Our research focuses on the molecular structure of the molecules and filaments involved in muscle contraction and its regulation. Our goal is to understand how structure underlies function in these systems. We use electron microscopy to study filament structure in the relaxed state and the changes in structure that are brought about by Ca2+ activation. We use a variety of EM techniques including sectioning, negative staining, shadowing, electron tomography and cryo-EM. Three-dimensional information is obtained by image processing techniques that take advantage of multiple views of structures observed in the micrographs; these techniques include helical, single particle and other approaches.
Striated muscles consist of numerous elongated cells running parallel to each other. Each cell is packed with parallel myofibrils consisting of repeating arrays of overlapping thin (actin-containing) and thick (myosin-containing) filaments. Contraction results from sliding of the actin filaments past the myosin filaments, which is brought about by cyclic pulling of myosin heads on actin.
|Section of rabbit skeletal muscle showing striated myofibrils running diagonally. Dark bands contain the myosin filaments and light bands the actin filaments.|