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Zhengzhong Shao - One of the best experts on this subject based on the ideXlab platform.

  • Comparison of Native and Regenerated Antheraea pernyi Silk Fibroin
    Materials Science, 2021
    Co-Authors: Yu Duan, Xin Chen, Zhengzhong Shao
    Abstract:

    The regenerated Antheraea pernyi silk fibroin (RASF) was harvested by dissolving the silk fibers in a calcium nitrate solution. XRD result demonstrated that both native and regenerated Antheraea pernyi silk fibroin involved the α-helix conformation, and DTG curves showed that their thermal decompositions were quite similar and proceeded three steps. However, rheological measurements figured out that the molecule weight of RASF decreased from 246 kDa to 199 kDa, comparing with native Antheraea pernyi silk fibroin. Also, the tensile properties of the RASF film, which were the same to those of regenerated Bombyx mori silk fibroin film, were observed.

  • understanding humidity induced actuation in Antheraea pernyi silks
    Giant, 2020
    Co-Authors: Zhen Wang, Zhengzhong Shao, Shihui Lin, Jing Ren, Ying Pei, Min Chen, Shengjie Ling
    Abstract:

    Abstract Although supercontraction of animal silks has been extensively investigated, reports regarding their humidity-induced actuation behavior, i.e., the cyclical response to humidity changes, are limited. Humidity-induced actuation is a unique characteristic of animal silks that responds to changes in surrounding humidity for matching the needs of biological functions. Therefore, the aim of this article is to systematically understand the interplay between Antheraea pernyi silks and water from an experimental and theoretical perspective. In particular, the cyclical response of silk to humidity has been primarily investigated. The reversible ordered GGY motifs in the amorphous region of silk are proposed to play a crucial role in humidity-induced actuation relied on the results from synchrotron Fourier transform infrared microspectroscopy as well as small- and wide-angle x-ray scattering. In addition, using the group interaction model, a model based on mean-field theory for understanding the energy storage and dispersion during mechanical loading, the entire humidity-silk response process, including both supercontraction and humidity-induced cyclic actuation, was well quantified. This fundamental understanding of the interplay between silk and water is not only crucial for analyzing the biological function of animal silks, but is also especially critical for inspiring the design of humidity-driven fiber actuators.

  • integrating tough Antheraea pernyi silk and strong carbon fibres for impact critical structural composites
    Nature Communications, 2019
    Co-Authors: Kang Yang, Juan Guan, Keiji Numata, Zhengzhong Shao, Robert O. Ritchie
    Abstract:

    High stiffness and strength carbon fibres are commonly used to reinforce epoxy-resin composites. While wild Antheraea pernyi silk fibres exhibit high toughness originating from their α-helix/random coil conformation structures and their micro-fibre morphology, their insufficient strength and stiffness hinders them from being used in similar structural composites. In this work, we use interply hybridization of silk and carbon fibres to reinforce epoxy-matrix composites. With increased carbon fibre content, the quasi-static tensile/flexural stiffness and strength increases following the rule of mixtures while more silk fibre acts to increase ductility and impact strength. This results in a composite comprising equal volumes of carbon and silk fibres achieving an impact strength of 98 kJ m-2, which is twice that of purely carbon-fibre reinforced composites (44 kJ m-2). This work shows tough natural silk fibres and strong synthetic fibres can be successfully integrated into epoxy-resin composites for tailored mechanical properties.

  • understanding the mechanical properties and structure transition of Antheraea pernyi silk fiber induced by its contraction
    Biomacromolecules, 2018
    Co-Authors: Yu Wang, Xin Chen, Jianchuan Wen, Bo Peng, Zhengzhong Shao
    Abstract:

    Like most major ampullate silks of spider, the length of Antheraea pernyi silkworm silk can shrink to a certain degree when the fiber is in contact with water. However, what happens in terms of molecule chain level and how it correlates to the mechanical properties of the silk during its contraction is not yet fully understood. Here, we investigate the water-induced mechanical property changes as well as the structure transition of two kinds of A. pernyi silk fiber, which are forcibly reeled from two different individuals (silkworm a and silkworm b; the silk fiber from either one represents the lower and upper limit of the distribution of mechanical properties, respectively). The tensile test results present that most of the mechanical parameters except the post-yield modulus and breaking strain for both silk fibers have the same variation trend before and after their water contraction. Synchrotron FTIR and Raman spectra show that the native filament from silkworm a contains more α-helix structures than t...

