Synthesis and physicochemical characterization of bovine lactoferrin supersaturated complex with iron (III) ions

Abstract

The aim of the study was to investigate the process of Fe3+ binding to bLTF. Moreover, the physicochemical characterization of the respective supersaturated complex was studied. The knowledge should be important for the description of processes that may take place in dairy products fortified with iron. Additionally, the synthesized complex can be utilized as a dietary supplement for the treatment of iron deficiency anemia (IDA). Finally, it was shown that formation of supersaturated iron-protein structures which include LTF often accompanies development of neurodegenerative diseases such as Alzheimer or Parkinson. Thus, the study can reveal some aspects of its pathogenesis process. The methodology of the investigation comprised the utilization of batch sorption study and applying Freundlich and Langmuir models. The complex also was characterized by numerous techniques: spectrometric (ICP-MS), spectroscopic (UV–Vis, ATR-FTIR), electron microscopy (TEM–EDX), SDS-PAGE. Based on obtained results the potential mechanisms of iron interaction with protein were described. Moreover, the molecular docking was applied to visualize possible metal binding sites. The respective complex contains ≈ 33.0 mg/g of iron which is nearly 50 Fe3+ per one protein molecule. The cytotoxicity of the obtained complex was evaluated by MTT reduction and LDH release assays on Caco-2 and nL929 cell lines.

The Multifaceted Roles of Bovine Lactoferrin: Molecular Structure, Isolation Methods, Analytical Characteristics, and Biological Properties

“…For example, FTIR spectrum obtained by Pryshchepa et al confirmed the contribution of tyrosine residues and deprotonated aspartate and glutamate side chains in the chelation of ferric ions. 165 What is important is that the performed deconvolution analysis by Hadden et al did not detect any visible difference in the secondary structure content of LF after the removal of iron. 116 So it was in later research.…”

“…Recently it was discovered that absorption peaks at 1690 and 1615 cm –1 frequently appear upon protein denaturation, while the band at 1627 cm –1 reflects the formation of amyloid aggregates. , FTIR spectroscopic analysis study of the protein–ligand molecular interactions might provide the important information on the iron role in the LF conformational stability. For example, FTIR spectrum obtained by Pryshchepa et al confirmed the contribution of tyrosine residues and deprotonated aspartate and glutamate side chains in the chelation of ferric ions . What is important is that the performed deconvolution analysis by Hadden et al did not detect any visible difference in the secondary structure content of LF after the removal of iron .…”

“…Despite this, the application of the UV–vis approach is limited in the case of supersaturated LF complexes. According to a basic assumption, holo-LF is capable of binding a maximum of two ferric ions ( q m 1.4 mg/g); however, Pryshchepa et al found the 54 total iron-binding sites ( q m 36.3 mg/g) in one bLF molecule …”

“…According to a basic assumption, holo-LF is capable of binding a maximum of two ferric ions (q m 1.4 mg/g); however, Pryshchepa et al found the 54 total iron-binding sites (q m 36.3 mg/g) in one bLF molecule. 165 8.1.2. Fluorescence Spectroscopy.…”

“…Nevertheless, Pryshchepa et al observed a slight difference in mobility between native bLF and supersaturated Fe−bLF. 187 Nagasako et al explained this phenomenon by the presence of additional metal binding sites which contribute to the modification of the protein surface charge. 52 Ying et al confirmed the difference in electrophoretic mobility between both saturated and unsaturated forms of LF.…”