Identification, characterization and binding sites prediction of calcium transporter-embryo egg-derived egg white peptides

Comparative analysis of the interaction between alpha-lactalbumin and two edible azo colorants equipped with different sulfonyl group numbers

Alpha-lactalbumin (α-La) is a crucial active component in whey protein. It would be mixed with edible azo pigments during processing. Spectroscopic analyses and computer simulations were used here to characterize the interaction between acid red 27 (C27) /acidic red B (FB) and α-La. Fluorescence, thermodynamics, and energy transfer showed the binding mechanism is a static quenching with a medium affinity. This binding process occurred spontaneously and was mainly driven by hydrophobic forces. Conformation analysis showed FB led to a greater change in the secondary structure of α-La compared with C27. C27 increased and FB decreased the surface hydrophobicity of α-La. The spatial structures of complexes were visualized with computer aid. The azo colorant binds to α-La easily and deeply with a smaller space volume and dipole moment and thereby affecting the α-La conformation and functionality. This study provides a theoretical basis for the application of edible azo pigments.

The Formation, Structural Characteristics, Absorption Pathways and Bioavailability of Calcium–Peptide Chelates

Calcium is one of the most important mineral elements in the human body and is closely related to the maintenance of human health. To prevent calcium deficiency, various calcium supplements have been developed, but their application tends to be limited by low calcium content and highly irritating effects on the stomach, among other side effects. Recently, calcium–peptide chelates, which have excellent stability and are easily absorbed, have received attention as an alternative emerging calcium supplement. Calcium-binding peptides (CaBP) are usually obtained via the hydrolysis of animal or plant proteins, and calcium-binding capacity (CaBC) can be further improved through chromatographic purification techniques. In calcium ions, the phosphate group, carboxylic group and nitrogen atom in the peptide are the main binding sites, and the four modes of combination are the unidentate mode, bidentate mode, bridging mode and α mode. The stability and safety of calcium–peptide chelates are discussed in this paper, the intestinal absorption pathways of calcium elements and peptides are described, and the bioavailability of calcium–peptide chelates, both in vitro and in vivo, is also introduced. This review of the research status of calcium–peptide chelates aims to provide a reasonable theoretical basis for their application as calcium supplementation products.