Myosin

It's amazing.

I read an article about myosin.

Myosin has, de- depending, depending on how you count, 11 to 14 highly conserved glycine residues.

This is because it, it shows up as glycine in multiple versions of my- myosin from multiple species.

Myosin is a muscle contractor protein.

It's the most common protein in muscle.

Okay.

Now for the relaxation portion.

In normal physiological states, the calcium is continuously pumped back into the sarcoplasmic reticulum, and when the concentration falls sufficiently, tropomyosin rolls back and covers the myosin binding sites on the actin-thin filament.

Myosin heads disengage and the muscle relaxes.

If there's a problem with the ryanodine receptor though, such as in malignant hypothermia, calcium levels stay high and the muscle continues to contract.

The excitation-contraction coupling process requires the conversion of ATP to ADP.

In the unbound state, myosin heads split ATP to ADP to become energized and ready to bind.

After the power stroke, the ADP is released Myosin and actin uncouple, and unbound myosin is ready to bind ATP once again.

As long as calcium and ATP remain sufficiently high, this process can continue.