Colloid Chemistry Group, Chemistry Institute, Federal University of Alfenas (UNIFAL-MG), Rua Gabriel Monteiro da Silva, 700, 37130-000 Alfenas, MG, Brazil.
Colloid Chemistry Group, Chemistry Institute, Federal University of Alfenas (UNIFAL-MG), Rua Gabriel Monteiro da Silva, 700, 37130-000 Alfenas, MG, Brazil; Colloidal and Macromolecular Green Chemistry Group (QUIVECOM), Department of Chemistry, Federal University of Viçosa, Av. P. H. Rolfs s/n, 36570900 Viçosa, MG, Brazil.
Int J Biol Macromol. 2021 Aug 1;184:990-999. doi: 10.1016/j.ijbiomac.2021.06.158. Epub 2021 Jun 28.
To explore in vivo application of quantum dots (QDs), it is essential to understand the dynamics and energetics of interactions between QDs and proteins. Here, surface plasmon resonance (SPR) and molecular docking were employed to investigate the kinetics and thermodynamics of interactions between human serum albumin (HSA) and CdTe QDs (~3 nm) functionalized with mercaptopropionic acid (MPA) or thioglycolic acid (TGA). Kinetic analysis showed that HSA-QD interactions involved transition-complex formation. Despite the structural similarities between MPA and TGA, the [HSA-CdTe@TGA] formation by association of free HSA and QDs demanded 70% more energy and higher entropic gain (E= 65.10 and T∆S= 28.62 kJ mol) than the formation of [HSA-CdTe@MPA] (E = 38.13 and T∆S = 0.53kJ mol). While the [HSA-CdTe@MPA] dissociation required higher energy and lower entropy loss (E = 49.96 and T∆S = - 32.18kJ mol) than the [HSA-CdTe@TGA] dissociation (E= 30.78 and T∆S= - 51.12 kJ mol). The stability of [HSA-QDs] was independent of the temperature and functionalizing group. However, the enthalpic and entropic components were highly affected by the substitution of MPA (ΔH° = - 11.83 and TΔS° = 32.72 kJ mol) with TGA (ΔH° = 34.31 and TΔS° = 79.73 kJ mol). Furthermore, molecular docking results indicated that the metal site on the QDs contributes to the stabilization of [HSA-QDs]. Therefore, differences in QD functionalization and surface coverage densities can alter the HSA-QD interaction, thus their application.
为了探索量子点（QD）的体内应用，了解 QD 与蛋白质相互作用的动力学和能量学至关重要。在这里，表面等离子体共振（SPR）和分子对接被用来研究巯基丙酸（MPA）或巯基乙酸（TGA）功能化的 CdTe QD（~3nm）与人血清白蛋白（HSA）之间相互作用的动力学和热力学。动力学分析表明，HSA-QD 相互作用涉及到过渡态复合物的形成。尽管 MPA 和 TGA 结构相似，但游离 HSA 与 QD 结合形成 [HSA-CdTe@TGA] 需要 70%的更多能量和更高的熵增益（E=65.10，T∆S=28.62kJmol），而形成 [HSA-CdTe@MPA]（E=38.13，T∆S=0.53kJmol）。虽然 [HSA-CdTe@MPA] 的解离需要更高的能量和更低的熵损失（E=49.96，T∆S=-32.18kJmol），但 [HSA-CdTe@TGA] 的解离（E=30.78，T∆S=-51.12kJmol）需要的能量和熵损失更高。[HSA-QDs]的稳定性与温度和功能化基团无关。然而，焓和熵分量受 MPA（ΔH°=-11.83 和 TΔS°=32.72kJmol）取代为 TGA（ΔH°=34.31 和 TΔS°=79.73kJmol）的影响很大。此外，分子对接结果表明，QD 上的金属位点有助于 [HSA-QDs]的稳定。因此，QD 功能化和表面覆盖率密度的差异会改变 HSA-QD 相互作用，从而影响它们的应用。
