Abstract
This paper deals with the molecular mechanism of muscle contraction. The changes of thermodynamic parameters of motor protein myosin during ATP hydrolysis reaction have been examined based on hydration study. The changes of protein hydration were measured by using microwave dielectric method. The hydrophobic hydration was also examined with solutions of hydrophobic amino acids and found to be proportional to the accessible surface area of hydrophobic moieties. It is consistent with the reported values of heat capacity change and entropy change of transfer from hydrocarbon to water. By this study the. ATP hydrolysis in myosin motor domain SI was successfully explained by conjugation between the interaction of hydrophobic moieties at the protein surface and the enthalpy increasing reaction such as hydrogen bond breaking inside protein. This mechanismof △H-△S conpensation can be applied to develop a linear motor system by a hydrophobicity gradient force. The enginerring model is also discussed.
