• International Journal of Industrial Entomology and Biomaterials
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• v.4 no.1
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• pp.1-4
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• 2002

Silk proteins consist of two major proteins, fibroin and sericin. There is currently an enormous reawakening of interest in these silk proteins as a biomaterial due to their mechanical and biological properties based on the detailed findings. Novel method for determination of the crystalline structure of silk proteins in an atomic level using nuclear magnetic resonance (NMR) was reviewed. Recent application of silks to biomaterials and prospects for future were discussed.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.719-722
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• 2001

Silk proteins from Nephila clavipes are fibrous proteins containing repetitive sequences with both crystalline and amorphous domains. In order to obtain high-level production of silk protein, the synthetic genes had 16 contiguous units of the consensus repeat sequence of the silk protein were expressed in Escherichia coli BL21(DE3) under the strong inducible T7 promoter. For production of recombinant silk protein in large amounts, pH-stat fed-batch cultures were carried out. The recombinant silk protein was produced as soluble forms in E. coli, and the recombinant silk protein content was as high as 11% of the total protein. When cells were induced at $OD_{600}$ of 60, the amount of silk protein produced was 6.49 g/L. After simple purification steps, 9.2 mg of silk protein that was more than 80% pure was obtained from a 50 mL culture, and the recovery yield was 26.3%.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.40
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• pp.10.1-10.6
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• 2018

Background: The objective of this study was to evaluate the changes in gene expression after incubation of cells with proteins released from different silk mat layers. Methods: A silk cocoon from Bombyx mori was separated into four layers of equal thickness. The layers were numbered from 1 to 4 (from the inner to the outer layer). The proteins were released by sonication of a silk mat layer in normal saline. The concentration of proteins was determined by spectrophotometry. They were incubated with RAW264.7 cells, and changes in the expression of genes were evaluated by cDNA microarray analysis and quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR). Results: Layer 1 and 4 groups had higher protein concentrations compared to those in layer 2 and 3 groups. The genes associated with inflammation and angiogenesis showed significantly higher expression in layer 1 and 4 groups. The results of qRT-PCR were in agreement with those of the cDNA microarray analysis. Conclusions: The silk mat from the middle portion of the silkworm cocoon yielded a lower protein release and caused an insignificant change in the expression of genes that are associated with inflammation and angiogenesis.

• Applied Microscopy
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• v.50
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• pp.16.1-16.11
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• 2020

Silk is produced by a variety of insects, but only silk made by terrestrial arthropods has been examined in detail. To fill the gap, this study was designed to understand the silk spinning system of aquatic insect. The larvae of caddis flies, Hydatophylax nigrovittatus produce silk through a pair of labial silk glands and use raw silk to protect themselves in the aquatic environment. The result of this study clearly shows that although silk fibers are made under aquatic conditions, the cellular silk production system is quite similar to that of terrestrial arthropods. Typically, silk production in caddisworm has been achieved by two independent processes in the silk glands. This includes the synthesis of silk fibroin in the posterior region, the production of adhesive glycoproteins in the anterior region, which are ultimately accumulated into functional silk dope and converted to a silk ribbon coated with gluey substances. At the cellular level, each substance of fibroin and glycoprotein is specifically synthesized at different locations, and then transported from the rough ER to the Golgi apparatus as transport vesicles, respectively. Thereafter, the secretory vesicles gradually increase in size by vesicular fusion, forming larger secretory granules containing specific proteins. It was found that these granules eventually migrate to the apical membrane and are exocytosed into the lumen by a mechanism of merocrine secretion.

