Cholera Toxin: Interaction of Subunits with Ganglioside G _M1

Abstract

Vibrio cholerae exotoxin is an aggregate of two different noninterconvertible subunits (molecular weights about 15,000 and about 25,000). Only the smaller subunit reacts with ganglioside G(M1), a possible biological receptor. The larger subunit, found only in active toxin molecules, can be eluted with 8 molar urea from insoluble complexes of toxin, ganglioside, and cerebroside.