Reduction of Allergenicity of Milk Protein by Conjugation with Acidic Oligosaccharides

通过与酸性低聚糖结合降低牛奶蛋白的过敏性

基本信息

批准号：
12660113
负责人：
HATTORI Makoto
金额：
$ 2.3万
依托单位：
Tokyo University of Agriculture and Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2000
资助国家：
日本
起止时间：
2000 至 2001
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-12660113/
关键词：
β-lactoglobulin protein conjugation reduction of allergenicity algmic acid oligosaccharide Maillard reaction

项目摘要

Bovine β-lactoglobulin-alginic acid oligosaccharide (β-LG-ALGO) conjugate was prepared by the Maillard reaction to reduce the allergenicity and improve the functional properties of β-LG. The molar ratio of β-LG to ALGO in the conjugates was 1 : 6. The isoelectric point of the conjugate was <4.6, which is lower than that of β-LG. Carbohydrate binding sites in β-LG were identified to be 60Lys, 77Lys, lOOLys, 138Lys and141Lys. CD spectra indicated that secondary structure of β-LG was almost maintained after conjugation with ALGO. Fluorescence studies suggested that the conformation around Trp had not changed in the conjugate and that the surface of the conjugate was covered with saccharide chain. Structural analyzes with monoclonal antibodies indicated that the conformation around 15Val29Ile and 8Lys-19-Trp in the conjugate had changed, while native structure was maintained around 125Thr-135Lys. By conjugation with ALGO, β-LG was endowed with high heat stability and improved emulsifying ability. The antiβ-LG antibody response was markedly reduced after immunization with the β-LG- ALGO conjugates in BALB/c, C57BL/6 and C3H/He mice. We determined the B and T cell epitopes of β-LG and the conjugate recognized in these mice and found that the linear epitope profiles of the β-LG- ALGO conjugate were similar to those of β-LG, while the immune response for each epitope was dramatically reduced. Masking of epitopes by ALGO was considered to be responsible for the decreased immunogenicity of the β-LG in the conjugate.

通过Maillard反应制备牛β-乳球蛋白 - 乳球蛋白 - 二酸寡糖（β-LG-Algo）结合物，以降低过敏性并改善β-LG的功能特性。在偶联物中，β-LG与ALGO的摩尔比为1：6。偶联物的等电点<4.6，低于β-LG的等电点。 β-LG中的碳水化合物结合位点被鉴定为60个，77个，loolys，138lys和141lys。 CD光谱表明，与ALGO结合后，几乎维持了β-LG的二级结构。荧光研究表明，偶联物周围的构象没有改变，偶联物的表面被糖链覆盖。单克隆抗体的结构分析表明，在共轭物中，约15val29ile和8lys-19-trp的构象发生了变化，而天然结构则在125thr-135 lys左右保持。通过与ALGO结合，β-LG具有高热稳定性和提高的乳化能力。用BALB/C，C57BL/6和C3H/HE小鼠免疫后，抗β-LG抗体反应显着降低。我们确定了在这些小鼠中识别的β-LG和共轭物的B和T细胞表位，并发现β-LG-ALGO偶联物的线性表位谱与β-LG相似，而每种表位的免疫响应大幅减少。艾尔戈（Algo）对表位的掩盖被认为是偶联物中β-LG的免疫原性的原因。