抗金黄色葡萄球菌IgY的酶解稳定性及活性研究

目的:考察抗金黄色葡萄球菌特异性IgY的酶解稳定性和酶解产物的活性。方法:以灭活的金黄色葡萄球菌免疫产蛋母鸡,抗体经水稀释及盐析分离纯化。抗体在不同条件下经胃蛋白酶或胰蛋白酶消化。抗体及酶解产物的特异性和活性分别用ELISA法和凝集法检测,酶解产物用SDS-PAGE和Western-blotting鉴定。结果:免疫产生的抗体具有特异性,能与金黄色葡萄球菌凝集而抑制其生长。分离纯化后抗体纯度与标准IgY相近。IgY在pH<4时完全酶解;pH等于4时部分酶解生成Fab片断,具有特异性和凝集活性;pH>4时,抗体稳定,不发生酶解。结论:抗金黄色葡萄球菌特异性IgY及其酶解生成的Fab片断,具有特异性和抑菌活性,有望代替抗生素用于细菌感染性疾病的治疗。

Digesting Stability and Activities of IgY against Staphylococcus Aureus

Objective:To estimate the digesting stability of IgY against Staphylococcus aureus and the activities of the digested products.Methods:Laying hens were immunized by injection inactivated S.aureus.IgY in yolk was separated by water dilution and salt precipitations.The specificity and activity oflgY and digested products under various conditions with pepsin or trypsin were evaluated by ELISA and agglutination reaction.SDS-PAGE and Western-blotting analysis were used to identify the digested products.Results: Antibodies in egg yolk could be isolated and purified at a high purity which was similar to standard IgY.IgY is digested partially at pH 4.0,completely at pH lower than 4,and wasn't digested at pH higher than 4.IgY and the Fab fragments digested at pH 4 were specific to S.aureus and able to inhibit its growth by agglutination.Conclusion:IgY and Fab fragments were specific and active to the antigens and were potential to use as alternatives of antibiotics.