Lattice Simulation And Thermal Adaptability Of Proteins

Proteins are a kind of macromolecules and are the best embodiment of life. The nature of life is adaptable. A typical example is the thermal adaptability of proteins, i.e., proteins with similar functions can work at different temperatures. So, it is interesting to understand the mechanism of this thermal adaptability of proteins. This in turn will be helpful to understand the stability and the folding of proteins. In this paper, we shall use lattice model to analyze the thermal adaptability of proteins. This includes three aspects:The first aspect is the selection of move set of lattice simulation: Lattice simulation is one important method to open out the universal principle of protein folding. The move sets is a basic element in lattice simulation. There are two move sets, dynamic move set and rigid rotation move, to run simulation. In order to select one for the following simulation, the thermodynamic and kinetic properties of a lattice protein model by using the two move sets were calculated and compared. The results indicate that the dynamic move set has advantage to simulate protein folding.The next aspect is to pursue the length scale effects of small protein folding by lattice modeling. Heat capacity and excess chemical potential computed in lattice simulation have been used to analysis folding transition temperature of the model proteins of different length. The results show that there is an evident phase transition when the lengths of the model proteins are similar to those of foldons. And it is found that the folding transition temperature is proportional to the sequence length. At the same time, we found that the entropy change of protein folding still show significant length effect, i.e., it decrease with the chain length in the range we used. The protein folding likes the lower entropy change.The third aspect is on composition difference of proteins with different thermal...