We study the conformational change of insulin fibril growth from three aspects: the impact of (i) incubation time; (ⅱ) nano-particles; (iii) and ion added. We used circular dichroism (CD) spectroscopy and fourier transform infrared spectroscopy (FT-IR) to obtain the structural transition of the insulin, and gain the morphology information of fibril by atomic force microscopy (AFM) and transmission electron microscopy (TEM). We show that the insulin transform from £\-helix to £]-sheet structure as increased incubated time. The addition of Au nanoparticles (NPs) caused the formation of coordination bond with insulin fiber and produced shorter and thicker insulin fibril . The Fe3O4 NPs, on the other hand, offered only van der Waals interaction toward insulin fibril. Hence they could be used to separate insulin fibril from solution. Finally, addition of salts can induce the conformation changes of insulin fibril ten times faster than that without salts. And the insulin fibril fragment was two or three times shorter than that produced without salts. At high salt concentration, insulin formed amorphous aggregates. This phenomenon was attribute to anions from salt: covering the surface charge of insulin fibril, they weaken the original electrostatic repulsion among insulin fibrils and result in their aggregation.
Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0802111-124018 |
Date | 02 August 2011 |
Creators | Chang, Chiung-Wen |
Contributors | CHAO-MING CHIANG, Michael Y. Chiang, Shuchen Hsieh |
Publisher | NSYSU |
Source Sets | NSYSU Electronic Thesis and Dissertation Archive |
Language | Cholon |
Detected Language | English |
Type | text |
Format | application/pdf |
Source | http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0802111-124018 |
Rights | user_define, Copyright information available at source archive |
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