Biophysical Characterization of the Interaction between a Transport Human Plasma Protein and the 5,10,15,20-Tetra(pyridine-4-yl)porphyrin
Autor: | Otávio Augusto Chaves, Bernardo A. Iglesias, Carlos Serpa |
---|---|
Jazyk: | angličtina |
Rok vydání: | 2022 |
Předmět: | |
Zdroj: | Molecules, Vol 27, Iss 16, p 5341 (2022) |
Druh dokumentu: | article |
ISSN: | 1420-3049 |
DOI: | 10.3390/molecules27165341 |
Popis: | The interaction between human serum albumin (HSA) and the non-charged synthetic photosensitizer 5,10,15,20-tetra(pyridine-4-yl)porphyrin (4-TPyP) was evaluated by in vitro assays under physiological conditions using spectroscopic techniques (UV-vis, circular dichroism, steady-state, time-resolved, synchronous, and 3D-fluorescence) combined with in silico calculations by molecular docking. The UV-vis and steady-state fluorescence parameters indicated a ground-state association between HSA and 4-TPyP and the absence of any dynamic fluorescence quenching was confirmed by the same average fluorescence lifetime for HSA without (4.76 ± 0.11 ns) and with 4-TPyP (4.79 ± 0.14 ns). Therefore, the Stern–Volmer quenching (KSV) constant reflects the binding affinity, indicating a moderate interaction (104 M−1) being spontaneous (ΔG°= -25.0 kJ/mol at 296 K), enthalpically (ΔH° = -9.31 ± 1.34 kJ/mol), and entropically (ΔS° = 52.9 ± 4.4 J/molK) driven. Binding causes only a very weak perturbation on the secondary structure of albumin. There is just one main binding site in HSA for 4-TPyP (n ≈ 1.0), probably into the subdomain IIA (site I), where the Trp-214 residue can be found. The microenvironment around this fluorophore seems not to be perturbed even with 4-TPyP interacting via hydrogen bonding and van der Waals forces with the amino acid residues in the subdomain IIA. |
Databáze: | Directory of Open Access Journals |
Externí odkaz: | |
Nepřihlášeným uživatelům se plný text nezobrazuje | K zobrazení výsledku je třeba se přihlásit. |
načítá se...