Photobehavior and docking simulations of drug within macromolecules: Binding of an antioxidative isoquinolindione to a serine protease and albumin proteins
•Modulation of photophysics in proteolytic globular enzyme and serum albumins.•Binding affinity of ANAP with albumins is much greater than trypsin.•Efficiency tunable FRET from excited Trp to ANAP.•Docking simulations of drug within biomolecules.•Hydrophobicity driven association of ANAP ensues for distinctive micropolarities in proteinous assembly.
The principal intent of the present contribution is to decipher the binding domain and structural changes of trypsin (TPS), a proteolytic globular enzyme and two serum proteins, namely, bovine serum albumin (BSA), human serum albumin (HSA) association with a newly synthesized bioactive isoquinolindione derivative (ANAP) by employing steady state, time resolved fluorescence and circular dichroism (CD) techniques. Intramolecular charge transfer emission (ICT) of ANAP is found to be responsible for the commendable sensitivity of the probe as an extrinsic fluorescent marker to the protein environments. A sharp distinctive feature of determined micropolarities in proteinous media clearly demarcates the differential extent of hydrophobicity around the encapsulated ANAP. A proficient efficiency tunable fluorescence (Förster type) resonance energy transfer (FRET) from the excited tryptophan to ANAP reveals that ANAP binds in the close vicinity of the tryptophan residue in protein. Molecular modeling simulation has been exploited for evaluating the probable interaction site of ANAP in proteinous assembly which shows subdomain IIA are earmarked to possess affinity for ANAP in serum albumins whereas S1 binding pocket in TPS has been found potential binding region for ANAP.
Graphical abstractTunable FRET response and docked pose of ANAP within biomolecules.Figure optionsDownload full-size imageDownload as PowerPoint slide
Journal: Journal of Photochemistry and Photobiology B: Biology - Volume 129, 5 December 2013, Pages 69–77