Which enzyme did Jens Christian Skou discover, earning the 1997 Nobel Prize in Chemistry?

Jens Christian Skou discovered sodium–potassium ATPase, earning the 1997 Nobel Prize in Chemistry.

Sodium–potassium ATPase, also called the sodium-potassium pump, is a membrane enzyme that uses energy from ATP to move ions across the cell membrane. In its classic cycle, it exports three sodium ions and imports two potassium ions for each ATP molecule hydrolyzed.

This unequal exchange helps maintain the ion gradients needed for nerve impulses, muscle contraction, and many transport processes. Skou identified the enzyme in crab nerve membranes in 1957 and showed that it was activated by sodium and potassium ions and inhibited by ouabain.

Skou shared the 1997 prize with Paul D. Boyer and John E. Walker, who were honored for explaining the enzymatic mechanism behind ATP synthesis. Their work concerned related energy-conversion systems, but Skou’s specific contribution was the sodium-potassium pump.