• BMB Reports
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• 제44권12호
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• pp.787-792
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• 2011

We investigated whether silk fibroin peptide derived from the silkworm, Bombyx mori, could inhibit inflammation and enhance the anti-inflammatory activity of Tat-superoxide dismutase (Tat-SOD), which was previously reported to effectively penetrate various cells and tissues and exert anti-oxidative activity in a mouse model of inflammation. Inflammation was induced by topical treatment of mouse ears with 12-O-tetradecanoylphorbol-13-acetate (TPA). Histological, Western blot, and reverse transcription-polymerase chain reaction data demonstrated that silk fibroin peptide or Tat-SOD alone could suppress elevated levels of cyclooxygenase-2, interleukin-6, interleukin-1beta, and tumor necrosis factor-alpha induced by TPA. Moreover, silk fibroin peptide significantly enhanced the anti-inflammatory activity of Tat-SOD, although it had no influence on in vitro and in vivo transduction of Tat-SOD. Silk fibroin peptide exhibited anti-inflammatory activity in a mice model of inflammation. Therefore, silk fibroin peptide alone or in combination with Tat-SOD might be used as a therapeutic agent for various inflammatory diseases.

• Journal of Microbiology and Biotechnology
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• 제23권12호
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• pp.1779-1784
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• 2013

Although enzyme-hydrolyzed silk fibroin has been reported to enhance cognitive function before, it has been still unknown which peptides can improve memory. Here we report that amino acid sequences of three novel peptides were identified from fibroin hydrolysate. Fibroin hydrolysate was obtained by hydrolysis with protease after partial hydrolysis with 5M $CaCl_2$. Synthesized peptides derived from these sequences improved scopolamine-induced memory impairments in mice. We confirmed this hydrolysate had effects that improved learning and memory abilities by performing the Rey-Kim test. From this hydrolysate of silk fibroin, amino acid sequences of eight peptides were identified by LC-MS/MS. Three peptides (GAGAGTGSSGFGPY, GAGAGSGAGSGAGAGSGAGAGY, and SGAGSGAGAGSGAGAGSGA) were synthesized to investigate whether they could improve memory. Passive avoidance test and Morris water maze test were performed, and all peptides showed memory-enhancing abilities on scopolamine-induced memory impairments in mice. In this study, we identified three novel peptides that could improve memory, and that silk fibroin hydrolysate was a mixture of various active peptides that could enhance memory.

• International Journal of Industrial Entomology and Biomaterials
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• 제20권2호
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• pp.87-91
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• 2010

Silk fibroin model peptide, alanine pentamer was synthesized through solid-phase method and modified with poly(ethylene glycol). Nuclear magnetic resonance spectrometry and Fourier-transform infrared spectroscopy showed the conformation of alanine pentamer, $\beta$-sheet structure and random coil conformation were not changed with PEGylation. Differential scanning calorimetry showed that relatively strong exothermic peak around $180^{\circ}C$ by PEGylation. No cytotoxicity of PEGylated pentamer was observed by L929 cell proliferation test.

• 한국잠사곤충학회지
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• 제39권2호
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• pp.197-202
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• 1997

To hydrolyze silk fibroin was treated with NaOH solution on various concentrations and times. And it was examined that the addition effects of NaHSO3 solution on the solubility and colouring of silk fibroin. As obtained results are as follows; The more increasement of concentration and time of NaOH treatment, the more increasement of solubility but solubility was slight above 3% concentration of NaOH. Fibroin yield was decreased above 3% concentration. This was due to formation of peptide or amino acids below molecular weight 3,000. Most of molecular weight distribution came out to be under 3,000 in 2% concentration and 4hrs of NaOH treatment. The more increasement of adding concentration and 4hrs of NaOH treatment. The more increasement of adding concentration of NaHSO3, the more reduction of solubility but white index of powder increased. In the results of FT-IR spectras of silk fibroin powder obtained by various concentrations of NaHSO3 treatment, the absorbent peak at 3,400 cm-1 which was considered as -CH=N- (azomethine) was disappeared by the more addition of NaHSO3. It showed that absorbent peak of $\beta$-fibroin moved into low temperature region and transferred to $\alpha$- and random coil structure through the DSC experiment. In the results of amino acid analysis, alkali hydrolysis reduced the oxy amino contents acid like serine and tyrosine, but increased the glycine content by the more addition of NaHSO3.

