Methods for the intracellular conversion of single-chain proteins into their two-chain form

1. Intracellular method of converting the single-chain clostridial toxin containing double-stranded loop portion, in its double-stranded form, comprising the following steps: a) growing cells comprising an expression construct double at 37 ° C for about 3.5 hours, the double expression construct comprises; i ) open reading frame encoding a single-chain clostridial toxin comprises a single-chain clostridial toxin enzymatic domain, translocation domain and a binding domain of double-stranded loop portion, with holding a TEV protease cleavage site; and ii) an open reading frame encoding a TEV protease; b) growing the cells at 22 ° C for about 16 to about 18 hours, while the growth in step (b) induces the expression of single-chain clostridial toxin protease from TEV dual expression construct; iproizvodimaya TEV protease cleaves single-chain clostridial toxin exogenous protease cleavage site is located within the double-stranded loop portion, thereby converting the single-chain clostridial toxin in its double stranded formu.2. Intracellular method according to claim 1, characterized in that the single-chain clostridial toxin comprises the following linear amino-carboxyl single polypeptide order of priority: 1) an enzymatic domain clostridial toxin double-stranded loop portion of which comprises a TEV protease cleavage site, translocation domain, and a clostridial toxin binding domain clostridial toxin; 2) clostridial toxin enzymatic domain, double-stranded loop portion of which comprises the cleavage site of TEV n