Study of interaction between nicotinamide and human serum albumin using spectroscopic techniques and molecular docking simulation simulation

Human serum albumin is one of the most important blood proteins that has the ability to bind a wide range of compounds and different drugs. Hence, knowing how drugs bind to albumin is crucial to understand their pharmacokinetics and pharmacodynamic properties. The binding of drugs to protein affects the drug's excretion, distribution and interaction in the target tissues. Nicotinamide (NA) is a safe and inexpensive medical supplement that used to prevent and treat vitamin B3 deficiency. In this research, the molecular mechanism of the interaction between nicotinamide and human serum albumin was studied by the utilization of spectroscopic and molecular docking methods. The effects of temperature, acidic/basic pHs, metal ions, urea, and glucose on the interaction between nicotinamide and human serum albumin were also investigated. The spectroscopic studies indicated that the interaction between nicotinamide and human serum albumin is mainly controled by hydrophobic forces and the interaction is spontaneous. The number of binding site and binding constant is 1 and 4.6×104 (L/mol), respectively, which were increased in the presence of glucose. The presence of metallic ions and basic pH decreased the binding constant of nicotinamide to albumin. The obtained results indicated that nicotinamide tend to binds to the similar sites wherever the molecules with acidic moieties bind. The results could be helpful to interpret the mechanisms of actions of nicotinamide in the various physiological phenomena in the human body.