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1.
The phenomena of creep, stress relaxation, and inverse relaxation/stress recovery were observed for mulberry and tasar silk. Instantaneous extension and secondary creep are both higher for tasar than for mulberry. The magnitude of inverse relaxation increases with the increase in peak tension and reduction in retraction for both varieties of silk. The extent of inverse relaxation was found to reduce because of cycling stressing. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 99: 3077–3084, 2006 相似文献
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Blend films of two types (I and II) were prepared by mixing Antheraea mylitta silk fibroin (AMF) and gelatin solution in various blend ratios via the solution casting method. Two different crosslinkers, namely glutaraldehyde and genipin, were used during blend preparation. The structural characteristics and thermal properties of the blend films were examined by Fourier transform infrared (FTIR) spectroscopy, X‐ray diffraction (XRD), Thermogravimetric analysis (TGA) and Diffrential scanning calorimetery (DSC). The FTIR spectra showed conformational alterations in type I blend films while type II films attained high β‐sheet crystallinity. The XRD diffractograms presented a high degree of crystallinity in type II blend films compared to type I, which showed an almost amorphous structure. Further, thermal and biological studies were conducted on type II films. According to the TGA thermograms, the degradation temperature of the crosslinked blend films shifted compared to pure gelatin and pure AMF films. Partial miscibility of the two components was indicated by DSC thermograms of the blends. The high water uptake capacity of type II blend films was found to imitate hydrogel behaviour. The blend films did not show any toxicity in 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyl tetrazolium bromide (MTT) assay and supported L929 fibroblast cell spreading and proliferation. The biodegradation of the blend films was significantly faster than the pure silk film. © 2020 Society of Industrial Chemistry 相似文献
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Weifei Wang Long Xu Yuxiao Zou Daorui Pang Wei Shi Lixia Mu Erna Li Dongming Lan Yonghua Wang Sentai Liao 《European Journal of Lipid Science and Technology》2020,122(2)
A comprehensive identification of lipid compositions and tocochromanols in Antheraea pernyi (A. pernyi) and Bombyx mori (B. mori) pupae oil is reported in the present study. Fatty acid profiling shows that both oils contain high levels (79.67% vs 71.11%) of unsaturated fatty acids, especially linoleic acid and linolenic acid. Moreover, linolenic acid is preferentially enriched at the sn‐2 positions of triacylglycerols (TAGs). Liquid chromatograph‐mass spectrometry (LC‐MS) analysis demonstrates that POO (TAG with one palmitoyl and two oleoyls) is the primary TAG form with percentages of 20.18% in A. pernyi and 15.00% in B. mori. The dominating phospholipid species are phosphatidylcholine (PC, 30.40% vs 54.61%) and phosphatidylethanolamine (PE, 34.82% vs 20.39%). Four sterol constituents with total contents of 382.56 ± 3.12 and 371.65 ± 2.98 µg g?1 are identified and analyzed quantitatively. Additionally, the levels of tocochromanols (20.15 ± 0.89 vs 17.15 ± 0.71 mg g?1) are quantified in both silkworm pupae oils. Overall, silkworm oil acts as an enriched source of functional lipids and tocochromanols. Practical Applications: A systematic investigation on the principal lipid classes and tocochromanols of Antheraea pernyi pupae and Bombyx mori pupae oil is reported in this study. The informative data provide supporting evidence for comprehensive utilization of silkworm oil for production of nutritional and healthy products. 相似文献
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Mana Yamano Ryoko Hirose Ping Ying Lye Keiko Takaki Rina Maruta Mervyn Wing On Liew Shinichi Sakurai Hajime Mori Eiji Kotani 《International journal of molecular sciences》2022,23(13)
