Ganglioside GM1is a monosialylated ganglioside and the prototypic ganglioside for those containing one sialic acid residue.1,2It is found in a large variety of cells, including immune cells and neurons, and is enriched in lipid rafts in the cell membrane.3It associates with growth factor receptors, including TrkA, TrkB, and the GDNF receptor complex containing Ret and GFRα, and is required for TrkA expression on the cell surface. Ganglioside GM1interacts with other proteins to increase calcium influx, affecting various calcium-dependent processes, including inducing neuronal outgrowth during differentiation. Ganglioside GM1acts as a receptor for cholera toxin, which binds to its oligosaccharide group, facilitating toxin cell entry into epithelial cells of the jejunum.4,5Similarly, it is bound by the heat-labile enterotoxin fromE. coliin the pathogenesis of traveler's diarrhea.6Ganglioside GM1gangliosidosis, characterized by a deficiency in GM1-β-galactosidase, the enzyme that degrades ganglioside GM1, leads to accumulation of the gangliosides GM1and GA1in neurons and can be fatal in infants.1Levels of ganglioside GM1are decreased in the substantia nigra pars compacta in postmortem brain from patients with Parkinson's disease.3Ganglioside GM1mixture contains a mixture of ovine ganglioside GM1molecular species with primarily C18:0 fatty acyl chain lengths, among various others. [Matreya, LLC. Catalog No. 1544] 1.Kolter, T.Ganglioside biochemistryISRN Biochem.506160(2012) 2.Mocchetti, I.Exogenous gangliosides, neuronal plasticity and repair, and the neurotrophinsCell Mol. Life Sci.62(19-20)2283-2294(2005) 3.Ledeen, R.W., and Wu, G.The multi-tasked life of GM1 ganglioside, a true factotum of natureTrends Biochem. Sci.40(7)407-418(2015) 4.Turnbull, W.B., Precious, B.L., and Homans, S.W.Dissecting the cholera toxin-ganglioside GM1 interaction by isothermal titration calorimetryJ. Am. Chem. Soc.126(4)1047-1054(2004) 5.Blank, N., Schiller, M., Krienke, S., et al.Cholera toxin binds to lipid rafts but has a limited specificity for ganglioside GM1Immunol. Cell Biol.85(5)378-382(2007) 6.Minke, W.E., Roach, C., Hol, W.G., et al.Structure-based exploration of the ganglioside GM1 binding sites of Escherichia coli heat-labile enterotoxin and cholera toxin for the discovery of receptor antagonistsBiochemistry38(18)5684-5692(1999)
Sphynolactone-7 (SPL7) acts as an agonist for the Striga hyposensitive to light receptor 7 (ShHTL7) found in the parasitic plant Striga hermonthica. SPL7 selectively targets ShHTL7 with an IC50 of 0.31 µM, demonstrating higher specificity compared to ShHTL2-6, ShHTL9-10, and the strigolactone receptor AtD14 at a concentration of 10 µM, though it still inhibits ShHTL8 and ShHTL11 with IC50s of 1.2 and 7.8 µM, respectively. This compound triggers fatal germination of Striga hermonthica seeds in the absence of a host by inducing suicidal germination at a minimum effective concentration of 10 fM. Additionally, SPL7 can reduce the emergence of this obligate parasite from the soil and alleviate Striga hermonthica-induced senescence in maize when applied at a 10 nM concentration to the soil of maize and Striga hermonthica seed co-cultures.