Investigations of effects on the secondary structure transition of spider silk

• Main Authors: Wen-Hui Lin, 林文惠
• Other Authors: 楊正昌
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/yyuz83

碩士 === 國立臺北科技大學 === 化學工程所 === 93 === In this research, the spider silk from the major ampullate gland of native Nephila pilipes was collected via the forced-silking apparatus at the reeling speed of 3 m/min. The obtained silk was dissolved in hexafluoro-isopropanol (HFIP). The influence of pH and temperature over the secondary structure of the silk protein in solution state was examined via Circular Dichroism (CD). The effect of silk concentration and electrical field strength on the structure conformation of silk protein during film casting process was investigated via FT-IR. During the drying process, the increase of silk concentration and the presence of electric field tend to form β-sheet and β-turn. Finally, the dried film of silk protein was treated with different temperatures and cation solutions to study the post-treatment effects. The results suggest that random coil is the dominant structure when the silk solution is adjusted to acid state, while the α-helix predominates when the solution is neutral and basic. When the silk protein solution is heated above 65℃, β-sheetl structure is dominate, and the same trend is observed for the cast film of silk protein. Nevertheless the heat induced structural transition is reversible. After drying, the potassium solution exhibits a great effect on the assisting the formation of β-sheet structure, while calcium and aluminum solution has no influence on the transition of spider silk protein. The understanding of structural manipulation of silk protein may boost the future development of advanced spinning technology.