• Journal of the Korean Magnetic Resonance Society
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• v.21 no.2
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• pp.50-54
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• 2017

Cupin-superfamily proteins represent the most functionally diverse groups of proteins and include a huge number of functionally uncharacterized proteins. Recently, YaiE, a cupin protein from Escherichia coli has been suggested to be involved in a novel activity of pyrimidine/purine nucleoside phosphorylase (PPNP). In the present study, we achieved a complete backbone NMR assignments of YaiE, by a series of heteronuclear multidimensional NMR experiments on its [$^{13}C/^{15}N$]-enriched sample. Subsequently, secondary structure analysis using the assigned chemical shift values identified 10 obvious ${\beta}-strands$ and a tentative $3_{10}-helix$. Taken all together, the results constitute the first structural characterization of a putative PPNP cupin protein.

• Biomolecules & Therapeutics
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• v.9 no.2
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• pp.79-87
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• 2001

Heat shock proteins serve as chaperone by preventing the aggregation of denatured proteins and promote survival of pathogens in harsh environments. In this study, heat shock gene encoding a 84-kDa (p84) protein, which is one of the three major heat shock proteins in S. pneumoniae, was cloned and characterized. PCR with a forward primer derived from N-terminal amino acid sequence of the p84 and a reverse primer derived from the conserved second ATP-binding region of Clp family was used for amplification of the gene encoding the p84 and subsequently the PCR product was used for sequence determination. Sequence analysis of the p84 gene demonstrated that it is a member of ClpL. The deduced amino acid sequence of pneumococcal ClpL shows homology with other members of the Clp family, and particularly, even in variable leader region, with bovine Clp-like protein and L. lactis ClpL. S. pneumoniae clpL is the smallest clop member (701 amono acids) containing the two conserved ATP-binding regions, and hydrophilic N-terminal variable region of pneu-mococcal Clp ATPase is much shorter than any known Clp ATPases. Histidine tagged ClpL was overexpressed and purified from E. coli. Immunoblot analysis employing antisera raised against pneumococcus p84 demonstrated no cross-reactivity with Clp analog in Eschericha coli, Staphylococcus aureus and human HeLa cells. Preimmunization of mice with ClpL extended mice life partially but did not protect them from death.

• Molecules and Cells
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• v.26 no.4
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• pp.323-328
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• 2008

Eukaryotic cells continuously integrate intrinsic and extrinsic signals to adapt to the environment. When exposed to stressful conditions, cells activate compartment-specific adaptive responses. If these are insufficient, apoptosis ensues as an organismal defense line. The mechanisms that sense stress and set the transition from adaptive to maladaptive responses, activating apoptotic programs, are the subject of intense studies, also for their potential impact in cancer and degenerative disorders. In the former case, one would aim at lowering the threshold, in the latter instead to increase it. Protein synthesis, consuming energy for anabolic processes as well as for byproducts disposal, can be a significant source of stress, particularly when difficult-to-fold proteins are produced. Recent work from our and other laboratories on the differentiation of antibody secreting cells, revealed a regulatory circuit that integrates protein synthesis, secretion and degradation (proteostasis), into cell lifespan determination. The apoptotic elimination - after an industrious, yet short lifetime - of terminal immune effectors is crucial to maintain immune homeostasis. Linking proteostasis to cell death, this paradigm might prove useful for biotechnological purposes, and the design of novel anti-cancer therapies.

• Journal of Microbiology and Biotechnology
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• v.18 no.10
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• pp.1655-1658
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• 2008

Cyanobacteria, blue-green algae, are a rich source of bioactive secondary metabolites with many potential applications. The ubiquitin-proteasome proteolytic system plays an important role in selective protein degradation and regulates cellular events including apoptosis. Cancer cells are more sensitive to the proapoptotic effects of proteasome inhibition than normal cells. Thus, proteasome inhibitors can be potential anticancer agents. Cyanobacteria have been shown to be a rich source of highly effective inhibitors of proteases. A proteasome inhibitor was screened from an extract of the culture of Scytonema hofmanni on the basis of its inhibitory activity, which led to the isolation of nostodione A with an $IC_{50}$ value of 50${\mu}M$. Its structure was determined by spectroscopic methods such as $^{1}H$-NMR and ESI-MS spectral analyses.

• Bulletin of the Korean Chemical Society
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• v.27 no.3
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• pp.386-388
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• 2006

Membrane proteins in highly oriented lipid bilayer samples are useful for membrane protein structure determination. We used in the past planar lipid bilayers which were aligned and supported on the glass slide. These samples were mechanically aligned in a magnetic field. However, these stacks of glass slides with planar lipid bilayers are not well suited for use with a commercial solid-state NMR probe with a round coil. Therefore, a homebuilt solid-state NMR probe was built and used with a stack of thin glass plates wherein the RF coil was wrapped directly around the flat square sample. Recently, we began to use magnetically aligned bicelles that are suitable for the structure determination of membrane proteins by solid-state NMR spectroscopy without any effort to build a flat square coil probe. These bicelle samples are well suited for use with a commercial solidstate NMR probe with a round coil, are very easy to prepare and are very stable, so that they can be kept for more than a year. In this paper, we present the solid-state NMR spectra of optimized and magnetically oriented bicelle samples of membrane proteins.

