Proguanylin Human ELISA

Research topic

Others, Renal disease

Features

• The total assay time is less than three hours.
• The kit measures total serum proguanylin.
• Quality controls are human serum based. No animal sera are used.

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

Proguanylin, the 116-amino acid prohormone, is a bioactive form of human guanylin that acts on intestinal guanylate cyclase, thereby regulating intestinal fluid and elektrolyte transport through the second messenger, cyclic GMP (cGMP). The cGMP increase inhibits salt absorption and stimulates chloride secretion into the gut. This imbalance of ions is accompanied by a massive accumulation of water in the gut that gives rise to diarrhea and dehydratation characteristic of enterotoxin activity. Proguanylin is found in circulation and plays an endocrine role by regulating the function of tissues such as the kidney and liver. Proguanylin is a significant marker in renal insufficiency. Plasma levels of proguanylin increase in patients with chronic renal failure who were undergoing hemodialysis. Studies have shown, that serum levels of Proguanylin has rise in patients with Cohn syndrome therefore it could be used as a novel marker in diagnostic and therapy of cardiac failure.

Assay format

Sandwich ELISA, HRP-labelled antibody

Sample requirements

20 µl/well

Applications

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

Calibration Curve

Calibration range

0.3 – 10 ng/ml

Limit of detection

Analytical Limit of Detection is calculated from the real proguanylin values in wells and is 0.09 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 = 0.09 ng/ml x 5 = 0.45 ng/ml

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

CV = 7.8 %

Inter-assay (Run-to-Run, n=6)

CV = 7.9 %

Spiking Recovery

93.4 %

Dilution Linearity

96.1 %

Cross-Reactivity

Human

References to this product

• Solichova P, Stejskal D, Proskova J . Guanylins - Agents with natriuretic effect. Biomed Pap Med Fac Univ Palacky Olomouc Czech Repub . Jul;150(1):85-7 (2006)
• Stejskal D, Solichova P, Lacnak B, Vaclavik J, Hanulova Z, Humenanska V, Sprongl L, Karpisek M . Proguanylin: development, analytical characterization, and clinical testing of a new ELISA. Gen Physiol Biophys . Mar;26(1):62-5 (2007)

References to summary

• Fan X, Wang Y, London R M, Eber S L, Kruse W J, Freeman R H, and Forte L R: Signaling Pathways for Guanylin and Uroguanylin in the digestive, Renal, Central Nervous, Reproductive, and Lymphoid Systems. Endocrinology 138, 4636–4648 (1997)
• Garcia k Ch, Sauvage F J, Strubles M, Henzel W, Reilly D, and Goeddel D V: Processing and Charecterization of Human Proguanylin Expressed in Escherichia coli. The Journal of Biological Chemistry 268, 22397–22401 (1993)
• Hamra F K, Fan X, Krause W J, et al: Prouroguanylin and Proguanylin: Purification from Colon, Structure, and Modulation of Bioactivyity by Proteases. Endocrinology 137, 257–265 (1996)
• Rudolph J A, Hawkins J A, and Cohen M B: Proguanylin secretion and role of negative – feedback inhibition in villous epithelial cell line. Am J Physiol Gastrointest Liver Physiol 238 G695-G702 (2002)
• Lauber T, Neudecker P, Rosch P, and Marx U C: Solution Structure of Human Proguanylin. The Journal of Biological Chemistry 278, 24118–24124 (2003)
• Lauber T, Nourse A, Schulz A, and Marx U C: Native and Recombinant Proguanylin Feature Identical Biophysical Properties and Are Monomeric in Solution. Biochemistry 41, 14602–14612 (2002)
• Sauvage J F, Keshav S, Kuang W-J, Gillett N, Henzel W, and Goeddel D V: Precursor structure, expression, and tissue distribution of human guanylin. Biochemistry 89, 9089–9093 (1992)