The ability of Fuc-GM1 ganglioside to mimic the receptor function of GM1 for cholera toxin (CT) has been investigated. For this purpose, rat glioma C6 cultured cells were enriched with Fuc-GM1 and the responsiveness to CT was compared with that of cells enriched with GM1 ganglioside. Fuc-GM1 was taken up by cells as rapidly and to the same extent as GM1. When comparable amounts of ganglioside were associated, the cells enriched with Fuc-GM1 bound the same amount of 125I-CT as did cells enriched with GM1. Under conditions in which GM1- and Fuc-GM1-enriched cells bound comparable amounts of CT, the Fuc-GM1-treated cells accumulated virtually the same amount of cyclic AMP as did GM1-treated cells, and activation of adenylate cyclase was also similar. The lag time preceding the CT-induced cAMP accumulation was the same in Fuc-GM1- and GM1-enriched cells. High-sensitivity isothermal titration calorimetry (ITC) experiments showed that the association constants of CT with Fuc-GM1 or GM1 ganglioside were comparable (4 x 10(7) M-1 and 1.9 x 10(7) M-1, respectively, at 25 degrees C). Also, the association constants of the B-subunit pentamer with Fuc-GM1 or GM1 ganglioside were comparable (about 3 x 10(7) M-1 and 7 x 10(7) M-1, respectively, at 25 degrees C).
|Citazione:||Masserini, M.E., Freire, E., Palestini, P., Calappi, E., & Tettamanti, G. (1992). Fuc-GM1 ganglioside mimics the receptor function of GM1 for cholera toxin. BIOCHEMISTRY, 31(8), 2422-2426.|
|Tipo:||Articolo in rivista - Articolo scientifico|
|Carattere della pubblicazione:||Scientifica|
|Titolo:||Fuc-GM1 ganglioside mimics the receptor function of GM1 for cholera toxin|
|Autori:||Masserini, ME; Freire, E; Palestini, PNA; Calappi, E; Tettamanti, G|
|Data di pubblicazione:||3-mar-1992|
|Appare nelle tipologie:||01 - Articolo su rivista|