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化学学报
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化学学报 ›› 2007, Vol. 65 ›› Issue (2): 111-115. 上一篇    下一篇

研究论文

Thioflavine T荧光探针法研究丝素结晶区典型肽段自聚集的β-片层结构

王建南*,1,2, 陆长德3, 白伦*,1   

  1. (1苏州大学材料工程学院 苏州 215021)
    (2苏州大学生命科学学院 苏州 215123)
    (3中国科学院上海生命科学学院生物化学与细胞生物学研究所 上海 200031)
  • 投稿日期:2006-03-11 修回日期:2006-07-09 发布日期:2007-01-28
  • 通讯作者: 王建南

Study on β-Sheet Structure Formed by Self-assembly of Fibroin Crystalline Typical Peptides Using Thioflavine T Fluorescence Probe

WANG Jian-Nan*,1,2; LU Chang-De3; BAI Lun*,1   

  1. (1 College of Material Engineering, Suzhou University, Suzhou 215021)
    (2 College of Life Science, Suzhou University, Suzhou 215123)
    (3 Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sci-ences, Shanghai 200031)
  • Received:2006-03-11 Revised:2006-07-09 Published:2007-01-28
  • Contact: WANG Jian-Nan

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为了深入研究蚕丝丝素基材料的自组织/自组装机制, 设计了四种结构单纯的蚕丝结晶区肽段: GXGAGAGXGA (X: A, S, Y, V), 保温培养1～15 d, 使之自聚集. 采用ThT 荧光光谱法和尿素抑制处理研究了它们形成β-片层结构的能力. 结果显示: 肽段GA在溶液中保温聚集1 d就明显有β-片层结构生成, 按A, S, Y, V的顺序分别保温12, 8, 14, 13 d, 聚集体中β-片层结构比例趋于稳定, 其中形成β-片层结构比例最高的是GS, 其次是GA, GY和GV较少. 肽段溶液中尿素的存在对β-片层的形成影响十分显著, 尿素浓度为1 mol/L时足以使GS, GY和GV自聚集时无法形成β-片层结构; 大于2 mol/L时开始影响GA的β-片层形成, 随着尿素浓度的增加β-片层结构的比例随之下降.

关键词: 丝素结晶区肽段, β-片层, ThT荧光探针, 尿素

To study the self-organization/self-assembly mechanism of silkworm fibroin based material, four kinds of structurally simple fibroin crystalline peptides, GXGAGAGXGA (X: A, S, Y, V), were designed and then incubated for 1～15 d to assemble by themselves. Their abilities to form β-sheet structure were studied by ThT fluorescence spectral analysis and urea denaturation methods. Results showed that: GA could form β-sheet after incubation for 1 d; after the peptide was incubated for 12, 8, 14 and 13 d respectively (in the order of A, S, Y and V), the ratio of β-sheet structure in the aggregation tended to be stable. Among the four peptides GS had the highest β-sheet content, GA took the second place, GY and GV had the lowest content. The presence of urea in peptide solution had an obvious effect on the formation of β- sheet. Urea (1 mol/L) could stop the forming of β-sheet structure from GS, GY and GV in the process of their self-assembly. When the concentration of urea was over 2 mol/L, the formation of β-sheet structure from GA could be affected, and the content of β-sheet decreased proportionally with increase of urea concentration.

Key words: fibroin crystalline peptide, β-sheet, ThT fluorescence probe, urea