Counterpointing Scenarios on the Fate of Different Prototropic Forms of Norfloxacin Housed in the Pocket of Lysozyme: The Nonelectrostatic Interactions in the Protein Interior Are in the Controlling Role on the Prototropic Equilibria of the Guest.

ABSTRACT: Herein, we report a comprehensive study on the interaction of three protomeric forms of the antibacterial drug norfloxacin (nfx) with the enzymatic protein human lysozyme (lyz). Norfloxacin, having the option for two-stage acid-base equilibria, converts from cationic (nfx⁺) to zwitterionic (nfx^±) form, followed by an anionic (nfx^-) species, with increasing pH. Among these protomeric forms, lysozyme binds nfx^± most robustly, whereas nfx^- has a weak association and nfx⁺ does not show any interaction. In lysozyme, the location of the drug was ascertained by competitive binding assay with 8-anilino-1-naphthalenesulfonate, and this was further examined with molecular docking simulation. The binding process was found to be primari

SUBMITTER: Das I 

PROVIDER: S-EPMC6044686 | biostudies-literature | 2017 Sep

REPOSITORIES: biostudies-literature