Binding of a potential anti-hepatoma drug cis,cis,trans-[Pt(NH₃)₂Cl₂(O₂CCH₂CH₂COOH)-(OCONHC₁₆H₃₃)] with serum albumin – thermodynamic and conformational investigations

Abstract

In this paper, a potential anti-hepatoma Pt 4+ drug cis,cis,trans-[Pt(NH 3 ) 2 Cl 2 (O 2 CCH 2 CH 2 COOH)-(OCONHC 16 H 33 )] was synthesized and selected to investigate its binding to human serum albumin (HSA) by spectroscopy and molecular docking methods. Fluorescence spectra show that the Trp residue, the intrinsic fluorophore in HSA, was induced to a less hydrophobic microenvironment with the addition of the Pt 4+ compound, which induces the denaturation of HSA. Moreover, the fluorescence quenching mechanism was determined to be static quenching. The binding constant (K A ) and the number of binding sites (n) were calculated based on the results of fluorescence measurements. Circular dichroism (CD), Fourier transform infrared spectroscopy (FTIR) and three dimensional fluorescence spectroscopy proved that the Pt 4+ compound could slightly change the secondary structure and induce unfolding of the polypeptides of protein. Thermodynamic parameters indicate that the Pt 4+ compound binds to HSA through electrostatic attraction with one binding site. The molecular docking study indicated that parecoxib is embedded into site I (subdomain IIA) of HSA.

Switchable Luminescent Probe for Trace-Level Detection of the Spodoptera litura Nuclear Polyhedrosis Virus via a Color-Changing Response

“…A negative value of the reaction enthalpy (Δ H = −2.85 kJ/mol) along with a positive entropy change (Δ S = 0.0179 kJ/mol) indicates that the quenching of the emission intensity of the 605 nm band was predominantly governed by the electrostatic interaction (Figure S3b,c). − Moreover, as discussed above, the extent of the optical change was found to be dependent on the pH of the medium, and almost no interaction was observed below pH 4 (Figure b). The protonation at the carboxylic ends of the amino acid residues of SLNPV at low pH probably weakens the electrostatic interaction between 1 and SLNPV.…”

On-Field Detection of Helicoverpa armigera Nuclear Polyhedrosis Virus Using Luminescent Amphiphilic Probe: Screening of Agricultural Crops and Commercial Formulations

“…Furthermore, changes in the thermodynamic parameters were also evaluated by variable temperature studies. A negative value of Δ H with positive entropy change (Δ S ) suggested that the optical response (at 395 nm band) may be largely governed by electrostatic interactions. , To substantiate this argument, we monitored the changes in the zeta potential values of HaNPV upon gradual addition of 1 . In the absence of probe, HaNPV showed a highly negative zeta potential value at pH 7.4 because of the presence of a negatively charged polyhedrin protein surface.…”

Recent Advances in the Chemistry of Metal Carbamates

“…More precisely, coupling of a Pt(IV) (bis)hydroxo species with an alkyl or aryl isocyanate affords the corresponding (bis)carbamate. Following optimization [260], allowing the reaction to be conducted in dimethylformamide and not in neat isocyanate, more than 60 different Pt(IV) species were thus prepared, arousing interest as possible anticancer agents (see Section 5) [261][262][263][264][265][266][267][268]. Reaction of hydroxido(oxido) ligands with organic isocyanates (Scheme 18d).…”

“…Platinum(IV) carbamato complexes with simple organic substituents on the nitrogen revealed a considerable cytotoxicity against various cancer cell lines, comparable or superior to that of the reference Pt(II) drug cisplatin [260,262,263]. A C 16 aliphatic chain (fatty acid-like) was introduced through the carbamato ligand to enhance cellular uptake [263,264,266,[366][367][368]. Following a different approach, the incorporation of a maleimide fragment enabled specific interactions with proteins (e.g., addition to thiol residues) for compounds showing a promising anticancer activity in vivo [261,268,369].…”