• International Journal of Industrial Entomology and Biomaterials
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• v.17 no.1
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• pp.109-113
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• 2008

Realizing the scope of utilizing by-products of silk cocoons by applying appropriate methods is the immediate crave to optimize returns. The nutritive value of pupae suits for human diet, feed for poultry, carps, fish, rabbits, piggery and dogs. The pupal skin, fat, oil, cocoon palade have applications in oleo chemical, soap, glycerin, cosmetic, artificial fibres, membranes and n-triacontanol isolation. The pupal proteins Chitin, Shinki fibroin, Serrapeptidase, glucosamine are latent precursors of post surgical, anti-carcinogenic, anti-inflammative, anti-bacterial, anti-histaminic, gastric, hepatitis, pancreatitis, leukocytopenia, neurological, ophthalmic, blood pressure, cardiac and diabetic medicines and for preparation of vitamins A, E and K. The silk and its proteins sericin and fibroin are potentially used for wound healing, diabetes, impotence, sinusitis, arthritis, edema, cystitis, epididymitis, tissue regeneration, cancer, post-surgical trauma and used as anti-oxidatives, bio-adhesives, ultra violet screens and bio-active textiles. The waste cocoons can be used in making art crafts like garlands, carpets, overcoats, decoratives and greeting cards. The in-depth research towards utility optimization and make aware this reality to sericulturists, reelers, weavers, traders, entrepreneurs, policy makers etc., is the upright want of the today's Sericulture industry.

• Proceedings of the Korean Society of Sericultural Science Conference
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• 2003.04a
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• pp.59-59
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• 2003

Silk sericin (SS) is one of essential components of cocoon filament, comprising granular and high molecular proteins with adhesive and gelatin-like characteristics. Silk fibroin (SF), another main component of cocoon filament, has been investigated by many researchers due to its good physicochenucal properties. Recently, Nam and Park reported that the effect of alcohol addition into the SF solution on the morphology and structural charateristics of SF. (omitted)

• Proceedings of the Korean Fiber Society Conference
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• 2001.10a
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• pp.392-396
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• 2001

Natural silk is formed by two proteins ; the crystalline fibroin (inside the silk thread) and amorphous sericin (as a tube outside the thread). The degumming process is used th eliminate the external sericin prior to dyeing ： generally it makes use of soaps at pH 10. (omitted)

• Journal of Sericultural and Entomological Science
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• v.53 no.2
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• pp.92-96
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• 2015

It is known that silk protein supports effectively proliferation of cell such as insect cell and hybridoma cell. Although there are many varieties of Bombyx mori silkworm, the effect of silkworm varieties on cell proliferation has not been considered in detail. We studied that characteristics of silk cocoon obtained from Baegokjam, Kumokjam, Daeseongjam silkworm varieties and whether silk protein affected cell proliferation or not. Silk sericin was prepared under high temperature and high pressure condition. Silk fibroin was prepared using $CaCl_2:H_2O:EtOH$ with different dissolution time. As a result, there are differences in silk cocoon from different silkworm varieties about cell proliferation. The proliferation was accelerated in the presence of Baegokjam silk sericin and Kumokjam silk fibroin with 5hr dissolution time. We expect that silk proteins could be a preferable culture medium supplement for stimulating the proliferation of cell. Then, this results suggest silk as a new material for medium supplement replacing with fetal bovine serum.

• Proceedings of the Korean Society of Sericultural Science Conference
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• 2001.10a
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• pp.24-29
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• 2001

no Abstract, See Full Text

• Animal cells and systems
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• v.6 no.4
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• pp.327-333
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• 2002

Among the silk glands in the black widow spider Latrodectus mactans, the ampullate one is the most predominant gland in both sexes, and is com-posed of three functional parts - excretory duct, storage ampulla and convoluted tail regions. This experiment was performed using mechanical pulling stimulation with electric motor equipment to reveal a correlation between silk usage and silk producing system in this poisonous spider. The mature secretory products in glandular epithelium are closely packed and appear as electron-opaque spherical vesicles. A part of the vesicles with fine fibrillar paracrystalline texture seems to store some proteins which will function at the time of final assembly into fibrils. Most of the secretory silk products which originated from the rough endoplasmic reticula of the glandular epithelial cells are grown by fusion with surrounding small vesi-cles. However, the Golgi complex does not seem to play an important role in this process of secretion. According to progressive maturation of secre-tory silk product, these granules are progressively filled with a fine fibrillar material, and thus appear much more electron-dense than those of earlier states. When the secretory product is extruded from the glandular cavity, the epithelium is rapidly changed to a thinner layer of tall columnar cells with less definitive cell membranes. After extruding there ave a few secre-tory droplets within these cells, thus causing this region to stain much lighter.