Valentinova N V, Gu Z W, Yang M, Yanushevskaya E V, Antonov I V, Guyton J R, Smith C V, Gotto A M, Yang C Y
Department of Medicine, Baylor College of Medicine, Houston, Texas 77030.
Biol Chem Hoppe Seyler. 1994 Oct;375(10):651-8. doi: 10.1515/bchm3.1994.375.10.651.
Thirteen monoclonal antibodies (MAbs) against apolipoprotein B-100 (apo B) were used to analyze changes in immunoreactivity of human LDL resulting from oxidation mediated by cupric ions and oxygen. Decrease in immunoreactivity of oxidized LDL was demonstrated by competitive ELISA with MAbs 5F8, BL3, Mb43, 2G8, B3, B5, and BL7 for which the epitopes are located within residues 1-1297, 4235-4355, 4027-4081, 3728-4306, 2239-2331, 1854-1878, and in the vicinity of residue 2331, respectively. Immunoreactivity of the epitope B6 (2239-2331) increased during first 4 hours of oxidation and then diminished gradually. Epitope B1 (405-539) had slightly reduced immunoreactivity during first 8 h of LDL oxidation and then its minor increase was observed. MAb 12G10, specific to the epitope within apo B thrombin-digest fragment T4 (1-1297), displayed either weak or strong binding to LDL. LDL with weak binding pattern demonstrated significant increase in immunoreactivity upon oxidation. In contrast, LDL with strong binding pattern showed little to no change. Epitopes Mb47 (3441-3569) and 8G4 (1-1297) remained unchanged in oxidized LDL. Immunoreactivity of apo B-100 epitope recognized by MAb 4C11 (residues 2377-2658) was shown to be a function of oxidation time: it increased progressively up to 16 h and was stabilized for another 24 h of LDL oxidation. This epitope may be unmasked by LDL oxidation and may provide a useful immunochemical marker to monitor the extent of LDL oxidation.
使用13种抗载脂蛋白B - 100（apo B）的单克隆抗体（MAb）分析了由铜离子和氧气介导氧化作用导致的人低密度脂蛋白（LDL）免疫反应性的变化。通过竞争性酶联免疫吸附测定（ELISA）证明，氧化型LDL与单克隆抗体5F8、BL3、Mb43、2G8、B3、B5和BL7的免疫反应性降低，这些抗体的表位分别位于第1 - 1297位、4235 - 4355位、4027 - 4081位、3728 - 4306位、2239 - 2331位、1854 - 1878位以及第2331位附近。表位B6（2239 - 2331）的免疫反应性在氧化的最初4小时内增加，然后逐渐减弱。表位B1（405 - 539）在LDL氧化的最初8小时内免疫反应性略有降低，随后观察到轻微增加。对apo B凝血酶消化片段T4（1 - 1297）内表位具有特异性的单克隆抗体12G10与LDL的结合表现为弱结合或强结合。具有弱结合模式的LDL在氧化后免疫反应性显著增加。相反，具有强结合模式的LDL几乎没有变化。表位Mb47（3441 - 3569）和8G4（1 - 1297）在氧化型LDL中保持不变。单克隆抗体4C11识别的apo B - 100表位（第2377 - 2658位）的免疫反应性显示是氧化时间的函数：在LDL氧化长达16小时时逐渐增加，并在另外24小时内保持稳定。该表位可能因LDL氧化而暴露，可作为监测LDL氧化程度的有用免疫化学标志物。
