邵正中
博士 教授 博士生导师
复旦大学 高分子科学系
结构性生物大分子及其在生物医药等
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- 姓名:邵正中
- 目前身份:在职研究人员
- 担任导师情况:博士生导师
- 学位:博士
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学术头衔:
博士生导师, 国家“百千万”人才工程国家级人选, 国家杰出青年科学基金获得者, 享受国务院特殊津贴专家 教育部“新世纪优秀人才支持计划”入选者,
- 职称:高级-教授
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学科领域:
高分子化学
- 研究兴趣:结构性生物大分子及其在生物医药等
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成果阅读
407
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成果数
9
邵正中, Jinrong Yao, Dahui Xiao, Xin Chen, Ping Zhou, Tongyin Yu, and Zhengzhong Shao *
Macromolecules 2003, 36, 7508-7512,-0001,():
-1年11月30日
With the step-growth polymerization of bis (oligopeptides) and diisocyanates, two silkproteinlike multiblock polymers (P1, P2), containing-(Ala)4-and-(GlyAlaGlyAla)-sequence derived from the crystalline region of spider dragline silk and silkworm (Bombyx mori) silk respectively, has been synthesized successfully. The intrinsic viscosities of P1 and P2 measured in dichloroacetic acid at 25℃ were 0.31 and 0.26dL/g. FT-IR, 13C CP/MAS NMR and WAXD measurements revealed the oligopeptide segments in these multiblock polymers could aggregate spontaneously into β-sheet structure in solid state. In addition, it was also found there were non-β-sheet structures in the synthetic polymers, which indicated such polymers had a solid-state structure similar to that of natural silks.
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【期刊论文】Structure and Behavior of Regenerated Spider Silk
邵正中, Zhengzhong Shao, *, †, § Fritz Vollrath, ‡, § Yong Yang, † and Hans C. Thøgersen┴
Macromolecules 2003, 36, 1157-1161,-0001,():
-1年11月30日
Molecule chains of spider silk protein readily self-assemble into ordered structure such as β-sheets when a filament is pulled away from dilute aqueous solution of spider major ampullate silk protein. There is no need to change the pH, the temperature, or the ionic strength of the solution to aid filament formation. Circular dichroism spectroscopy confirmed that the silk protein in such aqueous solution was initially in random coil formation but with time would transform to β-sheets; the process was temperature-dependent. Amino acid analysis showed that reassembled (regenerated) and native spider silks were similar in composition. The morphology and structure of the reassembled silk were investigated by scanning electron microscopy and Raman spectroscopy. The mechanical properties of the reassembled silk were studied in some detail. Our study indicates that reconstituted spider silk self-assembles into respectable filaments. However, it is clear that the spinning process is crucial for the desirable material properties of native silks.
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【期刊论文】Silk fibres produced by artificial reeling are superior to those that are spun naturally.
邵正中, Zhengzhong Shao *, Fritz Vollrath †
NATURE|VOL 418|15 AUGUST 2002 ,-0001,():
-1年11月30日
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【期刊论文】Toughness of Spider Silk at High and Low Temperatures**
邵正中, By Yong Yang, Xin Chen, Zhengzhong Shao, * Ping Zhou, David Porter, David p. Knight, Fritz, Vollath
Adv. Mater. 2005, 17, no.1 January 6,-0001,():
-1年11月30日
The outstanding strength and toughness of certain spider and lepidopteran silkst [1] has aroused considerable interest in recent years, [2] with research focusing primarily on the rela-tionship between molecular structure and mechanical proper-ties. [3] Environmental conditions such as ambient humidity, [4] acidity, [5] and UV radiation [6] a11 affect the mechanical proper-ties of native silks to some degre. [7] pronounced differences in mechanical properties were also observed when conditions such as the speed or temperature at spinning were varied [8] or when the silk was (or had been) submerged in solvents such as water, urea solution, or a range of alcohols, where it con-tracts in varying degrees. [9]
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邵正中, Z. Shao, X. W. Hu, S. Frische, F. Vollrath *
Polymer 40(1999)4709-4711,-0001,():
-1年11月30日
Previous work has shown that dragline silk of Nephila madagascariensis is not homogeneous in cross-section. We report here that the core of Nephila edulis silk also contains extremely fine elongated, electron lucent domains. These domains may contribute to the exceptional tensile strength and toughness of this material by acting as stress concentration parts or (and) fluid-filled canaliculi. q1999 Elsevier Science Ltd. All rights reserved.
