The B subunit of cholera toxin attaches the native toxin to eukaryotic cell surfaces and facilitates the translocation of the A subunit. It does not possess any intrinsic ADP-ribosyltransferase activity. The high affinity and specificity of the B subunit for ganglioside GM1 makes it a novel tool for probing the involvement of GM1 on growth and differentiation of neuronal and other cells. |