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Lecture
Material and Notes
Week 2, Lecture 4: Molecular
Motors using muscle as an example
Michael Regnier
Lecture theme and outline:
Contraction occurs via the process of energy (derived from ATP hydrolysis)
transduction from chemical to mechanical states. This process involves
protein-protein interactions that produce strain, tension, and/or relative
displacement of proteins in relation to each other. Myosin is a high copy
protein that performs these functions in muscle, and it has similar characteristics
to a variety of other motor proteins.
- Overview of contraction
- sarcomere is a repeating unit of contraction
- Protein composition of the
contractile lattice structure - the players.
- Which of these proteins
are essential for tension/strain development & motion
- Myosin is a protein enzyme
and motor - general structural features
- Acto-myosin interactions
- molecular interface characteristics
- Force & motion - sliding
filament theory
- Progression of techniques
developed to study contraction at cellular/molecular levels - what can
be determined & what are the limitations (this will be revisited by
Jerry Pollack).
- Myosin stuctural similarities
with other motor proteins - example is kinesin - processive vs. non-processive
motors.
- Duty cycles - determined
by motor properties - how do different myosin isoforms affect duty cycle?
- Designing motors.
Suggested reading:
- Textbook Sections: Molecular
Biology of the Cell. - Ch. 16, pp. 847-858
and Ch. 5, pp. 195-212.
- Reggiani, C., Bottinelli,
R. & Steinen, G.J.M. (2000). Sarcomeric
myosin isoforms: fine tuning of a molecular motor. NIPS 15:26-32.
- Vale, R.D. & Milligan, R.A.
(2000). The
way things move: looking under the hood of molecular motor proteins.
Science 288:88-95.
- Hancock, W. O., Huntsman,
L.L. & Gordon, A.M. (1997). Models
of calcium activation account for differences between skeletal and cardiac
force redevelopment kinetics. J. Mus. Res. Cell Motil. 18:671-681.
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