(Downloads - 0)
For more info about our services contact : help@bestpfe.com
Table of contents
A/. Introduction to molecular motors
1) Actin
1.1 Biochemical Properties of Actin
1.2 Mechanical properties of actin filaments
2) Myosin
2.1 Myosin II
2.2 Myosin 1
B/. Mechanical properties of molecular motors
1) Experiments on single molecules
1.1 The Three-Bead Geometry
1.2 Two-step force generation by myosins
1.3 Effects of an external load on myosin activity
1.4 Calcium regulation of myosin 1 activity
1.5 Non-productive attachments
2) In-vitro Motility Assay
2.1 General Principle
2.2 Processivity
C/. Working model for myosin
1) The power stroke model
2) A consequence of mechanosensitivity: non-linear stiffness of myosin
D/. Myosin in biological systems
1) Myosin II in muscles
1.1 Muscle contractions
1.2 Mechanical properties of muscle fibres : Force-Velocity relation
1.3 Transient response of a muscle fibre to sudden changes in length
1.4 Partial activation of muscles
1.5 Stretch activation of muscles
2) Myosin 1c and the mechanosensitivity of hair cells in the inner ear
2.1 Mechano-electrical transduction in the inner ear of vertebrates
2.2 Myosin 1c as an adaptation motor
2.3 Force-Displacement relation of a hair bundle
3) Spontaneous oscillations of acto-myosin systems
3.1 Spontaneous oscillations in muscle fibres
3.2 Spontaneous oscillations of hair cell bundles
3.3 Summary
E/. An intermediate scale
1) Evidence for collective motor effects
2) Theoretical descriptions of collective motor effects and oscillations
3) Spontaneous motor oscillations in a minimal actomyosin system
Part I Chapter I
A/. Instrumentation
1) The Optical Tweezers
1.1 Principle of the Optical Tweezers
1.2 Characteristics of our Optical Tweezers
2) Acousto-Optic Deflectors
2.1 Principle of Acousto-Optic Deflectors
2.2 Characteristics of our AODs
3) The Detection Method
3.1 Photodiodes
3.2 Calibration
4) Controlling the set-up
4.1 Moving the laser
4.2 Moving the stage
B/. Biochemical Tools
1) Myosins
1.1 Myosin II
1.2 Myosin 1b
2) Actin
2.1 Polymerisation
2.2 Actin bundles
3) Functionalization of the beads
4) Protein Attachment
4.1 Nitrocellulose Surfaces
4.2 Antibody-treated Surfaces
4.3 Silanized Surfaces
5) Additional molecular cocktails.
5.1 Anti-Bleaching Mixture
5.2 ATP regeneration
6) Experimental Procedure
6.1 Flow Cell Preparation
6.2 Molecular Motor Attachment
6.3 Incubation of actin and functionalized beads
6.4 Injection of the experimental solution and starting the experiment
6.5 Recording the collective effects of the motors
Part I Chapter II
A/. Characterization of the molecular motors
1) In-vitro motility assay
1.1 Nitrocellulose surfaces
1.2 Silane surfaces
2) Force generation
B/. Spontaneous oscillations under elastic loading
1) With single actin filaments
2) With polarized actin bundles
C/. Mechanical stimulus : Alternating steps
Part I Chapter III
A/. Motility Assay
B/. Force exerted by the motors
C/. Spontaneous oscillations and stimulation
Part II Introduction
A/. The Need for a New Molecular Force Sensor
B/. Auto-Assembled Magnetic Columns
C/. Magnetic columns as force sensors
Part II Chapter I
A/. Making the magnetic bead pattern
1) PDMS substrate fabrication
1.1 – Making the moulds
1.2 – PDMS casting
2) Depositing nucleator beads by capillary assembly
B/. Formation of the columns
1) The Magnetic Beads
2) The Electromagnet
2.1 Making the Electromagnet
2.2 Calibration of the Electromagnet
2.3 – Limits of the Electromagnet
C/. Characterization of the properties of the columns
1) The Experimental Set-Up
1.1 – The custom stage.
1.2 – The Cooling System
1.3 – The detection system
2) Observation of the columns from the side
3) Experimental Procedure
3.1 Procedure with the electromagnet
3.2 – Procedure with the permanent magnet
3.3 – Viewing the profile of the columns
Part II Chapter II
A/. Mechanical properties of magnetic columns
1) Stiffness
1.1 Variation of stiffness along the length of a column
1.2 Viewing the deformation profile of the columns:
2) Stiffness as a function of column length
3) Responsiveness and drag coefficients of the columns.
4) Influence of the external magnetic field on stiffness
B/. Theoretical behaviour of a magnetic column: interactions between magnetic dipoles .
1) Formation of the columns
2) Rotation of the beads in the magnetic field
3) Orientation of the individual dipoles in a deflected column
4) Stiffness of a column
5) Linearity of the force-displacement relation
6) Friction on a pivoting column
C/. Towards biological applications
Part II Chapter III
A/. Viability of the magnetic bead columns as force sensors
B/. A magnetic column as a biomimetic stereocilium
C/. Control of the height of the columns
D/. Future developments
Conclusion
A/. Part I: Molecular motor oscillations under elastic loading
B/. Part II: Auto-assembled magnetic bead columns as force sensors
