Abstracto

Hydrotropic function of intralentiuclar ATP.

Jack V Greiner, Thomas Glonek

Nearly 4 decades ago, ATP was measured for the first time in an intact ex vivo living organ, the crystalline lens, using 31P nuclear magnetic resonance [1]. At that time and during decades to follow, the millimolar concentrations of this metabolite, known to function principally as the energy currency of intracellular metabolism, was unexplainably and excessively high. In contrast, only micromolar concentrations are required and necessary for intracellular energy metabolism and any of the other known functions of ATP, combined. This elevated millimolar concentration of intralenticular ATP was reported in 14 different mammalian species [1-3], including avian and reptilian species [3]. Not until the report of Patel et al., however, was there evidence for the requirement of millimolar concentrations for ATP, where it functions as a hydrotrope, preventing protein aggregation in both cellular and tissue homogenate preparations.