Amino acid composition of Clostridium botulinum type F neurotoxin.

To develop reliable data on the amino acid composition of type F botulinum neurotoxin, three batches of the neurotoxin were analyzed. Each batch was isolated from a separate neurotoxin producing bacterial culture. Two batches had inoculum from one source and the other batch one from a different source. Two batches of the neurotoxin were purified by the same method and one was purified by a different method. The neurotoxin preparations were found comparable in purity and similar in amino acid composition. The best estimate of number of amino acid residues per neurotoxin molecule (mol. wt. 155,000) was: Asp218 Thr80 Ser105 Glu128 Pro47 Gly69 Ala47 Val72 CyS9 Met14 Ile128 Leu104 Tyr86 Phe60 Lys90 His13 Arg51 Trp23.