How Muscles Move

The scientists say they have found the design of a protein molecule that acts as a motor inside each muscle cell, burning chemical enerygy to produce force. The protein is called myosin.

Myosin creates force when it acts together with another protein, actin. The energy nedded for this is produced when myosin burns the chemical fuel adenosine triphosphate, or ATP. ATP is produced from the food we eat.

The chemical enrgy produced by the ATP then moves the myosin along the actin line. The myosin then attaches to another nearby line of actin. This pulling action causes the sarcomere, and the muscle, to become shorter. The motion of the actin and myosin proteins in a muscle creates force that produces motion and strenght. Studies show that problems with actin and myosin can kill animals.

Scientists think this is also true for people. They know that myosin problems cause some rare diseases. One is a generic heart condition called familial hypertrophic cardiomyophaty. It has killed many young athletes. The new research already has been able to show the real problem in this condition: the myosin cannot link strongly enough to the actin.