• Proceedings of the Korean Society for Applied Microbiology Conference
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• 2001.06a
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• pp.40-45
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• 2001

Raw starch-digesting amylase (BF-2A, M.W. 93, 000 Da) from Bacillus circulans F-2 was converted to two components during digestion with subtilisin. Two components were separated and designated as BF-2A' (63, 000 Da) and BF-2B (30, 000 Da), respectively. BF-2A' exhibited the same hydrolysis curve for soluble starch as the original amylase (BF-2A). Moreover, the catalytic activities of original and modified enzymes were indistinguishable in $K_{m}$, Vmax for, and in their specific activity for soluble starch hydrolysis. However, its adsorbability and digestibility on raw starch was greatly decreased. Furthermore, the enzymatic action pattern on soluble starch was greatly different from that of the BF-2A. A smaller peptide (BF-2B) showed adsorb ability onto raw starch. By these results, it is suggested that the larger peptide (BF-2A') has a region responsible for the expression of the enzyme activity to hydrolyze soluble substrate, and the smaller peptide (BF-2B) plays a role on raw starch adsorption. A similar phenomenon is observed during limited proteinase K, thermolysin, and endopeptidase Glu-C proteolysis of the enzyme. Fragments resulting from proteolysis were characterized by immunoblotting with anti-RSDA. The proteolytic patterns resulting from proteinase K and subtilisin were the same, producing 63- and 30-kDa fragments. Similar patterns were obtained with endopeptidase Glu-C or thermolysin. All proteolytic digests contained a common, major 63-kDa fragment. Inactivation of RSDA activity results from splitting off the C-terminal domain. Hence, it seems probable that the protease sensitive locus is in a hinge region susceptible to cleavage. Extracellular enzymes immunoreactive toward anti-RSDA were detected through whole bacterial cultivation. Proteins of sizes 93-, 75-, 63-, 55-, 38-, and 31-kDa were immunologically identical to RSDA. Of these, the 75-kDa and 63-kDa proteins correspond to the major products of proteolysis with Glu-C and thermolysin. These results postulated that enzyme heterogeneity of the raw starch-hydrolysis system might arise from the endogeneous proteolytic activity of the bacterium. Truncated forms of rsda, in which the gene sequence encoding the conserved domain had been deleted, directed the synthesis of a functional amylase that did not bind to raw starch. This indicates that the conserved region of RSDA constitutes a raw starch-binding domain, which is distinct from the active centre. The possible role of this substrate-binding region is discussed.d.

• Toxicological Research
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• v.22 no.4
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• pp.381-390
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• 2006

Astaxanthine is a pigment that belongs to the family of the xanthophylls, the oxygenated derivatives of carotenoids whose synthesis in plants derives from lycopene. Astaxanthine is also a carotenoid widely used in salmonid and crustacean aquaculture to provide the pink color characteristic of that. Recent study reported that astaxanthine has the role as a detoxicant against the free radicals. On our study, we estimated the genotoxicity in ICR mice and possibility as antioxidant reagents of mutant Phaffia rhodozyma strain over expressing the astaxanthine by gamma-lay and carophyll pink including astaxanthine in apoE knock out mice, respectively. In our study, we administered Phaffia rhodozyma (2 mg and 3 mg) and carophyll pink for 4 and 8 week. The clinical sign and mortality were not detected compared with control groups. In the mutant frequency of hprt gene and chromosome aberration in splenic cells, there was not detected abnormality. There was not critical change in hematological and serum biochemical test compared to control. In expression level of repair enzyme, increase of catalase were detected and increase of expression level of Nrf-2 was detected in Phaffia rhodozyma (3 mg) and carophyll pink in 8 week treated group. In GSH level, the group of treated with Phaffia rhodozyma (3 mg) showed the increase of the GSH. In conclusion, mutant Phaffia rhodozyma and caphyll pink may be applied to the effective food additives to reduce the free radical.

• Journal of Life Science
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• v.22 no.8
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• pp.1107-1113
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• 2012

In this experiment, the effects of Pueraria thunbergiana extracts on the activation of immune cells were studied. An immune cell-activating factor was partially purified from P. thunbergiana by means of physiological saline extraction, acetone precipitation, and heating inactivation. P. thunbergiana extracts increased the proliferation of spleen cells and induced the production of IL-2, IL-6, TNF-${\alpha}$, and IFN-${\gamma}$ by spleen cells. Also, they increased the proliferation of purified B cells and the production of IgM antibody in a dose-dependent fashion. The extract self-induced NO synthesis in a mouse macrophage cell line (RAW264.7). When cell lines were treated with extracts, the cytokines' (IL-$1{\beta}$, IL-6, and TNF-${\alpha}$) production was markedly increased. Therefore, P. thunbergiana extract can self-activate spleen cells, B cells, and macrophages. These results might be useful in further studies into a possible immune-activating agent derived from P. thunbergiana for the development of functional foods and drugs.

