• Parasites, Hosts and Diseases
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• v.39 no.3
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• pp.261-264
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• 2001

Trichinellosis is a parasitic zoonosis of public health importance. It is caused by Trichinella spiralis which has a wide host range including humans. In the present communication, the ELISA technique was employed on a total of 803 blood samples from 7 selected pig breeding farms in 1996 for diagnosis and surveillance of trichinellosis. Out of the entire 803 samples, nine were found to be suspected while one was positive by ELISA. But western blot analyses employed for further confirmation have shown that all of 10 samples did not react to larval excretory-secretory product antigens. These results indicate that pig breeding farms included in the present study are free from trichinellosis . However, it does not mean Korea is free from trichinellosis since human trichinellosis has recently been reported. The necessity of continued surveillance for trichinellosis in both pigs and wild animals was discussed.

• Food Science and Industry
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• v.55 no.1
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• pp.45-57
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• 2022

This study was proceeded the analytical methods using various analytical instruments for polycyclic aromatic hydrocarbons (PAHs) in food products. Various analytical methods were developed to determine levels of PAHs including benzo[a]pyrene, benzo[a]anthracene, benzo[b]fluoranthene, and chrysene formed in various food products using gas chromatography-mass spectrometry (GC-MS), enzyme-linked immunosorbent assay (ELISA) and raman spectroscopy. Recently, the rapid on-site response for the detection of hazardous substances in food aims to develop an onsite rapid detection of a simplified technical analysis method to reduce the time and cost required for analysis of PAHs. Current PAHs detection methods have been reviewed along with new raman spectroscopy analytical method.

• Journal of Korean Society on Water Environment
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• v.26 no.4
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• pp.574-579
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• 2010

In this study the enzyme inhibition method using dehydrogenase which has been popularly used to estimate ecotoxicity was optimized. When three bacterial strains, Escherichia coli HB101, Enterobacter asburiae KCAD-4, and Aeromonas media KCAD-13, were compared, KCAD-4 was considered as the adequate strain to estimate toxicity because of its sensitivity and reproducibility. The optimal bacterial density was estimated as $5.4{\times}10^9CFU/mL$, at which the maximum sensitivity was observed. The phosphate buffer was suitable for the reaction solution. When the reaction times required for inhibition of enzyme activity by contact of toxicants and for reaction of damaged bacteria and substrate were tested, the optimal value was estimated as 20 min and 2 hrs, respectively. It is expected that the optimized conditions can be used to develop the standardized kits to estimate ecotoxicity of heavy metals in effluent from the industrial wastewater treatment facilities.

• BMB Reports
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• v.34 no.2
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• pp.172-175
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• 2001

Catechol 1,2-dioxygenase $I_1$ ($CDI_1$) is the first enzyme of the $\beta$-ketoadipate pathway in Acinetobacter lowffii K24. $CDI_1$ has two cysteines (155, 202) and its enzyme activity is inhibited by the cysteine inhibitor, $AgNO_3$. Two mutants, $CDI_1$ C155V and $CDI_1$ C202V, were obtained by site-directed mutagenesis. The two mutants were overexpressed and the mutated amino acid residues (Cys$\rightarrow$Val) were characterized by peptide mapping and amino acid sequencing. Interestingly, $CDI_1$ C155V was inhibited by $AgNO_3$, whereas $CDI_1$ C202V was not inhibited. This suggests that $Cys^{202}$ is the sole inhibition site by $AgNO_3$ and is close to the active site of the enzyme. However, the results of the biochemical assay of mutated $CDI_1s$ suggest that the two cysteines are not directly involved in the activity of the catechol 1,2-dioxygenase of $CDI_1$.

• International Journal of Industrial Entomology and Biomaterials
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• v.25 no.2
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• pp.187-193
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• 2012

Serine proteases are major insect enzymes involved in the digestion of dietary proteins and in the process of blood meal digestion. In this study, cDNA was constructed using the whole body of Laccotrephes japonensis. The flanking sequences of the 5- and 3- end of this gene were characterized by RACE-PCR. Sequence analysis showed that this gene contained a 963-bp ORF encoding 320 amino acids. The deduced amino acid sequence showed 62% identity with the Creontiades dilutus serine protease, 58% with the Lygus lineolaris trypsin precursor, and 54% with the Triatoma infestans salivary trypsin. To assess the expression of the L. japonensis serine protease (JGsp), the JGsp gene was cloned into a baculovirus transfer vector, pBac-1, and expressed in Sf9 cells (Spodoptera frugiperda). SDS-PAGE and western blot analysis have shown that the JGsp recombinant protein was a monomer with a molecular weight of about 32 kDa. Recombinant JGsp has shown activity in the protease enzyme assay using gelatin as a substrate.

