以虾致敏蛋白Pen a 1(Tropomyosin)抗原表位为研究对象,建立了利用Pen a 1表位抗体亲和纯化致敏蛋白的新方法。Fmoc法合成致敏Pen a 1蛋白的C端含有3个抗原表位的第247~284位氨基酸对应的多肽片段,应用马来酰亚胺法将多肽与KLH(匙孔血蓝蛋白)、BSA(牛血清白蛋白)偶联制备人工免疫抗原(Peptide-KLH)和人工包被抗原(Peptide-BSA),免疫人工抗原免疫纯种新西兰白兔,获得多克隆抗血清,抗血清经辛酸-硫酸铵及特异性血清纯化预装柱(HiTrap rProtein A FF)纯化后与溴化氰活化琼脂糖凝4B(CNBr-Activated Sepharose 4B)进行偶联。ELISA(酶联免疫吸附试验)测定该多克隆抗体效价为2.05×106,多肽对抗体的IC50(50%抑制浓度)为0.21 mg/L,交叉试验表明该抗体与虾中非Pen a 1蛋白无交叉反应性;Bradford法测定CNBr-Activated Sepharose 4B与抗体的偶联率为90.76%。间接竞争ELISA测定1 mL偶联介质的吸附容量为2.84 mg Pen a 1,免疫亲和柱的加标回收率为89.6%~93.6%,亲和柱使用寿命为4次。
Abstract
A new method for the purification of shrimp allergenic protein Pen a 1 was developed.The epitope peptide(aa 247 to 284) of the Pen a 1 was synthesized by standard Fmoc and conjugated to KLH and BSA to get the artificial immune antigen(peptide-KLH) and the coating antigen(peptide-BSA),respectively.New Zealand white rabbits were immunized with immunogen peptide-KLH to produce antisera and the antisera were purified by bitterness-ammonium sulfat and HiTrap rProtein A FF.The pure antiserum was coupled to CNBr-Activated Sepharose 4B.The titer of purified antibody was 2.05×106 by indirect ELISA and the IC50 was 0.21 mg/L by indirect competitive ELISA method.There was no cross-reactivity between the antibody and the proteins from shrimp except for Pen a 1 by indirect competitive ELISA method.The coupling efficiency of the antibody with CNBr-Activated Sepharose 4B was 90.76% and the column capacity for 1 mL immunosorbents was 2.84 mg Pen a 1.The recoveries of the immunoaffinity column were in the range of 89.6%-93.6%.The service life of the immunoaffinity column was 4 cycles.The SDS-PAGE and Western Blot results displayed that the purified Pen a 1 had high immunogenicity.
关键词
Pen a 1表位抗体免疫亲和柱ELISA
Keywords
Pen a 1polyepitope antibodyimmunoaffinity columnELISA