Biopolymer, Fibrous protein, Microstructure
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邵正中, Zhengzhong Shao a, b, Robert J. Young c, Fritz Vollrath a, *
International Journal of Biological Macromolecules 24(1999)295-300,-0001,():
-1年11月30日
We used wel-defined, fluorescence-free Raman spectra of single silk fibres to study silk ultrastructure. Major ampullate (MA) silk was reeled from the Araneus diadematus spider under controlled conditions. With acustom-built stress-strain gauge, we examined the mechanical properties of this silk both before and after supercontraction in a range of solvents. The solvents were found to modify the material properties considerably. We suggest that the solvents with their different polarities affect different regions of the silk's composite microstructure, in particular the conformation of the molecular chains.
Araneus diadematus, Raman spectroscopy, Mechanical testing, Silk ultrastructure
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【期刊论文】The natural silk spinning process A nucleation-dependent aggregation mechanism?
邵正中, Guiyang Li , Ping Zhou , Zhengzhong Shao , Xun Xie , Xin Chen , Honghai Wang , Lijuan Chunyu and Tongyin Yu
Eur. J. Biochem. 268, 6600-6606(2001),-0001,():
-1年11月30日
The spinning mechanism of natural silk has been an open issue. In this study, both the conformation transition from random coil to b sheet and the b sheet aggregation growth of silk fibroin are identified in the B. mori regenerated silk fibroin aqueous solution by circular dichroism (CD) spectroscopy. A nucleation-dependent aggregation mechanism, similar to that found in prion protein, amyloid b (Ab) protein, and a-synuclein protein with the conformation transition from a soluble protein to a neurotoxic, insoluble b sheet containing aggregate, is a novel suggestion for the silk spinning process. We present evidence that two steps are involved in this mechanism: (a) nucleation, a ratelimiting step involving the conversion of the soluble random coil to insoluble b sheet and subsequently a series of thermodynamically unfavorable association of b sheet unit, i. e. the formation of a nucleus or seed; (b) once the nucleus forms, further growth of the b sheet unit becomes thermodynamically favorable, resulting a rapid extension of b sheet aggregation. The aggregation growth follows a first order kinetic process with respect to the random coil fibroin concentration. The increase of temperature accelerates the b sheet aggregation growth if the b sheet seed is introduced into the random coil fibroin solution. This work enhances our understanding of the natural silk spinning process in vivo.
silk fibroin, spinning mechanism, conformation transition, nucleation-dependent, CD spectroscopy.,
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邵正中, Yuhong Yang, Zhengzhong Shao, * Xin Chen, and Ping Zhou
Biomacromolecules, Vol. 5, No.3, 2004,-0001,():
-1年11月30日
Fluorescence and circular dichroism spectroscopy were used to monitor the conformational transition of regenerated Bombyx mori silk fibroin (RSF) in aqueous solutions under different conditions. According to the analysis of fluorescence spectra using anilinonaphthalene-8-sulfonic acid magnesium salt (ANS) as an external probe, the destruction of the hydrophobic core prior to the secondary structure change suggests that this collapse may initiate the conformational transition from random coil to β-sheet for RSF. The temperature dependence of the structural changes of RSF, detected by both fluorescence spectroscopy and circular dichroism, shows a reversible process upon heating and recooling, with the midpoint around 45℃. The results also indicate that most of the tryptophan (Trp) residues contained in silk fibroin are concentrated on the surface of the unfolded protein. However, they will change their location in the highly ordered structure (e. g., becoming more homogeneous) with the conformational transition of silk fibroin. Moreover, our studies also suggest that the presence of water plays a crucial role during the structure changes of fibroin.
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【期刊论文】The effect of solvents on the contraction and mechanical properties of spider silk
邵正中, Zhengzhong Shao, Fritz Vollrath *
Polymer 40(1999)1799-1806,-0001,():
-1年11月30日
We examined the mechanical characteristics of four major ampullate (MA) dragline silks during and after submersion in a range of solvents. The silks were reeled from four very different spiders: Araneus diadematus, Nephila edulis, Latrodectus mactans and Euprosthenops sp. They displayed significant differences in behaviour in the native state as well as during and after supercontraction in solvents such as water, urea solution and a set of alcohols. The different polarities of the solvents are thought to affect different regions of the silk's molecular conformation. We hypothesise that the observed mechanical properties of dragline silks are those of a hard elastic polymer; and we explain the supercontraction of the silks as changes of orientation in the molecular chains. q1999 Elsevier Science Ltd. All rights reserved.
Hydrogen bond, Hard elastic biopolymer, Ultrastructure
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