title: Partial amino acid sequences of botulinum neurotoxins types B and E.
abstract: Clostridium botulinum type E neurotoxin, a single-chain protein of Mr 147,000, was purified and subjected to amino acid sequencing. The same was done for single-chain botulinum type B neurotoxin (Mr 152,000), and for the heavy and light chains (Mr 104,000 and 51,000 respectively) derived from type B by limited trypsin digestion. Twelve to eighteen residues were identified and the following conclusions were drawn: The light chain of the nicked (dichain) type B is derived from the N-terminal one-third of the single-chain (unnicked) parent neurotoxin; sequence homologies are present between single-chain types B and E and the light chain of the nicked type A [J. J. Schmidt, V. Sathyamoorthy, and B. R. DasGupta (1984) Biochem. Biophys. Res. Commun. 119, 900-904]; the N-terminal regions of the heavy chains of types A and B have some structural similarity; and activation of type B neurotoxin cannot involve removal of amino acids or peptides from the N terminus.
mesh_terms: D000595:Amino Acid Sequence; D001905:Botulinum Toxins / Q000302:isolation & purification; D003014:Clostridium botulinum; D008970:Molecular Weight; D009498:Neurotoxins / Q000302:isolation & purification; D010446:Peptide Fragments / Q000302:isolation & purification; D011487:Protein Conformation; D014357:Trypsin
chemical_list: D009498:Neurotoxins; D010446:Peptide Fragments; D014357:Trypsin; D001905:Botulinum Toxins