Zinc-Alpha-2-Glycoprotein Human ELISA

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..

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.

Research topic

Energy metabolism and body weight regulation, Oncology

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Assay format

Sandwich ELISA, HRP-labelled antibody

Applications

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

Sample requirements

10 µl/well

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).

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

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

Monkey, Goat, Cat

References to this product

• Jernas M, Olsson B, Sjoholm K, Sjogren A, Rudemo M, Nellgard B, Carlsson LM, Sjostrom CD. Changes in adipose tissue gene expression and plasma levels of adipokines and acute-phase proteins in patients with critical illness. Metabolism. 2009 Jan;58 (1):102-8
• Ceperuelo-Mallafre V, Naf S, Escote X, Caubet E, Gomez JM, Miranda M, Chacon MR, Gonzalez-Clemente JM, Gallart L, Gutierrez C, Vendrell J. Circulating and adipose tissue gene expression of zinc-alpha2-glycoprotein in obesity: its relationship with adipokine and lipolytic gene markers in subcutaneous and visceral fat. J Clin Endocrinol Metab. 2009 Dec;94 (12):5062-9
• 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)
• Ding Q, Mracek T, Gonzalez-Muniesa P, Kos K, Wilding J, Trayhurn P, Bing C. Identification of macrophage inhibitory cytokine-1 in adipose tissue and its secretion as an adipokine by human adipocytes. Endocrinology. 2009 Apr;150 (4):1688-96
• Selva DM, Lecube A, Hernandez C, Baena JA, Fort JM, Simo R. Lower zinc-alpha2-glycoprotein production by adipose tissue and liver in obese patients unrelated to insulin resistance. J Clin Endocrinol Metab. 2009 Nov;94 (11):4499-507
• Selva DM, Lecube A, Hernandez C, Baena JA, Fort JM, Simo R. Lower zinc-alpha2-glycoprotein production by adipose tissue and liver in obese patients unrelated to insulin resistance. J Clin Endocrinol Metab. 2009 Nov;94 (11):4499-507
• 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;
• Roher AE, Maarouf CL, Sue LI, Hu Y, Wilson J, Beach TG. Proteomics-derived cerebrospinal fluid markers of autopsy-confirmed Alzheimer's disease. Biomarkers. 2009 Nov;14 (7):493-501
• Fain JN, Tagele BM, Cheema P, Madan AK, Tichansky DS. Release of 12 Adipokines by Adipose Tissue, Nonfat Cells, and Fat Cells From Obese Women. Obesity (Silver Spring). 2009 Oct 15;
• Yeung DC, Lam KS, Wang Y, Tso AW, Xu A. Serum zinc-alpha2-glycoprotein correlates with adiposity, triglycerides, and the key components of the metabolic syndrome in chinese subjects. J Clin Endocrinol Metab. 2009 Jul;94 (7):2531-6

