HUMAN PHYSIOLOGY
LOCOMOTION AND MOVEMENT
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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a-troponin
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b-tropomyosin
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c-meromyosin
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both b and c
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Detailed explanation-1: -However, the binding sites for actin are located in meromyosin.
Detailed explanation-2: -Each Actin Subunit Has Three Nebulin Binding Sites: Implications for Steric Blocking. Nebulin is a giant protein that spans most of the muscle thin filament 1, 2. Mutations in nebulin result in myopathies and dystrophies 3, 4.
Detailed explanation-3: -Meromyosin is a monomeric protein present in myosin filament. The globular head of the meromyosin contains the actin-binding site. Hence, this is the correct answer.
Detailed explanation-4: -The location of the myosin binding is an extended region encompassing the junction of domains 3/4 and domain 4a (residues 622-714, human; 566-657, chicken gizzard). Tropomyosin binds in a smaller region within domain 4a of caldesmon (residues 663-714, human; 606-657 chicken gizzard).
Detailed explanation-5: -The myosin head contains binding sites ATP binding site and actin binding site. Actin molecule has 2 other proteins tropomyosin and troponin are two other proteins found in small quantities in muscle. They help regulate muscle contraction.