Silk fibroin exhibits high biocompatibility and biodegradability, making it a versatile biomaterial for medical applications. However, contaminated silkworm-derived substances in remnant sericin from the filature and degumming process can result in undesired immune reactions and silk allergy, limiting the widespread use of fibroin. Here, we established transgenic silkworms with modified middle silk glands, in which sericin expression was repressed by the ectopic expression of cabbage butterfly-derived cytotoxin pierisin-1A, to produce cocoons composed solely of fibroin. Intact, nondegraded fibroin can be prepared from the transgenic cocoons without the need for sericin removal by the filature and degumming steps that cause fibroin degradation. A wide-angle X-ray diffraction analysis revealed low crystallinity in the transgenic cocoons. However, nondegraded fibroin obtained from transgenic cocoons enabled the formation of fibroin sponges with varying densities by using 1–5% (v/v) alcohol. The effective chondrogenic differentiation of ATDC5 cells was induced following their cultivation on substrates coated with intact fibroin. Our results showed that intact, allergen-free fibroin can be obtained from transgenic cocoons without the need for sericin removal, providing a method to produce fibroin-based materials with high biocompatibility for biomedical uses. 相似文献
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Yi Wei Xiao-Lin Zhou Tai-Hang Liu Peng Chen Xia Jiang Zhan-Qi Dong Min-Hui Pan Cheng Lu 《International journal of molecular sciences》2021,22(11)
The trachea of insects is a tubular epithelia tissue that transports oxygen and other gases. It serves as a useful model for the studying of the cellular and molecular events involved in epithelial tube formation. Almost all of the extracellular matrix can be degraded by Matrix metalloproteinases (MMPs), which is closely related to the processes of development and regeneration. The regulation of trachea by MMPs is roughly known in previous studies, but the detailed regulation mechanism and involved gene function are not fully explored. In this article, we found MMP1 expressed highly during tracheal remodeling, and knocked out it makes the tracheal branch number reduced in Bombyx mori. In trachea of transgenic BmMMP1-KO silkworm, the space expanding of taenidium and epidermal cells and the structure of apical membrane were abnormal. To explore the underlying mechanism, we detected that DE-cadherin and Integrin β1 were accumulated in trachea of transgenic BmMMP1-KO silkworm by immunohistochemistry. Moreover, 5-Bromo-2′-Deoxyuridine (BrdU) labeling showed that knockout of BmMMP1 in silkworm inhibited tracheal cell proliferation, and BmMMP1 also regulated the proliferation and migration of BmNS cells. All of the results demonstrated that BmMMP1 regulates the development of the tracheal tissue by expanding the space of tracheal cuticles and increases the number of tracheal branches by degrading DE-cadherin and Integrin β1. 相似文献
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Tian Li Chen Xu Jinzhi Xu Jian Luo Bin Yu Xianzhi Meng Chunfeng Li Guoqing Pan Zeyang Zhou 《International journal of molecular sciences》2021,22(9)
Silkworm Bombyx mori is an economically important insect and a lepidopteran model. Organelle proteome is vital to understanding gene functions; however, it remains to be identified in silkworm. Here, using the engineered ascorbate peroxidase APEX, we constructed transgenic B. mori embryo cells (BmE) expressing APEX-NLS, COX4-APEX, APEX-Rev, and APEX-KDEL in nucleus, mitochondrial matrix (MM), cytosol, and endoplasmic reticulum (ER), and isolated the biotin-labeled proteins using streptavidin-affinity purification, respectively. The isolated proteins were determined using LC-MS/MS and annotated by searching B. mori genomes downloaded from GenBank, SilkBase, SilkDB 2.0, and SilkDB 3.0, resulting in 842, 495, 311, and 445 organelle proteins identified, respectively. We mapped the 296 MM proteins annotated in the GenBank data to mitochondrial protein databases of the fly, human, and mouse, and found that 140 (47%) proteins are homologous to 80 fly proteins, and 65 (22%) proteins match to 31 and 29 human and mouse proteins, respectively. Protein orthology was predicted in multiple insects using OrthoMCL, producing 460 families containing 839 proteins we identified. Out of 460 families, 363 were highly conserved and found in all insects, leaving only three proteins without orthology in other insects, indicating that the identified proteins are highly conserved and probably play important roles in insects. A gene ontology enrichment analysis by clusterProfiler revealed that the nucleus proteins significantly enriched in cellular component terms of nucleus and nucleolus, the MM proteins markedly enriched in molecular function terms of nucleotide binding, and the cytosol proteins mainly enriched in biological process terms of small molecule metabolism. To facilitate the usage and analysis of our data, we developed an open-access database, Silkworm Organelle Proteome Database (SilkOrganPDB), which provides multiple modules for searching, browsing, downloading, and analyzing these proteins, including BLAST, HMMER, Organelle Proteins, Protein Locations, Sequences, Gene Ontology, Homologs, and Phylogeny. In summary, our work revealed the protein composition of silkworm BmE organelles and provided a database resource helpful for understanding the functions and evolution of these proteins. 相似文献
