Regulatory protein- (Mnemonic: Rett syndrome)
• Troponin
• Tropomyosin
Contractile protein- (Mnemonic: CAM)
• Actin
• Myocin
Structural protein-
• Titin: Present between the Z-line and M-line, covering half of the sarcomere’s length.
• Nebulin
• Dystrophin
• Desmin
Titin-
• Titin is one of the largest proteins in the human body
• Location: It spans half of the sarcomere, from the Z-line to the M-line.
• Function: It helps to stabilize the thick filaments (myosin) in place, ensuring the proper alignment of the sarcomere.
• Elasticity: Due to its spring-like nature, titin functions as a molecular spring, providing passive tension and resistance to stretch. This helps in restoring the sarcomere to its resting length after contraction.
Nebulin-
• It is aligned with actin filaments within the sarcomere.
• Location: It spans the entire length of the thin filament in the sarcomere, starting from the Z-line and extending towards the A-band.
Figure- Skeletal muscle
Figure- Titin: Present between the Z-line and M-line, covering half of the sarcomere’s length.
Figure- Titin & Nebulin