• Bulletin of the Korean Chemical Society
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• v.30 no.7
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• pp.1655-1657
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• 2009

• Journal of Microbiology and Biotechnology
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• v.16 no.3
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• pp.331-348
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• 2006

• Bulletin of the Korean Chemical Society
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• v.32 no.11
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• pp.4086-4088
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• 2011

• BMB Reports
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• v.45 no.4
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• pp.233-238
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• 2012

We present a top down separation platform for yeast ribosomal proteins using affinity chromatography and capillary electrophoresis which is designed to allow deposition of proteins onto a substrate. FLAG tagged ribosomes were affinity purified, and rRNA acid precipitation was performed on the ribosomes followed by capillary electrophoresis to separate the ribosomal proteins. Over 26 peaks were detected with excellent reproducibility (<0.5% RSD migration time). This is the first reported separation of eukaryotic ribosomal proteins using capillary electrophoresis. The two stages in this workflow, affinity chromatography and capillary electrophoresis, share the advantages that they are fast, flexible and have small sample requirements in comparison to more commonly used techniques. This method is a remarkably quick route from cell to separation that has the potential to be coupled to high throughput readout platforms for studies of the ribosomal proteome.

• Biotechnology and Bioprocess Engineering:BBE
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• v.11 no.3
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• pp.187-198
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• 2006

The aromatic hydrocarbons (AHs), which include benzene, polycyclic aromatic hydrocarbons, and dioxin, are important chemical and environmental contaminants in industry that usually cause various diseases. Over the years, numerous studies have described and evaluated the adverse health effects induced by AHs. Currently, "Omics" technologies, transcriptomics and proteomics, have been applied in AH toxicity studies. Proteomics has been used to identify molecular mechanisms and biomarkers associated with global chemical toxicity. It could enhance our ability to characterize chemical-induced toxicities and to identify noninvasive biomarkers. The proteomic approach (e.g. 2-dimensional electrophoresis [2-DE]), can be used to observe changes in protein expression during chemical exposure with high sensitivity and specificity. Matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) and electrospray ionization-quadrupole (ESI-Q)-TOF MS/MS are recognized as the most important protein identification tools. This review describes proteomic technologies and their application in the proteomic analysis of AH toxicity.

• Journal of Microbiology and Biotechnology
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• v.23 no.12
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• pp.1802-1805
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• 2013

Ginsenosides are the most important ingredient of ginseng and are known to possess many pharmacological and biological effects. Rb1, a major protopanaxadiol ginsenoside, is the most abundant ginsenoside in Panax ginseng C.A Meyer and can be hydrolyzed into more pharmaceutically potent minor ginsenosides. To identify a microorganism that is capable of converting Rb1 into other ginsenosides, we screened 12 Microbacterium spp., and M. trichothecenolyticum was identified as a likely candidate. M. trichothecenolyticum converted Rb1 into Rd and then into Rh2 based on TLC and HPLC analyses of reaction products. This biotransformation method can be easily applied for mass production of Rd and Rh2 by using Rb1.

• Bulletin of the Korean Chemical Society
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• v.25 no.12
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• pp.1833-1839
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• 2004

Recently mass spectrometry and separation methods such as liquid chromatography have become major tools in the field of proteomics. In this report, we describe in detail our efforts to develop ultra-high pressure capillary reverse-phase liquid chromatography (cRPLC) and its online coupling to a mass spectrometer by a nanoelectrospray (nanoESI) interface. The RPLC system is constructed in house to deliver LC solvents at the pressure up to 20,000 psig, which is four times higher than conventional RPLC systems. The high operation pressure allows the efficient use of packed micro-capillary columns (50, 75 and 150 ${\mu}$m i.d., up to 1.5 m long). We will discuss the effect of column diameter on the sensitivity of cRPLC/MS/MS experiments and the utility of the developed technique for proteome analysis by its application in the analysis of proteome samples having different levels of complexity.

• Environmental Mutagens and Carcinogens
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• v.22 no.4
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• pp.236-242
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• 2002

Using agarose-coupled methotrexate, we have successfully isolated two proteins, which have strong interactions with methotrexate. The two proteins were analyzed by Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry and identified as carbamoyl-phosphate synthetase 2 and phosphoribosylglycinamide formyltransferase, respectively. Interestingly, both of these two proteins are essential key enzymes in nucleotide biosynthetic pathways, like dihydrofolate reductase, a well-known methotrexate target. We confirmed the specificity of their interactions between methotrexate and two target proteins by the methods of competition binding assay, which were followed by western blotting using antibody against carbamoyl-phosphate synthetase 2 and phosphoribosylglycinamide formyltransferase, respectively. Moreover, we could observe that carbamoyl-phosphate synthetase 2 is overexpressed in methotrexate-resistant MOLT-3 cells comparing with control MOLT-3 cells. This result indicates that carbamoyl-phosphate synthetase 2 may be a novel target of methotrexate in cancer therapy. We propose that chemical proteomics can be a powerful technique to identify target proteins of a chemical.

• Bulletin of the Korean Chemical Society
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• v.30 no.6
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• pp.1313-1316
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• 2009

Cdc25 phosphatases have been considered as attractive drug targets for anticancer therapy due to the correlation of their overexpression with a wide variety of cancers. We have been able to identify five novel Cdc25 phosphatase inhibitors with micromolar activity by means of a structure-based de novo design method with a known inhibitor scaffold. Because the newly discovered inhibitors are structurally diverse and have desirable physicochemical properties as a drug candidate, they deserve further investigation as anticancer drugs. The differences in binding modes of the identified inhibitors in the active sites of Cdc25A and B are addressed in detail.

• BMB Reports
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• v.47 no.3
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• pp.149-157
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• 2014

The recent dramatic improvements in high-resolution mass spectrometry (MS) have revolutionized the speed and scope of proteomic studies. Conventional MS-based proteomics methodologies allow global protein profiling based on expression levels. Although these techniques are promising, there are numerous biological activities yet to be unveiled, such as the dynamic regulation of enzyme activity. Chemical proteomics is an emerging field that extends these types proteomic profiling. In particular, activity-based protein profiling (ABPP) utilizes small-molecule probes to monitor enzyme activity directly in living intact subjects. In this mini-review, we summarize the unique roles of smallmolecule probes in proteomics studies and highlight some recent examples in which this principle has been applied.