RESUMO
This study aimed to evaluate the quality of the royal jelly produced by Apis mellifera bees in the presence of different iron concentrations (ferrous sulfate heptahydrate-0, 25, 50, and 100 mg L-1). Two-dimensional electrophoresis was used for the fractionation of royal jelly proteins, and iron level was quantified using flame atomic absorption spectrometry technique. The proteins were identified using electrospray ionisation mass spectrometry. Analysis of variance followed by the Tukey test (P < 0.05) was utilised. Dietary supplementation with mineral Fe affected the protein content and number of proteins in the experimental period. Further, the diet containing the highest iron concentration showed a greater number of spots containing iron, as well as in the abdomen of the bees. The most protein containing Fe were classified as major royal jelly proteins. These results showed that Fe influenced the quality of royal jelly and can improve its nutritional value.
Assuntos
Ácidos Graxos/química , Compostos Ferrosos/análise , Proteínas de Insetos/análise , Animais , Abelhas , Suplementos Nutricionais , Ácidos Graxos/biossíntese , Compostos Ferrosos/administração & dosagem , Compostos Ferrosos/metabolismo , Proteínas de Insetos/metabolismoRESUMO
Predator fish can accumulate high levels of mercury, which qualifies them as potential indicators of this toxic metal. The predatory species Brachyplatystoma filamentosum, popularly known as filhote, is among the most consumed species in the Brazilian Amazon. Continuing the metalloproteomic studies of mercury in Amazonian fishes that have been developed in the last 5 years, the present paper provides the data of protein characterization associated with mercury in muscle and liver samples of filhote (Brachyplatystoma filamentosum) collected in the Madeira River, Brazilian Amazon. The mercury concentration in the muscle and liver samples was determined by graphite furnace atomic absorption spectrometry (GFAAS). The protein fraction was extracted in an aqueous medium, and later, a fractional precipitation procedure was performed to obtain the protein pellets. Then, the proteome of the tissue samples of this fish species was separated by two-dimensional polyacrylamide gel electrophoresis (2D-PAGE), and a mercury mapping of the protein spots was carried out by GFAAS after acid digestion. Protein spots that had mercury were characterized by mass spectrometry with electrospray ionization in sequence (ESI-MS/MS) after tryptic digestion. It was possible to characterize 11 mercury-associated protein spots that presented biomarker characteristics and could be used to monitor mercury in fish species of the Amazon region. Thus, the metalloproteomic strategies used in the present study allowed us to characterize 11 mercury-associated protein spots. It should be noted that the protein spots identified as GFRP, TMEM186, TMEM57B, and BHMT, which have coordination sites for elements with characteristics of soft acids, such as mercury, can be used as biomarkers of mercury contamination in monitoring studies of this toxic metal in fish species from the Amazon region.
Assuntos
Contaminação de Alimentos/análise , Mercúrio/análise , Metaloproteínas/análise , Proteômica , Rios/química , Poluentes Químicos da Água/análise , Animais , Biomarcadores/análise , Brasil , Peixes-Gato , Espectrofotometria AtômicaRESUMO
CE-ESI-MS with a liquid sheath interface and IT mass analyzer was used for analysis of siderophores from different strains of Methylobacterium spp. citrus endophyte extracts. Three Methylobacterium strains were investigated according to positive bioassay tests. Bacteria cultures were grown under Fe(III) absence (siderophore producing cultures) and under Fe(III) presence (control cultures). Siderophores were extracted from culture supernatant with polystyrene resins. BGE and sheath-liquid composition were optimized, respectively, in order to assure both, best peak resolution and ESI-MS sensitivity. The best analysis conditions were obtained with 100 mmol/L ammonium bicarbonate at pH 8 as BGE and methanol:H(2)O 25:75 + 0.05% formic acid as sheath liquid. CZE-ESI-MS analysis revealed two possible siderophores, according to bacterium species, presenting M(r) of 1004.3 and 798.3 Da.