Question

What are they Structure of various proteins?​

Answer 1

Structure of various proteins -

1. Contractile Proteins-

These are of two types

a. Actin Protein-

=> Actin protein (thin) filament is made of two 'F' (filamentous) actins helically wound to each other.

=> 'F' actin is a polymer of monomeric 'G'(Globular) actins.

b. Myocin Protein-

=> Each myosin (thick) filament is also polymerised protein. Many monomeric proteins called meromyocins constitute one thick filament.

=> Each meromyocin has two important parts of globular head with short arm and a tail.

=> The head and short arm project outwards at regular distance and angle from each other from the surface of a polymerized myosin filament and is known as cross arm.

=> The globular head is an active ATPase and has binding sites for ATP and active sites for actin.

2. Regulatory Proteins-

These are also of two types

a. Tropomyosin-

=> It is one type of contractile protein in the relaxed state of the muscle situated in such a way that the active sites remain covered by the tropomyosin and attached at the terminal of actin.

b. Troponin-

=> It is one type of protein which attached with one of ends of the tropomyosin molecules.