Department of Chemistry and Biochemistry, and Botulinum Research Center, University of Massachusetts Dartmouth, North Dartmouth, MA 02747, USA.
Biochem Biophys Res Commun. 2010 Jun 11;396(4):854-60. doi: 10.1016/j.bbrc.2010.05.006. Epub 2010 May 7.
The category A agent, botulinum neurotoxin (BoNT), is the most toxic molecule known to mankind. The endopeptidase activity of light chain domain of BoNT is the cause for the inhibition of the neurotransmitter release and the flaccid paralysis that leads to lethality in botulism. Currently, antidotes are not available to reverse the flaccid paralysis caused by BoNT. In the present study, we have identified three RNA aptamers through SELEX-process, which bind strongly to the light chain of type A BoNT (BoNT/A) and inhibit the endopeptidase activity, with IC(50) in low nM range. Inhibition kinetic studies reveal low nM K(I) and non-competitive nature of their inhibition. Aptamers are unique group of molecules as therapeutics, and this is first report of their development as an antidote against botulism. These data on K(I) and IC(50) strongly suggest that the aptamers have strong potential as antidotes that can reverse the symptom caused by BoNT/A.
A 型毒素(BoNT)是目前已知的人类最致命的毒素,其轻链结构域的内切酶活性是引起神经递质释放抑制和导致肉毒中毒的弛缓性瘫痪的原因。目前,还没有解毒剂可以逆转 BoNT 引起的弛缓性瘫痪。在本研究中,我们通过 SELEX 过程筛选出了三个 RNA 适体,它们与 A 型 BoNT(BoNT/A)的轻链强烈结合,并抑制内切酶活性,IC50 处于低 nM 范围。抑制动力学研究表明,它们的抑制具有低 nM 的 K(i)和非竞争性特征。适体作为治疗药物是一类独特的分子,这是它们作为肉毒中毒解毒剂发展的首次报道。这些关于 K(i)和 IC50 的数据强烈表明,这些适体具有作为解毒剂的巨大潜力,可以逆转 BoNT/A 引起的症状。