具有甲状腺素脱碘酶活性的抗体酶的制备及性质研究

Preparation and Properties of Abzyme with Thyroxine Deiodinase

首次以具有适当疏水性的甲状腺素衍生物 O-methyl-T4为半抗原 ,用杂交瘤技术得到相应的抗体( 6 E8) ,又经过苯甲基磺酰氟和 Na HSe的化学修饰引入了催化基团硒代半胱氨酸 ,制备出具有较高甲状腺素脱碘酶活力的抗体酶 ( Se-6 E8) .用 SDS-PAGE电泳对 Se-6 E8的纯度进行了鉴定 ,同时研究了其解离常数、温度及 p H等酶学性质 .结果表明 ,Se-6 E8活力为 2 0 1 0 U /μmol protein,纯度达到电泳纯 ,催化反应的最适温度为 5 7℃ ,最适 p H为 8.2 .

The abzyme (Se-6E8) with a higher thyroxine deiodinase activity was prepared by modifying the serine residues of monoclonal antibody (6E8) with phenylmethanesulfonyl fluoride and sodium hydrogen selenide, and the 6E8 against O-methyl-T 4, which is a kind of thyroxine derivatives and was taken as a hapten for the first time. Two bands were found corresponding to the 5.5 kD heavy chain and the 2.7 kD light chain respectively by SDS-PAGE. The characteristics of dissociation constants, pH, and temperature were also studied. The results show that the activity of Se-6E8 is 2 010 U/μmol protein , and the proper temperature and pH of the catalytic reactions is 57 ℃ and 8.2 respectively.