Zinc-Alpha-2-Glycoprotein Human ELISA

Research topic

Energy metabolism and body weight regulation, Oncology

Features

• The total assay time is less than three hours.
• The kit measures serum or plasma Zinc-Alpha-2-Glycoprotein.
• Standard is recombinant protein based.
• Quality controls are human-serum based.
• Components of the kit are in the lyophilized, concentrated and ready-to-use states.

Storage/Shipping

Store the kit at 2–8°C. Under these conditions, the kit is stable until the expiration date (see label on the box).

Summary

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..

Assay format

Sandwich ELISA, HRP-labelled antibody

Sample requirements

10 µl/well

Applications

Plasma-Citrate, Plasma-EDTA, Plasma-Heparin, Serum

Calibration Curve

Calibration range

3 to 100 ng/ml

Limit of detection

Analytical Limit of Detection is calculated from the real Zinc-Alpha-2-Glycoprotein values in wells and is 0.673 ng/ml

Limit of quantification

Assay Sensitivity takes the dilution of samples into consideration and is calculated according to the formula: Assay Sensitivity = Analytical Limit of Detection x sample dilution = 0.673 ng/ml x 5000 = 3365 ng/ml= 3.365 μg/ml

Intra-assay (Within-Run, n=8)

CV = 3.9 %

Inter-assay (Run-to-Run, n=4)

CV = 6.6 %

Spiking Recovery

96.2 %

Dilution Linearity

103.3 %

Cross-Reactivity

Human, Monkey, Goat, Cat

Find out more on biovendor.com

• Zinc-alpha2-glycoprotein in BioVendor News

References to this product

• Stejskal D, Karpisek M, Reutova H, Stejskal P, Kotolova H, Kollar P . Determination of serum zinc-alpha-2-glycoprotein in patients with metabolic syndrome by a new ELISA. Clin Biochem . Nov 29 (2007)
• Brettschneider J, Mogel H, Lehmensiek V, Ahlert T, Sussmuth S, Ludolph AC, Tumani H. Proteome Analysis of Cerebrospinal Fluid in Amyotrophic Lateral Sclerosis (ALS). Neurochem Res. 2008 May 15;

References to summary

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• Freije JP, Fueyo A, Uria JA, Velasco G, Sanchez LM, Lopez-Boado YS, Lopez-Otin C.: Human Zn-alpha 2-glycoprotein: complete genomic sequence, identification of a related pseudogene and relationship to class I major histocompatibility complex genes.Genomics. 1993 Dec;18(3):575–87
• Lopez-Boado YS, Diez-Itza I, Tolivia J, Lopez-Otin C.: Glucocorticoids and androgens up-regulate the Zn-alpha 2-glycoprotein messenger RNA in human breast cancer cells.Breast Cancer Res Treat. 1994;29(3):247–58.
• Sanchez LM, Lopez-Otin C, Bjorkman PJ.: Biochemical characterization and crystalization of human Zn-alpha2-glycoprotein, a soluble class I major histocompatibility complex homolog.Proc Natl Acad Sci U S A. 1997 Apr 29;94(9):4626–30.
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• Rolli V, Radosavljevic M, Astier V, Macquin C, Castan-Laurell I, Visentin V, Guigne C, Carpene C, Valet P, Gilfillan S, Bahram S.: Lipolysis is altered in MHC class I zinc-alpha(2)-glycoprotein deficient mice.FEBS Lett. 2007 Feb 6;581(3):394–400.