Recombinant Human Ku P70/P80

Source : Sf9 insect cells. KuP70/P80 Human Recombinant produced in SF9 insect cells is a glycosylated, polypeptide chain having a molecular mass of 70,638 Dalton for the p70 subunit and 83,528 Dalton for the p80 subunit. Ku (P70/P80) is expressed with a -6xHis tag and purified by proprietary chromatographic techniques. Ku antigen consists of two polypeptides (70 kDa and 80 kDa; the p80 subunit is occasionally called p86) . The Ku heterodimer provides DNA-binding and regulatory functions to DNA-dependent protein kinase which is a central enzyme for DNA recombination processes in eucaryotic cells. The Ku protein plays important roles in multiple nuclear processes including DNA repair, V (D) J recombination, telomere maintenance, and the regulation of specific gene transcription. Antibodies to Ku were originally reported in scleroderma-polymyositis overlap syndrome (up to 20% of patients) but have also been detectable in about 20 % of patients with primary pulmonary hypertension (as a complication of overlap), in 5-10 % of SLE and MCTD patients, and in up to 20 % of patients with primary Sjgren's syndrome.In IIF using HEp-2 cells, Ku-positive sera yield a dense, fine granular pattern with nucleolar staining that is typical but not specific for anti-Ku. Detection of Ku antibodies by Western blot may bear false-negative results since the main reactive epitope on the p70/p80 heterodimer is conformation-dependent.