Holden J A, Rolfson D H, Wittwer C T
Department of Pathology, University of Utah, Salt Lake City 84132.
Oncol Res. 1992;4(4-5):157-66.
Western blotting experiments with topoisomerase II antiserum were performed to measure type II topoisomerase content in human tissues. In this study, antiserum produced against the C-terminus of recombinant HeLa topoisomerase II recognized both p170 and p180 forms of the enzyme. Antisera specifically made against p180 selectively recognized that enzyme form. By using these antisera, a remarkable difference in topoisomerase content between the tissues studied was observed. Tissues with a high proportion of cycling cells contained predominantly the p170 form of the enzyme, but also smaller amounts of p180. In terminally differentiated organs or in neoplasms with a low percentage of cycling cells, topoisomerase II immunoprotein was not detected in whole tissue extracts. In term human placenta, this was because this tissue contained predominantly the p180 enzyme form, yet the concentration of this form of the enzyme was apparently in too low a concentration to be detected by the antibody in crude extracts. It was readily observed after concentration by chromatography on hydroxylapatite.
进行了使用拓扑异构酶II抗血清的蛋白质印迹实验，以测量人体组织中II型拓扑异构酶的含量。在本研究中，针对重组HeLa拓扑异构酶II的C末端产生的抗血清识别出该酶的p170和p180两种形式。专门针对p180制备的抗血清选择性地识别该酶形式。通过使用这些抗血清，在所研究的组织之间观察到拓扑异构酶含量存在显著差异。具有高比例循环细胞的组织主要含有该酶的p170形式，但也含有少量的p180。在终末分化器官或循环细胞百分比低的肿瘤中，在全组织提取物中未检测到拓扑异构酶II免疫蛋白。在足月人胎盘中，这是因为该组织主要含有p180酶形式，但该酶形式的浓度显然过低，无法在粗提取物中被抗体检测到。经羟基磷灰石层析浓缩后很容易观察到。
