Mao Ji-Hua, Zhang Kai, He Ying-Fei, Liu Jun, Shao Yan-Hong, Tu Zong-Cai
National R&D Center for Freshwater Fish Processing, College of Chemistry and Chemical Engineering, College of Life Science, Jiangxi Normal University, Nanchang, Jiangxi 330022, China.
Jiangxi Cancer Hospital, Nanchang, Jiangxi 330049, China.
Int J Biol Macromol. 2023 Apr 15;234:123640. doi: 10.1016/j.ijbiomac.2023.123640. Epub 2023 Feb 16.
Ovalbumin (OVA) was modified by fructose (Fru) and galactose (Gal) to study the structure, IgG/IgE binding capacity and effects on human intestinal microbiota of the conjugated products. Compared with OVA-Fru, OVA-Gal has a lower IgG/IgE binding capacity. The reduction of OVA is not only associated with the glycation of R84, K92, K206, K263, K322 and R381 in the linear epitopes, but also with conformational epitope changes, manifested as secondary and tertiary structural changes caused by Gal glycation. In addition, OVA-Gal could alter the structure and abundance of gut microbiota at phylum, family, and genus levels and restore the abundance of bacteria associated with allergenicity, such as Barnesiella, Christensenellaceae_R-7_group, and Collinsela, thereby reducing allergic reactions. These results indicate that OVA-Gal glycation can reduce the IgE binding capacity of OVA and change the structure of human intestinal microbiota. Therefore, Gal glycation may be a potential method to reduce protein allergenicity.
用果糖（Fru）和半乳糖（Gal）对卵清蛋白（OVA）进行修饰，以研究共轭产物的结构、IgG/IgE结合能力及其对人肠道微生物群的影响。与OVA-Fru相比，OVA-Gal具有较低的IgG/IgE结合能力。OVA的降低不仅与线性表位中R84、K92、K206、K263、K322和R381的糖基化有关，还与构象表位变化有关，表现为Gal糖基化引起的二级和三级结构变化。此外，OVA-Gal可在门、科和属水平上改变肠道微生物群的结构和丰度，并恢复与致敏性相关的细菌丰度，如巴内西氏菌属、克里斯滕森菌科_R-7_组和柯林斯菌属，从而减少过敏反应。这些结果表明，OVA-Gal糖基化可降低OVA的IgE结合能力并改变人肠道微生物群的结构。因此，Gal糖基化可能是一种降低蛋白质致敏性的潜在方法。
