Guanylin (human) (trifluoroacetate salt)

Guanylin is a peptide hormone activator of membrane-bound guanylate cyclase C (GC-C).^1,2 It contains four cysteines that can form disulfide bridges leading to two possible isoforms, with the active form containing disulfide bridges between Cys⁴ and Cys¹² and Cys⁷ and Cys¹⁵.¹ Guanylin is found in epithelial cells of the small intestine where it activates GC-C to increase intestinal chloride and fluid secretion.^2,3,4 Guanylin expression is reduced by 100- to 1,000-fold in greater than 85% of isolated tumors from patients with colorectal cancer compared with adjacent non-cancerous intestinal epithelial tissue.⁵

1.Nokihara, K., Wray, V., Ando, E., et al.Synthesis, solution structure, binding activity, and cGMP activation of human guanylin and its disulfide isomerRegul. Pept.70(2-3)111-120(1997) 2.de Sauvage, F.J., Keshav, S., Kuang, W.-J., et al.Precursor structure, expression, and tissue distribution of human guanylinProc. Natl. Acad. Sci. USA89(19)9089-9093(1992) 3.Hill, O., Kuhn, M., Zucht, H.-D., et al.Analysis of the human guanylin gene and the processing and cellular localization of the peptideProc. Natl. Acad. Sci. USA92(6)2046-2050(1995) 4.Forte, L.R., and Currie, M.G.Guanylin: A peptide regulator of epithelial transportFASEB J.9(8)643-650(1995) 5.Wilson, C., Lin, J.E., Snook, A.E., et al.The paracrine hormone for the GUCY2C tumor suppressor, guanylin, is universally lost in colorectal cancerCancer Epidemiol. Biomarkers Prev.23(11)2328-2337(2014)