β-Amino-thiols Inhibit the Zinc Metallopeptidase Activity of Tetanus Toxin Light Chain
作者:Loïc Martin、Fabrice Cornille、Pascale Coric、Bernard P. Roques、Marie-Claude Fournié-Zaluski
DOI:10.1021/jm981015z
日期:1998.8.1
Tetanus neurotoxin is a 150-kDa protein produced by Clostridium tetani, which causes the lethal spastic paralytic syndromes of tetanus by blocking inhibitory neurotransmitter release at central synapses. The toxin light chain (50 kDa) has a zinc endopeptidase activity specific for synaptobrevin, an essential component of the neuroexocytosis apparatus. Previous unsuccessful attempts to block the proteolytic activity of this neurotoxin with well-known inhibitors of other zinc proteases led us to study the design of specific inhibitors as a possible drug therapy to prevent the progressive evolution of tetanus following infection. Starting from the synaptobrevin sequence at the level of the cleavage site by tetanus neurotoxin (Gln(76)-Phe(77)), a thiol analogue of glutamine demonstrated inhibitory activities in the millimolar range. A structure-activity relationship performed with this compound led us to determine the requirement for the correct positioning of the thiol group, the primary amino group, and a carboxamide or sulfonamide group on the side chain. This resulted in the design of a beta-amino-(4-sulfamoylphenyl)glycine-thiol, the first significantly efficient inhibitor of tetanus neurotoxin with a K-i value of 35 +/- 5 mu M.