[Bacteriophage enzymes for the prevention and treatment of bacterial infections: stability and stabilization of the Streptococcus pyogenes cell lysing enzyme].

The effect of various compounds on the activity and stability of a phage-associated enzyme lysing cells of streptococci of groups A and C (PlyC) was investigated. Substantial inhibition of the enzyme activity was revealed at an increased ionic strength (in the presence of NaCl) and upon the addition of carbohydrates (mono-, di-, and polysaccharides), i.e., agents stabilizing many enzymes. It was established that the enzyme activity was substantially reduced in the presence of positively charged polyelectrolytes and surfactants, whereas incubation with micelle-forming substances and negatively charged polyelectrolytes led to PlyC activation and stabilization. It was shown that, in the mycelial polyelectrolyte composition M16, the enzyme retained its activity for 2 months; while in a buffer solution under the same conditions (pH 6.3, room temperature), it practically completely lost its activity in 2 days. Characteristics of the enzyme thermal inactivation were found, in particular, its semiinactivation time at various temperatures; these allowed us to estimate its behavior at any temperature and to recommend conditions for its storage and use.