A comparative study of structural and dynamical properties of bovine serum albumin in the presence of spermine

Bovine Serum Albumin (BSA) has many functions in plasma. Serum albumins function as a carrier for fatty acids, thyroid hormones, and steroids in the blood and are involved in stabilizing the volume of extracellular fluid. BSA is a polypeptide with 583 amino acids and a molecular weight of 66,463 Da. Polyamines have several roles in cell physiology; Such as protection against oxidative damage, gene expression, and protein synthesis. Spermine (as a polyamine) is present in all eukaryotic cells. Using the methods of spectroscopic, thermal denaturation, molecular docking, and molecular dynamics simulation, we were able to investigate the effect of spermine binding to BSA in Tris-HCl buffer with pH 7.4. By binding spermine to the BSA, the absorbance changed significantly at 280 nm. The addition of spermine alters the folding of BSA and regularly decreases intrinsic fluorescence intensity at temperatures 298 K and 308 K. The formation of the BSA-spermine complex was mainly by electrostatic interactions. According to the results, fluorescence quenching (Ksv) was static and revealed one binding site for spermine. Also, molecular dynamics simulation results demonstrated that spermine binds to BSA and due to the decrease in RMSD and RMSF and the increase in Tm, it can be said that spermine has a stabilizing effect on BSA.