Analysis of temporally evolved nanoparticle-protein corona highlighted the potential ability of gold nanoparticles to stably interact with proteins and influence the major biochemical pathways in Brassica juncea.

Nanoparticles (NPs) are known to adsorb proteins from their surroundings, forming NP-protein corona, which determines their fate, distribution, and effects, yet no information of protein corona (PC) has been gathered in the plants so far. Here we report, the analysis of temporally evolved (2 h-36 h) AuNP-protein coronas formed with Brassica juncea leaf crude protein & nuclear-enriched fraction. Protein coronas were characterized by the techniques including SDS PAGE (Sodium Dodecyl Sulfate Polyacrylamide Gel Electrophoresis), spectrophotometry, dynamic light scattering, zeta potential measurements, and Nano LC-MS/MS. Data analysis revealed the formation of two regimes (Regime I from 2 to 8 h & regime II from 16 to 36 h). Interestingly, coated AuNPs had approx. 30% higher zeta potential than pristine AuNPs after 36 h of interactions. The increase in hydrodynamic radii and adsorbed protein concentrations were consistent with the evolution of zeta potential, indicating the probable role of proteins in providing the better stability of AuNPs. MS analysis identified 97 proteins from regime I (soft corona) and 181 proteins from regime II (hard corona) of crude PC. On the other hand, 282 and 308 proteins were identified from nuclear soft and hard corona respectively, indicating better affinity of nuclear proteins. Besides, the high-affinity proteins (fold change ≥5) were found to be rich in lysine residues showing their involvement in promoting the adsorption. Notably, 27% of regime II corona proteins of the crude protein fraction were from energy-yielding pathways highlighting the potential ability AuNPs to influence the yield in Brassica juncea.