References to summary

• Araki T, Gejyo F, Takagaki K, Haupt H, Schwick HG, Burgi W, Marti T, Schaller J, Rickli E, Brossmer R, et al.: Complete amino acid sequence of human plasma Zn-alpha 2-glycoprotein and its homology to histocompatibility antigens.Proc Natl Acad Sci U S A. 1988 Feb;85(3):679–83.
• Tada T, Ohkubo I, Niwa M, Sasaki M, Tateyama H, Eimoto T.: Immunohistoche­mical localization of Zn-alpha 2-glycoprotein in normal human tissues.J Histochem Cytochem. 1991 Sep;39(9):1221–6.
• 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.
• Brysk MM, Lei G, Selvanayagam P, Brysk H, Tyring SK, Arany I.: Modulation by interferon-gamma of zinc-alpha 2-glycoprotein gene expression in human epithelial cell lines.Anticancer Res. 1997 Sep-Oct;17(5A):3387–91.
• Todorov PT, McDevitt TM, Meyer DJ, Ueyama H, Ohkubo I, Tisdale MJ.: Purification and characterization of a tumor lipid-mobilizing factor.Cancer Res. 1998 Jun 1;58(11):2353–8.
• Hirai K, Hussey HJ, Barber MD, Price SA, Tisdale MJ.: Biological evaluation of a lipid-mobilizing factor isolated from the urine of cancer patients.Cancer Res. 1998 Jun 1;58(11):2359–65.
• Brysk MM, Lei G, Adler-Storthz K, Chen Z, Brysk H, Tyring SK, Arany I.: Zinc-alpha2-glycoprotein expression as a marker of differentiation in human oral tumors.Cancer Lett. 1999 Mar 22;137(1):117–20.
• Hale LP, Price DT, Sanchez LM, Demark-Wahnefried W, Madden JF.: Zinc alpha-2-glycoprotein is expressed by malignant prostatic epithelium and may serve as a potential serum marker for prostate cancer.Clin Cancer Res. 2001 Apr;7(4):846–53.
• Hale LP.: Zinc alpha-2-glycoprotein regulates melanin production by normal and malignant melanocytes.J Invest Dermatol. 2002 Aug;119(2):464–70.
• Gohda T, Makita Y, Shike T, Tanimoto M, Funabiki K, Horikoshi S, Tomino Y.: Identification of epistatic interaction involved in obesity using the KK/Ta mouse as a Type 2 diabetes model: is Zn-alpha2 glycoprotein-1 a candidate gene for obesity?Diabetes. 2003 Aug;52(8):2175–81.
• Bing C, Bao Y, Jenkins J, Sanders P, Manieri M, Cinti S, Tisdale MJ, Trayhurn P.: Zinc-alpha2-glycoprotein, a lipid mobilizing factor, is expressed in adipocytes and is up-regulated in mice with cancer cachexia.Proc Natl Acad Sci U S A. 2004 Feb 24;101(8):2500–5.
• Russell ST, Zimmerman TP, Domin BA, Tisdale MJ.: Induction of lipolysis in vitro and loss of body fat in vivo by zinc-alpha2-glycoprotein.Bi­ochim Biophys Acta. 2004 Feb 27;1636(1):59–68.
• Sanders PM, Tisdale MJ.: Effect of zinc-alpha2-glycoprotein (ZAG) on expression of uncoupling proteins in skeletal muscle and adipose tissue.Cancer Lett. 2004 Aug 20;212(1):71–81.
• Hansson SF, Puchades M, Blennow K, Sjogren M, Davidsson P.: Validation of a prefractionation method followed by two-dimensional electrophoresis – Applied to cerebrospinal fluid proteins from frontotemporal dementia patients.Proteome Sci. 2004 Nov 18;2(1):7.
• Bao Y, Bing C, Hunter L, Jenkins JR, Wabitsch M, Trayhurn P.: Zinc-alpha2-glycoprotein, a lipid mobilizing factor, is expressed and secreted by human (SGBS) adipocytes.FEBS Lett. 2005 Jan 3;579(1):41–7.
• Russell ST, Tisdale MJ.: The role of glucocorticoids in the induction of zinc-alpha2-glycoprotein expression in adipose tissue in cancer cachexia.Br J Cancer. 2005 Mar 14;92(5):876–81.
• Russell ST, Tisdale MJ.: Effect of eicosapentaenoic acid (EPA) on expression of a lipid mobilizing factor in adipose tissue in cancer cachexia.Pros­taglandins Leukot Essent Fatty Acids. 2005 Jun;72(6):409–14.
• Jain S, Rajput A, Kumar Y, Uppuluri N, Arvind AS, Tatu U.: Proteomic analysis of urinary protein markers for accurate prediction of diabetic kidney disorder.J Assoc Physicians India. 2005 Jun;53:513–20.
• Kamoshida S, Watanabe K, Suzuki M, Mizutani Y, Sakamoto K, Sugimoto Y, Oka T, Fukushima M, Tsutsumi Y.: Expression of cancer cachexia-related factors in human cancer xenografts: an immunohistochemical analysis.Biomed Res. 2006 Dec;27(6):275–81.
• 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.

By research topic:

• Energy metabolism and body weight regulation
• Oncology

By molecule:

• Zinc-Alpha-2-Glycoprotein