• Journal of Life Science
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• v.28 no.8
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• pp.923-930
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• 2018

In this study, Tenebrio molitor (T. molitor) was fermented with Lactobacillus plantarum JBMI F3 (F3), Lactobacillus plantarum JBMI F5 (F5), Lactobacillus gasseri Ba9 (Ba9), Aspergillus kawachii KCCM 32819 (Ak), Saccharomyces cerevisiae KACC 93023 (Sc), and Bacillus subtilis KACC 91157 (Bs). After fermentation, the fermented products were extracted by water, ethanol, and methanol, and their physicochemical and biological properties were investigated. In a DPPH assay, the water extracts of the fermented products of T. molitor showed high antioxidant ability. Among the water extracts, the fermented product by Bs showed the highest DPPH radical scavenging activity. The total contents of phenolic compounds and flavonoids were highest in the fermented products by Ak and Bs, respectively. Reducing activity was detected the most high activity on ethanol extract of fermented product by Bs. The water extract of the fermented product by Bs exhibited strong enzymatic activity for fibrinogen and starch hydrolysis. Based on the observed physicochemical and biological properties, the fermented products of T. molitor by microorgansims can likely be applied as functional materials in various industries.

• Korean Journal of Agricultural Science
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• v.21 no.2
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• pp.142-147
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• 1994

Characteristics of TNP-cellulose which prepared from carboxymethyl cellulose powder, CM32, as substrate for cellulase activity assay were investigated. Enzymatic hydrolysis of TNP-cellulose occured on the cellulose moiety but not on amide bonds, following Michaelis-Menten kinetics. Three cellulase preparations from Trichoderma viride, Aspergillus niger, and Cellulomonas sp. were tested for their pH and temperature dependences and compared with the method determining the increase in reducing power. The enzyme activity was found to have the same temperature range in both methods, however the pH range was broadened in the case of using TNP-cellulose as substrate. The colorimetric method for cellulase assay using TNP-cellulose as substrate was compared with the other methods: one based on determination of the increase in reducing power; and the other based on determining the decrease in viscosity of Na-CM-cellulose solution. The activities measured by the colorimetric method showed a linear correlation with the enzyme concentration of certain range in all three enzymes tested, and the activity values were proportional to those obtained from the other methods. Depending on the enzyme, however, the activity values from this method were not always in proportion to those from the viscometric method. suggesting that this method was not specific for determination of the endo-type cellulase.

• Biomolecules & Therapeutics
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• v.23 no.5
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• pp.486-492
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• 2015

Drug metabolism mostly occurs in the liver. Cytochrome P450 (CYP) is a drug-metabolizing enzyme that is responsible for many important drug metabolism reactions. Recently, the US FDA and EU EMA have suggested that CYP enzyme induction can be measured by both enzymatic activity and mRNA expression. However, these experiments are time-consuming and their interassay variability can lead to misinterpretations of the results. To resolve these problems and establish a more powerful method to measure CYP induction, we determined CYP induction by using luminescent assay. Luminescent CYP assays link CYP enzyme activity to firefly luciferase luminescence technology. In this study, we measured the induction of CYP isozymes (1A2, 2B6, 2C9, and 3A4) in cryopreserved human hepatocytes (HMC424, 478, and 493) using a luminometer. We then examined the potential induction abilities (unknown so far) of mesalazine, a drug for colitis, and mosapride citrate, which is used as an antispasmodic drug. The results showed that mesalazine promotes CYP2B6 and 3A4 activities, while mosapride citrate promotes CYP1A2, 2B6, and 3A4 activities. Luminescent CYP assays offer rapid and safe advantages over LC-MS/MS and qRT-PCR methods. Furthermore, luminescent CYP assays decrease the interference between the optical properties of the test compound and the CYP substrates. Therefore, luminescent CYP assays are less labor intensive, rapid, and can be used as robust tools for high-throughput CYP screening during early drug discovery.

