J Agric Food Chem. 2018 Sep 19;66(37):9794-9800. doi: 10.1021/acs.jafc.8b03410. Epub 2018 Sep 7.
Ovalbumin (OVA) is a major allergen in avian egg white. Here, we investigated the conjugation of OVA and chlorogenic acid (CHA) to reduce the allergenic capacity of OVA. OVA-CHA conjugate was characterized by SDS-PAGE, MALDI-TOF-MS, differential scanning calorimetry, and multispectroscopic methods. Sites of the OVA-CHA conjugate were identified by LC-MS/MS. CHA possibly conjugated with Lys20 and Lys17 in OVA, which resulted in the unfolding of OVA. ELISA and Western blot assay indicated that the OVA-CHA conjugate reduced the IgE binding capacity of OVA. The results also indicated that the ability of the OVA-CHA conjugate to activate histamine release was reduced. The decreased allergenic capacity of OVA was attributed to changes in the protein structure. Moreover, the CHA binding site in OVA might directly shield the linear IgE epitope, thereby reducing the IgE binding ability. Also, the OVA-CHA conjugate showed high antioxidant activity. OVA conjugated with CHA may be a promising method of OVA hyposensitization.
卵清蛋白（OVA）是禽蛋清中的主要过敏原。在这里，我们研究了卵清蛋白和绿原酸（CHA）的缀合，以降低 OVA 的致敏能力。通过 SDS-PAGE、MALDI-TOF-MS、差示扫描量热法和多光谱方法对 OVA-CHA 缀合物进行了表征。通过 LC-MS/MS 鉴定了 OVA-CHA 缀合物的位点。CHA 可能与 OVA 中的 Lys20 和 Lys17 缀合，导致 OVA 展开。ELISA 和 Western blot 分析表明，OVA-CHA 缀合物降低了 OVA 的 IgE 结合能力。结果还表明，OVA-CHA 缀合物激活组胺释放的能力降低。OVA 致敏能力的降低归因于蛋白质结构的变化。此外，OVA 中的 CHA 结合位点可能直接屏蔽线性 IgE 表位，从而降低 IgE 结合能力。此外，OVA-CHA 缀合物具有很高的抗氧化活性。OVA 与 CHA 的缀合可能是 OVA 脱敏的一种有前途的方法。