  • Insight into the Structure of Single Antheraea pernyi Silkworm Fibers Using Synchrotron FTIR Microspectroscopy
    2016
    Co-Authors: Shengjie Ling, Zhengzhong Shao, David P Knight, Yufang Huang, Lei Huang, Huan Zhou, Xin Chen
    Abstract:

    Synchrotron FTIR (S-FTIR) microspectroscopy was used to monitor both protein secondary structures (conformations) and their orientations in single cocoon silk fibers of the Chinese Tussah silk moth (Antheraea pernyi). In addition, to understand further the relationship between structure and properties of single silk fibers, we studied the changes of orientation and content of different secondary structures in single A. pernyi silk fibers when subjected to different strains. The results showed that the content and orientation of β-sheet was almost unchanged for strains from 0 to 0.3. However, the orientation of α-helix and random coil improved progressively with increasing strain, with a parallel decrease in α-helix content and an increase in random coil. This clearly indicates that most of the deformation upon stretching of the single fiber is due to the change of orientation in the amorphous regions coupled with a conversion of some of the α-helix to random coil. These observations provide an explanation for the supercontraction behavior of certain animal silks and are likely to facilitate understanding and optimization of postdrawing used in the conjunction with the wet-spinning of silk fibers from regenerated silk solutions. Thus, our work demonstrates the power of S-FTIR microspectroscopy for studying biopolymers

Li Qin - One of the best experts on this subject based on the ideXlab platform.

  • the mitochondrial genome of qinghuang_1 the first modern improved strain of chinese oak silkworm Antheraea pernyi lepidoptera saturniidae
    Journal of Insects as Food and Feed, 2021
    Co-Authors: Yanqun Liu, Dong-bin Chen, Rusong Zhang, M M Chen, Y Q Liu, Li Qin
    Abstract:

    Chinese oak silkworm, Antheraea pernyi Guerin-Meneville 1855 (Lepidoptera: Saturniidae), is a traditional edible insect in China and is considered the edible insect with the highest potential. Info...

  • Peptidoglycan recognition proteins regulate immune response of Antheraea pernyi in different ways.
    Journal of invertebrate pathology, 2019
    Co-Authors: Wei Liu, Sheng-lin Shi, Yi-ren Jiang, Yong Wang, Jinglin Zhou, Ying Zhang, Deyi Wang, Li Qin
    Abstract:

    Peptidoglycan recognition proteins (PGRPs) are evolutionarily conserved molecules that act in innate immune responses against invading pathogens. Insect PGRPs activate the Toll and/or immune deficiency (IMD) signal transduction pathways. They induce cellular and humoral immune defense reactions that effectively protect insects from invasion of microorganisms. In this study, four cDNA clones encoding PGRPs (ApPGRP-A, ApPGRP-B, ApPGRP-C, ApPGRP-LE) were isolated from the Chinese oak silkworm, Antheraea pernyi. The deduced amino acid sequences of ApPGRP-B and -C share high identity with enzymatically active PGRP proteins and contain the amino acids required for amidase activity. The spatiotemporal expression patterns of ApPGRPs and their response to immune stimulations were determined, and suggest that PGRPs might act as a broad-spectrum pattern recognition protein and participate in the pathway activation system. Here, using an RNA-interference approach, we examined the function of PGRPs in response to immune stimulation. We observed that RNAi-mediated silencing of ApPGRP-A decreased the tested antimicrobial peptides (Attacin, Attacin 2, Ceropin, Gloverin, lysozyme and Lebocin) in response to Enterococcus pernyi challenge. However, reducing the ApPGRP-B, -C mRNA levels led to a strong increase of the AMP genes (except for Lebocin). These results suggest that ApPGRPs are necessary for pathway initiation complex formation and activate AMP generation. Our data also indicated that PGRP-B and -C down-regulate AMPs generation in the immune response.

