Binding of Sulfamerazine and Sulfamethazine to Bovine Serum Albumin and Nitrogen Purine Base Adenine: A Comparative Study

Abstract

ABSTRACT. Quenching of bovine serum albumin (BSA) and DNA base (adenine) by sulfamerazine (SM) and sulfamethazine (SMT) was studied using UV-visible, fluorescence cyclic voltammetry and molecular docking methods. A strong fluorescence quenching reaction of SM and SMT to BSA/adenine was observed and the quenching mechanism was suggested as static. Both drugs can bind to BSA and adenine with stoichiometric ratio of 1:1 and the protein -drug complexes are stabilized mainly by hydrogen bonds and van der Waals interaction. Compared to SM, SMT contributes substantially higher binding efficiency with BSA/adenine. With addition of drug solution to the adenine/BSA, the oxidation and the reduction peaks shifted towards high and low potentials, respectively. R o , J, r and E values in the BSA-drugs are higher than that of adeninedrug molecules suggest that binding of the sulfa drugs with BSA is higher than adenine -drug molecules. Docking method specify that bioactive site of sulfa drugs moiety, the aniline group is interacted with the BSA molecules.

Spectroscopic, electrochemical and molecular docking studies of dothiepin and doxepin with bovine serum albumin and DNA base

“…The drop of the voltammetric reduction current in the presence of BSA/adenine may be attributed to slow diffusion of the BSA/adenine binding with TCA drugs. The results also specified that interactions between drugs and BSA/adenine happened in the reaction and that the electrode process was irreversible .…”

“…There was no marked UV–visible spectral shift observed in BSA and adenine when varying the drug concentration, except a decrease in the absorption maxima. The changes in the absorption spectra indicated that there was interaction of the TCA drugs with BSA and adenine to form protein–drug complexes .…”

Study of the Interaction of Ciprofloxacin and Sparfloxacin with Biomolecules by Spectral, Electrochemical and Molecular Docking Methods

“…The population size was set to 150. During the search, a translational step of 0.2 Å, and quaternion and torsion steps of 5 were applied [20][21][22][23][24][25].…”

“…In general, when a small molecule interacts with biomolecules changes in absorbance and in the position of the band should occur [20][21][22][23][24][25][26]. If the binding mode is intercalation, the π* orbital of the intercalated molecule can couple with the π orbital of the biomolecules base pairs, thus, decreasing the π → π* transition energy and resulting in the bathochromism.…”

“…This technique is predominantly useful for chemical compounds due to their accessible redox states. Multiple oxidation states of the same species as well as mixtures of several interacting species can be observed simultaneously [20][21][22][23][24][25]. Equilibrium constants (K) for the interaction of the drug with biomolecules can be obtained from shifts in peak potentials, and the number of base pair sites involved in bindings through intercalative, electrostatic or hydrophobic interactions by the reliance of the current passed during oxidation or reduction of the bound species on the amount of biomolecules added.…”