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Xiaoting Hua Quan Zhang Wei Xu Xiaogang Wang Fei Wang Ping Zhao Qingyou Xia 《International journal of molecular sciences》2021,22(14)
Bombyx mori nucleopolyhedrovirus (BmNPV) is a pathogen that causes great economic losses in sericulture. Many genes play a role in viral infection of silkworms, but silkworm metabolism in response to BmNPV infection is unknown. We studied BmE cells infected with BmNPV. We performed liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS)-based non-targeted metabolomics analysis of the cytosolic extract and identified 36, 76, 138, 101, 189, and 166 different molecules at 3, 6, 12, 24, 48, and 72 h post BmNPV infection (hpi) compared with 0 hpi. Compounds representing different areas of metabolism were increased in cells post BmNPV infection. These areas included purine metabolism, aminoacyl−tRNA biosynthesis, and ABC transporters. Glycerophosphocholine (GPC), 2-hydroxyadenine (2-OH-Ade), gamma-glutamylcysteine (γ-Glu-Cys), hydroxytolbutamide, and 5-pyridoxolactone glycerophosphocholine were continuously upregulated in BmE cells post BmNPV infection by heat map analysis. Only 5-pyridoxolactone was found to strongly inhibit the proliferation of BmNPV when it was used to treat BmE cells. Fewer infected cells were detected and the level of BmNPV DNA decreased with increasing 5-pyridoxolactone in a dose-dependent manner. The expression of BmNPV genes ie1, helicase, GP64, and VP39 in BmE cells treated with 5-pyridoxolactone were strongly inhibited in the BmNPV infection stage. This suggested that 5-pyridoxolactone may suppress the entry of BmNPV. The data in this study characterize the metabolism changes in BmNPV-infected cells. Further analysis of 5-pyridoxolactone, which is a robust antiviral molecule, may increase our understanding of antiviral immunity. 相似文献
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Thangaraju Elakkiya Govindaswamy Malarvizhi Sheeja Rajiv Thirupathur Srinivasan Natarajan 《Polymer International》2014,63(1):100-105
Silk fibroin from Bombyx mori silk cocoons was electrospun into silk nanofibers (SNFs). SEM images show that 9% w/v of SNFs was smooth and beadless having an average diameter in the range 30–150 nm. Curcumin (0.5–1.5 wt%) was incorporated into the silk fibroin solution and electrospun to obtain curcumin incorporated silk nanofibers (CSNFs) with diameters between 50 and 200 nm. The dispersion of curcumin in the SNFs was confirmed by TEM. The amorphous nature of curcumin upon incorporation into SNFs was confirmed by XRD. The functional groups of SNF and CSNF were confirmed by Fourier transform infrared spectroscopy. The SNFs and CSNFs were thermally stable up to ca 350 °C as evidenced by TGA. The glass transition temperature (Tg) of SNFs (168 °C) increased to 184 °C in the case of CSNFs as confirmed by DSC. The storage modulus, loss modulus and tan δ were determined by dynamic mechanical analysis. The percentages of porosity and water uptake of SNFs were 85% and 150%, respectively. The percentage in vitro cumulative release of curcumin at the end of the tenth day for 0.5, 1 and 1.5 wt% formulations was 82%, 84% and 80%, respectively. © 2013 Society of Chemical Industry 相似文献
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Masuhiro Tsukada Takayuki Arai Stefan Winkler Giuliano Freddi Hiroshi Ishikawa 《应用聚合物科学杂志》2001,79(10):1764-1770
Silk fibers from Bombyx mori silkworms were grafted using a novel grafting monomer, vinyltrimethoxysilane (VTMSi), with various grafting initiators. The effects of these grafting initiators were evaluated. It was possible to successfully copolymerize VTMSi within the silk fiber matrix without disturbing the fine structure of the fiber matrix, which was shown by FTIR analysis and refractive index measurements. The physical properties of VTMSi grafted silk were analyzed and compared to fibers grafted with conventional monomers such as methyl methacrylate, methacrylamide, and 2‐hydroxyethyl methacrylate. No trend in the tensile strength and elongation at break was observed when grafting silk fibers with VTMSi. Crease recovery in the wet state improved significantly, suggesting that this new grafting technique is important for the production of washable silk fabrics. The thermal stability of VTMSi grafted silk fibers was improved as shown by the shift of the endothermic peak for the thermal decomposition toward higher temperatures. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 79: 1764–1770, 2001 相似文献
