Identification and characterization of the peptides with calcium‐binding capacity from tilapia (Oreochromis niloticus) skin gelatin enzymatic hydrolysates

Abstract

The aim of this study was to isolate and identify the peptides with calcium‐binding capacity from the different tilapia skin gelatin enzymatic hydrolysates. The complex protease was selected and its hydrolysates were further separated using gel filtration chromatography (Sephadex G‐25) and reverse phase high‐performance liquid chromatography. Two purified peptides with strong calcium‐binding capacity were identified as Tyr‐Gly‐Thr‐Gly‐Leu (YGTGL, 509.25 Da) and Leu‐Val‐Phe‐Leu (LVFL, 490.32 Da). The calcium‐binding capacities of YGTGL and LVFL reached 76.03 and 79.50 µg/mg, respectively. The structures of the complex of purified peptides and calcium (YGTGL‐Ca and LVFL‐Ca) were characterized by ultraviolet‐visible spectroscopy (UV‐VIS), scanning electron microscopy (SEM), X‐ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and mass spectrometry (LC‐MS/MS). The results of UV‐VIS, SEM, and XRD indicated that YGTGL‐Ca and LVFL‐Ca were formed as new compounds. The results of FTIR and LC‐MS/MS indicated the nitrogen atom of the amino group and the oxygen atom of the carboxyl group in terminates of the peptides provided primary binding sites. Moreover, the hydrophobic amino acids in purified peptides could provide more chelating spaces. This study was of great significance for the development of calcium supplement foods.Practical ApplicationCompared with inorganic calcium and organic calcium, the bioactive gelatin peptide chelated calcium has the characteristics of high utilization rate, high solubility, and high absorption rate. The raw materials are extracted from the tilapia processed waste, which reduce the cost, make full use of resources, and improve the bioavailability. The tilapia skin gelatin peptide calcium chelate can be directly absorbed by the human body, and the absorption efficiency is high, further improving the resource utilization rate and having high economic benefits, which is a comprehensive supplement that can also be used as a functional food.

Purification, Identification, Chelation Mechanism, and Calcium Absorption Activity of a Novel Calcium-Binding Peptide from Peanut (Arachis hypogaea) Protein Hydrolysate

“…After introducing calcium ions, FA6-calcium chelate exhibited regularly ordered and tightly aggregated sheets or block structures. This conclusion is similar to the work of Liu et al, who showed that the peptides YGTGL and LVFL interacted with calcium ions to generate novel molecules in flake or block structures . It is possible that this came about as a result of the interaction between calcium ions and carboxyl groups, which attracted FA6 and created an aggregate connected by a hydrogen bond.…”

KFP‐1, a Novel Calcium‐Binding Peptide Isolated from Kefir, Promotes Calcium Influx Through TRPV6 Channels

“…These peptides include GY (17.94 µg μmole −1 ) and EG (13.84 µg μmole −1 ), which were isolated from whey protein hydrolysate [ 6,7 ] ; FY (42.28 µg μmole −1 ), which was isolated from unicellular algae ( Schizochytrium sp .) protein hydrolysate [ 29 ] ; and YGTGL (38.72 µg μmole −1 ) and LVFL (38.99 µg μmole −1 ), which were isolated from tilapia skin gelatin hydrolysate [ 8 ] (Table 1). Based on the binding capacity, the calcium‐binding efficiency was calculated as one mole of KFP‐1 binding 0.73 moles of calcium.…”

“…[ 5 ] Food protein derived peptides released by enzymatic hydrolysis or by fermentation processes can form peptide‐calcium complexes to enhance the bioavailability and absorption of calcium. Known food sources of these peptides include milk, [ 6,7 ] fish byproducts, [ 8,9 ] wheat germ, [ 10 ] and algae. [ 11 ] For example, caseinophosphopeptides (CPPs) were the first and the most extensively studied calcium‐binding peptides from the casein protein from milk.…”

Peptide–Mineral Complexes: Understanding Their Chemical Interactions, Bioavailability, and Potential Application in Mitigating Micronutrient Deficiency

“…Following complexation, the extent of peptide chelation of calcium ions is elucidated by quantification of Ca 2+ in the supernatant using AAS [ 38 ]. This method has since been modified to incorporate the binding activity of several calcium-chelating peptides, such as those derived from Antarctic krill and tilapia skin gelatin enzymatic hydrolysates, including the use of flame AAS instead [ 39 , 40 ].…”