Jens Skou

The Na⁺/K⁺-ATPase, commonly called the sodium-potassium pump, is an enzyme in the cell membrane that uses energy from ATP to pump three sodium ions out of the cell while bringing two potassium ions in. Skou first identified this enzyme in 1957 while studying crab nerve membranes at Aarhus University in Denmark. The pump maintains the electrochemical gradient essential for nerve impulses, muscle contraction, and nutrient transport.

The Na⁺/K⁺-ATPase maintains the concentration differences of sodium and potassium across the cell membrane that all excitable tissues—neurons, cardiac muscle, skeletal muscle—depend on. The gradient it creates drives secondary transport of glucose and amino acids and allows action potentials to fire. The pump is estimated to consume roughly 20–30% of the body's ATP at rest.

Skou was awarded the 1997 Nobel Prize in Chemistry, receiving half the prize for his discovery of the Na⁺/K⁺-ATPase. The other half was shared by Paul Boyer and John Walker for their work on the mechanism of ATP synthase. Remarkably, forty years elapsed between Skou's initial 1957 discovery and his Nobel recognition.

Skou spent essentially his entire career at Aarhus University in Denmark, where he made his sodium-potassium pump discovery while studying how local anesthetics affect nerve membranes. He discovered the ATPase activity by chance while examining enzyme reactions in crab leg nerve tissue. Aarhus University remains a major center for membrane protein research.