Comparison of antigenicity and conformational changes to β-lactoglobulin following kestose glycation reaction with and without dynamic high-pressure microfluidization treatment

• Published in: Food chemistry Vol. 278; pp. 491 - 496
• Main Authors: Zhong, Junzhen, Yu, Hongda, Tu, Yue, Zhou, Lei, Liu, Wei, Luo, Shunjing, Liu, Chengmei, Prakash, Sangeeta
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 25.04.2019
• Subjects: 1-Kestose; Antigen-Antibody Reactions; Antigenicity; Antigens - immunology; Chromatography, High Pressure Liquid; Circular Dichroism; Combined treatment; Glycosylation; Lactoglobulins - chemistry; Lactoglobulins - immunology; Mass Spectrometry; Modulation mechanism; Molecular Weight; Monosaccharides - chemistry; Pressure; Protein Structure, Secondary; Spectrometry, Fluorescence; β-Lactoglobulin; Modulation mechanism; Combined treatment; Antigenicity; β-Lactoglobulin; 1-Kestose
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2018.11.094

•Antigenicity of conjugate formed at 80 MPa was half the value of that under 0.1 MPa.•One conjugate formed using 0.1 MPa and its conformation scarcely changed.•Two conjugates formed using 80 MPa and the unfolding of their conformation occurred.•Two treatments have a synergistic effect on the decrease of its antigenicity. Previous work indicated that conformational changes of β-lactoglobulin (β-LG) induced by dynamic high pressure microfluidization (DHPM) was related to the increase of antigenicity. In this study, β-LG glycated with 1-kestose and combined with DHPM decreased the antigenicity of β-LG. The antigenicity of control, β-LG-kestose (0.1 MPa) and β-LG-kestose (80 MPa) were 100, 79 and 42 μg/mL respectively. The molecular weight of β-LG conjugated to kestose increased from 18.4 to 19.6 kDa and its conformation scarcely changed. Conversely, combined with DHPM treatment (80 MPa), β-LG conjugated to kestose formed two conjugates with molecular weight of 18.8 and 19.8 kDa, respectively. Furthermore, the unfolding of β-LG as a result of the treatments is reflected by a decrease of intrinsic and synchronous fluorescence intensity and changes to the secondary structure. The conformational changes induced by DHPM and glycation treatments synergistically decrease the antigenicity of β-LG due to more masked or disrupted epitopes.