• Journal of Marine Bioscience and Biotechnology
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• v.14 no.2
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• pp.133-142
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• 2022

The increased production and consumption of polyethylene terephthalate (PET)-based products over the past several decades has resulted in the discharge of countless tons of PET waste into the marine environment. PET microparticles resulting from the physical erosion of general PET wastes end up in the ocean and pose a threat to the marine biosphere and human health, necessitating the development of new technologies for recycling and upcycling. Notably, enzyme-mediated PET degradation is an appealing option due to its eco-friendly and energy-saving characteristics. PETase, a PET-hydrolyzing enzyme originating from Ideonella sakaiensis, is one of the most thoroughly researched biological catalysts. However, the industrial application of PETase-mediated PET recycling is limited due to the low stability and poor reusability of the enzyme. Here we developed the whole-cell catalyst (WCC) in which functional PETase is attached to the outer membrane of Escherichia coli. Immunoassays are used to identify the surface-expressed PETase, and we demonstrated that the WCC degraded PET microparticles most efficiently at 30℃ and pH 9 without agitation. Furthermore, the WCC increased the PET-degrading activity in a concentration-dependent manner, surpassing the limited activity of soluble PETase above 100 nM. Finally, we demonstrated that the WCC could be recycled up to three times.

• BMB Reports
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• v.48 no.6
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• pp.313-318
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• 2015

Matrix metalloproteinases (MMPs) are zinc-dependent endopeptidases that degrade the extracellular matrix (ECM) and regulate the extracellular microenvironment. Despite the significant role that MMP activity plays in cell-cell and cell-ECM interactions, migration, and differentiation, analyses of MMPs in vitro and in vivo have relied upon their abundance using conventional immunoassays, rather than their enzymatic activities. To resolve this issue, diverse nanoprobes have emerged and proven useful as effective activity-based detection tools. Here, we review the recent advances in luminescent nanoprobes and their applications in in vitro diagnosis and in vivo imaging of MMP activity. Nanoprobes with the purpose of sensing MMP activity consist of recognition and detection units, which include MMP-specific substrates and luminescent (fluorescent or bioluminescent) nanoparticles, respectively. With further research into improvement of the optical performance, it is anticipated that luminescent nanoprobes will have great potential for the study of the functional roles of proteases in cancer biology and nanomedicine. [BMB Reports 2015; 48(6): 313-318]

• BMB Reports
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• v.39 no.2
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• pp.189-196
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• 2006

Alterations in the amino acid structure or sequence can generate neo-epitopes from self-proteins causing autoaggressive immune attack. Reactive nitrogen species are an important factor that induces post-translational modification of proteins by cellular reduction and oxidation mechanism; cysteinyl-nitrosylation or tyrosine nitration leading to potentially pathogenic pathways. It was thought of interest to investigate the immunogenicity of nitrated poly L-tyrosine vis-$\`{a}$-vis its possible role in the induction of antibodies in systemic lupus erythematosus (SLE). Commercially available poly L-tyrosine was exposed to nitrating species and the damage was monitored by UV spectroscopy and alkaline gel electrophoresis. The results indicated the formation of 3-nitrotyrosine. Nitrated poly L-tyrosine induced higher titre antibodies as compared to the native form. Nitrated poly L-tyrosine was recognized by the autoantibodies present in the sera of patients suffering from SLE by enzyme immunoassays and band shift assay. The possible role of nitrated self-proteins has been discussed in the production of circulating anti-DNA antibodies in SLE.

• The Journal of Internal Korean Medicine
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• v.21 no.3
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• pp.433-441
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• 2000

Objective : To analyze the effects of Yukmijihwang-tang, Taeksa-tang, Silbi-um on mesangial cell proliferation, fibronectin synthesis and MHC-class II expression. Methods : Laboratory studies were performed with the method of surface enzyme immunoassays or flow cytometry after addition of peripheral blood mononuclear cells(PBMC) supernatants treated with medications using the cultured human mesangial cells. Results : 1. Silbi-um produces more suppressive effect than control group and hydrocortisone group on the mesangial cell proliferation. In Yukmijihwang-tang, Taeksa-tang and Silbi-um, mesangial cell proliferation significantly decreased than in hydrocortisone group 2. In the 'without fetal bovine serum' study, Yukmijihwang-tang take more suppressive effect than Control group on the fibronectin synthesis. In the 'with fetal bovine serum' study, Yukmijihwang-tang, Taeksa-tang, Silbi-um all have suppressive effect, but it hasn' t any statistical significance. 3. Yukmijihwang-tang, Taeksa-tang, Silbi-um all have a suppressive effect on the MHC-class II expression. Conclusions : Herb medicine generally show a suppressive effect on the suppression of the mesangial cell proliferation, fibronectin synthesis and MHC-class II expression.