  • transcriptome analysis of the midgut of the chinese oak silkworm Antheraea pernyi infected with Antheraea pernyi nucleopolyhedrovirus
    PLOS ONE, 2016
    Co-Authors: Guobao Wang, Yi-ren Jiang, Ying Sun, Wei Liu, Fengcheng Wang, Li Qin
    Abstract:

    The Antheraea pernyi nucleopolyhedrovirus (ApNPV) is an exclusive pathogen of A. pernyi. The intense interactions between ApNPV and A. pernyi cause a series of physiological and pathological changes to A. pernyi. However, no detailed report exists regarding the molecular mechanisms underlying the interactions between ApNPV and A. pernyi. In this study, four cDNA libraries of the A. pernyi midgut, including two ApNPV-infected groups and two control groups, were constructed for transcriptomic analysis to provide new clues regarding the molecular mechanisms that underlie these interactions. The transcriptome of the A. pernyi midgut was de novo assembled using the Trinity platform because of the lack of a genome resource for A. pernyi. Compared with the controls, a total of 5,172 differentially expressed genes (DEGs) were identified, including 2,183 up-regulated and 2,989 down-regulated candidates, of which 2,965 and 911 DEGs were classified into different GO categories and KEGG pathways, respectively. The DEGs involved in A. pernyi innate immunity were classified into several categories, including heat-shock proteins, apoptosis-related proteins, serpins, serine proteases and cytochrome P450s. Our results suggested that these genes were related to the immune response of the A. pernyi midgut to ApNPV infection via their essential roles in regulating a variety of physiological processes. Our results may serve as a basis for future research not only on the molecular mechanisms of ApNPV invasion but also on the anti-ApNPV mechanism of A. pernyi.

  • cDNA cloning and expression pattern of two enolase genes from the Chinese oak silkworm, Antheraea pernyi
    2016
    Co-Authors: Yanqun Liu, Huan Wang, Runxi Xia, Haolei Wan, Li Qin, Defu Jiang, Zhonghuai Xiang
    Abstract:

    In this study, two enolase genes were isolated and charac-terized from the Chinese oak silkworm, Antheraea perny, which were designated as enolase I and II, respectively. The enolase I cDNA sequence was 1712 bp with an open reading frame (ORF) of 1302 bp encoding 433 amino acids. The enolase II cDNA sequence was 1549 bp with an ORF of 1296 bp encoding 431 amino acids. The amino acid sequences of the two genes share several conserved features/sites of enolase. Antheraea pernyi enolase I shows 93%–97 % sequence identity to enolases of lepidopterans available to date, 75%–82 % identity to enolases of other invertebrates, 60%–72 % identity to enolases of other organisms including vertebrates, plants, and fungi. Antheraea pernyi enolase II shows 84 % identity to Bombyx mori enolase II, but 60 % identity to A. pernyi enolase I. I

  • morphological and molecular characterization of nosema pernyi a microsporidian parasite in Antheraea pernyi
    Parasitology Research, 2015
    Co-Authors: Yong Wang, Sheng-lin Shi, Yi-ren Jiang, Wei Liu, Ling Huang, Muhammad Irfan, Ruisheng Yang, Li Qin
    Abstract:

    Nosema pernyi is a lethal pathogen that causes microsporidiosis in the Chinese oak silkworm, Antheraea pernyi. In this study, we presented its morphological and some molecular characteristics. The mature spores were measured to be 4.36 × 1.49 μm. The spore wall consisted of an electron-dense exospore (EX) and electron-lucent endospore (EN) layer. The polar filament (PF) was isofilar with 10-12 coils that were frequently arranged in a single row. Investigation results indicated that N. pernyi can infect the gut wall, silk glands, and other tissues. A full-length SMART cDNA library of N. pernyi was constructed, and then 824 expressed sequence tags (ESTs) were sequenced. Ninety unigenes, out of 197 assembled unigenes, showed significant homology to known genes of Nosema ceranae, Nosema bombycis, Encephalitozoon cuniculi, and other microsporidian species. Based on the nucleotide sequence of the α- and β-tubulin genes and amino acid sequence of actin gene, phylogenetic trees analysis showed that N. pernyi was closely related to Nosema philosamiae and Nosema Antheraeae. It was correctly assigned to the Nosema group.

Subhas C Kundu - One of the best experts on this subject based on the ideXlab platform.

