Hydrophobicity and aggregation, but not glycation, are key determinants for uptake of thermally processed β-lactoglobulin by THP-1 macrophages.
The aim of this study is to investigate the immunological relevance of modifications of food protein structure due to thermal processing. We investigated the uptake of β-lactoglobulin, treated with 3 different processing methods, by THP-1 macrophages: wet heating (60 °C in solution) and high- or low-temperature (130 °C or 50 °C, respectively) dry heating, combined with either of 8 types of saccharides or without saccharide. The processing method that was applied significantly affected the uptake of BLG by THP-1 macrophages, while the type of saccharide only had an influence in high-temperature dry heated samples. A set of physicochemical parameters of processed samples was determined, to determine the samples' molecular weight, hydrophobicity, amyloid-like structure, surface charge and secondary structure. Analysis of protein structure alterations indicated the uptake to be linked to the wet heating processing method and percentage of α-helix structure, amyloid-like structures, polymers, and hydrophobicity. We hypothesize that both amyloid-like structures and molecular weight were related to the increased hydrophobicity and therefore postulate that the exposure of hydrophobic regions is the leading physicochemical characteristic for the observed uptake of wet heated BLG samples by THP-1 macrophages. This work demonstrates how differential thermal processing of foods, through protein modification, can have an impact on its interaction with the immune system.
['Deng|Ying|Y|', 'Govers|Coen|C|', 'Bastiaan-Net|Shanna|S|', 'van der Hulst|Nina|N|', 'Hettinga|Kasper|K|', 'Wichers|Harry J|HJ|']
D000485:Allergens D000682:Amyloid D000818:Animals D001692:Biological Transport D002417:Cattle D004044:Dietary Proteins D005511:Food Handling D006031:Glycosylation D006358:Hot Temperature D006801:Humans D057927:Hydrophobic and Hydrophilic Interactions D007782:Lactoglobulins D008264:Macrophages D015416:Maillard Reaction D008892:Milk D015394:Molecular Structure D008970:Molecular Weight D009844:Oligosaccharides D011108:Polymers D066329:Protein Aggregates D017433:Protein Structure, Secondary D000074084:THP-1 Cells D014867:Water
Hydrophobicity Aggregation Glycation Uptake Thermal processing β-Lactoglobulin THP-1 macrophage