Molecular interactions between micellar polysialogangliosides and affinity-purified tetanotoxins in aqueous solution.

摘要: Two-affinity purified tetanotoxin forms, TeToA and TeToB, with different affinities for gangliosides were characterized by analytical ultracentrifuge, circular dichroism (CD), amino acid composition. Both toxin forms share a common sedimentation coefficient of about 6-7 S similar a-helicity values, but they vary in Incubation TeToB micellar polysialogangliosides results formation high (21-24 S) medium (13-15 size toxin-micellar ganglioside aggregates as revealed ultracentrifuge technique. At TeToB/[Nacetylneuraminyll- galactosyl- N- acetylgalactosaminyl[N- acetylneuraminyl- acetylneuraminyl] - galactosylglucosylceramide (GTIb) molar ratios >26, molecular weight (Mr 2 700,000) which contain between 3 5 monomers are formed, whereas at <15, 1-2 present. does not form the presence gangliosides. A marked increase a-helix from 20 to 39% is apparent CD spectrum after interaction mixture (Gib). Cerebrosides, sulfatides, sphingomyelin, phosphatidylserine also a-helix, presumably because an overall effect lipids on protein. fragment B C undergo changes Glb, suggesting that specific. The polarity spectra number shifted negative positive value tetanotoxin. data consistent interpretation discrete hydrophobic domain heavy chain interacts macromolecular complexes.