Mercury fractionation in muscle tissue from fishes collected in the area of influence of Jirau Power Plant-Basin Madeira river using metaloprotemics strategies

Author(s)

Paula Martin de Moraes

• Document type: Doctoral Thesis
• Press: Botucatu. 2015-06-17.
• Institution: Universidade Estadual Paulista (Unesp). Instituto de Biociências. Botucatu
• Defense date: 2014-01-21
• Advisor: Pedro de Magalhães Padilha

Abstract

Inserted in the context of mercury contamination of Amazonian rivers, this work pursues through metaloproteomic study the identification and characterization of proteins from muscle tissue of three different species of fish from Madeira River that may act as potential biomarkers of toxicity of this element in the region of influence of Jirau Power Plant. The strategies for this study were separated into three distinct components: selectivity, sensitivity and structural. Throughout this research, different methodologies were used in these steps for metaloproteomic study: component of selectivity - 2D PAGE in two-dimensional proteins fractionation; components of sensitivity - SR XRF and GFAAS for mercury identification and quantification in protein spots, respectively; structural component - ESI MS MS in the characterization of proteins identified with mercury in its structure. The species studied were: dourada (Brachyplatystoma rousseauxii), pacu (Mylossoma sp., Myleus sp.) and jaraqui (Semaprochilodus sp.). Among the results, the 2D PAGE proved efficient in protein fractionation of fish muscle tissue. Using qualitative analysis by SR XRF was possible to identify the presence of mercury in the spot 68 of dourada (molar mass of 20.8 kDa and pI 5.6) and spot 72 of pacu (molar mass of 19.8 kDa and pI 7.5). Determinations by GFAAS allowed the mercury quantification in muscle tissue and in 28 spots that showed concentrations from 11.3 to 41.2 mg g-1 of mercury in its composition; these results enabled an estimative calculation of the number of mercury atoms per protein molecule between the spots studied. After analysis by ESI MS MS it was possible to characterize eight proteins with different isoforms in 21 spots that showed pI 3.5 to 9.8 and molar mass between 9.9 and 18.1 kDa, indicating that these proteins may be potential candidates for mercury biomarkers in ... (AU)

• FAPESP's process: 09/54856-8 - Development of analytical methods for mercury metallomics studies in fish collected in the AHE JIRAU - Madeira River Basin area of influence
• Grantee: Paula Martin de Moraes
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)