Adipsin Human, Sf9

Complement Factor D belongs to the trypsin family of peptidases. It is a single-chain glycoprotein with a molecular mass of approximately 26.01 kDa, although it may appear larger on SDS-PAGE due to glycosylation . The protein is secreted by adipocytes into the bloodstream and has a high level of expression in adipose tissue, suggesting a role for adipose tissue in immune system biology .

The recombinant form of Complement Factor D is produced in Sf9 cells using the baculovirus expression system. Sf9 cells are derived from the fall armyworm (Spodoptera frugiperda) and are commonly used for the production of recombinant proteins due to their ability to perform complex post-translational modifications, including glycosylation .

The recombinant protein produced in Sf9 cells is a single, glycosylated polypeptide chain containing 241 amino acids (21-253 a.a.) and is expressed with an 8 amino acid His tag at the C-terminus. This His tag facilitates purification using affinity chromatography .

Complement Factor D is used in various research applications, particularly in studies related to the immune system and infectious diseases. The protein is typically supplied as a sterile, filtered, colorless solution in phosphate-buffered saline (pH 7.4). For long-term storage, it is recommended to store the protein at -20°C with a carrier protein to prevent degradation .