ISSN:
1573-4919
Keywords:
botulinum neurotoxin
;
toxoid
;
tetranitromethane
;
tyrosine residues
;
cross-linking
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
Notes:
Abstract Botulinum neurotoxin serotypes A, B and E were modified at pH 7.9 with tetranitromethane, a reagent highly specific for tyrosine residues. The type B and E neurotoxins were completely detoxified without significant damage to their serological activities. Under similar modification conditions, the type A neurotoxin was incompletely detoxified with some alteration in its serological reactivity. Modification of only tyrosine residues to nitrotyrosine was evident from amino acid analysis of the acid hydrolysates of the modified proteins. The completely detoxified type B and E neurotoxins, used as toxoid, elicited antibodies in rabbits. The antisera precipitated and neutralized the homologous neurotoxin. The two toxoids, type B and E, were prepared with 〉99% pure neurotoxins as tested by sodium dodecyl sulfate-polyacrylamide gel electrophoresis whereas the traditional toxoids produced with formaldehyde are very crude preparations of the neurotoxin (∼ 90% impure). Chemical modification using tetranitromethane is more specific than products that form during ∼ 7 days of reaction between a protein and formaldehyde. The toxoids produced with tetranitromethane may be considered second-generation toxoids, compared with the first-generation toxoids (crude preparation of neurotoxins detoxified with formaldehyde).
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00577111
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