Fluorescence properties of 2' (or 3')-O-(2,4,6-trinitrophenyl) adenosine 5'-triphosphate and its use in the study of binding to heavy meromyosin ATPase.

2' (or 3')-O-(2,4,6-Trinitrophenyl) adenosine 5'-triphosphate (N3ph-ATP), which contains a Meisenheimer complex moiety, is one of the class of compounds which do not fluoresce in water but fluoresce both in low polarity solvents and when bound to the protein molecule. Fluorescence intensity of N3ph-ATP in the range of 540 nm, when excited at 410 nm, decreased with increasing the solvent polarity accompanying the increment of the wavelength of maximum emission. When bound to heavy meromyosin ATPase, the fluorescence properties of N3ph-ADP were almost the same as those of N3ph-ATP in a low polarity solvent, suggesting that N3ph-ADP was bound to hydrophobic area on heavy meromyosin ATPase.