Yamasaki S, Binz T, Hayashi T, Szabo E, Yamasaki N, Eklund M, Jahn R, Niemann H
Department of Microbiology, Federal Research Center for Virus Diseases of Animals, Tübingen, FRG.
Biochem Biophys Res Commun. 1994 Apr 29;200(2):829-35. doi: 10.1006/bbrc.1994.1526.
Tetanus toxin and the botulinum neurotoxins types A to F inhibit neurotransmitter release from presynaptic nerve endings by selectively proteolysing the synaptic proteins synaptobrevin, syntaxin, or SNAP-25. Here, we show that botulinum toxin type G cleaves rat synaptobrevin 2 between Ala81 and Ala82, a peptide bond that differs from those attacked by tetanus toxin and the botulinal toxins types B, D, and F. Synaptobrevin isoforms carrying a Gly in the P1 position are poor substrates. Analyses of N-terminal deletion mutants of rat synaptobrevin 2 showed that a substrate starting at Leu54 is cleaved efficiently, whereas substrates beginning at Leu60 or Phe77 are cleaved partially or not at all, respectively.
破伤风毒素以及A至F型肉毒杆菌神经毒素通过选择性地蛋白水解突触蛋白突触小泡蛋白、 syntaxin或SNAP-25，抑制突触前神经末梢释放神经递质。在此，我们表明G型肉毒杆菌毒素在Ala81和Ala82之间切割大鼠突触小泡蛋白2，这是一个不同于破伤风毒素以及B、D和F型肉毒杆菌毒素所作用的肽键。在P1位置携带甘氨酸的突触小泡蛋白同工型是较差的底物。对大鼠突触小泡蛋白2的N端缺失突变体的分析表明，起始于Leu54的底物能被有效切割，而起始于Leu60或Phe77的底物分别被部分切割或完全不被切割。
