• Biotechnology and Bioprocess Engineering:BBE
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• v.6 no.2
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• pp.144-149
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• 2001

For the production and purification of a single chain human insulin precursor, four types of fusion peptides $\beta$-galactosidase (LacZ), maltose binding protein (MBP), glutathione-S-transferase (GST), and (His)(sub)6-tagged sequence (HTS) were investigated. Recombinant E. coli harboring hybrid genes was cultivated at 37$\^{C}$ for 1h, and gene induction occurred when 0.2mM of isopropyl-D-thiogalactoside (IPTG) was added to the culture broth, except for E. coli BL21 (DE3) pLysS harboring a pET-BA cultivation with 1.0mM IPTG, followed by a longer than 4h batch fermentation respectively. DEAE-Sphacel and Sephadex G-200 gel filtration chromatography, amylose affinity chromatography, glutathione-sepharose 4B affinity chromatography, and a nickel chelating affinity chromatography system as a kind of immobilized metal ion affinity chromatography (IMAC) were all employed for the purification of a single chain human insulin precursor. The recovery yields of the HTS-fused, GST-fused, MBP-fused, and LacZ-fused single chain human insulin precursors resulted in 47%, 20%, 20%, and 18% as the total protein amounts respectively. These results show that a higher recovery yield of the finally purified recombinant peptides was achieved when affinity column chromatography was employed and when the fused peptide had a smaller molecular weight. In addition the pET expression system gave the highest productivity of a fused insulin precursor due to a two-step regulation of the gene expression, and the HTS-fused system provided the highest recovery of a fused insulin precursor based on a simple and specific separation using the IMAC technique.

• Molecules and Cells
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• v.20 no.1
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• pp.1-16
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• 2005

The peptidyl transferase center (PTC) is located in a protein free environment, thus confirming that the ribosome is a ribozyme. This arched void has dimensions suitable for accommodating the 3'ends of the A-and the P-site tRNAs, and is situated within a universal sizable symmetry-related region that connects all ribosomal functional centers involved in amino-acid polymerization. The linkage between the elaborate PTC architecture and the A-site tRNA position revealed that the A-to P-site passage of the tRNA 3'end is performed by a rotatory motion, which leads to stereochemistry suitable for peptide bond formation and for substrate mediated catalysis, thus suggesting that the PTC evolved by genefusion. Adjacent to the PTC is the entrance of the protein exit tunnel, shown to play active roles in sequence-specific gating of nascent chains and in responding to cellular signals. This tunnel also provides a site that may be exploited for local co-translational folding and seems to assist in nascent chain trafficking into the hydrophobic space formed by the first bacterial chaperone, the trigger factor. Many antibiotics target ribosomes. Although the ribosome is highly conserved, subtle sequence and/or conformational variations enable drug selectivity, thus facilitating clinical usage. Comparisons of high-resolution structures of complexes of antibiotics bound to ribosomes from eubacteria resembling pathogens, to an archaeon that shares properties with eukaryotes and to its mutant that allows antibiotics binding, demonstrated the unambiguous difference between mere binding and therapeutical effectiveness. The observed variability in antibiotics inhibitory modes, accompanied by the elucidation of the structural basis to antibiotics mechanism justifies expectations for structural based improved properties of existing compounds as well as for the development of novel drugs.

• Parasites, Hosts and Diseases
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• v.46 no.4
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• pp.209-216
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• 2008

