title: Spontaneous nicking in the nontoxic-nonhemagglutinin component of the Clostridium botulinum toxin complex.
abstract: The nontoxic-nonhemagglutinin (NTNHA) component, in both isolated form and the neurotoxin (NT)/NTNHA complexed form, was prepared protease-free from toxin complexes produced by Clostridium botulinum type D strain 4947. NTNHA in both preparations was found to be spontaneously converted to the nicked NTNHA form leading to 15- and 115-kDa fragments with the excision of several amino acid residues at specific sites on SDS-PAGE during long-term incubation, while that of the NT/NTNHA/hemagglutinin complexed form remained unnicked single-chain polypeptides under the same conditions. Considering that the NTNHA preparation contained small amounts of the nicked form of NTNHA and the addition of trypsin accelerated the cleavage, it is speculated that a nicked form of NTNHA remaining after the purification and/or NTNHA itself catalyzes the cleavage of intact NTNHA.
authors.affiliation: Department of Food Science and Technology, Faculty of Bioindustry, Tokyo University of Agriculture, 196 Yasaka, Abashiri 099-2493, Japan.
authors.forename: Yoshimasa
authors.initials: Y
authors.lastname: Sagane
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Watanabe
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Kouguchi
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Sunagawa
authors.forename: Shigehiro
authors.initials: S
authors.lastname: Obata
authors.forename: Keiji
authors.initials: K
authors.lastname: Oguma
authors.forename: Tohru
authors.initials: T
authors.lastname: Ohyama
mesh_terms: D000595:Amino Acid Sequence; D001905:Botulinum Toxins / Q000737:chemistry / Q000378:metabolism*; D006388:Hemagglutinins / Q000737:chemistry / Q000378:metabolism; D007700:Kinetics; D037102:Lectins; D046911:Macromolecular Substances; D008969:Molecular Sequence Data; D009498:Neurotoxins / Q000737:chemistry / Q000378:metabolism; D011480:Protease Inhibitors / Q000494:pharmacology; D016415:Sequence Alignment; D014357:Trypsin / Q000737:chemistry
chemical_list: C405516:Clostridium botulinum L toxin; C080139:Clostridium botulinum M toxin; D006388:Hemagglutinins; D037102:Lectins; D046911:Macromolecular Substances; D009498:Neurotoxins; D011480:Protease Inhibitors; D014357:Trypsin; D001905:Botulinum Toxins