• Journal of Life Science
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• v.23 no.8
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• pp.1064-1072
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• 2013

Circadian rhythm is controlled by hormonal oscillations governing the physiology of all living organisms. In mammals, the main function of the pineal gland is to transform the circadian rhythm generated in the hypothalamic suprachiasmatic nucleus into rhythmic signals of circulating melatonin characterized by a largely nocturnal increase that closely reflects the duration of night time. The pineal gland has lost direct photosensitivity, but responds to light via multi-synaptic pathways that include a subset of retinal ganglion cells. Rhythmic control is achieved through a tight coupling between environmental lighting and arylalkylamine-N-acetyltransferase (AANAT) expression, which is the rhythm-controlling enzyme in melatonin synthesis. Previous studies on the nocturnal expression of AANAT protein have described transcriptional, post-transcriptional, and post-translational regulatory mechanisms. Molecular mechanisms for dependent AANAT expression provide novel aspects for melatonin's circadian rhythmicity. Extensive animal research has linked pineal melatonin for the expression of seasonal rhythmicity in many mammalian species to the modulation of circadian rhythms and to sleep regulation. It has value in treating various circadian rhythm disorders, such as jet lag or shift-work sleep disorders. Melatonin, also, in a broad range of effects with a significant regulation influences many of the body's physiological functions. In addition, this hormone is known to influence reproductive, cardiovascular, and immunological regulation as well as psychiatric disorders.

• Journal of Life Science
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• v.26 no.12
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• pp.1477-1486
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• 2016

Lactulose (4-O-${\beta}$-D-galactopyranosyl-D-fructose) is a non-digestible synthetic ketose disaccharide which can used in food and pharmaceutical fields due to its useful functions for encephalopathy, chronic constipation, hyperammonemia, etc. Therefore, the lactulose is regarded as one of the most important disaccharides and have been concentrated much interesting as an attractive functional material in the current industry. From this reason, the research related on the production of lactulose has been carried out various academic and industrial research groups. To produce lactulose, two main methods, chemical production and enzymatic production have been used. Commercially lactulose produced by alkaline isomerization of lactose as chemical production method but it has many disadvantages such as rapid lactulose degradation, purification, and waste management. From these reasons, lactulose produced by enzymatic method which solves these problems has been suggested as a proper method for lactulose production. Two different enzymatic methods have been reported as methods for lactulose production. Lactulose can be obtained through hydrolysis and transfer reaction catalyzed by a ${\beta}$-galactosidase which requires fructose as co-substrate and exhibits a low conversion. Alternatively, lactulose can be produced by direct isomerization of lactose to lactulose catalyzed by cellobiose 2-epimerase which requires lactose as a single substrate and achieves a high lactulose yield. This review summarizes the current state of lactulose production by chemical and biological methods.

• Journal of Applied Biological Chemistry
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• v.60 no.4
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• pp.327-332
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• 2017

In this study, the whitening activity of Nymphoides indica extract in B16F10 cells were measured. Inhibition rate of tyrosinase from mushroom was 42% at $1,000{\mu}g/mL$. And inhibition of tyrosinase and melanin biosynthesis in B16F10 cells were 26 and 25% at $5{\mu}g/mL$, respectively. The expression levels of cAMP and protein kinase A (PKA), which are higher levels of melanin-related factors, were found to be decreased in a dose-dependent manner. In addition, the expression rate of protein and mRNA of tyrosinase, tyrosinase related protein 1 (TRP1), tyrosinase related protein 2 (TRP2) and microphthalmia associated transcription factor (MITF). In this study, it was confirmed that the N. indica extract effectively inhibited the activity of tyrosinase, TRP1, TRP2 and MITF as well as the activity of PKA by effectively inhibiting cAMP. Therefore, it was confirmed that the N. indica extract has high value as a functional material.

