title: Molecular composition of progenitor toxin produced by Clostridium botulinum type C strain 6813.
abstract: The molecular composition of the purified progenitor toxin produced by a Clostridium botulinum type C strain 6813 (C-6813) was analyzed. The strain produced two types of progenitor toxins (M and L). Purified L toxin is formed by conjugation of the M toxin (composed of a neurotoxin and a non-toxic nonhemagglutinin) with additional hemagglutinin (HA) components. The dual cleavage sites at loop region of the dichain structure neurotoxin were identified between Arg444-Ser445 and Lys449-Thr450 by the analyses of C-terminal of the light chain and N-terminal of the heavy chain. Analysis of partial amino acid sequences of fragments generated by limited proteolysis of the neurotoxin has shown to that the neurotoxin protein produced by C-6813 was a hybrid molecule composed of type C and D neurotoxins as previously reported. HA components consist of a mixture of several subcomponents with molecular weights of 70-, 55-, 33-, 26 through 21- and 17-kDa. The N-terminal amino acid sequences of 70-, 55-, and 26 through 21-kDa proteins indicated that the 70-kDa protein was intact HA-70 gene product, and other 55- and 26 through 21-kDa proteins were derived from the 70-kDa protein by modification with proteolysis after translation of HA-70 gene. Furthermore, several amino acid differences were exhibited in the amino acid sequence as compared with the deduced sequence from the nucleotide sequence of the HA-70 gene which was common among type C (strains C-St and C-468) and D progenitor toxins (strains D-CB16 and D-1873).
authors.affiliation: Department of Food Science, Faculty of Bioindustry, Tokyo University of Agriculture, Abashiri, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Watanabe
authors.forename: Y
authors.initials: Y
authors.lastname: Sagane
authors.forename: H
authors.initials: H
authors.lastname: Kouguchi
authors.forename: H
authors.initials: H
authors.lastname: Sunagawa
authors.forename: K
authors.initials: K
authors.lastname: Inoue
authors.forename: Y
authors.initials: Y
authors.lastname: Fujinaga
authors.forename: K
authors.initials: K
authors.lastname: Oguma
authors.forename: T
authors.initials: T
authors.lastname: Ohyama
mesh_terms: D000595:Amino Acid Sequence; D001905:Botulinum Toxins / Q000096:biosynthesis / Q000737:chemistry* / Q000302:isolation & purification; D002852:Chromatography, Ion Exchange; D003014:Clostridium botulinum / Q000737:chemistry*; D004591:Electrophoresis, Polyacrylamide Gel; D006388:Hemagglutinins / Q000096:biosynthesis / Q000737:chemistry* / Q000302:isolation & purification; D037102:Lectins; D008969:Molecular Sequence Data; D009498:Neurotoxins / Q000096:biosynthesis / Q000737:chemistry* / Q000302:isolation & purification
chemical_list: C405516:Clostridium botulinum L toxin; C405517:Clostridium botulinum LL toxin; C080139:Clostridium botulinum M toxin; D006388:Hemagglutinins; D037102:Lectins; D009498:Neurotoxins; D001905:Botulinum Toxins