Identifi cation of egg protein-derived peptides as xanthine oxidase inhibitors:virtual hydrolysis,molecular docking,and in vitro activity evaluation

The purpose of this study was to screen the xanthine oxidase(XO)inhibitory peptides from egg white proteins through virtual hydrolysis,in vitro activity validation,and molecular docking.The results demonstrated that tripeptide EEK from ovalbumin exhibited potent XO inhibitory activity with an IC50 value of 141μmol/L.The molecular docking results showed that tripeptide EEK bound with the active center of XO via 3 carbon hydrogen bond interactions,2 salt bridges,5 conventional hydrogen bond interactions,and 4 attractive charge interactions.The residues Glu802,Phe1009,and Arg880 may play key roles in the XO catalytic reaction.Especially,the key intermolecular forces of inhibiting XO activity may be special type of hydrogen bonds including carbon hydrogen bond interactions and attraction charge interactions.The novel tripeptide EEK is potential candidates for controlling hyperuricemia.

Peptidomic analysis of whey protein hydrolysates and prediction of their antioxidant peptides

Enzymatic hydrolysis of proteins is a breakdown process of peptide bond in proteins,releasing some peptides with potential biological functions.Previous studies on enzymatic hydrolysis of whey proteins have not identified the complete peptide profiles after hydrolysis.In this study,we reconstructed a profile of peptides from whey hydrolysates with two enzymes and different processing conditions.We also developed an ensemble machine learning predictor to classify peptides obtained from whey hydrolysis.A total of 2572 peptides were identified over three process conditions with two enzymes in duplicate.499 peptides were classified and chosen as potential antioxidant peptides from whey proteins.The peptides classified as antioxidants in the hydrolysates had a proportion of 13.1%-24.5%regarding all peptides identified.These results facilitate the selection of promising peptides involved in the antioxidant properties during the enzymatic hydrolysis of whey proteins,aiding the discovery of novel antioxidant peptides.

Potential Applications of Milk Fractions and Valorization of Dairy By-Products: A Review of the State-of-the-Art Available Data, Outlining the Innovation Potential from a Bigger Data Standpoint

The unique composition of milk makes this basic foodstuff into an exceptional raw material for the production of new ingredients with desired properties and diverse applications in the food industry. The fractionation of milk is the key in the development of those ingredients and products;hence continuous research and development on this field, especially various levels of fractionation and separation by filtration, have been carried out. This review focuses on the production of milk fractions as well as their particular properties, applications and processes that increase their exploitation. Whey proteins and caseins from the protein fraction are excellent emulsifiers and protein supplements. Besides, they can be chemically or enzymatically modified to obtain bioactive peptides with numerous functional and nutritional properties. In this context, valorization techniques of cheese-whey proteins, by-product of dairy industry that constitutes both economic and environmental problems, are being developed. Phospholipids from the milk fat fraction are powerful emulsifiers and also have exclusive nutraceutical properties. In addition, enzyme modification of milk phospholipids makes it possible to tailor emulsifiers with particular properties. However, several aspects remain to be overcome;those refer to a deeper understanding of the healthy, functional and nutritional properties of these new ingredients that might be barriers for its use and acceptability. Additionally, in this review, alternative applications of milk constituents in the non-food area such as in the manufacture of plastic materials and textile fibers are also introduced. The unmet needs, the cross-fertilization in between various protein domains,the carbon footprint requirements, the environmental necessities, the health and wellness new demand, etc., are dominant factors in the search for innovation approaches;these factors are also outlining the further innovation potential deriving from those “apparent” constrains obliging science and technology to take them into account.

Biotechnological Alternatives for the Utilization of Dairy Industry Waste Products

The industrial obtainment and manufacturing of food cause high levels of pollution because of the generation of waste byproducts. Over the past few years, there has been a significantly increased interest in preserving, restoring and establishing an ecological balance during food production. Many investigators propose biotechnological solutions to the treatment of industrial wastes, especially waste from the dairy industry. The aim of this review is to present biotechnological approaches to the treatment and utilization of wastes from the dairy industry, specifically for milk whey and also discussed biotechnological methods to reduce environmental pollution and obtain chemical compounds with potential applications in the industry.

Identification of two novel dipeptidyl peptidase-IV inhibitory peptides from sheep whey protein and inhibition mechanism revealed by molecular docking

In this study,the peptides with dipeptidyl peptidase-IV(DPP-IV)inhibitory activities were obtained by trypsin hydrolysis from sheep whey protein.The results showed that the highest DPP-IV inhibitory activity of the hydrolysate(77.80%±1.87%)was obtained by trypsin enzymolysis for 4.0 h with 24.50%±0.05%of the degree of hydrolysis(DH).Peptides with inhibitory activity against DPP-IV were purified using anion-exchange(DEAE-52)and size-exclusion(G15 dextran gel)chromatography.A total of 86 peptides were identified using LC-MS/MS.The binding energies of RLYLHENK(RL8)and MQEHFTCCR(MQ9)to DPP-IV were determined to be-11.29 kcal/mol and-10.79 kcal/mol with molecular docking in silico,respectively.RL8 and MQ9 could bind to DPP-IV mainly through hydrogen bonds and hydrophobic interactions,and inhibit the DPP-IV enzyme by occupying the S2 pocket.The IC50 values of RL8 and MQ9 in vitro were 166.4μmol/L and 214.8μmol/L,respectively.The inhibitory activities in situ modes of the two peptides were evaluated using Caco-2 cells.The IC50 values of RL8 and MQ9 in situ were 158.3μmol/L and 251.6μmol/L,respectively.The RL8 and MQ9 derived from sheep whey protein can be considered as a potential source of natural DPP-IV inhibitor.