Function
Dystrophin is a protein located between the sarcolemma and the outermost layer of myofilaments in the muscle fiber (myofiber). It is a cohesive protein, linking actin filaments to another support protein that resides on the inside surface of each muscle fiber’s plasma membrane (sarcolemma). This support protein on the inside surface of the sarcolemma in turn links to two other consecutive proteins for a total of three linking proteins. The final linking protein is attached to the fibrous endomysium of the entire muscle fiber. Dystrophin supports muscle fiber strength, and the absence of dystrophin reduces muscle stiffness, increases sarcolemmal deformability, and compromises the mechanical stability of costameres and their connections to nearby myofibrils; as shown in recent studies where biomechanical properties of the sarcolemma and its links through costameres to the contractile apparatus were measured, and helps to prevent muscle fiber injury. Movement of thin filaments (actin) creates a pulling force on the extracellular connective tissue that eventually becomes the tendon of the muscle.
Diseases
Defects in the Dystrophin gene are the cause of Duchenne and Becker Muscular Dystrophies. DMD is characterized by muscle weakness in the hips, pelvic region, and shoulders that leads to skeletal muscle swelling and enlargement. The prime cause of lethality of DMD is when heart and respiratory muscles lose function. Becker Muscular Dystrophy is a mild version of DMD, spreading slower.
This is a sample scene created with SAT to by Group, and another to make of the protein. You can make your own scenes on SAT starting from scratch or loading and editing one of these sample scenes.
