• Korean Journal of Environmental Biology
• /
• v.39 no.4
• /
• pp.445-451
• /
• 2021

In this study, we described the production of an antibody to living modified organisms (LMOs) containing the gene encoding for 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) from Agrobacterium tumefaciens strain CP4 EPSPS provides resistance to the herbicide glyphosate (N- (phosphonomethyl) glycine). These LMOs were approved and have recently been used in the feed, food production, and processing industries in South Korea. Highly efficient monoclonal antibody (mAb) production is crucial for developing assays that enable the proper detection and quantification of the CP4 EPSPS protein in LMOs. This study describes the purification and characterization of recombinant CP4 EPSPS protein in E. coli BL21 (DE3) based on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and matrixassisted laser desorption/ionization time-of-flight mass spectrometry. The production of mAbs was undertaken based on the standard operating procedure of Abclon, Inc.(South Korea), and the purity of the mAbs was assessed using SDS-PAGE. The following five mAb clones were produced: 2F2, 4B9, 6C11, 10A9, and 10G9. To verify the efficiency and specificity of the five developed mAbs, we performed Western blotting analysis using the LM (living modified) cotton crude extracts. All mAbs could detect the CP4 EPSPS protein in the LM cotton traits MON1445 and MON88913 with high specificity, but not in any other LM cottons or non-LM cottons. These data indicate that these five mAbs to CP4 EPSPS could be successfully used for the further development of antibody-based detection methods to target CP4 EPSPS protein in LMOs.

• Microbiology and Biotechnology Letters
• /
• v.50 no.2
• /
• pp.235-239
• /
• 2022

Psychrophiles have evolved to produce cold-adapted enzymes to enable survival in low-temperature environments. In this study, the cold adaptation of 5-enolpyruvylshikimate-3-phosphate synthase (CpsEPSPS) from Colwellia psychrerythraea, a model psychrophile, was analyzed. The optimum temperature for the activity of CpsEPSPS was found to be 25℃, with 35% activity remaining at 5℃. However, the unfolding temperature of CpsEPSPS was 54℃. This phenomenon is frequently observed in cold-active enzymes. As is the cases for most cold-active enzymes, the K_m values of CpsEPSPS for its substrates were higher than those of Escherichia coli EPSPS. These results indicate that CpsEPSPS is cold-adapted, but not perfectly.

• Horticultural Science & Technology
• /
• v.28 no.4
• /
• pp.648-655
• /
• 2010

This study is the first comprehensive report on the molecular cloning, structural characterization, sequence comparison between wild and mutant types, copy number in the genome, expression features and activities of a gene encoding 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) in Korean lawn grass ($Zoysia$ $japonica$). The full length cDNA of the EPSPS from Korean lawn grass ($zj$EPSPS) obtained from a 3' and 5' RACE method was 1540 bp, containing a 1176 bp ORF, a 144 bp leader sequence (5' UTR) and a 220 bp 3' UTR, which was eventually decoded 391 amino acid residues with a molecular mass of 41.74 kDa. The Southern blot detection of the $zj$EPSPS showed that the gene exists as a single copy in the Korean lawn grass genome. Sequence comparison of the $zj$EPSPS gene demonstrated that the glyphosate-tolerant mutant (GT) having a Pro-53 to Ser substitution in the gene seems to have a preferred binding activity of the enzyme to phosphoenol pyruvate(PEP) over glyphosate, which allows the continuous synthesis of aromatic amino acids in the shikimate pathway. From the Northern blotting analysis, the $zj$EPSPS was found to be highly expressed, with continuous increase until 36 hours after 0.5% glyphosate treatment in both wild and mutant samples, but 1.5-fold higher EPSP synthase activity was observed in the tolerant mutant when exposed to the glyphosate treatment. The molecular information of the $zj$EPSPS gene obtained from this study needs to be further dissected to be more effectively applied to the development of gene-specific DNA markers and zoysiagrass cultivars; nevertheless, the glyphosate-tolerant mutant having the featured $zj$EPSPS gene can be provided to turfgrass managers for weed problems with timely adoptable management options.