A monoclonal antibody against Toxoplasma gondii of Tg556 clone (Tg556) blotted a 29 kDa protein, which was localized in the dense granules of tachyzoites and secreted into the parasitophorous vacuolar membrane (PVM) after infection to host cells. A cDNA fragment encoding the protein was obtained by screening a T. gondii cDNA expression library with Tg556, and the full-length was completed by 5'-RACE of 2,086 bp containing an open reading frame (ORF) of 669 bp. The ORF encoded a polypeptide of 222 amino acids homologous to the revised GRA3 but not to the first reported one. The polypeptide has 3 hydrophobic moieties of an N-terminal stop transfer sequence and 2 transmembrane domains (TMD) in posterior half of the sequence, a cytoplasmic localization motif after the second TMD and an endoplasmic reticulum (ER) retrival motif in the C-terminal end, which suggests GRA3 as a type III transmembrane protein. With the ORF of GRA3, yeast two-hybrid assay was performed in HeLa cDNA expression library, which resulted in the interaction of GRA3 with calcium modulating ligand (CAMLG), a type II transmembrane protein of ER. The specific binding of GRA3 and CAMLG was confirmed by glutathione S-transferase (GST) pull-down and immunoprecipitation assays. The localities of fluorescence transfectionally expressed from GRA3 and CAMLG plasmids were overlapped completely in HeLa cell cytoplasm. In immunofluorescence assay, GRA3 and CAMLG were shown to be co-localized in the PVM of host cells. Structural binding of PVM-inserted GRA3 to CAMLG of ER suggested the receptor-ligand of ER recruitment to PVM during the parasitism of T. gondii.

• Biomolecules & Therapeutics
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• v.29 no.1
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• pp.73-82
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• 2021

Hsp90 is often overexpressed with activated form in cancer cells, and many key cellular proteins are dependent upon the Hsp90 machinery (these proteins are called "client protein"). Nowadays, more client proteins and more inhibitors of Hsp90 are being discovered. Chaetocin has been identified as an inhibitor of histone methyl transferase SUV39H1. Herein, we find that Chaetocin is an inhibitor of Hsp90 which binds to the C-terminal of Hsp90α. Chaetocin inhibited a variety of Hsp90 client proteins including AMl1-ETO and BCL-ABL, the mutant fusion-protein in the K562 and HL-60 cells. SUV39H1 mediates epigenetic events in the pathophysiology of hematopoietic disorders. We found that inhibition of Hsp90 by Chaetocin and 17-AAG had ability to induce degradation of SUV39H1 through proteasome pathway. In addition, SUV39H1 interacted with Hsp90 through co-chaperone HOP. These results suggest that SUV39H1 belongs to a client protein of Hsp90. Moreover, Chaetocin was able to induce cell differentiation in the two cells in the concentration range of Hsp90 inhibition. Altogether, our results demonstrate that SUV39H1 is a new client protein of Hsp90 degradated by Chaetocin as a novel C-terminal inhibitor of Hsp90. The study establishes a new relationship of Chaetocin and SUV39H1, and paves an avenue for exploring a new strategy to target SUV39H1 by inhibition of Hsp90 in leukemia.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.11
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• pp.1516-1521
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• 2009

This study was carried out to estimate beneficial effects of medicinal plant [Oenanthe javanica (MNR), Coicis lachryma-jobi L. var. (YM), Plantaginis asiatica L. (CJJ)] water extracts on activities of key enzymes such as lipoprotein lipase (LPL), acyl-CoA synthetase (ACS) and carnitine acetyltransferase (CAT) on lipid metabolism. LPL and ACS were extracted from the epididymal adipose tissue and liver of Zucker lean rats (lean) and Zucker fatty rats (fa/fa). MNR or YM water extract treatment significantly reduced the activity of lean and fa/fa LPL. When 10000 ppm of MNR, YM, and CJJ water extracts were tested, they decreased fa/fa LPL activity by 32.5%, 30.1% and 22.8%, respectively. The lean ACS activity was significantly higher in YM water extract treatment compared to the control and the MNR water extract treatment significantly increased the activity of fa/fa ACS, compared to the activity in the control (p<0.05). MNR water extract activated fa/fa ACS activity by 12-fold compared with control at 10000 ppm concentration. CAT activity was significantly higher in 10000 ppm and 20000 ppm CJJ water extract treatment than in the control. Thus, the MNR, YM and CJJ water extracts may have beneficial effects due to activities of enzymes related with fat metabolism in obese humans.

