Heavy Metals Contamination Of Fishes From Lakes Of Wuhan And Functional Researches

With the increasing of contamination of heavy metals, the study of toxicity on fishery products has been attached more importance to. Heavy metals combine with protein and enzyme inside organism after being absorbed, which results in irreversible denaturalization and obstacle of physiological and metabolizable. The researches of enrichment in aquatic lives and toxic mechanism of heavy metals have made a rapid progress, Whereas, there were few reports on the effects of process and configuration on protein. Therefore heavy metals, such as Zn, Cu, Pb, Cr and Cd, of three representative waters and freshwater fishes in Wuhan were determined. The effects of heavy metals on the rheological and gel properties of actomyosin and myosin were analyzed, and the effects on ATPase activity and total sulfhydryl content were also discussed. At the same time the influences on configuration of actomyosin and myosin were studied. These main results were indicated as follows:1,Contamination of water and freshwater fishes in lakes of WuhanSamples were analyzed for Zn, Cu, Pb, Cr and Cd by ICP-OES in clays, waters and fishes from representative lakes -South Lake, East Lake and Yezhi Lake in Wuhan. The results were obtained as follow: the Cu concentration from Yezhi Lake and the Cd concentration from East Lake were respectively 0.010mg/L and 0.0054mg/L, and higher than that in the standard of water quality in freshwater cultivation. The Cd concentrations of three lakes sediments were 0.95mg/L, 1.07mg/L and 1.13mg/L respectively, and also higher than that in the habitat surroundings requirement of harmless aquatic products. The variety of heavy metals concentrations had been observed in different tissues and organs. Heavy metals were mainly accumulated in scales and gills. The concentrations of heavy metals of mussels were much lower than the health standard of consumptions.2,The effects of heavy metals on rheological and gel properties of actomyosin and myosinThe effects of Zn²⁺,Cu²⁺,Pb²⁺,Cr³⁺,Cd²⁺on the rheological and gel properties of actomyosin and myosin were determined by a rotary rheometer and texture analyzer. Results showed that the solutions of actomyosin and myosin were artificial model liquid. Comparing heavy metals treatments with no added ones, some changes of viscosity index and rheological coefficient happened. The viscosity index of actomyosin and myosin resolution increased after decreasing, whereas, rheological coefficient had a reverse trend. Heavy metals affected hardness, consistency, viscosity and cohesiveness of resolution. Hardness and consistency firstly had a drop, then had a distinct rise after an addition of Zn²⁺, Cr³⁺ and Cd²⁺, but viscosity and cohesiveness were oppositional. There were no clear effects of Cu²⁺ and Pb²⁺ Heavy metals had notable effects on hardeness, cohesiveness, gumminess, chewiness of gel properties, which reduced edible value.3,The effects of heavy metals on ATPase activity and total sulfhydryl content of actomyosin and myosinATPase activity and total sulfhydryl content of actomyosin and myosin was studied. The results showed similar trend of actomyosin and myosin by adding heavy metals. With the increasing of Pb²⁺ and Cd²⁺concentration, ATPase activity and total sulfhydryl content of actomyosin firstly raised slightly, and then decreased obviously. ATPase activity of myosin dropped, and total sulfhydryl content of myosin is similar to one of actomyosin. But the accession of Cu²⁺ concentration reduced ATPase activity and total sulfhydryl content evidently, which displayed terribly toxicity.4,The study of heavy metals on actomyosin and myosin by FTIR and CDThe effects of Zn²⁺, Cu²⁺, pb²⁺, Cr³⁺ and Cd²⁺ were analyzed by FTIR. The results showed that metals had a similar effect on actomyosin and myosin, and the acyl, hydroxyl, carbonyl and amide were matched. Aider metals and protein complexed, concluded hydroxyl had Einstein shift, and the position and relative intensity of amideâ… and amideâ…¡had changes. At low concentration, there was no major metal-protein reciprocity. With the rise of concentration, some changes occurred in the intensity and location of apex. There were changes ofα-helix andβ-sheet in the presence of high cation concentration,α-helix decreased andβ-sheet rised.The effect of heavy metal Cu²⁺ and Pb²⁺ on actomyosin and myosin was also studied by CD. The result indicated that considerable changes were observed from those of theα-helix(40.1%) andβ-sheet(16.5%) in the uncomplexed actomyosin to the Cu²⁺ complexesα-helix(25.8%) andβ-sheet(25.0%), and to the Pb²⁺ complexesα-helix(26.8%) andβ-sheet(22.4%). At the same time, there were notable changes from those of theα-helix(56.9%) andβ-sheet(13.8%) in the uncomplexed myosin to the Cu²⁺ complexesα-helix(48.1%) andβ-sheet(13.8%), and to the Pb²⁺ complexesα-helix(38.5%) andβ-sheet(30.2%)...