TOP1 70kDa Human
Greater than 95% as determined by SDS-PAGE.
Description
Recombinant TOP1 70kDa protein is an enzyme fragment having a molecular mass of 72KDa (pH 9.4). TOP1 70kDa protein is fused to a hexa-histidine purification tag.
Product Specs
Topoisomerase I (TOP1) is a crucial nuclear enzyme responsible for altering the supercoiling of DNA. It facilitates the conversion of supercoiled DNA into the necessary topological structures required for essential processes like DNA replication and transcription. TOP1 serves as the target antigen for TOP1 autoantibodies. These antibodies are considered a highly specific marker for scleroderma patients (with a specificity ranging from 98% to 100%). Notably, the presence of TOP1 antibodies is linked to the occurrence of diffuse skin involvement and pulmonary fibrosis in these patients. In human tissues, the TOP1 enzyme is primarily synthesized as a precursor protein with a molecular weight of 100 kDa. Subsequently, a significant portion of this precursor undergoes proteolytic processing, resulting in a truncated form with a molecular weight of 70 kDa. This 70 kDa form of TOP1 is the source from which the TOP1 antigen derives its name.
Recombinant TOP1 70kDa protein is a fragment of the TOP1 enzyme. It has a molecular weight of 72 kDa when measured at a pH of 9.4. A hexa-histidine tag is fused to this protein to facilitate purification.
TOP1 70kDa is supplied in a 20mM HEPES buffer with a pH of 8.0. The buffer also contains 500mM NaCl and 20% glycerol.
1. It can bind to human auto-antibodies of the IgG type.
2. It can be used in standard ELISA tests, including checkerboard analysis using positive and negative samples. It is also suitable for immunodot tests with positive and negative samples.
This protein is suitable for use in Western blot experiments when using a positive sample for anti TOP1 70kDa autoantibody or a monoclonal anti-hexa-His-tag antibody.
The recommended coating concentration for this protein is 0.5-0.8 µg/ml. However, this can vary depending on the ELISA plate type and the buffer used for coating. It is suitable for labeling functional groups.
The purity of this protein is greater than 95% as determined by SDS-PAGE analysis.
If the entire vial will be used within 2-4 weeks, it can be stored at 4°C. For longer storage periods, it should be stored frozen at -20°C. Avoid repeatedly freezing and thawing the protein.
Product Science Overview
TOP1 is initially synthesized as a protein with a molecular weight of approximately 100 kDa in human tissues. However, most of this precursor is proteolytically processed to a 70 kDa form, which is the basis for the name "70kDa Recombinant Human" . The recombinant form of TOP1 is often fused to a hexa-histidine purification tag to facilitate its purification .
The enzyme works by creating transient single-strand breaks in the DNA molecule, allowing the DNA to unwind and relieve the torsional stress. Once the stress is relieved, TOP1 re-ligates the broken DNA strand, thus maintaining the integrity of the DNA molecule .
TOP1 is the target antigen for autoantibodies known as Scl-70, which are specific markers in scleroderma patients. These autoantibodies are associated with diffuse skin involvement and pulmonary fibrosis . The presence of Scl-70 antibodies is highly specific (98-100%) for scleroderma, making TOP1 a valuable diagnostic marker for this condition .
Recombinant TOP1 70kDa protein is widely used in various laboratory research applications, including:
The recombinant TOP1 70kDa protein is typically supplied in a buffer containing HEPES, sodium chloride, and glycerol to ensure stability . It is recommended to store the protein at 4°C if it will be used within 2-4 weeks, or at -20°C for longer periods. Multiple freeze-thaw cycles should be avoided to maintain the protein’s integrity .