  • chinese oak tasar silkworm Antheraea pernyi silk proteins current strategies and future perspectives for biomedical applications
    Macromolecular Bioscience, 2019
    Co-Authors: Simone S Silva, Banani Kundu, Rui L Reis, Subhas C Kundu
    Abstract:

    Chinese nonmulberry temperate oak tasar/tussah, Antheraea pernyi (Ap) silk is a natural biopolymer that has attracted considerable attention as a biomaterial. The proteinaceous components of Ap silk proteins, namely fibroin and sericin may represent an alternative over mulberry Bombyx mori silk proteins. In fact, the silk fibroin (SF) of Ap is rich in Arginyl-Glycyl-Aspartic acid (RGD) peptides, which facilitate the adhesion and proliferation of various cell types. The possibility of processing Ap silk proteins into different distinct 2D- and 3D-based matrices is described in earlier studies, such as membranes, nanofibers, scaffolds, and micro/nanoparticles, contributing to a different rate of degradation, mechanical properties, and biological performance useful for various biomedical applications. This review summarizes the current advances and developments on nonmulberry Chinese oak tasar silk protein (fibroin and sericin)-based biomaterials and their potential uses in tissue engineering, regenerative medicine, and therapeutic delivery strategies.

  • ion induced fabrication of silk fibroin nanoparticles from chinese oak tasar Antheraea pernyi
    International Journal of Biological Macromolecules, 2015
    Co-Authors: Juan Wang, Banani Kundu, Shanshan Zhang, Tieling Xing, Subhas C Kundu
    Abstract:

    Abstract Silk protein fibroin in nanoparticles form is a promising material for drug delivery due to its pleiotropic properties, including biocompatibility, biodegradability, ease in fabrication into smaller diameters, high bioavailability, and therapeutic retention at target sites. In the present study, silk nanoparticles are fabricated from regenerated fibroin solution of the Chinese temperate oak tasar Antheraea pernyi by novel ion-induced self-assembly in a very short time under mild conditions. The resultant fibroin nanoparticles range in size from 100 to 500 nm. The molecular conformation of regenerated fibroin changes from α-helical to a β-sheet structure as a rapid function of the ionic strength and the hydrophobic and electrostatic interactions. The mild conditions are potentially advantageous for the encapsulation of sensitive drugs and therapeutic molecules such as doxorubicin hydrochloride, an amphiphilic anticancer therapeutic. In vitro release of doxorubicin from nanoparticles is pH sensitive, with approx. 65% doxorubicin remaining in the fibroin nanoparticles after 11 days. The activity of fibroin nanoparticles on hepatomas indicates the efficacy of the fibroin nanoparticles to maintain the bioactivity of the loaded doxorubicin and impart a dose-dependent cell growth inhibition. The results suggest that Chinese temperate oak tasar silk fibroin nanoparticles can be used as a sustained drug delivery vehicle.

Yanqun Liu - One of the best experts on this subject based on the ideXlab platform.

  • the mitochondrial genome of qinghuang_1 the first modern improved strain of chinese oak silkworm Antheraea pernyi lepidoptera saturniidae
    Journal of Insects as Food and Feed, 2021
    Co-Authors: Yanqun Liu, Dong-bin Chen, Rusong Zhang, M M Chen, Y Q Liu, Li Qin
    Abstract:

    Chinese oak silkworm, Antheraea pernyi Guerin-Meneville 1855 (Lepidoptera: Saturniidae), is a traditional edible insect in China and is considered the edible insect with the highest potential. Info...

  • Transcriptomic analysis of the prothoracic gland from two lepidopteran insects, domesticated silkmoth Bombyx mori and wild silkmoth Antheraea pernyi
    Nature Publishing Group, 2019
    Co-Authors: Hai-xu Bian, Huan Wang, Runxi Xia, Dong-bin Chen, Xi-xi Zheng, Yi-ren Jiang, Yanqun Liu
    Abstract:

    Abstract The prothoracic gland (PG) is an important endocrine organ of synthesis and secretion of ecdysteroids that play critical roles in insects. Here, we used a comparative transcriptomic approach to characterize some common features of PGs from two lepidopteran species Bombyx mori and Antheraea pernyi. Functional and pathway annotations revealed an overall similarity in gene profile between the two PG transcriptomes. As expected, almost all steroid hormone biosynthesis genes and the prothoracicitropic hormone receptor gene (Torso) were well represented in the two PGs. Impressively, two ecdysone receptor genes, eleven juvenile hormone related genes, more than 10 chemosensory protein genes, and a set of genes involved in circadian clock were also presented in the two PGs. Quantitative real time -PCR (qRT-PCR) validated the expression of 8 juvenile hormone and 12 clock related genes in B. mori PG, and revealed a different expression pattern during development in whole fifth larval instar. This contribution to insect PG transcriptome data will extend our understanding of the function and regulation of this important organ

