دانلود رایگان مقاله انگلیسی تعامل فضاگزینی اناتیتومر اسید لاکتیک با HSA: اسپکتروسکوپی و کاربرد اتصال - الزویر 2019

ABSTRACT

Lactic acid enantiomers, normally found in fermented food, are absorbed into the blood and interact with plasma carrier protein human serum albumin (HSA). Unveiling the effect on the function and structure of HSA during chiral interaction can give a better understanding of the different distribution activities of the two enantiomers. Multi-spectroscopic methods and molecular modelling techniques are used to study the interactions between lactic acid enantiomers and HSA. Time-resolved and steady-state fluorescence spectra manifest that the fluorescence quenching mechanism is mainly static in type, due to complex formation. Binding interactions, deduced by thermodynamic calculation, agree with the docking prediction. Docking results and kinetic constants represent chiral-recognizing discriminations consistently. The bindings of lactic acid enantiomers lead to some microenvironmental and slight conformational changes of HSA as shown by circular dichroism (CD), synchronous and three-dimensional fluorescence spectra. This investigation may yield useful information about the possible toxicity risk of lactic acid enantiomers to human health.

4. Conclusions

In this research, the enantioselective interactions between L-Lac/DLac and HSA were investigated using multi-spectroscopic methods and molecular modelling. The binding mechanisms of lactic acid enantiomers with HSA were investigated to obtain important information, including the binding constants, binding energy, binding sites, binding forces, and conformational changes. Fluorescence quenching of HSA by lactic acid enantiomers could be caused by forming the protein-ligand ground-state complex, and thermodynamic analysis shows evidence of the interaction force type, which agrees with the results of molecular docking. The CD, synchronous and 3D fluorescence results show that the binding of lactic acid enantiomers results in slight microenvironmental and conformational changes of HSA. These results provide useful information for understanding the delivery process of lactic acid enantiomers in vivo. Taking lactic acid enantiomers as an example, the chiral binding mechanisms of HSA with L-Lac/D-Lac yield potential data for understanding the interaction patterns of HSA with other chiral molecules used as food ingredients (e.g. tartaric acid enantiomers, glucose enantiomers.). The study is thus valuable for reinforcing the supervision of food nutrition and safety.