• Journal of Plant Biotechnology
• /
• v.38 no.4
• /
• pp.272-277
• /
• 2011

Plants expressing Agrobacterium sp. strain CP4 5-enolpyruvylshikimate-3-phosphate synthase (CP4 EPSPS) are known to be resistant to glyphosate, a potent herbicide that inhibits the activity of the endogenous plant EPSPS. In order to develop herbicide-resistant rice, we prepared transgenic rice plants with CP4 EPSPS gene under the control of CaMV 35S promoter for over-expression. A recombinant plasmid was transformed into rice via Agrobacterium-mediated transformation. A large number of transgenic rice plants were obtained with glyphosate and most of the transformants showed fertile. The integration and expression of CP4 EPSPS gene from regenerated plants was analyzed by Southern and northern blot analysis. The transgenic rice plants had CP4 EPSPS enzyme activity levels more than 15-fold higher than the wild-type plants. EPSPS enzyme activity of transgenic rice plants was also identified by strip-test method. Field trial of transgenic rice plants further confirmed that they can be selectively survived at 100% by spay of glyphosate (Roundup$^{(R)}$) at a regular dose used for conventional rice weed control.

• Korean Journal of Food Science and Technology
• /
• v.36 no.3
• /
• pp.369-374
• /
• 2004

Genetically modified (GM) soybean Roundup Ready carries Agrobacterium sp. CP4 gene, which expresses 5-enolpyruvylshikimate-3-phosphate synthase (CP4EPSPS). CP4EPSPS in GM soybeans and soybean curds was screened using CP4EPSPS-specific polyclonal and monoclonal antibodies (pab and mab, respectively) by immunoblotting. Isolated recombinant CP4EPSPS was detected at detection limits of $0.006\;and\;0.0006{\mu}g$, whereas those of CP4EPSPS expressed in GM soybean were $0.001\;and\;0.0001{\mu}g$g, using mab and pab, respectively. From nine screened soybean curds, two had positive results with pab Immunoblotting method with pab and mab developed in this study could be applied to screen glyphosate-tolerant GM soybeans in soybean products.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.41 no.9
• /
• pp.1310-1314
• /
• 2012

Gastrointestinal digestibility of new proteins inserted in the food supply is a significant parameter for assessing the safety of GM foods based on the assumption that digestive stability is undesirable. In this study, we performed in vitro digestion of CP4EPSPS, a new protein, expressed in genetically modified (GM) soybean in order to evaluate its digestibility in three different ratios of simulated gastric fluid with preheating. Ratios of GM soybean to simulated gastric fluid were 2:2, 2.5:1.5, and 1.5:2 and preheating was conducted at $100^{\circ}C$ for 5 min. Electrophoresis and Western blotting were used to confirm changes in soybean protein patterns and CP4EPSPS gene expression after in vitro digestion. At ratios in which the amount of gastric fluid was equal to (2:2) or relatively higher than that of soybean (1.5:2), no CP4EPSPS (47.4 kDa) protein was detected after 15 seconds of simulated gastric fluid incubation, the earliest time interval evaluated. However, when the ratio of GM soybean to gastric fluid was 2.5:1.5, CP4EPSPS was detected in 5 min and gradually decreased according to time. After preheating, no CP4EPSPS protein was detected after 15 seconds under all conditions. From these results, we concluded that the digestibility of CP4EPSPS in simulated gastric fluid increased upon preheating. Accordingly, we suggest that it is important to account for the ratio of gastric fluid to GM food in in vitro digestibility assessment models of GM food.

• Journal of Microbiology and Biotechnology
• /
• v.16 no.1
• /
• pp.25-31
• /
• 2006

Changes of CP4 5-enolpyruvylshikimate-3-phosphate synthase (CP4 EPSPS) in the glyphosate-tolerant Roundup Ready soybean were examined using purified CP4 EPSPS produced in cloned Escherichia coli as a control. CP4 EPSPS in genetically modified soybean was detected by twodimensional gel electrophoresis (2-DE) and identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and electrospray ionization tandem mass spectrometry (ESI-MS/MS) with databases. CP4 EPSPS in soybean products was resolved on 2-DE by first isoelectric focusing (IEF) based on its characteristic pI of 5.1, followed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) based on its molecular mass of 47.5 kDa. We quantified various percentages of soybean CP4 EPSPS. The quantitative analysis was performed using a 2D software program on artificial gels with spots varying in Gaussian volumes. These results suggested that 2-DE image analysis could be used for quantitative detection of GM soybean, unlike Western blotting.