  • cDNA cloning and expression pattern of two enolase genes from the Chinese oak silkworm, Antheraea pernyi
    2016
    Co-Authors: Yanqun Liu, Huan Wang, Runxi Xia, Haolei Wan, Li Qin, Defu Jiang, Zhonghuai Xiang
    Abstract:

    In this study, two enolase genes were isolated and charac-terized from the Chinese oak silkworm, Antheraea perny, which were designated as enolase I and II, respectively. The enolase I cDNA sequence was 1712 bp with an open reading frame (ORF) of 1302 bp encoding 433 amino acids. The enolase II cDNA sequence was 1549 bp with an ORF of 1296 bp encoding 431 amino acids. The amino acid sequences of the two genes share several conserved features/sites of enolase. Antheraea pernyi enolase I shows 93%–97 % sequence identity to enolases of lepidopterans available to date, 75%–82 % identity to enolases of other invertebrates, 60%–72 % identity to enolases of other organisms including vertebrates, plants, and fungi. Antheraea pernyi enolase II shows 84 % identity to Bombyx mori enolase II, but 60 % identity to A. pernyi enolase I. I

  • supercooling capacity and cold tolerance of the wild silkworm Antheraea pernyi lepidoptera saturniidae
    Journal of Economic Entomology, 2016
    Co-Authors: Yanqun Liu, Runxi Xia, Xi-xi Zheng, Qirui Zhang
    Abstract:

    While wild silkworms have served humans for several thousand years, little attention on cold hardiness has been paid to these economically important species. In the present study, supercooling capacity and low temperature tolerance of Chinese oak silkworm, Antheraea pernyi (Guerin-Meneville) (Lepidoptera: Saturniidae), an economic insect reared both for silk production as well as human food, were examined under laboratory conditions. The supercooling points (SCPs) of pupae dropped significantly from a mean of -15.6°C in prediapause to -20.1°C in diapause, and then increased to -17.5°C during postdiapause development. Sex and voltinism influenced body mass but had no significant effect on the SCP. Our data demonstrated that cold tolerance of A. pernyi is tightly linked to life stage. Exposure of eggs to -5°C for up to 8 h had no effect on the hatching rate, whereas silkworm larvae failed to break through the chorion and hatch following a 4-8-h exposure to -10°C. Mean SCPs of intact eggs and naked larvae one day before hatching were similar, -23.3°C and -22.3°C, respectively, indicating that chorion does not significantly affect SCP. Comparison of lower lethal temperature (LLT50) and SCP means suggested that both pupae and eggs of A. pernyi are chill intolerant. These data will improve our understanding of low temperature tolerance in this commercially important species.

  • the complete mitochondrial genome of the wild type of Antheraea pernyi lepidoptera saturniidae
    Annals of The Entomological Society of America, 2012
    Co-Authors: Yanqun Liu, Huan Wang, Runxi Xia, Minhui Pan, Chunli Chai, Zhonghuai Xiang
    Abstract:

    ABSTRACT Antheraea pernyi (Guerin-Meneville) (Lepidoptera: Saturniidae), a well-known economically important insect, was domesticated from its wild type. In this study, the complete mitochondrial genome (mitogenome) of the wild type of A. pernyi was determined and compared for nucleotide variation with its domesticated type. The mitogenome of the wild type of A. pernyi is 15,537 bp in size, thus 29 bp smaller than that of the domesticated type. The gene content, order, and orientation of the complete mitogenome of the wild type are identical to those of the domesticated type, as are those of the other completely sequenced lepidopteran mitogenomes. A striking difference between the two mitogenomes was found in the A+T-rich region because of the numbers of tandem repeat units. The wild type has five tandem repeat units, whereas the domesticated type has six. Comparative analysis of the two mitogenomes revealed a relatively lower level of sequence divergence (1.70%). Within the two mitogenomes, there are no ...

Yaopeng Zhang - One of the best experts on this subject based on the ideXlab platform.

