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Cell-free Biochemical Fluorometric Enzymatic Assay for High-throughput Measurement of Lipid Peroxidation in High Density Lipoprotein
Published on: October 12, 2017
Mitigation of malondialdehyde-induced protein lipoxidation by epicatechin in whey protein isolate
Wenhua Yao1, Xingya Hao1, Zhangjie Hu1
1Key Laboratory for Quality and Safety of Agricultural Products of Hangzhou City, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 311121, China.
Abstract:
Malondialdehyde (MDA) can induce lipoxidation in whey protein isolate (WPI). The physicochemical changes in this reaction with or without the presence of a phenolic compound epicatechin (EC) were characterized in this study. Results suggested the content of MDA was significantly reduced during co-incubation of MDA and EC. The addition of EC dose-dependently alleviated MDA-induced protein carbonylation, Schiff base formation and loss of tryptophan fluorescence. The interruption of MDA-binding to WPI was directly visualized by immunoblotting analysis. Observation of the surface microstructure of WPI showed that MDA-induced protein aggregation was partially restored by EC. Meanwhile, EC was found to promote loss of both protein sulfhydryls and surface hydrophobicity due to possible phenol-protein interactions. These observations suggested the potential of EC in the relief of MDA-mediated protein lipoxidation.
Insights
Epicatechin (EC) can mitigate malondialdehyde (MDA)-induced lipoxidation in whey protein isolate (WPI). EC reduces MDA binding, protein carbonylation, and aggregation, offering potential for alleviating protein damage.
Area of Science:
- Food Chemistry
- Protein Science
- Oxidative Stress
Background:
- Malondialdehyde (MDA) is a reactive aldehyde known to induce lipoxidation in proteins.
- Whey protein isolate (WPI) is susceptible to oxidative modifications, impacting its functionality.
- Phenolic compounds, like epicatechin (EC), are investigated for their antioxidant properties.
Purpose of the Study:
- To investigate the protective effects of epicatechin (EC) against malondialdehyde (MDA)-induced lipoxidation in whey protein isolate (WPI).
- To characterize the physicochemical changes in WPI during MDA-induced lipoxidation with and without EC.
- To elucidate the mechanisms by which EC mitigates MDA-mediated protein damage.
Main Methods:
- Co-incubation of MDA and WPI with varying concentrations of EC.
- Assessment of MDA content and protein modifications (carbonylation, Schiff base formation, tryptophan fluorescence, sulfhydryl content).
- Immunoblotting analysis to visualize MDA-WPI binding and surface microstructure observation.
Main Results:
- EC significantly reduced MDA content during co-incubation.
- EC dose-dependently alleviated MDA-induced protein carbonylation, Schiff base formation, and loss of tryptophan fluorescence.
- EC partially restored WPI microstructure by reducing MDA-induced aggregation and interrupted MDA-binding to WPI.
Conclusions:
- Epicatechin (EC) effectively mitigates malondialdehyde (MDA)-induced lipoxidation in whey protein isolate (WPI).
- EC protects WPI by reducing MDA binding, protein carbonylation, and aggregation.
- EC exhibits potential in preventing or alleviating MDA-mediated protein damage, with possible interactions affecting protein sulfhydryls and hydrophobicity.
