1. Introduction[The elasticity of alpha-helix, pi-helix]

Vitruvian Man or Canon of Proportions is a 1485 work by Leonardo da Vinci. It is said that when Da Vinci painted this picture, he did not accept the ancient theory of human proportions as it is, but actually took a person and wrote down the measurement results while holding a ruler. As such, human beings have been conducting research on life from a long time ago using mathematics and physics with a lot of interest and curiosity about the nature of life, that is, the original shape and structure of living things. Such research has extended its scope to the microscopic world of molecular units that make up the human body. Among them, protein, which constitutes most of the human body, has attracted the attention of numerous biologists and has a wide range of applications for research. Therefore, we propose a protein as a physical model with elasticity and try to understand the physical properties of the protein by obtaining the bending-modulus using molecular dynamics simulation based on the designed model.