Biological complexity: calcium pump for muscles (Introduction)

by David Turell , Tuesday, February 08, 2022, 15:40 (805 days ago) @ David Turell

Irreducibly complex:

https://phys.org/news/2022-02-calcium-motions-captured-action.html

"The pumping action of the calcium pump protein—an intricate molecular machine with several moving parts that helps control muscle contraction—has been detailed with exquisite precision by RIKEN biophysicists. By providing a blueprint of structural changes that occur during operation of the protein, the findings could aid the development of new treatments for skeletal myopathies and heart disease.

"Muscle movement is fundamentally a calcium-driven process. When a muscle cell receives the signal to contract from its associated nerves, it releases a flood of calcium ions from a special intracellular container known as the sarcoplasmic reticulum. Those ions then set the muscle's molecular motors into action, spurring contractions until the calcium is removed.

"That's where the calcium pump comes in. After a frenzied wave of calcium-induced activity, the pump uses energy in the form of adenosine triphosphate (ATP) to return calcium ions to their intracellular storehouse.

***

"Using sophisticated computer models that account for structural changes and energetic profiles, the researchers identified a handful of transition states. They also demonstrated how the rapid exchange of calcium ions for protons at the pump's inner face is critical for releasing calcium into the sarcoplasmic reticulum."

Comment: see the illustration. Pure evidence of design.