• Applied Biological Chemistry
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• v.2
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• pp.41-44
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• 1961

The amino acid analysis of ground rice and the crude protein isolated from rice were performed by the most recent method of Moore, Spackman and Stein, using Amberlite IR-120. The effect of carbohydrates on the hydrolysis of rice was found to be definite in losing several amino acids nevertheless Dustin's claim that large excess of hydrolyzing acid reduces the losses of amino acid. Consequantly the removal carbohydrates as much as possible is considered to facilitate the amino acid determination. The amino acid composition of the crude rotein of rice was very similar to that previously found by other investigators.

• YAKHAK HOEJI
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• v.45 no.4
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• pp.347-351
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• 2001

A rapid and sensitive method for the determination of glyphosate, a phosphated amino acid herbicide, in whole blood is presented. After removal of protein, the whale blood was purified by using the anion exchange resin (Dowex 1), and derivatized with 9-fluorenylmethyl chloroformate (FMCL). Derivatized glyphosate from blood sample was injected onto a Whatman partisil 10SAX column and separated with 0.1M phosphate buffer (pH 2.5) and acetonitrile (ratio=3:1). The high performance liquid chromatography-fluorescence detection gave the detection limit of 86pg and linearity of 0.9999 in the range of 0.25 $\mu$g/ml and 25 $\mu$g/ml. The recoveries of glyphosate added to the blood samples were ranged from 75.3% to 100.4% compared to the samples prepared in water. The derivatized glyphosate was stable at various acidity and temperature. This method has been successfully applied to the blood samples of lethal intoxication with the herbicide glyphosate.

• Journal of Environmental Science International
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• v.17 no.12
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• pp.1325-1330
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• 2008

This study was carried out with the detection for multiresidue of the carbamate pesticide such as carbaryl and cabofuran by enzyme-inhibition method. The check time for determination of acetylcholinesterase(AChE) activity was selected at 60 sec. The AChE activity in chicken brain determined by the Ellman's method was $162{\mu}$mol/min/g protein. $I_{50}$ for AChE by carbamate pesticide with wet kit was 0.169mg/L of carbaryl and 0.089mg/L of cabofuran, respectively. The incubation time for enzyme kit with substrate kit was 30min for determination of AChE activity. Enzyme kit with substrate kit was stable at $4^{\circ}C\;and\;25^{\circ}C$ for 5 days. Limit detection concentration of carbaryl with dry kit for AChE was 0.05mg/L. The dry kit such as wet kit applied Enzyme-Inhibition(EI) method with AChE was confirmed the multi residue method to detect the carbamate pesticides.

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.277.1-277.1
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• 2003

A high-performance liquid chromatographic method using the liquid extraction procedure was developed for the determination of L -FMAUS. a new L -FMAU derivative, in rat plasma and urine using 3-aminophenyl sulfone as an internal standard. A 100-${\mu}\ell$ aliquot of distilled water containing the L -cysteine (100 mg/$m\ell$) was added to a 100-${\mu}\ell$ aliquot of biological sample. L-Cysteine was employed to protect binding between 5'-thiol of l and protein in the biological sample. (omitted)

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.5
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• pp.386-395
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• 2006

The core questions for determining nitrogen topdress rate (Npi) at panicle initiation stage (PIS) are 'how much nitrogen accumulation during the reproductive stage (PNup) is required for the target rice yield or protein content depending on the growth and nitrogen nutrition status at PIS?' and 'how can we diagnose the growth and nitrogen nutrition status easily at real time basis?'. To address these questions, two years experiments from 2001 to 2002 were done under various rates of basal, tillering, and panicle nitrogen fertilizer by employing a rice cultivar, Hwaseongbyeo. The response of grain yield and milled-rice protein content was quantified in relation to RVIgreen (green ratio vegetation index) and SPAD reading measured around PIS as indirect estimators for growth and nitrogen nutrition status, the regression models were formulated to predict PNup based on the growth and nitrogen nutrition status and Npi at PIS. Grain yield showed quadratic response to PNup, RVIgreen around PIS, and SPAD reading around PIS. The regression models to predict grain yield had a high determination coefficient of above 0.95. PNup for the maximum grain yield was estimated to be 9 to 13.5 kgN/10a within the range of RVIgreen around PIS of this experiment. decreasing with increasing RVIgreen and also to be 10 to 11 kgN/10a regardless of SPAD readings around PIS. At these PNup's the protein content of milled rice was estimated to rise above 9% that might degrade eating quality seriously Milled-rice protein content showed curve-linear increase with the increase of PNup, RVIgreen around PIS, and SPAD reading around PIS. The regression models to predict protein content had a high determination coefficient of above 0.91. PNup to control the milled-rice protein content below 7% was estimated as 6 to 8 kgN/10a within the range of RVIgreen and SPAD reading of this experiment, showing much lower values than those for the maximum grain yield. The recovery of the Npi applied at PIS ranged from 53 to 83%, increasing with the increased growth amount while decreasing with the increasing Npi. The natural nitrogen supply from PIS to harvest ranged from 2.5 to 4 kg/10a, showing quadratic relationship with the shoot dry weight or shoot nitrogen content at PIS. The regression models to estimate PNup was formulated using Npi and anyone of RVIgreen, shoot dry weight, and shoot nitrogen content at PIS as predictor variables. These models showed good fitness with determination coefficients of 0.86 to 0.95 The prescription method based on the above models predicting grain yield, protein content and PNup and its constraints were discussed.