Okay, I’ll keep this short.
The sodium potassium pump is more important than we realize. It is involved in a wide range of cellular and physiological functions. Here's a quick list of just a few things:
1. Insulin secretion from the pancreas
2. Neuron action potentials (70% of ATP in neurons is for my protein)
3. Heart contraction
4. Import of glucose and amino acids (via facilitated transport)
5. Absorption of water by the kidneys
|Bound Potassium Ions|
The sodium potassium pump is also structurally impressive. It is a relatively large protein which spans the cell membrane. The central alpha helices form a tunnel (purple) for sodium and potassium ions and can selectively bind Na+ or K+ depending upon its state (phosphorylated or dephosphorylated). The army green region is where the ATPase function is located. The yellow spheres represent phosporylation. The discovery of this protein resulted in a Nobel Prize in 1997. Thus, it goes without saying, this protein deserves to be in the protein hall of fame.
For a brief function summary, see the figures below.
|Overview of ion pumping cycle|
And let's wrap up with some quick pictures.
|Ouabain - an inhibitor is bound|