Spectroscopic and Molecular Modeling Investigation on the Interaction between Folic Acid and Bovine Lactoferrin from Encapsulation Perspectives.

Loredana Dumitrașcu,Iuliana Aprodu,Gabriela Râpeanu,Gabriela-Elena Bahrim,Nicoleta Stănciuc

doi:10.3390/foods9060744

Loredana Dumitrașcu, Iuliana Aprodu + Show 3 more

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https://doi.org/10.3390/foods9060744

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Abstract

The impact of thermal treatment on the ability of lactoferrin (FL) to bind folic acid (FA) was investigated by employing fluorescence spectroscopy, molecular dynamics and docking tests. The structural and conformational particularities of LF upon heating at 80 °C and 100 °C were first estimated based on the intrinsic fluorescence changes in respect to the native protein. The emission spectra indicated gradual unfolding events accompanied by Trp exposure with increasing temperature. In agreement with the experimental results, molecular modeling investigations showed that the secondary and tertiary structure of LF are slightly affected by the thermal treatment. Some minor unfolding events related particularly to the α-helical regions of LF were observed when the temperature increased to 100 °C. The LF fluorescence quenching upon FA addition indicated that a static mechanism stands behind LF-FA complex formation. Regardless of the simulated temperature, the hydrogen bonds played an important role in regulating the interaction between the protein and ligand. FA binding to LF equilibrated at different temperatures occurred spontaneously, and all complexes displayed good thermodynamic stability. The obtained results support the suitability of LF as biocompatible material, for obtaining micro- and nanoparticles for delivery of dietary supplements or for enhancing the functionality of target delivery systems.

Highlights

IntroductionThere is a great challenge in understanding the kinetics and thermodynamics of the interactions between small molecules and proteins, due to the ability of the later to bind different drugs and/or biologically active compounds as micro- and/or nano-carriers [1], with significant applications in clinical medicine, chemistry, food science and biotechnology
Nowadays, there is a great challenge in understanding the kinetics and thermodynamics of the interactions between small molecules and proteins, due to the ability of the later to bind different drugs and/or biologically active compounds as micro- and/or nano-carriers [1], with significant applications in clinical medicine, chemistry, food science and biotechnology.Folates are a group of heterocyclic compounds with a 4-(pteridin-6-methylamino) benzoic acid skeleton, conjugated with one or more residues of l-glutamic acid [2]
The fluorescence spectroscopy, molecular docking and molecular dynamics simulation were employed to investigate the interaction of folic acid with bovine lactoferrin

Summary

Introduction

There is a great challenge in understanding the kinetics and thermodynamics of the interactions between small molecules and proteins, due to the ability of the later to bind different drugs and/or biologically active compounds as micro- and/or nano-carriers [1], with significant applications in clinical medicine, chemistry, food science and biotechnology. Folates are a group of heterocyclic compounds with a 4-(pteridin-6-methylamino) benzoic acid skeleton, conjugated with one or more residues of l-glutamic acid [2]. The folates play key roles in fundamental biological processes including synthesis of nucleic acids and proteins, it is highly important to assure the appropriate intake, preventing congenital diseases, such as neural tube defects [3]. Folic acid (4-[(pteridin-6-yl-methyl) amino] benzoic acid) (FA) is a synthetic and more stable form of folate, being usually used for fortification of different food matrices and for formulating different pharmaceuticals [2]. Several studies reported that FA is very sensitive to light, pH, temperature, oxygen exposure, ultraviolet light and heat, being degraded

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