Multiple spectroscopic and theoretical investigation of meso-tetra-(4-pyridyl)porphyrin‑ruthenium(II) complexes in HSA-binding studies. Effect of Zn(II) in protein binding

Interactions of a Ruthenium‐Ketoprofen Compound with Human Serum Albumin and DNA: Insights from Spectrophotometric Titrations and Molecular Docking Calculations

“…[64] Thus, the in silico calculations suggested major groove of DNA strands and subdomain IB of HSA as the main binding sites for the [Ru 2 O(keto) 2 (py) 6 ](PF 6 ) 2 compound. The same trend for both DNA and HSA was previously observed in silico for some other ruthenium complexes, including Ru(II)-polypyridyl [Ru(NÀ N) 2 (PTCP)](ClO 4 ) 2 (where NÀ N : 1,10-phenanthroline; 2,9-dimethyl-1,10-phenanthroline, or 4,40-di-tert-butyl-2,20-bipyridine), [65] meso-tetra(4pyridylvinylphenyl)porphyrin functionalized with [Ru(bpy) 2 Cl] + units, [66] 10,15,20-tetrakis(4-pyridyl)-21H,23H-porphyrin functionalized with [Ru(bpy) 2 Cl] + units, [67] [Ru(tmp) 2 (dpq)] 2 + , [Ru-(tmp) 2 (dppz)] 2 + , and [Ru(tmp) 2 (11,12-dmdppz)] 2 + . [68] Aditionally, the highest docking score value for HSA compared with DNA suggested that [Ru 2 O(keto) 2 (py) 6 ](PF 6 ) 2 interacts stronger with albumin than with DNA, being in agreement with the experimental trend, as well as the experimental number of binding site indicated a proportion HSA:[Ru 2 O(keto) 2 (py) 6 ](PF 6 ) 2 of 1 : 1 and molecular docking score values for albumin clearly show a high difference among the three binding sites, also indicating one main binding site.…”

Synthesis, Photophysics, Computational Approaches, and Biomolecule Interactive Studies of Metalloporphyrins Containing Pyrenyl Units: Influence of the Metal Center

“…[21,46,47] The significant red shift upon successive additions of porphyrins in the BSA solution, suggests that the albumin structure and microenvironment around the fluorophore's residues changed upon ligand binding. [48][49][50] The values for fluorescence quenching (K SV , k q ) and binding (K app , n) constants were obtained via steady-state fluorescence quenching and the results are summarized in Table 9. Since the bimolecular quenching rate constant values (k q ~10 12 -10 13 M À 1 s À 1 , Table 8) are higher than the diffusion rate constant (k diff ~7.40 × 10 9 M À 1 s À 1 , at 298.15 K, according to Smoluchowski-Stokes-Einstein theory) [43] , indicate that the probable mechanism of fluorescence quenching is static, implying in a groundstate association between the fluorophore of BSA and each quencher (pyrenyl-porphyrins).…”

“…These results are in accordance with the experimental data, that indicated as main binding pocket those that presents the tryptophan residue (ground-state association). From literature, some metalloporphyrins were described to interact with site III, [21,50] probably due to the high volume of this macrocycle. Inside subdomain IB, molecular docking results suggested van der Waals force as the main intermolecular interaction that stabilize the BSA:porphyrins complex.…”

“…The number of binding sites (n) in all compounds is between to 0.85 and 1.25, suggesting the presence of one main binding site for each compound in the BSA structure. [50,54] Investigation on the main binding site, as well as the amino acid residues involved in the binding process was explored by molecular docking calculations as described in the next section.…”

Bromo‐Substituted Diazenyl‐pyrazolo[1,5‐a]pyrimidin‐2‐amines: Sonogashira Cross‐Coupling Reaction, Photophysical Properties, Bio‐interaction and HSA Light‐Up Sensor

“…To analyze the data from the quenching assays, we used the Stern-Volmer Equation ( 3) above, where F and F 0 are the fluorescence intensities in the presence and absence of a quencher, respectively. K SV , k q , τ 0 and [Q] denote Stern-Volmer constant, quenching rate constant, the original lifetime of HSA (τ 0 = 5.67 ns) [45] and the concentration of quencher, respectively. According to Equation ( 3), the Stern-Volmer constants (K SV ) were calculated from the slope and k q is equal K SV /τ 0 .…”