Selenium Speciation In Edible Mushrooms And Interaction Of BSA With Selenium

Selenium is a typical dual-function element,its safety threshold is very narrow,too high or too low will affect human health.Soil selenium deficiency is a world problem,nations have a different degree of selenium deficiency areas.The selenium forms in the nature mainly inorganic selenium,but the available selenium of people is organic selenium.Edible mushrooms through the metabolism of hyphae,to enrich selenium and make inorganic selenium to organic selenium.So in the edible mushroom selenium content is very rich and the selenium speciation also very rich.In the case of generally inadequate intake of selenium,there is no doubt that have a great future to make edible mushroom as a selenium source.However,due mainly to start late of investigations of speciations,as well as the lack of research of selenium speciation and bioavailability for mushroom.Edible mushroom can provide rich selenium,but different selenium form have different biological activity and bioavailability,so that we lack of theoretical basis for the safety assessment of edible mushroom as rich-selenium food.HPLC-ICP-MS is an element speciation analysis techniques and developed rapidly in recent years for its high sensitivity,low detection limit,fast analysis speed and so on.In this article firstly we studied the total amount and speciation of selenium in the edible mushroom in normal selenium areas and rich selenium areas using HPLC-ICP-MS,through optimized the sample pretreatment method,mobile phase,separation column and parameter of apparatus we achieve the effective separated Se(?),SeMet and Se(?)Within 8min.the sample analysis results show that the content of selenium in Enshi is higher than Qingyuan,and the content of selenium in xianggu,huagu,chashugu,and zhujun are more richer than other mushrooms,but there is no much difference about selenium form between the edible mushroom in Qingyuan and Enshi.They both have the Se(IV),but the content is not high,the selenium is much more exists in the mushroom as small organic molecular.Most of the selenium in edible mushroom is organic form,so mushrooms is a good selenium-rich foods.For another,after selenium enter organism,it can combination with harmful heavy metal ions which has positive charge,such as Hg,to form a metal-Se-protein complexes.By this way it can reduce the accumulation of heavy metals in the body to lift the heavy metal poisoning.In order to study the interaction mechanism of selenium and protein,selenium lift of mercury poisoning mechanism,we studied the interaction between selenium,mercury with BSA in vitro simulated conditions by using atomic fluorescence spectroscopy,synchronous fluorescence spectroscopy,circular dichroism spectroscopy,and ultraviolet absorption spectroscopy,and so on.Atomic fluorescence spectroscopy results showed that there is no obvious fluorescence quenching between selenium and BSA.The quenching mechanism between mercury and BSA is static quenching,the number of binding site is 1,the mainly acting force is hydrophobic force.The circular dichroism spectroscopy results showed that the selenium and mercury make the content of the Alpha-helical of BSA reduced,?-fold content is always 0%,rotation and random content increaseed.We also studied the secondary structure changes of BSA after adding selenium and mercury together by using the circular dichroism spectroscopy.Thus provide a useful theoretical basis for further understanding of selenium bioavailability and explore methods for prevention and treatment of mercury poisoning.