	US 7,611,856 B2
	Mass spectrometry-based methods for detection and differentiation of botulinum neurotoxins
Jurgen G. Schmidt, Los Alamos, N. Mex. (US); Anne E. Boyer, Atlanta, Ga. (US); Suzanne R. Kalb, Atlanta, Ga. (US); Hercules Moura, Tucker, Ga. (US); John R. Barr, Suwannee, Ga. (US); and Adrian R. Woolfitt, Atlanta, Ga. (US)
Assigned to Los Alamos National Security, LLC, Los Alamos, N. Mex. (US)
Filed on Nov. 03, 2004, as Appl. No. 10/980,346.
Claims priority of provisional application 60/517792, filed on Nov. 05, 2003.
Prior Publication US 2006/0024763 A1, Feb. 02, 2006
Int. Cl. G01N 30/72 (2006.01)

U.S. Cl. 435—7.72

13 Claims

1. A method for detecting the presence of clostridial botulinum neurotoxins in a sample comprising the steps of:

a) mixing a sample that may comprise serotypes of clostridial neurotoxins with a peptide substrate, wherein said peptide substrate is KGSNRTRIDEANORATRMLGGK-(SEQ ID NO: 1), and optionally, one or more peptide substrates selected from the group consisting of SEQ ID NO:14, 21, and 28, for proteolytic activity of said clostridial neurotoxin serotypes, such that at least a portion of the amount of the substrate is proteolytically cleaved by a serotype to produce a mixture comprising uncleaved substrate and peptide cleavage products;

b) analyzing the mixture on a mass spectrometer to produce a signal corresponding to the mass of at least one peptide cleavage product;

c) using the signal corresponding to the peptide cleavage products to identify the clostridial neurotoxin serotype;

d) quantitating the amount of proteolytic cleavage of the peptide substrate for the clostridial neurotoxin serotype by stable isotope dilution mass spectrometry.