Jens C. Skou didn’t just discover an enzyme. He found the mechanism that keeps nerve cells firing and muscles contracting. Without this tiny biological machine, your thoughts wouldn’t move from one neuron to the next. Your heart wouldn’t beat.
Skou was born in Lemvig, Denmark, on October 8, 1918. He died in Aarhus on May 28, 2018. For most of his life, he was a biophysicist teaching at Aarhus University. But his legacy rests on a single, monumental breakthrough: the discovery of sodium-potassium-activated adenosine triphosphatase (Na+-K+ ATPase).
This discovery earned him the 1997 Nobel Prize in Chemistry. He shared the honor with Paul D. Boyer and John E. Walker. But while the others mapped out how ATP works, Skou identified the actual pump that drives it.
From Nerves to Crab Membranes
Skou studied medicine at the University of Copenhagen. He earned his doctorate from Aarhus University in 1954. His research didn’t start in a vacuum. It built on the work of Sir Alan Hodgkin and Richard Keynes.
Those English scientists had been watching sodium and potassium move through nerve cells. They noticed something odd. When a neuron fired, sodium ions flooded in. To reset the cell for the next signal, those ions had to be pushed back out.
This wasn’t passive. It went against the natural flow. The concentration of sodium was higher outside the cell than inside. Moving it back in required energy. Specifically, it required adenosine triphosphate (ATP).
Skou took this puzzle further. In the late 1950s, he proposed a radical idea. An enzyme was responsible for moving molecules across the cell membrane. It wasn’t just a barrier. It was an active transporter.
He tested this theory using membranes from crab nerve cells. Crabs were chosen for their large, accessible nerves. The results were undeniable. He had isolated the enzyme now known as Na+-K+ ATPase.
How the Pump Actually Works
The enzyme sits in the plasma membrane of animal cells. It acts as a strict gatekeeper.
It activates when it detects specific conditions. External potassium triggers it. Internal sodium fuels it. Once engaged, it performs a relentless cycle:
- It pumps sodium out of the cell.
- It pulls potassium into the cell.
This exchange maintains a critical balance. Inside the cell, potassium stays high. Sodium stays low. Outside, the reverse is true. This gradient is not optional. It is essential for life.
The enzyme pumps sodium out of the cell and potassium into it, thereby maintaining a high intracellular concentration of potassium and a low concentration of sodium relative to the surrounding external environment.
Skou’s findings did more than explain nerve signals. They revealed a fundamental class of biological machines. Other enzymes worked the same way. They included the ion pumps that control muscle contraction.
Why This Matters to You
You might wonder why crab nerves matter to humans. They matter because the biology is conserved. The sodium-potassium pump in your brain works exactly like the one Skou studied in crabs