• Korean Journal of Food Science and Technology
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• v.31 no.6
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• pp.1661-1666
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• 1999

Yungmijihwgang-Won, Yollyunggobon-Dan and Palmi-Hwan, Korea traditional prescriptions composed of oriental medical herbs, have been used successfully to improve human health and regimen. This study was designed to examine the mechanism of healthful effects of the Korea traditional prescriptions through its antioxidative potentials. Using in vitro antioxidative activity assay system such as DPPH radical quenching assay, superoxide anion radical scavenging assay and inhibition of TBARS production, three Korea traditional prescriptions were observed to have nearly the same antioxidative potentials as ascorbic acid, a well-known strong water-soluble antioxidant. Moreover, we observed reinforced antioxidative effects of these drugs in liver from mouse fed these drugs with 4 weeks. When liver homogenate was incubated with 2.2'-azobis(amidinopropane) dihydrochloride(AAPH), as a free radical initiator, we observed that oxidative damages were decreased and antioxidative potentials were increased in liver homogenate treated these drugs. However, enzymatic antioxidative system as superoxide dismutase, catalase, glutathione peroxidase and glutathione reductase was not affected by drug administration.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.1
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• pp.152-158
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• 2016

Glutamate is one of the major excitatory neurotransmitters in the central nervous system of vertebrates. Human GDH (hGDH) is the enzyme that regulates the glutamate metabolism and its expression is higher in the brains of schizophrenia patients than in normal subjects. This study examined the changes in the hGDH enzymatic activity caused by antipsychotic drugs (haloperidol, risperidone, (${\pm}$)-sulpride, chlopromazine hydrochloride, melperone, (${\pm}$)butaclamol, domperidone, clozapine) related to schizophrenia. First of all, hGDH isozymes (hGDH1, hGDH2) were synthesized by genetic recombination. As a result of the enzyme assay, haloperidol, (${\pm}$)-sulpride, melperone and clozapine had an inhibitory effect on the hGDH isozymes. In addition, haloperidol showed a non-competitive inhibition against the substrate, 2-oxoglutarate. In contrast, it showed an uncompetitive inhibition against another substrate, NADH. The inhibitory effect of haloperidol on hGDH2 was abolished by the presence of L-leucine, an allosteric effector of hGDH, but by not other antipsychotic drugs. These results revealed the inhibition of enzyme activity by psychotropic drugs in hGDH isoenzymes (hGDH1 and hGDH2) and the possibility that haloperidol may be used to regulate the GDH activity and glutamate concentration in the central nervous system.

• Journal of Life Science
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• v.29 no.3
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• pp.287-294
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• 2019

Calystegia soldanella is distributed in coastal sand dunes and has high environmental adaptability; it is also known to be effective for anti-oxidant, anti-pyretic, anti-septic, and diuretic action. This study investigated the effect of crude extracts and organic solvent fractions of C. soldanella on MMP-2 and MMP-9 expression, MMP activity, and cell mobility in phorbol-12-myristate-13-acetate (PMA)-induced fibrosarcoma HT-1080 cells. C. soldanella was twice extracted, once with methylene chloride (MC) and once with methanol (MeOH). After the MC and MeOH extracts were combined, their suppressive effects on MMP-2 and MMP-9 expression, MMP enzymatic activity, and gene and protein expression were measured by gelatin zymography, enzyme-linked immunosorbent assay, reverse-transcription polymerase chain reaction, and western blot method. Cell mobility for the HT-1080 cells was observed by wound healing assay. The combined crude extracts showed a significant suppressive effects on MMP-2 and MMP-9 expression. To explore active inhibitory elements, the combined extracts were fractionated according to polarity into with n-hexane, 85% aqueous methanol, n-butanol, and water. Across these four solvent fractions, MMP-2 and MMP-9 activity and cell mobility in the HT-1080 cells were all strongly inhibited by the n-hexane fraction. These results suggest that C. soldanella extract and organic solvent fractions could be used as potent MMP inhibitors for effective anti-cancer treatments to suppress cancer invasion and metastasis.

• Journal of Oral Medicine and Pain
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• v.33 no.3
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• pp.229-240
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• 2008

