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Recombinant fragment, corresponding to amino acids 401 - 600 of Human Topoisomerase I.
This product can be used as part of an assay for sumoylation activity. Human Aos 1 + Uba 2 (ab3804), Ubc 9 (ab3803) and Sumo 1 (ab3801) can be used to promote in vitro sumoylation of a sumoylation marker (human Topoisomerase I protein fragment) (ab3828). The reaction products can be detected using our Sumo 1 (ab3819 and ab3824) and Topoisomerase I (ab3825) antibodies. Sumoylation assays are carried out in a final volume of 20µl in reaction conditions (20 mM Hepes pH 7.5, 5mM MgCl2, 2mM ATP). This antibody is equivalent to the antibody used in our Sumoylation Control kits. Sumoylation Protocol: 1. Prepare a suitable purified substrate protein. (For the control, use 2µl Topoisomerase I marker for each reaction.) 2. In each reaction, add 4µl E2 to substrate first, then 2µl Sumo 1, 2µl 10x reaction buffer, 2µl E1. Finally, add H2O to bring up to 20µl. We would recommend adding fresh 2mM ATP to be sure that sufficient energy is supplied. 3. The best reaction concentration of proteins is as following: Aos 1 + Uba 2: 7.5µg/ml. Ubc 9: 50µg/ml. SUMO 1: 50µg/ml. For the control assay we recommend running the assay at 37ºC for 30-60 minutes. 4. Detect the reaction products by Western blot using a suitable antibody. For the control reaction use 1/1000 dilution of the supplied Topoisomerase I antibody. Four sumoylated bands should be seen on the gel for the control reaction. This assay has been shown to work with crude extracts. Be aware that Uba 2 contains his-rich regions which might cross-react with antibodies against the 6x-His epitope tag. During western analysis with anti-6x-His antibodies, Uba 2 at 80 kDa might be shown.
Our Abpromise guarantee covers the use of ab3825 in the following tested applications.
The application notes include recommended starting dilutions; optimal dilutions/concentrations should be determined by the end user.
|ICC/IF||Use at an assay dependent concentration. PubMed: 20655466|
|IHC-Fr||Use at an assay dependent concentration.|
|WB||1/500 - 1/1000. Detects a band of approximately 92 kDa (predicted molecular weight: 91 kDa).|
|IP||Use at an assay dependent concentration. PubMed: 17290216|
|ChIP||Use at an assay dependent concentration. PubMed: 20655466|
ab3825 staining Topoisomerase I in human 293T cells by ICC/IF (Immunocytochemistry/immunofluorescence). Cells were fixed with paraformaldehyde, permeabilized with 0.5% Triton X-100 and blocked with 3% BSA for 1 hour at 22°C. Samples were incubated with primary antibody (1/100 in PBS + 1% BSA) for 1 hour at 22°C. An Alexa Fluor® 488-conjugated donkey anti-rabbit IgG polyclonal (1/1000) was used as the secondary antibody.
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