  • fabrication and characterization of regenerated Antheraea pernyi silk fibroin scaffolds for schwann cell culturing
    European Polymer Journal, 2019
    Co-Authors: Shengzhi Zou, Huili Shao, Xinru Wang, Suna Fan, Jiaming Zhang, Yaopeng Zhang
    Abstract:

    Abstract Antheraea pernyi silk, which is from a kind of non-mulberry silkworm produced in China, has better mechanical properties and cytocompatibility than the extensively studied silk from mulberry silkworm (Bombyx mori). In this work, the regenerated Antheraea pernyi silk fibroin (RASF) scaffolds were prepared from RASF aqueous solutions with different concentrations by a freeze-drying method. The morphologies, structures and properties of the obtained RASF scaffolds were investigated. It was found that with the decrease of RASF solution concentration and the increase of freezing temperature, the porosity of the scaffold increased while its apparent density decreased. The micro-morphology of the scaffold from the 1 wt% RASF solution was irregular. When the solution concentration was increased to the range of 4–13 wt%, the micro-morphologies of the obtained scaffolds mainly showed lamellar-like structure. And with the increase of solution concentration, the lamellar gap of the scaffold decreased while the lamellar thickness of the scaffold increased. However, with the further increase of solution concentration, the morphology of scaffold could gradually transfer into porous structure. In addition, the scaffold micro-morphology could be also affected by freezing temperature. Moreover, with the increase of RASF solution concentration or (and) the decrease of freezing temperature, the obtained scaffold had higher content of β-sheet conformation and higher crystallinity, which could improve its mechanical properties. It was further found that the swelling ratio and degradation rate of RASF scaffold prepared for tissue engineering increased with the decrease of solution concentration. The results of MTT indicated that the obtained RASF scaffold had no cytotoxicity. Moreover, the results of field emission scanning electron microscopy and laser confocal scanning microscopy revealed that the viability, cytocompatibility and migration ability of Schwann cells cultured on RASF scaffold were much better than those cultured on regenerated Bombyx mori silk fibroin (RBSF) scaffold. The RASF scaffold prepared in this work may have great potential applications in the area of nerve tissue engineering.

  • Antheraea pernyi silk fiber a potential resource for artificially biospinning spider dragline silk
    BioMed Research International, 2010
    Co-Authors: Yaopeng Zhang, Huili Shao, Hongxia Yang, Xuechao Hu
    Abstract:

    The outstanding properties of spider dragline silk are likely to be determined by a combination of the primary sequences and the secondary structure of the silk proteins. Antheraea pernyi silk has more similar sequences to spider dragline silk than the silk from its domestic counterpart, Bombyx mori. This makes it much potential as a resource for biospinning spider dragline silk. This paper further verified its possibility as the resource from the mechanical properties and the structures of the A. pernyi silks prepared by forcible reeling. It is surprising that the stress-strain curves of the A. pernyi fibers show similar sigmoidal shape to those of spider dragline silk. Under a controlled reeling speed of 95 mm/s, the breaking energy was J/kg, the tensile strength was 639 MPa and the initial modulus was 9.9 GPa. It should be noted that this breaking energy of the A. pernyi silk approaches that of spider dragline silk. The tensile properties, the optical orientation and the -sheet structure contents of the silk fibers are remarkably increased by raising the spinning speeds up to 95 mm/s.

  • Antheraea pernyi silk fiber a potential resource for artificially biospinning spider dragline silk
    BioMed Research International, 2010
    Co-Authors: Yaopeng Zhang, Hongxia Yang, Huili Shao
    Abstract:

    The outstanding properties of spider dragline silk are likely to be determined by a combination of the primary sequences and the secondary structure of the silk proteins. Antheraea pernyi silk has more similar sequences to spider dragline silk than the silk from its domestic counterpart, Bombyx mori. This makes it much potential as a resource for biospinning spider dragline silk. This paper further verified its possibility as the resource from the mechanical properties and the structures of the A. pernyi silks prepared by forcible reeling. It is surprising that the stress-strain curves of the A. pernyi fibers show similar sigmoidal shape to those of spider dragline silk. Under a controlled reeling speed of 95 mm/s, the breaking energy was 1.04 x 10(5) J/kg, the tensile strength was 639 MPa and the initial modulus was 9.9 GPa. It should be noted that this breaking energy of the A. pernyi silk approaches that of spider dragline silk. The tensile properties, the optical orientation and the beta-sheet structure contents of the silk fibers are remarkably increased by raising the spinning speeds up to 95 mm/s.