Effects of substrate and substrate analogues on the trinitrophenylation of myosin

The effects of ATP, ATP analogues, Mg²⁺ and actin on the trinitrophenylation of myosin and on the enzymic properties of trinitrophenylated samples were studied.

1. 1. Trinitrophenylation of myosin was inhibited by the presence of ATP and its analogues during the treatment in the order ADP > ATP > pyrophosphate > AMP.

2. 2. The alteration of the enzymic properties due to trinitrophenylation of myosin was prevented by the presence of ATP or ADP and somewhat less by that of pyrophosphate and AMP during trinitrophenylation, but only if Mg²⁺ was also present.

3. 3. Neither the degree of trinitrophenylation nor the enzymic properties of the trinitrophenylated myosin were influenced by the presence of actin during the treatment of myosin.

Abbreviations: TBS; 2; 4; 6-trinitrobenzene sulphonate