pH值对丝素蛋白构象转变的影响

高等学校化学学报 ›› 2004, Vol. 25 ›› Issue (5): 961.

pH值对丝素蛋白构象转变的影响

谢栒¹, 周平¹, 邓风², 武培怡¹, 宗小红¹, 姚文华³

1. 复旦大学高分子科学系, 聚合物分子工程教育部重点实验室, 上海 200433;
2. 中国科学院武汉物理与数学研究所, 波谱与原子分子物理国家重点实验室, 武汉 430071;
3. 复旦大学分析测试中心, 上海 200433

收稿日期:2003-04-03 出版日期:2004-05-24 发布日期:2004-05-24
通讯作者: 周　平(1961年出生),女,博士,副教授,主要从事生物大分子体系的结构与应用、核磁共振波谱学、拉曼及红外光谱学等研究.E-mail:pingzhou@fudan.edu.cn E-mail:pingzhou@fudan.edu.cn
基金资助:
国家自然科学基金(批准号:20274009,29974004)资助

Influence of pH Value on the Conformation Transition of Silk Fibroin

XIE Xun¹, ZHOU Ping¹, DENG Feng², WU Pei-Yi¹, ZONG Xiao-Hong¹, YAO Wen-Hua³

1. Key Laboratory of Molecular Engineering of Polymers of Ministry of Education, Department of Macromolecular Science, Fudan University, Shanghai 200433, China;
2. State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics & Mathematics, Chinese Academy of Sciences, Wuhan 430071, China;
3. The Analytical Measurement Center, Fudan University, Shanghai 200433, China

Received:2003-04-03 Online:2004-05-24 Published:2004-05-24

摘要/Abstract

摘要： 模仿家蚕吐丝过程中伴随丝素蛋白自然脱水的纤维化过程,研究了再生丝素蛋白在各种pH值的磷酸盐缓冲溶液体系中自然干燥脱水成膜后的构象转变.利用激光拉曼散射光谱及其二维相关光谱,定性分析了丝素蛋白酰胺区(1600～1700cm^-1)散射峰的相关组成及结构.在此基础上,利用¹³CCP-MAS固体核磁共振谱对丝素蛋白丙氨酸C_β峰(δ14.5～22)进行了解析拟合.从而确定了体系中与Silk及Silk构象相关的组成含量与pH值的关系.结果表明,pH=5.2的酸性溶液有利于蚕丝丝素蛋白从Silk向Silk构象转变,而中性与碱性溶液(pH=6.9和8.0)则对丝素蛋白的构象转变影响甚小.

关键词: 丝素蛋白, 构象转变, pH值影响, 核磁共振, 拉曼光谱

Abstract: Both ¹³C CP-MAS solid state NMR and laser Raman scattering spectroscopy were used to investigate the influence of pH values on the conformation transition of silk fibroin of Bombyx mori silkworm. The regenerated silk fibroins in the phosphate buffer solution were used to imitate the silk fibroins of the gland. A series of membranes formed in buffer solutions with different pH values were obtained by the evaporation of water at room temperature(for mimicking the gradual loss of water in spinning process). The composes and conformation in the fibroin membranes were determined qualitatively by Raman and Generalized Two-Dimensional Correlation Raman Spectroscopy for amide Ⅰ region( 1 600—1 700 cm^-1) of the silk fibroins. There are four types of conformations at least existing in the fibroin membranes, including conformations of typical silk Ⅰ(α-form and/or random coil), typical silk Ⅱ(β-sheet), silk Ⅰ transition and silk Ⅱ transition, etc.. Based on the qualitative results from 2D Raman spectrum, the relationship between pH value and conformation contents in the studied systems was determined quantitatively by simulation of C_β peak (δ14.5—22) in ¹³C CP-MAS solid state NMR spectrum. The results show that acidic solution(pH=5.2) is more favorable than neutral(pH=6.9) and basic(pH=8.0) ones for the conformation transition from Silk Ⅰ to Silk Ⅱ because the silk fibroin molecular backbones are easier to extend and then to form β-sheets in acidic solution.

