TARS Human, Sf9

Threonyl-tRNA Synthetase is a glycosylated polypeptide chain with a molecular mass of approximately 83 kDa . The enzyme catalyzes the aminoacylation of tRNA by transferring threonine, ensuring that the correct amino acid is incorporated into the growing polypeptide chain during protein synthesis . This enzyme is also recognized as an autoantigen by PL-7 antibodies, which are found in a subset of patients with polymyositis and dermatomyositis .

The human recombinant form of Threonyl-tRNA Synthetase is produced in Sf9 insect cells. This expression system is commonly used for producing recombinant proteins due to its ability to perform post-translational modifications, such as glycosylation, which are essential for the proper function of many human proteins .

Threonyl-tRNA Synthetase has several applications in research and diagnostics:

1. Autoantibody Detection: It binds IgG-type human auto-antibodies, making it useful in the diagnosis of autoimmune diseases like polymyositis and dermatomyositis .
2. ELISA Tests: It is used in standard ELISA tests for the detection of specific antibodies in sera panels .
3. Biotinylation and Iodination: The enzyme is suitable for labeling functional groups, which can be used in various biochemical assays .

The recombinant enzyme is supplied as a sterile filtered clear solution and is formulated in 20mM HEPES buffer (pH 8), 200mM sodium chloride, and 20% glycerol . For short-term storage, it can be kept at 4°C if used within 2-4 weeks. For longer periods, it should be stored frozen at -20°C to avoid multiple freeze-thaw cycles .

Preliminary data suggest that PL-7 antibodies, which recognize Threonyl-tRNA Synthetase, may indicate an increased risk for lung involvement in patients with polymyositis and dermatomyositis . However, further studies are needed to confirm this association in a larger number of cases.