• Biomolecules & Therapeutics
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• v.17 no.4
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• pp.455-460
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• 2009

Foods of plant origin, especially fruits and vegetables, have attracted attention because of their potential benefits to human health. In this report, Rubi Fructus (RF), the dried unripe fruit of Rubus coreanus Miq (Rosaceae) and ellagic acid (EA) purified from RF were used to test their potential hepatoprotective effect against acetaminophen (AAP)-induced hepatotoxicity in rats. RF extract (RFext) and EA reduced the elevated levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST) in serum and the content of lipid peroxide in liver by AAP administration, while the increment of the cellular glutathione (GSH) content and the induction of glutathione S-transferase (GST) and glutathione peroxidase (GSH-PX) which were decreased by AAP administration. RFext and EA from RFext did not affect the two major form of cytochrome P450s, cytochrome P450 2E1 (CYP2E1) and cytochrome P450 1A2 (CYP1A2), but downregulated the cytochrome P450 3A4 (CYP3A4) related to the conversion of AAP to N-acetyl-P-benzoquinone imine (NAPQI). These results suggest that RFext and EA from RF exhibit a hepatoprotective effect not only by increasing antioxidant activities but also by down-regulating CYP3A4 in the AAP-intoxicated rat.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.15 no.1
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• pp.127-139
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• 2002

This study was carried out to prove the therapeutic effects of BNJB on the catract. The objects of this study were CXSD mice that spontaneously eye rupture occurred from three weeks after birth and eventually generate cataract within 12 weeks. We applied eyewash made from BNJB to eyes of CXSD mice twice in a day till all the eyes of the negative control showed up the symptoms of a cataract and recorded the increasing patterns of cataractous eyes. To explained the therapeutic effects of the BNJB, We carried out the ex vivo experiment which cultivating eyeballs were offered oxidative stress condition by $0.03{\%}$ $H_2O_2$ during three days. Total co-enzyme was extracted from the cultured eyeballs and used to measure activities of catalase, superoxide dismutase, glutathion S-transferase and content of GSH. The results were obtained as follows: 1. When we treated the catalin to CXSD mouse as a positive control, it represented the delaying effect for cataract generation for 2-3 days compare with negative control. But it seems that it doesn't appropriate as a therapeutic, or delaying agent. 2. In the experimental BNJB group, Cataract formation rate was dramatically reduced by BNJB. This rate was much lower than positive group and means our new formulation for the therapy of cataract has a good potential. 3. In the analysis of individual medicines of BNJB, Mok-Jeok-Cho, Hwang-Lyun and Ha-Go-Cho didn't have a major effect of BNJB. 4. The cataract formation rate was repressed by Bing-Pyun and Jin- Joo-Boon about $40{\%}$ and $50{\%}$, respectively. We can presume that the anti-cataract effect of BNJB was caused by these two medicines. 5. When we surveyed the anti-oxidant activities of BNJB, enzyme activities of GSH, SOD, and Catalase increased about $10{\%},\30{\%}$, and 2.5 folds, respectively.

• Nutrition Research and Practice
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• v.2 no.4
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• pp.234-239
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• 2008