Key words: Silk fibroin, Conformation transition, Influence of pH value, NMR, Raman spectroscopy

中图分类号:

O636
O641

TrendMD:

谢栒, 周平, 邓风, 武培怡, 宗小红, 姚文华. pH值对丝素蛋白构象转变的影响. 高等学校化学学报, 2004, 25(5): 961.

XIE Xun, ZHOU Ping, DENG Feng, WU Pei-Yi, ZONG Xiao-Hong, YAO Wen-Hua . Influence of pH Value on the Conformation Transition of Silk Fibroin. Chem. J. Chinese Universities, 2004, 25(5): 961.

参考文献

[1] Gosline J.M.,DeMont M.E.,Denny M.W..Endeavour[J],1986,10(1):37—43 [2] Shao Z.Z.,Fritz V..Nat ure[J],2002,418:741—742 [3] Li G.Y.,Zh ou P.,Sh ao Z.Z.et al..Eur.J.Biochem.[J],2001,268:6 600—6 606 [4] Magoshi J.,Magosh i Y.,Nakamura S..Silk Polymers A CS[C],1994,544:292—310 [5] LI Gui-Yang(李贵阳),ZHOU Ping(周　平),SUN Yao-Jun(孙尧俊)et al..Chem.J.Chinese Universities(高等学校化学学报) [J],2001,22(5):860—862 [6] Chen X.,Knight D.P.,Vollrat h F..Biochemist ry[J],2002,41(50):14 944—14 950 [7] Asakura T.,Wat anabe Y.,Uch ida A.et al..Macr omolecules[J],1984,17(5):1 075—1 081 [8] Gao Q.W.,Shao Z.Z.,Sun Y.Y.et al..Polym.J.[J],2000,32(3):269—274 [9] Ish ida M.,Asakura T.,Yok oi M.et al..Macromolecules[J],1990,23(1):88—94 [10] Jan K.,Petr P.,Timot hy A.K..Appl.Spectrosc.[J],1999,53(6):666—671 [11] Yeo S.D.,Debenedett i P.G.,Pat ro S.Y.et al..J.Pharmaceutical Sci.[J],1994,83:1 651—1 656 [12] LI Guang-Xian(李光宪),YU Tong-Yin(于同隐).Chinese Sci.Bull.(科学通报)[J],1989,21:1 656—1 659 [13] Zheng S.,Li G.,Yao W.et al..Appl.Spect rosc.[J],1989,43(7):1 269—1 272 [14] LIU Yong-Cheng(刘永成),SHAO Zheng-Zhong(邵正中),SUN Yu-Yu(孙玉宇)et al..Polymer Bullet in(高分子通报)[J],1998,3:17—23 [15] Noda I..Appl.Spectrosc.[J]1993,47(9):1 329—1 336 [16] XU Jin-Ze(徐金泽),ZHAO Yu(赵　雨),ZHAO Bing(赵　冰)et al..Chem.J.Chinese Universities(高等学校化学学报)[J],2002,23(6):1 110—1 112 [17] Asakura T.,Yao J.M.,Yamane T.et al..J.Am.Ch em.Soc.[J],2002,124:8 794—8 795 [18] Roman T.,Pet er E.P.Jr.,George J.T.Jr..Biochemist ry[J],1996,35:4 619—4 627 [19] Ochsenf eld C.,Brown S.P.,Schnell I.et al..J.Am.Chem.Soc.[J],2001,123:2 597—2 606 [20] Spera S..Bax Ad..J.Am.Chem.Soc.[J],1991,113:5 490—5 492 [21] Sait oH.,Tabet a R.,Shoji A.et al..Macromolecules[J],1983,16:1 050—1 057 [22] Zhou P.,Li G.Y.,Shao Z.Z.et al..J.Phys.Ch em.B.[J],2001,105(50):12 469—12 476