Roles of Titin in the Structure and Elasticity of the Sarcomere
Figure 2
Electron micrographs of negatively stained titin, illustrating domain substructure and flexibility (a), and the effect of bundling on the apparent stiffness of the molecule (b). (a) Note that each of the flexibility “waves” seen in the titin contour contains about 4 domains. This number is comparable with the number of domains (3-4) expected for segments of about the persistence length of the protein. (b) This micrograph shows partially dissolved titin “end-filament”. The “wavy” contours of the molecules in the unbundled region contrast with their relatively straight shapes in the bundled part. Magnification: bar (a) 20 nm; (b) 50 nm.
