Ganglioside–basic protein interaction: Protection of gangliosides against neuraminidase action

Abstract

The ability of acidic phospho- and sphingolipids to interact with basic proteins was studied by double diffusion analysis. The phospholipids, tri- and diphosphoinositide, and the sphingolipid, sulfatide, interacted with myelin basic protein as evidenced by precipitin line formation. Of the sialoglycosphingolipids (gangliosides) tested, only the myelin-specific monosialoganglioside, G_M4 1 The ganglioside nomenclature used here is according to the system of Svennerholm [1963]. The gangliosides are designated as follows: G_M4 = I³NeuAcGalCer; G_M3 = II³NeuAcLacCer; G_M1 = II³NeuAcGgOse₄Cer; G_D1a = IV³ NeuAc, II³NeuAcGgOse₄Cer; G_D1b = II³(NeuAc)₂GgOse₄Cer; and G_T1b = IV³NeuAc, II³(NeuAc)₂GgOse₄Cer. , formed a precipitin line with myelin basic protein. In addition, myelin basic protein retarded the activity of Clostridium perfringens neuraminidase against G_M4 and the disialoganglioside, G_D1b. Examination of purified rat brain myelin suggested the presence of a neuraminidase activity intrinsic to myelin. This finding, in concert with ganglioside-myelin basic protein complexes which selectively protect against neuraminidase, may provide a physiological explanation for the simplified ganglioside pattern found in myelin.