• Journal of Animal Science and Technology
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• v.57 no.4
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• pp.13.1-13.5
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• 2015

As an alternative to radioimmunoassay a simple and highly sensitive enzyme immunoassay (EIA) was developed and validated for androstenedione quantification in plasma of Karan Fries bulls using second antibody coating technique. The wells of the microtitreplate were coated with affinity-purified goat immunoglobulin (antirabbit IgG) that binds the hormone specific antibody. The EIA was performed to analyze androstenedione directly in $40{\mu}l$ of bull plasma. The androstenedione standards ranged from 0.20 to 200 pg/$40{\mu}l$/well and the sensitivity of the assay was 5 pg/ml plasma. Serially diluted bull plasma containing high endogenous androstenedione showed good parallelism with bovine androstenedione standard curve. Intra- and inter-assay coefficients of variation (CV) were found to be 8 and 9%, respectively. Peripheral plasma androstenedione concentrations determined in young and adult bull samples ranged between 104-990 pg/ml and 184-2040 pg/ml, respectively.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.43 no.4
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• pp.228-233
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• 1998

Seed storage proteins have been used for studying biochemical genetics and end-use quality aspects. We conducted enzyme-linked immunosorbent assay (ELISA) and one-dimensional SDS-PAGE (1D SDS-PAGE) to evaluate different cereal crop species and Korean wheat lines for rye secalin proteins. The antisecalin antibody showed consistent specificity for rye secalin with little cross-reactivity to gliadins. Immunological cross-reactivities measured by the ELISA technique using competition assay showed significant differences of absorbance among rye, triticale, wheat-rye translocated wheat and non-translocated wheat. The absorbance values were lowest in rye followed by triticale, translocated wheat and non-translocated wheat. The ELISA for discrimination of wheat-rye translocation on the basis of antigen-antibody reactivity showed that none of the Korean wheat lines possessed 1RS and secalin proteins. The competitive ELISA experiment demonstrated specific determination for secalin that was originated from rye chromosomal parts. The result of 1D SDS-PAGE for identifying rye secalin subunits showed all three rye specific secalin protein subunits (75 KDa, 45 KDa, and 40 KDa) for rye and triticale, and 1RS specific secalins (45 KDa and 40 KDa) for 1AL/1RS and 1BL/1RS translocated wheats. All Korean wheats were lacking 1RS of rye chromosome and secalin.

• Journal of Microbiology and Biotechnology
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• v.12 no.3
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• pp.530-533
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• 2002

This paper describes the development of an enzymatic assay system for the identification of specific inhibitors of sortase, a transpeptidase that cleaves surface proteins of Cram-positive bacteria, from Staphylococcus aureus ATCC 6538p for antibacterial drug discovery. The coding region of the enzyme was amplified with the exception of the N-terminal membrane anchor sequence, cloned into a vector providing His-Patch-thioredoxin-tag at the N-terminus, expressed in Escherichia coli, and purified by metal chelate affinity chromatography. The enzyme activity was determined by quantifying increased fluorescence intensity upon cleavage of synthetic Dabcyl-QALPETGEE-Edans peptide. The results suggest that the developed in vitro assay system call be used in the search for sortase inhibitors In a short period of time.

• Clinical and Experimental Reproductive Medicine
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• v.40 no.1
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• pp.12-22
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• 2013

Objective: We investigated the norepinephrine transporter (NET) expression in normal and pre-eclamptic placentas and analyzed the invasion activity of trophoblastic cells based on norepinephrine (NE)-NET regulation. Methods: NET and NE expression levels were examined by western blot and enzyme-linked immunosorbent assay, respectively. Trophoblast invasion activity, depending on NE-NET regulation, was determined by NET-small interfering RNA (siRNA) and NET transfection into the human extravillous trophoblast cells with or without NE treatment and invasion rates were analyzed by zymography and an invasion assay. Results: NET mRNA was expressed at a low level in pre-eclamptic placentas compared with normal placentas and NE concentration in maternal plasma increased significantly in pre-eclamptic women compared to normal pregnant women (p<0.05). NET gene upregulation and NE treatment stimulated trophoblast cell invasion up to 2.5-fold (p<0.05) by stimulating matrix metalloproteinase-9 activity via the phosphoinositol-3-kinase/AKT signaling pathway, whereas NET-siRNA with NE treatment reduced invasion rates. Conclusion: NET expression is reduced by inadequate regulation of NE levels during placental development. This suggests that a complementary balance between NET and NE regulates trophoblast cell invasion activities during placental development.

• Korean Journal of Veterinary Research
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• v.31 no.4
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• pp.403-409
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• 1991

This experiment was carried out to develop a sensitive, rapid, solid-phase microtitre plate assay of progesterone using the monoclonal antibody to this hormone. Monoclonal antibody to progesterone was much higher titre and binding affinity about 10 times than conventional polyclonal antibody to progesterone. Dot-blot analysis of monoclonal antibody revealed a single precipitation band when reacted with anti-mouse IgM and anti-mouse K. A competitive reaction was used with a reaction time of 2 hours. The standard dose-response curve was linear through 1,000pg/well. This ELISA system approach is applicable to evaluation for the rapid assessment of luteal function and reproductive status in both clinical and research in a wide variety of species.