• Journal of Applied Biological Chemistry
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• v.63 no.1
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• pp.75-82
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• 2020

In this study, extracts from the Green ball apple peel (GBE) and the newly bred green ball apple from Korea showed inhibition effects on photo-aging factor regulation associated with skin aging. To investigate the inhibition effect on photo-aging factor regulation in skin, GBE was treated with UVB to induce photo-aging related factors in CCD986sk fibroblast cells. Photo-aging factor regulation effects showed that GBE inhibited UVB-stimulated matrix metalloproteinase (MMP)-1 and MMP-9 protein synthesis in collagen type I alpha 2 chain (COL1A2), MMP-1, MMP-9, and tissue inhibitors of metalloproteinase (TIMP)-1 protein expression. The expression of COL1A2 and TIMP-1 protein was significantly increased. The mRNA expression levels of COL1A2, MMP-1, MMP-9, hyaluronan synthase (HAS)2, transforming growth factor (TGF)-β, and TIMP-1 were decreased by GBE. The expression of TIMP-1 and TGF-β, which are regulators involved in matrix metalloproteinase and type I procollagen expression, was found to increase with increasing expression of COL1A2. The expression of HAS2, which is involved in the production of hyaluronic acid, one of the structural proteins constituting the skin, was also confirmed. Therefore, GBE showed excellent efficacy against photo-aging factor regulation and could be used as functional material to prevent and treat skin aging.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.8
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• pp.5452-5457
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• 2015

Conjugating a phytochemical, a strong antioxidant, with a functional peptide not only compensates for its stability, but also improves its solubility and anti-wrinkle effects, thereby contributing to the possibility of becoming an excellent cosmetic ingredient. Thus, in this study we examined the potential cosmetic use of a phytochemical-peptide derivative using gallic acid, a phytochemical with antioxidant, anti-inflammatory, and anti-cancer effects. To evaluate the antioxidant and wrinkle-improving efficacy of 5 synthesized gallic acids conjugated with LVH, IVH, KTTKS, YGGFM, and YGGFLRKYP respectively, we observed the expression of genes related to wrinkle improvement using DPPH radical scavenging activity and real-time PCR. As a result, all 5 derivatives had excellent free radical scavenging effects. The expression level of genes involved collagen synthesis also increased, and the secreted peptides during collagen production contributed to their antioxidant and wrinkle improving effects. These results mark the potential use of gallic acid peptide derivatives as a cosmetic ingredient for anti-oxidation and wrinkle improvement.

• Food Science and Biotechnology
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• v.18 no.1
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• pp.228-233
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• 2009

This study was conducted to examine the changes in the molecular structure and physiological activities of silk fibroin by gamma irradiation. The results of gel permeation chromatography and sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed that the molecular weight of fibroin was increased depending upon the irradiation dose. Secondary structure of fibroin determined by using circular dichroism revealed that the ratio of $\alpha$-helix was increased up to 10 kGy and then decreased depending upon the irradiation dose. Whereas, the ratio of $\beta$-sheet, $\beta$-turn, and random coil were decreased and then increased with an alteration in the $\alpha$-helix secondary conformation. The 2.2-diphenyl-1-picryl-hydrazil (DPPH) radical scavenging activity of fibroin was increased by gamma irradiation at 5 kGy, but was decreased above 10 kGy depending upon the irradiation dose. Also, the inhibition activities of tyrosinase and melanin synthesis of fibroin were increased by gamma irradiation. These results indicated that gamma irradiation could be used as an efficient method to make fibroin more suitable for the development of functional foods and cosmetics.

• Applied Chemistry for Engineering
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• v.7 no.3
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• pp.496-503
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• 1996

Aromatic and aliphatic copolyesters for the dispersing agent were synthesized by two stage reaction, esterification and polycondensation. Copolyesters were blended with PET in the melt state and their thermal and rheological properties were investigated. From GPC analysis Mn's and Mw's of copolyesters were about 30000 and 65000g/mol, respectively. From DSC experiment copolyesters had melting range of $90{\sim}150^{\circ}C$. Copolymer composition was in good agreement with comonomer feed ratio from $^1H$-NMR analysis. Copolyesters and SPA (standard sample) were blended with PET in the melt state. From DSC experiment, copolyesters and SPA were miscible with PET. From the dynamic melt viscosity experiment, melt viscosity of blended sample was increased as the content of aromatic copolyester was increased, while it was decreased as the content of aliphatic and SPA were increased. As for volume resistivity of dry color containing carbon black and copolyesters with dispersing time, aromatic copolyester showed highest value. It was conferred from this result that aromatic copolyester was the best dispersing agent for carbon black in PET resin.