Apolipoprotein-D is mainly associated with high density lipoproteins in human plasma. Apolipoprotein-D is an atypical apolipoprotein and, based on its primary structure, Apolipoprotein-D is a member of the lipocalin family. Lipocalins adopt a beta-barrel tertiary structure and transport small hydrophobic ligands. Apolipoprotein-D binds cholesterol, progesterone, pregnenolone, bilirubin and arachidonic acid. Apolipoprotein-D is expressed in numerous tissues having high levels of expression in spleen, testes and brain. Apolipoprotein-D is present at high concentrations in the cyst fluid of women with gross cystic disease of the breast, a condition associated with increased risk of breast cancer. Apolipoprotein-D accumulates in regenerating peripheral nerves and in the cerebrospinal fluid of patients with neurodegenerative conditions, such as Alzheimer's disease. Apolipoprotein-D participates in maintenance and repair within the central and peripheral nervous systems. Apolipoprotein-D is a multi-ligand, multi-functional transporter and transports a ligand from 1 cell to another within an organ, scavenge a ligand within an organ for transport to the blood or could transport a ligand from the circulation to specific cells within a tissue.
Apoliprotein-D Human Recombinant His Tag fusion protein at C-terminus (7 highlighted a.a.) produced in E.Coli is a single, non-glycosylated, Polypeptide chain containing 174 amino acids and having a molecular mass of 19.82kDa. The protein a.a sequence corresponds to the UniProtKB/Swiss-Prot entry P05090. The Following gene modifications were made: Trp99His, Cys116Ser, Ile118Ser, Leu120Ser amino acids exchanges were introduced at the surface of Apoliprotein-D to enhance the protein’s solubility and another three Leu23Pro, Pro133Val, Asn134Ala amino acids exchanges which facilitate its genetic manipulation. The Apoliprotein-D is purified by proprietary chromatographic techniques.