Suwa A, Hirakata M, Takeda Y, Okano Y, Mimori T, Inada S, Watanabe F, Teraoka H, Dynan W S, Hardin J A
Department of Medicine, Medical College of Georgia School of Medicine, Augusta, 30912-3100, USA.
J Clin Invest. 1996 Mar 15;97(6):1417-21. doi: 10.1172/JCI118562.
DNA-dependent protein kinase (DNA-PK) is an important nuclear enzyme which consists of a catalytic subunit known as DNA-PKcs and a regulatory component identified as the Ku autoantigen. In the present study, we surveyed 312 patients in a search for this specificity. 10 sera immunoprecipitated a large polypeptide which exactly comigrated with DNA-PKcs in SDS-PAGE. Immunoblot analysis demonstrated that this polypeptide was recognizable by a rabbit antiserum specific for DNA-PKcs. Although the patient sera did not bind to biochemically purified DNA-PKcs in immunoblots or ELISA, they were able to deplete DNA-PK catalytic activity from extracts of HeLa cells in a dose-dependent manner. We conclude that these antibodies should be useful probes for studies which aim to define the role of DNA-PK in cells. Since six sera simultaneously contained antibodies to the Ku protein, these studies suggest that relatively intact forms of DNA-PK complex act as autoantigenic particles in selected patients.
DNA依赖性蛋白激酶（DNA-PK）是一种重要的核酶，它由一个被称为DNA-PKcs的催化亚基和一个被鉴定为Ku自身抗原的调节成分组成。在本研究中，我们调查了312名患者以寻找这种特异性。10份血清免疫沉淀出一种大的多肽，该多肽在SDS-PAGE中与DNA-PKcs精确共迁移。免疫印迹分析表明，这种多肽可被针对DNA-PKcs的兔抗血清识别。尽管患者血清在免疫印迹或ELISA中不与生化纯化的DNA-PKcs结合，但它们能够以剂量依赖的方式从HeLa细胞提取物中消耗DNA-PK催化活性。我们得出结论，这些抗体应是用于旨在确定DNA-PK在细胞中作用的研究的有用探针。由于6份血清同时含有针对Ku蛋白的抗体，这些研究表明相对完整形式的DNA-PK复合物在选定患者中充当自身抗原颗粒。
