[Contractile proteins of nerve endings as a possible target of the presynaptic action of tetanus toxin].

Tetanus toxin (TT) in a dose of 0.25--250 DLM/ml inhibits the superprecipitation reaction of actomyosin-like protein (AMLP) of the bovine brain in response to Mg-ATP addition. Gangliosides of the bovine brain exert a similar action. Combined action of gangliosides (0.25 g/ml) and TT (0.25 DLM/ml) results in additivity of their effects. TT in a dose of 1600 DLM/ml blocks the formation of a complex of isolated synaptic vesicles (SV) of the rat brain. This effect was assessed from light scattering in response to MgCl2 and ATP addition. Under these conditions TT also inhibits release of the endogenous mediator noradrenaline from SV of bovine hypothalamus, with antitetanus serum reversing the effect of toxin. It is postulated that ALP associated with the synaptic membrane may be a potential TT target in the nerve endings.