Assessment of Binding Interaction between Bovine Lactoferrin and Tetracycline Hydrochloride: Multi-Spectroscopic Analyses and Molecular Modeling

Abstract

In this paper, the interaction between bovine lactoferrin (bLf) and tetracycline hydrochloride (TCH) was researched by microscale thermophoresis (MST), multi-spectroscopic methods, and molecular docking techniques. Normal fluorescence results showed that TCH effectively quenched the intrinsic fluorescence of bLf via static quenching. Moreover, MST confirmed that the combination force between bLf and TCH was very strong. Thermodynamic parameters and molecular docking further revealed that electrostatic forces, van der Waals, and hydrogen bonding forces played vital roles in the interaction between bLf and TCH. The binding distance and energy transfer efficiency between TCH and bLf were 2.81 nm and 0.053, respectively. Moreover, the results of circular dichroism spectra (CD), ultraviolet visible (UV-vis) absorption spectra, fluorescence Excitation-Emission Matrix (EEM) spectra, and molecular docking verified bLf indeed combined with TCH, and caused the changes of conformation of bLf. The influence of TCH on the functional changes of the protein was studied through the analysis of the change of the bLf surface hydrophobicity and research of the binding forces between bLf and iron ion. These results indicated that change in the structure and function of bLf were due to the interaction between bLf and TCH.

Chimeric nanocomposites for the rapid and simple isolation of urinary extracellular vesicles

“…It was similar to some other published papers that found no peaks in the UV‐Vis spectrum of Fe 3 O 4 NPs (Vollath, 2013 ). Meanwhile, LF showed a peak in the UV region at the wavelength of 280 nm (Figure 2b , curve b), in agreement with other reported studies (Sun et al., 2018 ). The LF‐ bis ‐MPA‐MNPs showed a peak at the wavelength of 275 nm (Figure 2b , curve c), which indicated that LF was successfully coated on Fe 3 O 4 NPs.…”

Bovine Lactoferrin Quantification in Dairy Products by a Simple Immunoaffinity Magnetic Purification Method Coupled with High-Performance Liquid Chromatography with Fluorescence Detection

“…Alternatively, bLf could be detected by its intrinsic fluorescence. 30,31 Therefore, we optimized the fluorescent condition with excitation and emission wavelengths of 280 and 344 nm, respectively. As a result, the fluorescent detection showed a much higher sensitivity than UV detection (Figure S5).…”

Characterization of Conjugates between α-Lactalbumin and Benzyl Isothiocyanate—Effects on Molecular Structure and Proteolytic Stability

“…The CD spectra showed a decrease in negative band intensity as a result of the increasing degree of derivatization with TCH. They explained the reduction by breaking of hydrogen bonds due to TCH conjugation of lactoferrin and hypothesized that the altered secondary structure might also affect physiological functions [ 51 ].…”

“…Furthermore, the determination of freely available amino groups plays a crucial role with regard to the properties and functionality of proteins [ 1 , 152 ]. Knowledge of the influence of chemical modifications on protein structure and surface hydrophobicity allows conclusions to be drawn about solubility, aggregation, and physical stability [ 52 , 153 ], which are particularly important with regard to food processing and food safety [ 1 , 51 ].…”

“…However, this needs confirmation, as the effects of covalent interactions are complex and can influence protein folding or the three-dimensional structure successively, being crucial for technofunctional and functional properties (e.g., viscosity, gelling, foam formation, solubility, emulsification, color, smell, and taste), as well as biological characteristics such as digestibility [ 48 , 49 , 50 ]. Although the reactions of ITC and whey proteins have already been studied several times, it is not yet possible to predict the effect of modification on protein structure and function [ 1 , 51 ]. Further structural characterization of unmodified and ITC-modified proteins remains highly important to estimate the impact on protein structure and functionality and to avoid or even use such covalent modifications to optimize protein functionality in the future.…”