Peanut selenium distribution, concentration, speciation, and effects on proteins after exogenous selenium biofortification

Fortification of Se is vital importance for both nutritional demand and prevention of Se-deficiency-related diseases. To better understand t selenium distribution, concentration, speciation, its effects on proteins, and cytotoxic activity, the biofortification of exogenous Se in peanut was conducted in this study. Our data have shown that foliar spraying of Se-riched fertilizer was more efficient for biotransformation of inorganic Se to organic Se by peanut plant. Besides, the Se content in peanut was increased in a dose-dependent manner. Our present study also confirmed that SeCys₂, MeSeCys, and SeMet were the main Se speciation within peanut proteins. Moreover, the secondary structure and thermostability of peanut protein were altered as a result of the Se treatments, and these alterations could be attributed to the replacements of cysteine and methionine by selenocysteine and selenomethionine, respectively. The Se-enriched peanut protein could significantly inhibit the growth of Caco-2 and HepG2 in a concentration-dependent manner.