• Food Science and Biotechnology
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• v.17 no.3
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• pp.623-630
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• 2008

A non-instrumental immunochromatographic (ICG) strip-test and direct competitive enzyme-linked immunosorbent assay (DC-ELISA) for aflatoxin B1 (AFB1) determination were developed and optimized. The detection limits of ICG strip-test and DC-ELISA were 0.5 and 0.004 ng/mL, respectively, and these methods possessed a cross-reaction to aflatoxins. The results of spiked samples by both methods were coincided with the amount spiked AFB1 and the comparative analyses of 172 real samples by 2 immunoassays and high performance liquid chromatography (HPLC) showed a good agreement. Especially, the ICG strip-test is easier to perform and quicker, but less sensitivity than DC-ELISA. Both methods could analyze a high sample throughput with short time, but the sample throughput of ICG strip-test was better. Therefore, the ICG strip-test can be used as a simple, easy, non-instrumental, and fast screening technique for AFB1 determination.

• Journal of Physiology & Pathology in Korean Medicine
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• v.18 no.6
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• pp.1694-1698
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• 2004

We hope to evaluate the effects of Sabaek-san for the bronchial asthma using assesment on the metrix metalloproteinase-9(MMP-9) after Sabaek-san was intravenously administered OVA-sensitized and -challenged mice. Seventy-two female mice, 8-10 weeks of age and free of murine specific pathogens, were used. Of the seventy-two mice, twenty-four mice were not sensitized and forty-eight mice were sensitized by intraperitoneal injection of OVA. Of the sensitized mice, twenty-four mice didn't administrate Sabaek-san and twenty-four administrated Sabaek-san. Mice were sensitized on days 1 and 14 by intraperitoneal injection of 20 fig OVA. On days 21, 22 and 23 after the initial sensitization, the mice were challenged for 30 minutes with an aerosol of 1% OVA in saline. Sabaek-san administered 200㎎/㎏ in the tail of the mouse, one time per day, for 7 days, beginning 14 days after first sensitization. Bronchoalveolar lavage was performed 72 hours after the last challenge, and total cell numbers in the BAL fluid were count. Also, level of MMP-9 in the BAL fluid were measured by Enzyme immunoassays and Western blot analysis. Enzyme immunoassay revealed that MMP-9 levels in the BAL fluids significantly increased 72 h after OVA inhalation compared with levels in the control group. After administration of the Sabaek-san, the levels of the MMP-9 in BAL fluids 72 h after OVA inhalation reduced dramatically. Western blot analysis revealed that MMP-9 levels increased in the all mice which were challenge with OVA without administered Sabaek-san compared the normal mouse. However, in the groups of the administered Sabaek-san, the MMP-9 level markedly decreased. Sabaek-san might be effect the treatment of the bronchial asthma as a inhibition of the MMP-9.

• BMB Reports
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• v.31 no.5
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• pp.519-523
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• 1998

We have previously reported that anti-glucose-6-phosphate dehydrogenase (G6PD) serum raised against native G6PD (nG6PD) enzyme recognized nG6PD antigen poorly in competitive enzyme-linked immunosorbent assay (ELISA) (Kim, 1997). In the present study, we investigated whether anti-G6PD serum raised against nG6PD can react with denatured G6PD effectively in competitive ELISA. We used partially active G6PD (paG6PD) by repeated freeze-thawing or SDS-denatured G6PD (SDS-G6PD) as both immobilized and soluble antigens, and anti-G6PD serum raised against nG6PD for competitive ELISA. The polystyrene cuvettes coated with either paG6PD or SDS-G6PD were challenged with a mixture of a limiting amount of anti-G6PD serum and various doses of paG6PD or SDS-G6PD as competitors, followed by incubation with alkaline phosphatase-anti-IgG conjugate. The competitive ELISA with paG6PD or SDS-G6PD antigen exhibited the sigmoidal dose-response curve characteristic of competition immunoassays. Furthermore, Triton-denatured G6PD (Triton-G6PD) was used in competitive ELISA. The paG6PD, SDS-G6PD, or Triton-G6PD used as competitors increased the inhibition of antibody binding to immobilized either of nG6PD or denatured G6PD compared with nG6PD competitor. The inhibition by denatured G6PD competitors was more pronounced at high competitor concentrations than at low counterparts. We conclude that anti-G6PD serum raised against nG6PD can effectively react with denatured G6PD in competitive ELISA and that our anti-G6PD serum recognizes denatured enzymes better than active enzymes.