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Silk and wool fibers were acylated with two acid anhydrides, dodecenylsuccinic anhydride (DDSA) and octadecenylsuccinic anhydride (ODSA), at 75°C with N,N-dimethylformamide (DMF) or dimethyl sulfoxide (DMSO) as the solvent, the latter of which allowed higher weight gains to be reached. The weight gain and acyl content of wool was always higher than that of silk. Tensile properties of silk remained unchanged regardless of weight gain, whereas wool displayed a noticeably higher extensibility at high weight gain. Fine structural changes of acylated wool were detected by DSC analysis. Moisture regain and water retention of acylated silk and wool decreased significantly, whereas water repellency increased. SEM analysis showed the presence of foreign material firmly adherent to the surface of both silk and wool, whose amount increased with increasing weight gain. These deposits were attributed to the presence of the modifying agents at the fiber surface on the basis of the characteristic IR bands. The possible application of silk and wool fibers acylated with DDSA or ODSA for the preparation of water-repellent textile materials is discussed. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 2832–2841, 2001 相似文献
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Dimitrios A. Stavroulakis Nicolas Kalogerakis Leo A. Behie Kostas Iatrou 《加拿大化工杂志》1991,69(2):457-464
The growth characteristics of the BM-5 insect cell line of Bombyx mori (silkworm) have been experimentally investigated in order to develop optimal growth protocols when these cells are used to produce large quantities of biopesticides or human proteins by recombinant baculoviruses. Experiments were performed in 2 mL wells and 200 mL spinner flasks. Spinner flasks were operated at 80 rpm with 0.3% methyl cellulose (MCL) added to the medium in order to protect the cells from liquid shear stress. In addition to the effect of agitation rate and amount of MCL added to the medium, the cell response during the adaptation to growth in suspension from stationary cultures is reported. Exposure of the cells to varying nutrient and metabolite concentrations is accomplished through batch and repeated-batch modes in 2 mL wells. The results imply that glutamine is a limiting nutrient and lactate has an inhibitory effect on cell growth. Ammonia depletion from the medium was accompanied by uric acid accumulation, suggesting that ammonia is converted to this metabolic product by the “uricotelic” and “nucleicolytic” metabolic pathways. 相似文献
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In this article, we propose a new modification method for obtaining porous silk fibers with excellent wet elastic resilience and flexibility. Bombyx mori silks were modified by calcium‐salt treatment and subsequent epoxy crosslinking with glycerin triglycidyl ether. The effects of temperature, time, and catalyst (sodium carbonate) on the crosslinking reaction of the silk fibers were investigated, and the best conditions of reaction were determined as a temperature of 120°C, a crosslinking agent concentration of 7%, and immersion for 1 h with 2% Na2CO3 solution before the crosslinking reaction. The change in the structure and the physical properties of the silk fibers after calcium‐salt treatment and epoxy crosslinking was studied. Separating behavior of the microfibers occurred on the surface of the silk fiber after calcium‐salt treatment, and a porous structure formed in the interior of the silk. This porous structure of the silk was enlarged by subsequent epoxy crosslinking, and accordingly, the moisture conduction of the silk fibers improved remarkably. The breaking strength, breaking elongation, and wet elastic resilience of the silk fibers increased evidently after modification, and the modified silks exhibited a better flexibility. The conformation of silk fibroin fibers changed from β sheet to random coil after calcium‐salt treatment, whereas the β‐sheet content in the silk fibers increased after subsequent epoxy crosslinking. The significant reductions in the crystallinity and crystalline sizes in the silk fibers after the crosslinking reaction indicated that the crosslinking reaction occurred within the crystalline region because the calcium‐salt treatment increased the reaction accessibility. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 相似文献
