A second function of small GTPases in vesicle formation is in the pinching off of a completed vesicle from the parent membrane

TLS Online TPP Program

#Id: 8153

#XL - Q Biochemistry

A second function of small GTPases in vesicle formation is in the pinching off of a completed vesicle from the parent membrane

TLS Online TPP Program

#Id: 8412

#XL - Q Biochemistry

Binding of Ca2+ ions to TN-C

triggers movement of TM to a new position on the filament, thereby exposing the myosin-binding sites on actin.

TLS Online TPP Program

#Id: 8411

#XL - Q Biochemistry

In the absence of Ca2+, muscle is relaxed

TM blocks myosin’s interaction with F-actin

TLS Online TPP Program

#Id: 8410

#XL - Q Biochemistry

TN-C is the calcium-binding subunit, controls the

position of TM on the surface of an actin filament through the TN-I and TN-T subunits

TLS Online TPP Program

#Id: 8409

#XL - Q Biochemistry

Troponin, a complex of three polypeptides, 

TN-T (tropomyosin-binding)

TN-I  (inhibitory)

TN-C (Ca2+-binding)

TLS Online TPP Program

#Id: 8408

#XL - Q Biochemistry

Tropomyosin (TM) is a ropelike molecule, about 40 nm in length, binds to 7 actin subunits in an actin filament.

TLS Online TPP Program

#Id: 8406

#XL - Q Biochemistry

Vertebrate skeletal muscle contraction, also depends on set of specialized accessory proteins that are closely associated with the actin thin filaments:

a) Tropomyosin

b) Troponin