Negri S, Roma P, Fogliatto R, Uboldi P, Marcovina S, Catapano A L
Institute of Pharmacological Sciences, University of Milano, Italy.
Atherosclerosis. 1993 Jun;101(1):37-41. doi: 10.1016/0021-9150(93)90099-g.
We studied the immunochemical stability of the epitopes for six monoclonal antibodies to human apolipoprotein B-100 upon Cu(2+)-mediated (20 microM) oxidation of LDL. The antibodies used in this study, some of which are known to interfere with the interaction of LDL with their cellular receptors, recognize epitopes in the amino terminal region (Mb 19), in the middle part (6B, 2A, 7A, and 9A) and near aa 3500 (Mb 47) of native apo B. All antibodies except one (7A) recognized native and oxidized LDL (OxLDL) equally well; the immunoreactivity of the epitope for Ab 7A was markedly reduced upon LDL oxidation. Since antibodies 2A, 7A, 9A, and Mb 47 inhibit the LDL-receptor interaction and OxLDL poorly interact in vitro with the LDL receptor we conclude that: (1) various epitopes for monoclonal antibodies against native apo B are spared upon LDL oxidation; and (2) the epitopes for antibodies 2A, 9A, and Mb 47 do not define a unique domain of apo B directly involved in the binding of LDL to their receptor.
我们研究了在铜离子（20微摩尔）介导的低密度脂蛋白（LDL）氧化过程中，六种抗人载脂蛋白B-100单克隆抗体表位的免疫化学稳定性。本研究中使用的抗体，其中一些已知会干扰LDL与其细胞受体的相互作用，它们识别天然载脂蛋白B氨基末端区域（Mb 19）、中间部分（6B、2A、7A和9A）以及靠近第3500个氨基酸（Mb 47）处的表位。除一种抗体（7A）外，所有抗体对天然LDL和氧化LDL（OxLDL）的识别能力相同；LDL氧化后，抗体7A所识别表位的免疫反应性显著降低。由于抗体2A、7A、9A和Mb 47抑制LDL-受体相互作用，且OxLDL在体外与LDL受体的相互作用较弱，因此我们得出以下结论：（1）针对天然载脂蛋白B的单克隆抗体的各种表位在LDL氧化后得以保留；（2）抗体2A、9A和Mb 47所识别的表位并未定义载脂蛋白B中直接参与LDL与受体结合的独特结构域。