The purpose of this study was to investigate the effects of green tea ingestion on hepatocarcinogenesis before and after its initiation. Male Sprague-Dawley rats were fed an AIN76A diet with or without green tea. Initiation was induced by a single dose (200 mg/kg) of diethylnitrosamine at week 4 and 0.02% (w/w) 2-acetylaminofluorene was supplied in the diets. The control group had free access to water for 13 weeks (CTR13). Tea infusion was provided from the beginning of the experiment for 13 weeks (PRE13) or from the post-initiation stage until week 13 (POST13). Three other groups (CTR24, PRE24 and POST24) were added to examine the longer-term effects (24 weeks) with the same experimental design. The percentage area of liver sections that were positive for hepatic placental glutathione S-transferase (GST-P), which was used as a marker of preneoplastic lesions, was smaller in PRE13 ($20.2{\pm}5.0%$, $mean{\pm}SD$) and POST13 ($26.0{\pm}4.8%$) than in CTR13 ($33.2{\pm}5.8%$, p<0.05). Over the longer period, the GST-P lesions were significantly smaller for both PRE24 and POST24 ($21.6{\pm}8.5%$ and $22.2{\pm}4.0%$, respectively) than for CTR24 ($28.6{\pm}5.1%$, p<0.05), but there was no significant difference between PRE24 and POST24. The liver content of thiobarbituric acid reactive substances was significantly lower in the tea groups than in the controls (p<0.05). However, no significant differences were observed among groups of GST activity. The results show that tea consumption exhibits a stronger short-term initiation-inhibiting ability in liver carcinogenesis, but over a longer period, the preventive effects of green tea ingestion do not differ in post- and pre-initiation.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.125-125
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• 2017

The roots of Platycodon grandiflorum are commonly used for treating bronchitis, asthma, tuberculosis, diabetes, and other inflammatory diseases. Since the molecular mechanism underlying the roots of the plant is unclear. Therefore, the present study was conducted to profile proteins from liquid cultured tetraploid roots of Platycodon grandi orum fl using high throughput proteome approach. Two-dimensional gels stained with CBB, a total of 659 differentially expressed proteins were identified from the liquid medium cultured tetraploid roots of which 32 proteins spots (${\geq}1.5-fold$) were sorted for mass spectrometry analysis. Out of these 32 proteins, a total of 15 proteins were up-regulated such as Serine carboxypeptidase-like 27, Transcription factor bHLH150, 60 kDa jasmonate-induced protein, Cytosolic Fe-S cluster assembly factor NBP35, Regulatory associated protein of TOR 2 and a total of 17 proteins were down-regulated such as Protein G1-like2, Phenylalanine ammonia-lyase, Fructokinase-2, Trihelix transcription factor GT-3a, Guanine nucleotide-binding protein alpha-1 subunit. However, the frequency distribution of identified proteins was carried out within functional categories based on molecular functions, cellular components, and biological processes. Functional categorization revealed that the most of the identified proteins from the explants were mainly associated with the nucleic acid binding, oxidoreductase, transferase activity, protein binding and hydrolase activity. In addition, the proteomic feedback of tetraploid roots of P. grandiflorum may potentially be used to understand the characteristics of proteins and their functions.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.131-131
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• 2017

Though the Platycodon grandiflorum, has a broad range of pharmacologic properties, but the mechanisms underlying these effects remain unclear. In order to profile proteins from the nodal segment, callus, root and shoot, high throughput proteome approach was executed in the present study. Two-dimensional gels stained with CBB, a total of 84 differential expressed proteins were confirmed out of 839 protein spots using image analysis by Progenesis SameSpot software. Out of total differential expressed spots, 58 differential expressed protein spots (${\geq}2-fold$) were analyzed using MASCOT search engine according to the similarity of sequences with previously characterized proteins along with the UniProt database. Out of 58 differential expressed protein, 32 protein spots were up-regulated such as ribulose-1,5-bisphosphate carboxylase, endoplasmic oxidoreductin-1, heat stress transcription factor A3, RNA pseudourine synthase 4, cysteine proteinase, GntR family transcriptional regulator, E3 xyloglucan 6-xylosyltransferase, while 26 differential protein spots were down-regulated such as L-ascorbate oxidase precursor, late embryogenesis abundant protein D-34, putative SCO1 protein, oxygen-evolving enhancer protein 3. However, the frequency distribution of identified proteins using iProClass databases, and assignment by function based on gene ontology revealed that the identified proteins from the explants were mainly associated with the nucleic acid binding (17%), transferase activity (14%) and ion binding (12%). Taken together, the protein profile may provide insight clues for better understanding the characteristics of proteins and its metabolic activities in various explants of this essential medicinal plant P. grandiflorum.