Binding mechanism of Cr(PLB)3 and Hg(PLB)2 complexes with human serum albumin: Spectroscopic, thermodynamic, and molecular docking investigations
Year: 2025
Type: article
Abstract: Plumbagin (PLB) and its metal complexes are of pharmacological interest due to their potential biomedical applications. This study systematically investigates, for the first time, the interactions of Cr(PLB)₃ and Hg(PLB)₂ complexes with human serum albumin (HSA) using UV–Vis, FT-IR, NMR , fluorescence, circular dichroism (CD) spectroscopy, and thermodynamic analyses . Both complexes bind at site IIA of HSA, with binding constants ( K b ) of 3.8 × 10 4 L/mol for Cr(PLB)₃ and 2.5 × 10 4 L/mol for Hg(PLB)₂. Their binding perturbs the Trp214 environment and reduces the α-helical content of HSA from 62 % to 55 % (Cr) and 57 % (Hg). FRET analysis estimated the donor–acceptor distance to be approximately 2.5 nm. Thermodynamic data revealed that the Cr(PLB)₃–HSA interaction is enthalpy-driven ( ΔH = −3.7 kcal/mol, ΔS = +8.7 cal/mol. K ), while the Hg(PLB)₂–HSA interaction is also enthalpy-driven but with negligible entropy change ( ΔH = −5.2 kcal/mol, ΔS = +0.7 cal/mol.K ). Molecular docking suggested hydrogen bonding , van der Waals, and hydrophobic interactions as key forces, with Cr(PLB)₃ showing stronger binding affinity. These findings offer insight into the interaction mechanisms of metal–PLB complexes with HSA, supporting their further biomedical evaluation.
Source: Results in Chemistry
Authors: Nguyen Van Thoi, Tran Khanh Luan, Tran Phuoc Vy, Tran Nguyen Minh An, Le Van Tan
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: gold
Estimated APC paid: $1,870
Award: G2343226509
OpenAlex ID: W4411090451