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 2003년도 The Korea-Japan Joint Symposium
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• pp.88-89
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• 2003

A series of novel spinning acrylic polymer containing silk protein were synthesized by copolymerization of acrylonitrile (AN) and silk fibroin peptide (SFP) modified by acryloyl chloride (AC) with vinyl groups. The viscosity values of these copolymers showed that the copolymers have good spinnability, which are synthesized under the condition of putting a micro amount of metal ions into synthesizing solvent. The fiber based on the poly (AN-co-SFP) was prepared and characterized by SEM, FTIR measurement of its shell and core flakes, and moisture absorption. The fiber appeared a smooth surface and could be assumed to have excellent adhesive between SFP and PAN. Furthermore, these fibers showed a shell-core structure and excellent moisture absorption.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2005년도 생물공학의 동향(XVI)
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• pp.440-440
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• 2005

• 생약학회지
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• 제33권4호통권131호
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• pp.312-318
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• 2002

Effect of the acid hydrolysate of silk fibroin on obesity was investigated in obese(057BL/KsJ-db/db) mice. After 8 weeks feeding of 1%(w/w) or 3%(w/w) fibroin hydrolysate, the extents of reduction in body weight were significantly higher than that of obese control. The weight reduction in female mice was higher than that in male mice. Plasma leptin in male mice increased up to 1.8-fold higher level than obese control by feeding hydrolysate. In case of female mice, however, it rather decreased with increased feeding concentration of hydrolysate. From the results of high glycine and serine contents of peptide fractions contained in fibroin hydrolysate, it was inferred that fibroin peptides might affect xylosyltransferase(XT) activity on chondroitin sulfate synthesis causing to change susceptibility of adipocytes to hormones such as insulin followed by the reduced leptin synthesis in female mice. The result of the higher lipolysis in hydrolysate-fed group than obese control indicated that the reduction in body weight was due to the increased lipolytic activities in male and female mice in common.

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 2003년도 The Korea-Japan Joint Symposium
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• pp.87-87
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• 2003

Three kinds of acrylic polymers containing silk protein were synthesized, which are (1) blending of silk fibroin (SF) fiber and polyacrylonitrile (PAN); (2) graft-copolymer of PAN onto SFs; (3) random-copolymer synthesized by copolymerization of acrylonitrile (AN) and silk fibroin peptide (SFP) with vinyl groups, and their solubility, thermal property, and moisture absorption was investigated, respectively. These polymers have difference solubility and attributable to their structure. Their excellent thermal stabilities and better moisture absorptions were indicated.

• Journal of Microbiology and Biotechnology
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• 제22권4호
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• pp.494-500
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• 2012

Silk fibroin (SF) peptide has been traditionally used as a treatment for flatulence, spasms, and phlegm. In this study, we examined whether SF peptide enhanced the anti-inflammatory effect of PEP-1-FK506 binding protein (PEP-1-FK506BP) through comparing the anti-inflammatory activities of SF peptide and/or PEP-1-FK506BP. In the presence or absence of SF peptide, transduction levels of PEP-1-FK506BP into HaCaT cells and mice skin and anti-inflammatory activities of PEP-1-FK506BP were identified by Western blot and histological analyses. SF peptide alone effectively reduced both mice ear edema and the elevated levels of cyclooxygenase-2, interleukin-6 and $-1{\beta}$, and tumor necrosis factor-${\alpha}$, showing similar anti-inflammatory effect to that of PEP-1-FK506BP. Furthermore, co-treatment with SF peptide and PEP-1-FK506BP exhibited more enhanced anti-inflammatory effects than the samples treated with SF peptides or PEP-1-FK506BP alone, suggesting the possibility that SF peptide and PEP-1-FK506BP might interact with each other. Moreover, the transduction data demonstrated that SF peptide did not affect the transduction of PEP-1-FK506BP into HaCaT cells and mice skin, indicating that the improvement of anti-inflammatory effect of PEP-1-FK506BP was not caused by enhanced transduction of PEP-1-FK506BP. Thus, these results suggest the possibility that co-treatment with SF peptide and PEP-1-FK506BP may be exploited as a useful therapy for various inflammation-related diseases.

• 생명과학회지
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• 제10권2호
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• pp.188-195
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• 2000

In order to understand molecular events during silk synthesis and provide genetic resources for molecular breeding, we had analyzed the cDNA library constructed from the posterior silkgland of Antheraea yamamai and partially sequenced 276 randomly selected genes from the cDNA library. Database comparisons of the expressed sequence tags (ESTs) revealed that 26 non-redundant clones showed a high similarity with previously identified genes. Among them, 17 clones exhibited a homology with previously identified insect genes and 9 clones were identical to genes that were previously identified from other organisms. A functional categorization showed that silk synthesis-defense- or stress-related genes, as well as genes involved in the metabolic pathways and in the transcriptional or translational apparatus are represented. In this report, the clone (AY479) which had high similarity with fibroin from A. pernyi was particularly analyzed in detail. The AY479 clone was carboxyl terminal region of fibroin. The 472 bp cDNA has 123 amino acids that shared 85% homology with the fibroin from A. pernyi and its deduced peptide had unique feature, that is, sites of alanine rich residues.