Assembly of selenium nanoparticles by protein coronas composed of yeast protease A

Abstract

The biosafety profile of protein corona-encapsulated selenium nanoparticles (SeNPs) has stimulated great interest among biomedical and therapeutic researchers. However, elucidating the potential mechanisms underlying the assembly process remains a significant challenge. Herein, we synthesized protein corona-encapsulated SeNPs using Saccharomyces boulardii, and then systematically investigated the complex constituents. The corona-forming protein constituents were analyzed after separation and purification. Protein sequencing results confirmed that PEP4p vacuolar aspartyl protease (protease A, PrA) participates in the SeNP-encapsulating protein corona assembly process. Additionally, protein- encapsulated SeNPs were produced using wild-type and mutant strains to determine the potential mechanism of corona formation. Phylogenetic analysis showed that the mutant strain promoted the accumulation of SeNPs and facilitated extensive production of protein corona-SeNP complexes, which is a universal cellular stress response among yeasts. This study provides an important theoretical and practical basis for the synthesis of various protein corona-coated NP complexes. The protein corona-encapsulated SeNPs fell within an acceptable size range and were effectively protein coated, indicating their potential for nutritional and pharmaceutical applications for humans and animals.