- It is intended for research use only
- The total assay time is less than 3 hours
- The kit measures zinc-alpha-2-glycoprotein in serum and plasma (EDTA, citrate, heparin)
- Assay format is 96 wells
- Quality Controls are human serum based. No animal sera are used
- Standard is recombinant protein based
- Components of the kit are provided ready to use, concentrated or lyophilized
Energy metabolism and body weight regulation, Oncology
Zinc-alpha-2-glycoprotein (ZAG, ZA2G, Azgp1, ZNGP1, Lipid-Mobilizing Factor, LMF) is a soluble 41 kDa glycoprotein belonging to the immunoglobuline protein family and consisting of a single polypeptide chain. Human ZAG shares 59% sequence identity with the murine homolog.
ZAG is closely related to antigens of the class1 major histocompatibility complex (MHC I) and shares 30-40 % sequence identity with the heavy chain of MHC I. Most MHC-I members heterodimerize with beta-2-microglobuline (b2m) and bind peptides derived from intracellular proteins to present them to cytotoxic T cells. In contrast, ZAG is a soluble protein rather than being anchored to plasma membranes that acts independently on b2m and binds the hydrophobic ligand which may relate to its function in lipid metabolism.
ZAG is widespread in body fluids and is also found in various human tissues such as adipose tissue, prostate, breast, skin, salivary gland, trachea, broncheus, lung, gastrointestinal tract, pancreas, liver and kidney. ZAG acts as a lipid mobilizing factor to induce lipolysis in adipocytes and plays an important role in lipid utilization and loss of adipose tissue, especially during cachexia, which occurs in patient suffering from cancer, AIDS and other chronic illnesses. The role of ZAG in cancer cachexia is also connected with its ability to directly influence expression of uncoupling proteins (UCPs) which are implicated in the regulation of energy balance. In human adipocytes, ZAG expression is regulated particularly through TNF-alpha and the PPAR gamma nuclear receptor. ZAG expression is also upregulated by glucocorticoides and attenuated by eicosapentaenoic acid (EPA) and beta-3-adrenoreceptor antagonists.
ZAG is overexpressed in certain human malignant tumors such as prostate, breast, lung or bladder cancer and can relate to tumor differentiation. Additionally, ZAG plays a role in obesity, diabetic kidney disorders, frontotemporal dementia and regulation of melanin production by melanocytes.
ZAG is proposed to have a therapeutic use in obesity and cachexia. It can be used as a marker for clinical analysis of diabetic nephropathy and as a marker for certain tumors..