| 초록 |
We have investigated the correlation between primary structure and mechanical property related with its crystal structure of silkworm silk and Nephila spider silk using atomistic molecular dynamics simulation. The β-pleated conformations of poly(Ala)n and poly(Gly-Ala-Gly-Ala-Gly-Ser)n were generated by CHARMM program as the models of the crystalline phase for spider silk and silkworm silk, respectively. The initial β-sheet structures were energy-minimized, and then molecular dynamics simulations at constant pressure (1 atm) and temperature (300 K) were performed for 1ns to obtain equilibrated structures of crystalline state of the silk molecule. It is shown from the equilibration simulations that β-sheet structures are energetically stable. In order to measure the mechanical properties, tensile simulations under a constant rate of stress were executed at 1 atm and 300 K. Our tensile simulation indicates the crystalline structure of silkworm silk yields higher modulus, which quantitatively agrees well with the recent experimental reports. |
