title: Molecular diversity of neurotoxins from Clostridium botulinum type D strains.
abstract: The molecular properties of Clostridium botulinum type D South African (D-SA) were compared with those of neurotoxins from type D strain 1873 (D-1873) and type C strains Stockholm and 6813. D-SA toxin, purified 610-fold from the culture supernatant in an overall yield of 30%, consisted of an intact peptide chain with a molecular weight of 140,000. Limited proteolysis of the toxin by trypsin formed a dichain structure consisting of a light chain (Mr, 50,000) and a heavy chain (Mr, 90,000) linked by a disulfide bond(s) and enhanced the lethal activity about fourfold. Antibodies against the D-SA toxin light chain reacted with D-1873 toxin but not with C1 toxins. On the other hand, antibodies against the heavy chain of D-SA toxin cross-reacted with type C strain Stockholm, D-1873, and type C strain 6813 toxins in that order. Amino-terminal sequences of heavy and light chains of D-SA and D-1873 toxins were similar but not identical. These results indicate that within the type D strains, neurotoxins differ in molecular structure and antigenicity.
authors.affiliation: Department of Biochemistry, Faculty of Veterinary Medicine, Hokkaido University, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Moriishi
authors.forename: B
authors.initials: B
authors.lastname: Syuto
authors.forename: S
authors.initials: S
authors.lastname: Kubo
authors.forename: K
authors.initials: K
authors.lastname: Oguma
mesh_terms: D000595:Amino Acid Sequence; D000596:Amino Acids / Q000302:isolation & purification; D000942:Antigens, Bacterial / Q000276:immunology; D001905:Botulinum Toxins / Q000276:immunology / Q000302:isolation & purification*; D003014:Clostridium botulinum / Q000276:immunology*; D003429:Cross Reactions; D007526:Isoelectric Point; D008969:Molecular Sequence Data; D009498:Neurotoxins / Q000276:immunology / Q000302:isolation & purification*
chemical_list: D000596:Amino Acids; D000942:Antigens, Bacterial; D009498:Neurotoxins; D001905:Botulinum Toxins