Reverse engineering of the giant muscle protein titin

Top Cited Papers
Publisher Website
Google Scholar
Abstract
Through the study of single molecules it has become possible to explain the function of many of the complex molecular assemblies found in cells1,2,3,4,5. The protein titin provides muscle with its passive elasticity. Each titin molecule extends over half a sarcomere, and its extensibility has been studied both in situ6,7,8,9,10 and at the level of single molecules11,12,13,14. These studies suggested that titin is not a simple entropic spring but has a complex structure-dependent elasticity. Here we use protein engineering and single-molecule atomic force microscopy15 to examine the mechanical components that form the elastic region of human cardiac titin16,17. We show that when these mechanical elements are combined, they explain the macroscopic behaviour of titin in intact muscle6. Our studies show the functional reconstitution of a protein from the sum of its parts.