Micelle formation between 5-hydroxytryptamine and adenosine triphosphate in platelet storage organelles.

As judged by analytical ultracentrifugation, 5-hydroxytryptamine and adenosine-5'-triphosphate form micelles in artificial mixtures and also in storage organelles containing 5-hydroxytryptamine of blood platelets of rabbits. Their average apparent molecular weights depend on the concentration and on the molar ratio of the two constituents. The 5-hydroxytryptamine and adenosine triphosphate of these 5-hydroxytryptamine organelles may be stored in vivo together as micelles with apparent molecular weights of several hundred thousands or more.