Animal mucins have structural characteristics similar to human salivary mucins. Animal mucins have been regarded as suitable substances for saliva substitutes. Since animal mucin molecules in saliva substitutes and host-derived antimicrobial salivary molecules exist simultaneously in whole saliva and the pellicles of patients with dry mouth, interactions may occur between these molecules. The purpose of this study was to investigate the influence of animal mucins on peroxidase activity in solution and on the surface of hydroxyapatite(HA) surfaces. The effects of animal mucins on peroxidase activity were examined by incubating porcine gastric mucin(PGM) or bovine submaxillary mucin (BSM) with either bovine lactoperoxidase(bLPO) or saliva samples. For solid-phase assays, immobilized animal mucins or peroxidase on three different HA surfaces(HA beads, HA disc, and bovine tooth) were used. Peroxidase activity was determined with an NbsSCN assay. The obtained results were as follows: 1. PGM enhanced the enzymatic activity of bLPO in solution phase. PGM did not affect the enzymatic activity of peroxidase in saliva sample(POS). 2. BSM did not affect the enzymatic activities of both bLPO and POS in solution phase. 3. HA-adsorbed PGM increased subsequent bLPO adsorption in all three HA phases. The activity of POS was increased on both the HA beads and bovine tooth. 4. The peroxidase activities on the HA beads and disc were increased when the HA surfaces were exposed to a mixture of bLPO and PGM. 5. The binding affinity of bLPO to PGM was greater than that of bLPO to BSM. Collectively, our results suggest that animal mucins affects the enzymatic activity of peroxidase on the HA surfaces as well as in solution. Saliva substitutes containing animal mucins may affect the function of antimicrobial components in natural saliva and saliva substitutes.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.12
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• pp.1905-1911
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• 2015

Melanin is one of the most important factors affecting skin color. Melanogenesis is the bioprocess of melanin production by melanocytes in the skin and hair follicles and is mediated by several enzymes, such as tyrosinase, tyrosinase related protein (TRP)-1, and TRP-2. Convenient enzymatic transformation of the simple phenol pyrogallol with polyphenol oxidase originating from pear to an oxidative product, purpurogallin, was efficient. The structure of the pyrogallol oxidation product was identified on the basis of spectroscopic methods. The biotransformation product purpurogallin showed significant inhibitory effects against both melanin synthesis and tyrosinase activity in a dose-dependent manner in B16 melanoma cells. In addition, purpurogallin significantly attenuated melanin production by inhibiting TRP-1, and TRP-2 expression through modulation of their corresponding transcription factors, and microphthalamia- associated transcription factor in B16 cells. Consequently, purpurogallin derived from convenient enzymatic transformation of pyrogallol might be a beneficial material for reducing skin hyperpigmentation.

• Korean Journal of Microbiology
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• v.50 no.3
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• pp.239-244
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• 2014

ErmSF is one of the four antibiotic resistance factor proteins expressed by Streptomyces fradiae, antibiotic tylosin producer, which renders $MLS_B$ (macrolide-lincosamide-streptogramin B) antibiotic resistance through dimethylating A2058 of 23S rRNA, thereby reducing the affinity of antibiotic to ribosome. Unlike other Erm proteins, ErmSF harbors long N-terminal end region. To investigate its role in enzyme activity, mutant ErmSF deleted of 1-38 amino acids was overexpressed and activity in vivo and in vitro was observed. In vitro enzymatic assay showed that mutant protein exhibited reduced activity by 20% compared to the wild type enzyme. Due to the reduced activity of the mutant protein, cells expressing mutant protein showed weaker resistance to erythromycin than cells with wild type enzyme. Presumably, the decrease in enzyme activity was caused by the hindrance in substrate binding and (or) product release, not by defect in the methyl group transfer occurred in active site.

• Microbiology and Biotechnology Letters
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• v.26 no.1
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• pp.15-22
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• 1998

The dnrF gene, responsible for conversion of aklavinone to $\varepsilon$-rhodomycinone via C-11 hydroxylation, was mapped in the daunorubicin gene cluster of Streptomyces peucetius subsp. caesius ATCC 27952, close to drrAB, one of the anthracycline resistance genes. To characterize the enzymatic properties of the aklavinone 11-hydroxylase, the dnrF gene was overexpressed in Escherchia coli. The pET-22(+) plasmid which has the T7 promoter under the control of lacUV5 gene was used for the overexpression of the dnrF gene, and the recombinant plasmid pET213 that contains the dnrF gene linked to the T7 promoter of pET-22b(+) was introduced into the E. coli BL2l. When the expression of the dnrF gene was induced by IPTG at the final concentration of 1 mM, the induced protein could be detected in SDS-PAGE only in insoluble precipitate. The insoluble protein was electroeluted from the gel and used for the preparation of antiserum in mice. Various culture conditions were tested to maximize the expression of the aklavinone 11-hydroxylase in soluble form. The enzymatic activity was checked by the bioconversion experiment, and the protein was confirmed by the SDS-PAGE and the Western blot analysis. From the analysis of the data, it was concluded that the culture induced with IPTG at the final concentration of 0.02 mM at 37$^{\circ}C$ yielded the best productivity of active form of enzyme.