The selenium link: the missing link in our understanding of biochemical trigger reactions?
'Inorganic' selenium (Se), e.g. selenite and selenate, is assumed to be transformed into selenide and to be incorporated into selenoproteins, but this has never been proved. There is evidence, however, that vitamin C reduces selenite to elemental Se. Elemental sulphur (S) and Se bind easily to sulphides and selenides, forming links containing two or more S or Se atoms. Such links exist in natural minerals and have been found in proteins in living organisms. There are many indications that selenocysteine in special proteins combines with elemental Se to form Se links that transfer electrons from redoxable agents to oxygen (O2). This implies a reduction to hydrogen peroxide (H2O2) or H2O, while gaining energy and achieving trigger effects. H2O2 supplies anaerobic reactions with energy eventually via adenosine 5'-triphosphate (ATP) or guanosine 5'-triphosphate (GTP). Without Se links, redoxable agents can be oxidized by oxygen, which leads to the formation of oxygen products and inhibition of further electron transference. Nitrous oxide (NO) is one product of oxidation that, firmly binding to heme structures, may result in a system of protection. NO can prevent O2 from binding to them and thereby stop destroying oxidations.
Nyberg-Swenson
B E
BE
swenson@fy-chalmers.se
D000818:Animals; D002395:Catecholamines / Q000378:metabolism; D004579:Electron Transport; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism; D007453:Iodide Peroxidase / Q000378:metabolism; D008954:Models, Biological; D009609:Nitrous Oxide / Q000378:metabolism; D011506:Proteins / Q000378:metabolism; D012643:Selenium / Q000378:metabolism*; D051140:Selenoproteins; D015293:Transducin / Q000378:metabolism; D014968:Xanthine Dehydrogenase / Q000378:metabolism; D014969:Xanthine Oxidase / Q000378:metabolism
D002395:Catecholamines; D011506:Proteins; D051140:Selenoproteins; D006861:Hydrogen Peroxide; D007453:Iodide Peroxidase; D014968:Xanthine Dehydrogenase; D014969:Xanthine Oxidase; D015293:Transducin; D012643:Selenium; D009609:Nitrous Oxide