| Citation | Distinguished (1) for his work on the development and application of photolabile compounds capable of releasing physiological substrates within milliseconds of being illuminated, and (2) for his work on the active transport of ions across cell membranes. "Caged ATP" (a nitrobenzyl ester of ATP which releases ATP when photocleaved), and corresponding compounds of ADP and orthophosphate, were invented by him, and were first used by him and colleagues in elegant investigations into the mechanism of the Na,K-ATPase. The extension of this approach to other substances by others has led to important work in a variety of fields. Recently Kaplan has developed a photolabile divalent cation chelator whose affinity falls by five orders of magnitude on illumination, so that it can be used for Ca2+-jump and Mg2+-jump experiments. |