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Liangli Yang Yue Zhao Quan Gan Dan Liang Rui Shu Song Jiang Ruiping Xie Yan Meng 《International journal of molecular sciences》2022,23(17)
BmSuc1, a novel animal-type β-fructofuranosidase (β-FFase, EC 3.2.1.26) encoding gene, was cloned and identified for the first time in the silkworm, Bombyx mori. BmSuc1 was specifically and highly expressed in the midgut and silk gland of Bombyx mori. Until now, the function of BmSuc1 in the silk gland was unclear. In this study, it was found that the expression changes of BmSuc1 in the fifth instar silk gland were consistent with the growth rate of the silk gland. Next, with the aid of the CRISPR/Cas9 system, the BmSuc1 locus was genetically mutated, and homozygous mutant silkworm strains with truncated β-FFase (BmSUC1) proteins were established. BmSuc1 mutant larvae exhibited stunted growth and decreased body weight. Interestingly, the molecular weight of part of Sericin1 (Ser1) in the silk gland of the mutant silkworms was reduced. The knockout of BmSuc1 reduced the sericin content in the silkworm cocoon shell, and the mechanical properties of the mutant line silk fibers were also negatively affected. These results reveal that BmSUC1 is involved in the synthesis of Ser1 protein in silk glands and helps to maintain the homeostasis of silk protein content in silk fibers and the mechanical properties of silk fibers, laying a foundation for the study of BmSUC1 regulation of silk protein synthesis in silk glands. 相似文献
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Salvador D. Aznar-Cervantes Ana Pagn María J. Candel Jos Prez-Rigueiro Jos L. Cenis 《International journal of molecular sciences》2022,23(7)
High-performance fibroin fibres are ideal candidates for the manufacture of scaffolds with applications in tissue engineering due to the excellent mechanical properties and optimal biocompatibility of this protein. In this work, the manufacture of high-strength fibres made from the silk glands of Samia cynthia ricini is explored. The glands were subjected to soaking in aqueous dissolutions of acetic acid and stretched to manufacture the fibres. The materials produced were widely characterized, in terms of morphology, mechanical properties, crystallinity and content of secondary structures, comparing them with those produced by the standard procedure published for Bombyx mori. In addition, mechanical properties and biocompatibility of a braided scaffold produced from these fibres was evaluated. The results obtained show that the fibres from B. mori present a higher degree of crystallinity than those from S. c. ricini, which is reflected in higher values of elastic modulus and lower values of strain at break. Moreover, a decrease in the elongation values of the fibres from S. c. ricini was observed as the concentration of acetic acid was increased during the manufacture. On the other hand, the study of the braided scaffolds showed higher values of tensile strength and strain at break in the case of S. c. ricini materials and similar values of elastic modulus, compared to those of B. mori, displaying both scaffolds optimal biocompatibility using a fibroblast cell line. 相似文献
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A series of experiments have been conducted using a recombinant baculovirus/insect cell expression system (Bm5/Bm5.NPV.CAT) to establish the optimum temperature for both cell growth and virus infection. Bm5 cell growth was found to be limited at temperatures below 22°C and ceased completely at temperatures above 34°C. In the range between 24 and 28°C, final cell densities always reached 96% of the highest achievable viable cell density. The shortest population doubling time was obtained at 28°C. Overall, a consistent increase in metabolism with increasing temperatures was observed. During the infection/viral replication phase, an increase in the temperature from 25 to 31°C resulted in a faster decrease in viable cell density and an earlier production of chloramphenicol acetyltransferase (CAT). Furthermore, protein yield at temperatures above 28°C was significantly reduced. Overall, the best temperature for the infection phase for the Bm5/Bm5.NPV expression system was found to be 25°C when the cells are cultured in serum free media. 相似文献
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