The effects of single-walled carbon nanotubes (SWCNTs) on the structure and function of human serum albumin (HSA): Molecular docking and molecular dynamics simulation studies

Abstract

Here, the interaction of single-walled carbon nanotubes (SWCNTs) and human serum albumin (HSA) as one of the most important proteins for carrying and binding of drugs was investigated and the impact of radius to volume ratio and chirality of the SWCNTs was evaluated using molecular docking method. Molecular docking results represented that zigzag SWCNT with radius to volume ratio equal to 6.77 x 10(-3) (-2) has the most negative binding energy (-17.16 kcal mol(-1)) and binds to the HSA cleft by four pi-cation interactions. To study the changes of HSA structure, the complex of HSA-SWCNT was subjected to 30 ns molecular dynamics simulation. The MD results showed that HSA was compressed about 2 after interaction with SWCNT. The equilibrated structure of HSA-SWCNT complex was used to compare the binding of warfarin to HSA in the absence and presence of SWCNT. The obtained results represent that warfarin-binding site was changed in the presence of SWCNT and its binding energy was increased. Really, warfarin was bound on the surface of SWCNT instead of its binding site on HSA. It means that HSA function as a carrier for warfarin is altered, the free concentration of warfarin is changed, and its release is decreased in the presence of SWCNT.