Botulinum Neurotoxin Detection and Differentiation by Mass Spectrometry

摘要

Botulinum neurotoxins (BoNTs) are proteases thatcleave specific cellular proteins essential for neurotransmit-ter release. Seven BoNT serotypes (A–G) exist; 4 usuallycause human botulism (A, B, E, and F). We developed arapid, mass spectrometry–based method (Endopep-MS) todetect and differentiate active BoNTs A, B, E, and F. Thismethod uses the highly specific protease activity of the tox-ins with target peptides specific for each toxin serotype.The product peptides derived from the endopeptidaseactivities of BoNTs are detected by matrix-assisted laser-desorption ionization time-of-flight mass spectrometry. Inbuffer, this method can detect toxin equivalents of as littleas 0.01 mouse lethal dose (MLD)50and concentrations aslow as 0.62 MLD50/mL. A high-performance liquid chro-matography–tandem mass spectrometry method for quan-tifying active toxin, where the amount of toxin can becorrelated to the amount of product peptides, is alsodescribed