• Journal of the Korean Dietetic Association
• /
• v.8 no.2
• /
• pp.175-184
• /
• 2002

This study is to investigate consequent nutrient intake status, influence of body mass index(BMI), and fat distribution on the silk amino peptide(SAP) and dietary fiber supplementation. During 2 months of this research (January to March, 2002), 45 women aged 20yr – 30yr (average age 24.6yr) were selected as subjects. Nutrient intake was investigated by questionnaire, 24-hr recall method. Antropometric assessments of the subjects were investigated by SBIA method(Segmental bioimpedance assay, In body 3.0). The results are as follows: mean body weight 57.7kg, mean body height 161.9cm mean BMI 22.0, and mean food habit score was 8.47. Defecation frequency was increased by dietary fiber supplementation. Frequency of pain during defecation was significantly decreased by dietary fiber supplementation (p<0.01). Feeling of residual feces was significantly improved by dietary fiber supplementation(p<0.001). Status of energy and carbohydrate intakes significantly decreased after dietary fiber supplementation(P<0.05). Body fat and WHR(waist hip ratio) significantly decreased after dietary fiber supplementation(P<0.001), and percent body fat was decreased by dietary fiber supplementation, significantly(P<0.05). Above results of this study show that dietary fiber-added routine diet improves defecation condition, and lessens body fat, percent body fat without losing body muscle. Especially, declination of abdominal fat and WHR were notable. That meant decreased risk factor.

• Proceedings of the Korean Fiber Society Conference
• /
• 2003.10a
• /
• pp.87-87
• /
• 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.

• Microbiology and Biotechnology Letters
• /
• v.34 no.2
• /
• pp.115-120
• /
• 2006

Enzymatic hydrolysis of silk fibers were investigated for the preparation of soluble silk peptides by ten food-grade proteases from Bacillus, Aspergilius, and plant sources. Silk fibers were dissolved for 1 hr in a 2:1 cosolvent (50% $CaCl_2$: ethanol) by heating at $90^{\circ}C$. The silk solution was filtered to remove Impurity particles and desalted for 50 hours by a dialysis process to remove the used cosolvent. When the silk hydrolysis was performed at $45^{\circ}C$ for 2 hours, most proteases from Bacillus and Aspergillus generated large amounts of insoluble aggregates. On the contrary, proteases from plant sources produced much less aggregates during prolonged incubations and also exhibited high hydrolysis activities. In regards of the solubility and broad molecular sizes of produced silk peptides, Bromelain was finally selected and applied for the enzymatic hydrolysis of silk fibers.

• Journal of Sericultural and Entomological Science
• /
• v.39 no.2
• /
• pp.197-202
• /
• 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.

• Journal of Sericultural and Entomological Science
• /
• v.2
• /
• pp.1-31
• /
• 1962

The purpose of this treatise is to prove the presence of cystine in silk fiber through wide sampling throughout all the sericultural processes of Bombyx mori.; also to show that disulfide cross linkages exist in the silk fiber. The conclusions reached were as follows: 1. Crystalline cystine was obtained from silk fibroin using Folin's Method. 2. Analytical data showing the cystine content of silk fiber and its related materials were obtained using Sullvan's Method as follows: Material Percent Cystine A. Mulberry leaf protein 0.175 B. Silkworm egg 0.33 C. Silkworm Body, matured, fat extracted, without silk gland 0.41 D. Silk gland, matured 1.23 E. Silkworm feces none F. Silkworm pupa, fat extracted 0.30 G. Silkworm moth, fat extracted 0.60 H. Raw Silk 0.22 I. Fibroin 0.175 J. Sericin 0.30 3. The presence of cystine in the silkworm was substantiated the existence of 0.175 % methionine in mulberry leaves and 0.12% methionine in the silk gland. 4. Part of the sulfhydryl compounds in the silk gland is believed to transfer to serine and methionine, with the former being secreted into the liquid silk finally as silk fiber and the latter used for nutritive purposes in the growing of silk gland tissue. 5. The cystine content is variable by mulberry species, silkworm species, sex, breeding process, and other culturing environments. 6. Hybrid silkworms require more nutritive amino acids for effective growth than the original parents, and secrete less of them as silk fiber. 7. From such an observation, the amino acid composition of silk fiber is believed to be fairly flexible. Cystine if included in the amorphous part of the fiber, especially in sericin. 8. The result from enriching the silkworm diet with pure cystine or wool cystine did not result in any advantage, therefore it is believed that the natural cystine and methionine contents in the mulberry leafaregoodenoughforsilkwormnutrition. 9. The disulfide cross linkage in silk fiber was verified by using the Harris Method. Contraction took place following the treatment of the fiber with various salts and acids. Comparisons were made with wool fiber. 10. During these experiments, the fibrious structure of silk fiber and the net-globular liquid form were photographed microscopically. It is believed that the globules of liquid silk are net-formed by the inter attraction of the OH ion of the globular peptide and the H ion of water as shown by the hair cracking behavior of the film. The net-globular protein precipitation from the mulberry protein solution showed that mulberry is a proper diet for the formation of fibrous protein in the silk fiber. 11. The significance of the presence of cystine in silk fiber as emphasized in this paper should result in modification of the general conception that cystine is absent from this fiber. NOTICE: A part of this treatise was presented at the annual Korea Sericultural Society meeting held in 1961.

