Contents
1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4
2 A New View on Mechanism of Functional Expression
of an ATP-Driven Molecular Motor . . . . . . . . . . . . . . . . . . . . . . . . .
5
2.1 Coupling of a Molecular Motor and ATP Hydrolysis
Reaction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5
2.1.1 Thermodynamics of ATP Hydrolysis Reaction . . . . . . . .
5
2.1.2 ATP Hydrolysis Cycle Where a Molecular Motor
Acts as a Catalyst for Hydrolysis Reaction . . . . . . . . . . .
6
2.2 Involvement of a Protein or Protein Complex Catalyzing
ATP Hydrolysis Reaction in ATP Hydrolysis Cycle . . . . . . . . . .
7
2.3 Crucial Importance of Hydration Entropy in Functional
Expression of a Molecular Motor . . . . . . . . . . . . . . . . . . . . . . .
8
2.4 Mechanism of Force Generation by Water for Moving
or Rotating a Protein . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
2.5 Entropic Excluded-Volume Effect and Entropic Force
and Potential Generated by Water . . . . . . . . . . . . . . . . . . . . . . . 11
2.5.1 Entropy-Driven Formation of Ordered Structure . . . . . . . 11
2.5.2 Simple Examples of Entropic Force and Potential . . . . . . 14
2.6 Roles of Electrostatic Interaction in Aqueous Solution Under
Physiological Condition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
2.7 Translational, Configurational Entropy of Water Leading
Receptor-Ligand Binding and Protein Folding . . . . . . . . . . . . . . 19
2.8 Essential Roles of Water-Entropy Effect in Biological
Processes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
2.9 Recent Papers Pointing Out Crucial Importance of Hydration
Effect on Unidirectional Movement of Myosin Along F-Actin . . . 23
2.10 Problems in Prevailing View on Functional Expression of a
Molecular Motor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
ix
1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4
2 A New View on Mechanism of Functional Expression
of an ATP-Driven Molecular Motor . . . . . . . . . . . . . . . . . . . . . . . . .
5
2.1 Coupling of a Molecular Motor and ATP Hydrolysis
Reaction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5
2.1.1 Thermodynamics of ATP Hydrolysis Reaction . . . . . . . .
5
2.1.2 ATP Hydrolysis Cycle Where a Molecular Motor
Acts as a Catalyst for Hydrolysis Reaction . . . . . . . . . . .
6
2.2 Involvement of a Protein or Protein Complex Catalyzing
ATP Hydrolysis Reaction in ATP Hydrolysis Cycle . . . . . . . . . .
7
2.3 Crucial Importance of Hydration Entropy in Functional
Expression of a Molecular Motor . . . . . . . . . . . . . . . . . . . . . . .
8
2.4 Mechanism of Force Generation by Water for Moving
or Rotating a Protein . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
2.5 Entropic Excluded-Volume Effect and Entropic Force
and Potential Generated by Water . . . . . . . . . . . . . . . . . . . . . . . 11
2.5.1 Entropy-Driven Formation of Ordered Structure . . . . . . . 11
2.5.2 Simple Examples of Entropic Force and Potential . . . . . . 14
2.6 Roles of Electrostatic Interaction in Aqueous Solution Under
Physiological Condition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
2.7 Translational, Configurational Entropy of Water Leading
Receptor-Ligand Binding and Protein Folding . . . . . . . . . . . . . . 19
2.8 Essential Roles of Water-Entropy Effect in Biological
Processes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
2.9 Recent Papers Pointing Out Crucial Importance of Hydration
Effect on Unidirectional Movement of Myosin Along F-Actin . . . 23
2.10 Problems in Prevailing View on Functional Expression of a
Molecular Motor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
ix