Understanding how the giant protein titin stretches and relaxes

The molecular mechanisms governing the reversible mechanical folding of cardiac titin

During the course of a heartbeat, the muscle expands as the chambers fill with blood and then relaxes as the force of the contraction pushes oxygenated blood around the body. The versatile, elastic function of the heart is so important to its normal function that researchers are keen to understand what drives it. This is important because many types of heart disease can arise from a gradual stiffening of heart tissue and a loss of elasticity in the muscle. Dr Sergi Garcia-Manyes and Dr Mathias Gautel from King’s College London have been awarded a 3-year grant to investigate the properties of a giant protein called titin, which controls the elasticity of heart muscle. Titin acts like both a spring and a scaffold, enabling heart muscle to continually stretch and then relax as the heart contracts. The researchers will use state-of-the art equipment to observe each individual molecule of titin in minute detail. Their findings will allow better understanding of how the heart normally contracts, and how it can go wrong. The researchers’ findings may also help those who have inherited genetic errors that affect the way titin works.