Amazon is “the largest reservoir of mercury in the ecosystem and largest potential source of mercury for aquatic environments”. The Amazon is a natural facilitator in the production of mercury, leading to the production of methylmercury (MeHg). As shown in some studies (Correia, Miranda, & Guimarães, 2012), these areas are im- portant sites of MeHg production, which are part of the function of their trophic level. In fact, fsh from the Basin had a high concentration of mercury in the muscle (Bastos et al., 2015). The concentration of mercury is distributed diferently among the organs of research, for example: liver > muscle > gonads > blood (Cizdziel, Hinners, Cross, & Pollard, 2003). However, the central nervous system is subject to critical mercury toxicity (Pereira et al., 2014). Bioaccumulation is a process that occurs when a chemical element, in the case, mercury accumulates at high concentrations in the organ- isms of lower trophic levels. Contamination for mercury or for others chemistry elements of the food, chain causes an increase these element concentration, at each trophic level, which is the biomagnifcation process (U.S. Geological Survey, 2009). One of the most widely used methods for the quantifcation of mercury is Cold Vapor Atomic Absorption Spectrometry (CVAAS), but for a few years a new, simple, fast and sensitive method for the de- termination of mercury concentrations in fsh tissue using the Atomic Absorption Spectrometry in Graphite Furnace (GFAAS) (Moraes et al., 2013) has been adopted. When the mercury contamination occurs the methylmercury https://doi.org/10.1016/j.foodchem.2019.125460 Received 8 April 2019; Received in revised form 18 August 2019; Accepted 3 September 2019 ⁎ Corresponding author. E-mail address: brucavecci@gmail.com (B. Cavecci-Mendonça). Food Chemistry xxx (xxxx) xxxx 0308-8146/ © 2019 Elsevier Ltd. All rights reserved. Please cite this article as: Bruna Cavecci-Mendonça, et al., Food Chemistry, https://doi.org/10.1016/j.foodchem.2019.125460