• Korean Journal of Pharmacognosy
• /
• v.33 no.4 s.131
• /
• pp.312-318
• /
• 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.

• Korean Journal of Community Nutrition
• /
• v.8 no.3
• /
• pp.356-367
• /
• 2003

This study was to investigate the effects of a silk peptide, and prune and raspberry mixture on the body fat, serum lipid composition and fat distribution in Korean women during the time they received these supplements. During the 4 month period of this research (June to October, 2002), 75 women (average age 22.9 yr) were selected as subjects. Their nutrient intake was investigated by use of a questionnaire and the 24-hour recall method. Antropometric assessments of the subjects were investigated by using the SBIA Method (Segmental Bioimpedance Assay, Inbody 3.0). The results were as follows: their mean body weight was 59.3 kg, their mean body height was 161.7 cm and their mean Basal Metabolic Indices (BMI) was 22.7. The status of their dietary fiber intake significantly increased (p < 0.05) after use of the supplements. Their body fat significantly decreased following the $3^{rd}$ stage of supplementation (p < 0.05), and their percent of body fat signiflcantly decreased after supplementation (p < 0.05). Their triceps and suprailiac circumference significantly decreased following the $3^{rd}$ stage of supplementation (p < 0.05). Their waist circumferences and waist-hip ratios (WHR) significantly decreased after both the $2^{nd}$and $3^{rd}$ stage of supplementation (p < 0.05). Their total cholesterol significantly decreased following the $3^{rd}$ stage of supplementation, as compared to their baseline results and those obtained following the 1$^{st}$ stage of supplementation (p < 0.05). Their LDL-cholesterol and LDL / HDL ratios significantly decreased following the $3^{rd}$ stage of supplementation, as compared to their baseline results and those obtained following the 1$^{st}$ stage of supplementation (p < 0.05). Their 4-HNE and total antioxidant statuses significantly decreased following the $2^{nd}$ and $3^{rd}$stage of supplementation, as compared to their baseline results and those obtained following the $1^{st}$ stage of supplementation (p <0.05). Their $2^{nd}$ stage supplementation results were significantly negatively correlated with their triceps measurements and WHR (p < 0.05). Their $3^{rd}$stage supplementation results were significantly negatively correlated with their anterior thigh measurements (p < 0.05). The above results show that prune, raspberry, silk peptide and dietary fiber supplementation to a routine diet improves body fat distribution, total cholesterol, and triglyceride levels. The decrease of abdominal fat and WHR were especially noteworthy. This implies a decrease of risk factors. (Korean J Community Nutrition 8(3) : 356~367, 2003)003)

• Proceedings of the Korean Society of Sericultural Science Conference
• /
• 2002.10a
• /
• pp.64-64
• /
• 2002

No Abstract, See Full Text

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.36 no.5
• /
• pp.554-562
• /
• 2007

Ceramide rich intercellular lipid lamellae are thought to be particularly important in maintaining the structural integrity of epidermal barrier. Ceramide is synthesized de novo by serine palmitoyltransferase (SPT) phospholipid intermediates, serine and palmitic acid persist within the stratum corneum. The ceramide which is synthesized is degraded with fatty acid and sphingosine by degradative enzyme ceramidase. The depletion of ceramide in stratum corneum was reported in the atopic dermatitis. As an effort to search for the dietary source for improving the level of ceramide in epidermis, the dietary effects of various-typed silk protein were compared. Seventy male NC/Nga mice, an animal model of atopic dermatitis, were divided into seven groups: group CA as an atopic control with control diet, group S: 1% crude sericin diet, group F: 1% crude fibroin diet, group PS : peptide pattern of sericin(Mw 5000), group PF: peptide pattern of fibroin (Mw 1500), group AS: manufactured the same as amino acid profile of sericin and group AF: manufactured the same as amino acid profile of fibroin. Ten male BALB/c mice were served as group C (control group) control diet. All mice were fed on diet and water ad libitum for 10 weeks. Dry skin condition was established in group CA as ceramide content was decreased. Despite a marked decrease of mRNA and prorein expression of SPT, enzyme do novo synthesis, ceramide content of group S was dramatically increased by inhibiting the mRNA and protein expression of degradative enzyme ceramidase. However, dietary supplementation of crude silk fibroin protein (group F) and in other groups that were supplemented with either amino acid or peptide type of sericin or fibroin did not increase the level of ceramide. Together, our data demonstrate that dietary supplementation of crude sericin is more effective at improving ceramide level in epidemis of NC/Nga mice.

• Journal of Life Science
• /
• v.10 no.2
• /
• pp.188-195
• /
• 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.