[Effect of staphylococcus active substances on ATPase activity of smooth muscle actomyosin and myosin].

The effect of staphylococcus active substances--protein A (PA) and peptidoglican (PG) at concentrations 10(-6)-10(-2) mg/ml on the ATPase activity of pig stomach natural actomyosin and myosin was studied. It was shown that PA and PG at direct contact with smooth muscle contractile proteins caused the activation and inhibition of ATPase activity, respectively. On the basis of this investigation it was assumed that staphylococcal active substances were able to modify of the ATPase activity smooth muscle contractile proteins perhaps via direct action on the myosin molecule, which could be accompanied by conformational changes of the active center of myosin ATPase.

[The immunosuppressive activity of Streptococcus aureus peptidoglycan].

The immunosuppressive activity of peptidoglycan, obtained from S. aureus was studied in mouse experiments on the model of delayed hypersensitivity (DH) to guinea pig antigens. The study revealed that PG suppressed DH, this action being linked with its insoluble fraction.