• Korean Journal of Plant Tissue Culture
• /
• v.24 no.6
• /
• pp.341-344
• /
• 1997

Calli were induced from the cotyledon and the hypocotyl of alfalfa and the callus lines were tested for the resistance to glyphosate in the liquid medium containing 0.01-3.00 mM glyphosate. Some resistant cell lines were selected from the gradual increase of glyphosate concentration and the lines resistant to 10 mM glyphosate were analyzed with EPSPS activity. Vigorous callus proliferation from the cotyledon and the hypocotyl was observed from the MS medium containing 1 mg/L 2,4-D and 0.5 mg/L kinetin. The hypocotyl was thought to be better explant source for callus induction than the cotyledon. $ID_{50}$ (Inhibition Dosage of 50%) to glyphosate was between 0.1 mM and 0.2 mM level. A49-10G and A58-10G cell lines selected as resistant to 10 mM glyphosate had 8.0 and 9.1 fold increased EPSPS activity to those of the control lines, respectively.

• Korean Journal of Food Science and Technology
• /
• v.35 no.4
• /
• pp.556-560
• /
• 2003

It was determined whether the sandwich ELISA using specific anti-CP4 EPSPS polyclonal and monoclonal antibodies, developed in the previous study, could be applied to detect GM soybean or not. The soybeans (47 imported and 20 domestic soybeans) were analyzed by a sandwich ELISA. The results of imported soybeans were divided into two groups which were high contents $(39.1{\pm}13.5\;{\mu}g/g,\;n=33)$ and low contents of CP4 EPSPS $(2.6{\pm}1.2\;{\mu}g/g,\;n=14)$. The ratio of GM in imported soybeans was about 70.2%. One the other hand, the contents of CP4 EPSPS in domestic soybeans was very low $(0.9{\pm}0.5\;{\mu}g/g,\;n=20)$ which determined to be non-GM soybeans. In case of soybean sprouts, the contents of CP4 EPSPS in soybean sprouts were different between GM and non-GM soybean sprout. The CP4 EPSPS in cotyledon of GM soybeans sprout was higher than that in root hair. The contents of CP4 EPSPS in soybeans sprout of domestic soybeans were very low. Thus, it was possible to determine that the soybeans sprout was made of GM or non-GM soybeans. Also, PCR experiment showed that the sandwich ELISA was accurate to distinguish the soybeans to be GM or non-GM. These results showed the sandwich ELISA could determine the soybeans were GM or non-GM, rapidly and simply.

• Journal of Microbiology and Biotechnology
• /
• v.14 no.2
• /
• pp.390-394
• /
• 2004

The genetically modified glyphosate-tolerant soybean contains the following introduced DNA sequences: the EPSPS (5-enol-pyruvylshikimate-3-phosphate synthase) gene from Agrobacterium sp. strain CP4, the 35S promoter from the cauliflower mosaic virus, and the NOS terminator from Agrobacterium tumefaciens. In the present study, detection of these introduced DNAs was performed by amplification using the polymerase chain reaction (PCR). A multiplex PCR method was also applied to prevent false positive results. When primers for 35S promoter, nos3', CTP(chloroplast transit peptide), and CP4 EPSPS (EPSPS from Agrobacterium sp. CP4) were used, positive results were obtained in PCR reactions using DNA from genetically modified glyphosate-tolerant soybeans. There were no false positive results when using DNA from non-genetically modified soybeans. The CP4 EPSPS gene was detected when less than 125 pg glyphosate-tolerant soybean DNA was amplified. Lectin Lel and psb A were amplified from both non-genetically modified and genetically modified glyphosate-tolerant soybean DNA. Multiplex PCR was performed using different primer sets for actin Sacl, 35S promoter and CP4 EPSPS. The actin gene was detectable in both non-genetically modified and glyphosate-tolerant soybeans as a constant endogenous gene. Target DNAs for the 35S promoter, and CP4 EPSPS were detected in samples containing 0.01-0.1% glyphosate-tolerant soybean, although there were variations depending on primers by multiplex PCR. Soybean seeds from five plants of non-genetically modified soybean were co-cultivated for six months with those of genetically modified soybean, and they were analyzed by PCR. As a result, they were not positive for 35S promoter, nos3' or CP4 EPSPS. Therefore, these results suggest there was no natural crossing of genes between glyphosate-tolerant and non-genetically modified soybean during co-cultivation, which indicates that gene transfer between these plants is unlikely to occur in nature.