• The Journal of Pediatrics of Korean Medicine
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• v.20 no.1
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• pp.181-194
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• 2006

Objective : Author evaluate the effects of Citri Reticulatae Viride Pericarpium for the bronchial asthma using assesment of the vascular endothelial growth factor after Citri Reticulatae Viride Peicarpium was intravenously administered Ovalbumine(OVA)-sensitized and -challenged mice. Material and Methods : Twenty-four female mice, 8-10 weeks old and free of murine specific pathogens, were sensitized by intraperitoneal injection of OVA. Of the sensitized mice, ten mice didn't administrate Citri Reticulatae Viride Pericarpium and the other ten mice administrated Citri Reticulatae Viride Pericarpium. Mice were sensitized on the first and fourteen days introspectional injection of 20 ${\mu}g$ OVA. After$21^{st}\;22^{th}\;and\;23^{rd}$, the initial sensitization, the mice were challenged for 30 minutes with an aerosol of 1% OVA in saline. Citri Reticulatae Viride Pericarpium administered 200mg/kg in the tail of the mouse, one a day, for 7 days and beginning 14 days after first sensitization. Bronchoalveolar lavage was performed 72 hours after the last challenge, and total cell numbers in the BAL fluid were count. Also, lever of VEGF in the BAL fluid was measured by Enzyme immunoassays and Western blot analysis. Results: Total cell numbers in BAL fluid were significantly greater than from 72 hrs after OVA inhalation compared with cell numbers in the control group. However, there was no difference of the total cell numbers between OVA-challenge groups without Citri Reticulatae Viride Pericarpium, and OVA-challenge with Citri Reticulatae Viride Pericarpium. Enzyme immunoassay revealed that VEGF levels in the BAL fluids were significantly increased 72 hrs after OVA inhalation compared with levels in the control group. After administration of the Citri Reticulatae Viride Pericarpiu, the levels of the VEGF in BAL fluids 72 hrs after OVA inhalation reduced dramatically. Western blot analysis revealed that VEGF protein levels were increased in the all mice which were challenge with OVA, without administered Citri Reticulatae Viride Pericarpium, compared the normal mouse. However, in the groups of the administered Citri Reticulatae Viride Pericarpium, the VEGF protein level markedly decreased. Conclusion: Citri Reticulatae Viride Pericarpium might affect the treatment of the bronchial ashma as a inhibition of the VEGF.

• Mycobiology
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• v.48 no.5
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• pp.399-409
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• 2020

Many of the 𝛽-glucans are known to have antihypertensive activities, but, except for angiotensin-converting enzyme II inhibition, the underlying mechanisms remain unclear. Corin is an atrial natriuretic peptide (ANP)-converting enzyme. Activated corin cleaves pro-ANP to ANP, which regulates water-sodium balance and lowers blood pressure. Here, we reported a novel antihypertensive mechanism of 𝛽-glucans, involved with corin and ANP in mice. We showed that multiple oral administrations of 𝛽-glucan induced the expression of corin and ANP, and also increased natriuresis in mice. Microarray analysis showed that corin gene expression was only upregulated in mice liver by multiple, not single, oral administrations of the 𝛽-glucan fraction of Phellinus baumii (BGF). Corin was induced in liver and kidney tissues by the 𝛽-glucans from zymosan and barley, as well as by BGF. In addition to P. baumii, 𝛽-glucans from two other mushrooms, Phellinus linteus and Ganoderma lucidum, also induced corin mRNA expression in mouse liver. ELISA immunoassays showed that ANP production was increased in liver tissue by all the 𝛽-glucans tested, but not in the heart and kidney. Urinary sodium excretion was significantly increased by treatment with 𝛽-glucans in the order of BGF, zymosan, and barley, both in 1% normal and 10% high-sodium diets. In conclusion, we found that the oral administration of 𝛽-glucans could induce corin expression, ANP production, and sodium excretion in mice. Our findings will be helpful for investigations of 𝛽-glucans in corin and ANP-related fields, including blood pressure, salt-water balance, and circulation.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.28 no.1
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• pp.135-149
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• 2002

To date, research on the regulation of melanogenesis has focused on factors which affect tyrosinase, the rate-limiting enzyme in the melanogenic pathway, by searching for chemicals which competitively inhibit tyrosinase function. Many types of tyrosinase inhibitors have been developed, but no satisfactory results have been made clinically until now, To find a new whitening agent, which effectively inhibits melanogenesis, we synthesized several compounds and selected compounds by cell-based assay system. Finally, 3, 4, 5-trimethoxy cinnamaie thymol ester(TCTE, Melasolv) was selected and the effects of TCTE on melanogenesis were investigated. Treatment of mouse-derived melanocyte melan-a cells with TCTE results in a marked down-regulation of tyrosinase activity. 80% decrease of tyrosinase activity occurs with 30uM TCTE treatment for 72 hours without affecting cell growth. The inhibition of tyrosinase activity is dose-dependent and melanin content was also decreased to 40%. From the in vitro tyrosinase assay using cell extract, TCTE does not act as a direct inhibitor of the enzyme. Treatment of melan-a cultures with TCTE blocks the increase in tyrosinase activity by either forskolin, 3-isobutyl-1-methtyl-xanthine. TCTE decreased the expression of tyrosinase, TRP-1 without effects on TRP-2 protein expression through the down regulation of tyrosinase and TRP-1 mRNA. From the results of cAMP immunoassays, intracellular levels of the cyclin nucleotide are unaffected in cells treated with TCTE. The inhibitory effects of melanin synthesis were also shown in reconstitute human epidermis model by topical application. These findings suggest that TCTE can be used for studying the regulation of melanogenesis and depigmenting agent.