• Journal of Microbiology and Biotechnology
• /
• v.10 no.6
• /
• pp.805-810
• /
• 2000

An antifungal protein antagonistic to the rice blast fungus, Pyricularia oryzae was purified from Paenibacillus macerans PM-1 by ammonium sulfate fractionation, Q Sepharose Fast Flow column chromatography, Phenyl Sepharose CL-4B column chromatography and Superose 12 gen filtration. An apparent molecular mass of the purified antifungal protein was determined as 8 kDa by SDS-PAGE and 9 kDa by analytical gel filtration, respectively, suggesting that the purified protein is a monomer. The antifungal protein was stable at pH range from 7-12 and up to $100^{\circ}C$. The protein was also stable at 0.1-1% Tween 20 and Triton X-100. The N-terminal amino acid sequence of the antifungal protein was Thr-Glu-Leu-Pro-Leu-Gly-Ile-Val-Met-Asp-Lys-Tyr-Thr-Asp-Ala-Phe-Lys-Phe-Asp-Met-Phe. Comparison of the determined sequence with other peptide and DNA sequences did not reveal homology at all. Therefore, the purified antifungal protein was speculated to be a novel protein. The condidial germination in vitro of P. oryzae KJ301:93-39 by the purified protein ($5.9{\mu} g/ml$) was limited to $9{\pm}3.2%$ only, compared with $69{\pm}2.4%$ of the control. Ungerminated conidia were swollen at basa and mid cell by the purified protein. In vivo bioassay for inhibition of conidial germination of P. oryzae KJ 301, one of the most predominating racesin Korea. the purified protein ($5.9{\mu} g/ml$)strongly inhibited the conidial germination. The conidia, even though germinated, could not develop any further to produce appressoria efficiently.

• Journal of Pharmaceutical Investigation
• /
• v.7 no.1_4
• /
• pp.1-12
• /
• 1977

Free amino acid in ethanol extracts and total amino acid hydrolysates of Coicis semen were analyzed by amino acid autoanalyzer. The sample A (unpolished Coicis Semen) and sample B(polished Coicis Semen) are used in this experiments. The results obtained from this study are as follows: 1) 17 kinds of free amino acid (Asp, Thr, Ser, Glu, Pro, Gly, Ala, Val, Cys, Met, Ileu, Lew, Try, Phe, Lys, His, Arg,) including 7 kinds of essential amino acid (Val, Lew, Ileu, Thr, Lys, Met, Phe,) as human nutrition were identified and quantified but tryptophan. 2) Total free amino acids of sample A is more than about 3 folds that of sample B. 3) The distribution of free amino acids contained in sample A, threonine is the richiest and then comes Ala, Glu, Asp, and Pro, in that order. In sample B, glutamic acid is the richiest and then comes Thr, Asp, Ala, and Gly, in that order. 4) 17 kinds of total amino acid (Asp, Thr, Ser, Glu, Pro, Gly, Ala, Val, Cys, Met, Ileu, Lew, Tyr, Pher, Lys, including 7 kinds of essential amino acid (Val, Leu, Ileu, Thr, Lys, Met, Phe,) in human nutrition except tryptophan were identified and quanified. 5) Total amino acid content of sample A is more than about 1.06 folds that of sample B. 6) Total amino acid content of sample A in acid hydrolysates is more than about 1.06 folds that of sample B in acid hydrolysates. 7) Unknown chromatogram of ethanol extracts and acid hydrolysates of Coicis Semen were identified as Ornitine.

• Journal of Sericultural and Entomological Science
• /
• v.42 no.1
• /
• pp.14-23
• /
• 2000

The mitochondrial genome of domesticated silkworm (Bombyx mori) was mapped with five restriction endonucleases (BamHI, EcoRI, HindIII, PstI and XbaI), the entire genome was cloned with HindIII and EcoRI. From the end sequencing results of 5$^1$and 3$^1$region for full genome set of eleven mitochondrial clones, the seven mitochondrial genes (NADH dehydrogenase 6, ATPase 6, ATPase 8, tRN $A^{Lys}$, tRN $A^{Asp}$, tRN $A^{Thr}$ and tRN $A^{Phe}$ of mori were identified on the basis of their nucleotide sequence homology. The nucleotide composition of NADH dehydrogenase 6 was heavily biased towards adenine and thymine, which accounted for 87.76%. On basis of the sequence similarity with published tRNA genes from six insect species, the tRN $A^{Lys}$, tRN $A^{Asp}$ and tRN $A^{Thr}$ were showed stable canonical clover-leaf tRNA structures with acceptible anticodons. However, both the DHU and T$\psi$C arms of tRN $A^{Phe}$ could not form any stable stem-loop structure. The two overlapping gene pairs (tRN $A^{Lys}$ -tRN $A^{ASP}$ and ATPase8-ATPase6) were found from our sequencing results. The genes are encoded on the same strad. ATPase8 and ATPase6 overlaps (ATGATAA) which are a single example of overlapping events between abutted protein-coding genes are common, and there is evidence that the two proteins are transcribed from a single bicistronic message by initiation at 5$^1$terminal start site for ATPase8 and at an internal start site for ATPase6. Ultimately, this result will provide assistance in designing oligo-nucleotides for PCR amplification, and sequencing the specific mitochondrial genes for phylogenetics of geographic races, genetically improved silkworm strains and wild silkworm (mandarina) which is estimated as ancestal of domesticated silkworm.sticated silkworm.

• Journal of Astronomy and Space Sciences
• /
• v.16 no.2
• /
• pp.241-254
• /
• 1999

Differential time-series observations of BL Camelopardalis classified as a double mode SX Phoenicis type variable were secured with a charge coupled device. The observed photometric data was reduced using the IRAF Package and the differential magnitudes were obtained through aperture photometry. The periods of BL Cam were analyzed with the Generalized Least-Square Method by Vanicek (1971) and the Fourier Decomposition Method. It was found that the first and second period of BL Cam were 0.0391 day respectively which lead the period ratio of P1/P0=0.81. This period ratio is much different from 0.78 determined by other investigators and also much more larger than that of other double-mode SX Phe type variables. In addition, this period ratio is much different from the value expected from the relation between the metallicity and period ratio. From these results, it can be confirmed that BL Cam is the most extreme case among all double-mode SX Phe type variables.

• Journal of the Korean Magnetic Resonance Society
• /
• v.13 no.1
• /
• pp.27-34
• /
• 2009

HP (2-20), a 19-residue peptide derived from the N-terminus of Helicobacter pylori Ribosomal Protein L1, has antimicrobial activity but is not cytotoxic to human erythrocytes. Previously, we have synthesized several analogue peptides to investigate the effects of substitutions on the structure and antimicrobial activity. Substitution of $Gln^{16}$ and $Asp^{18}$ with Trp (Anal 3) caused a dramatic increase in bacterial and fungal lytic activities. In this study, analogue peptides were synthesized to investigate the effects of substitution of Gin and Asp with Phe (Anal 6) or Tyr (Anal 7) in HP (2-20) on its structure and antimicrobial activity. Substitution of Gin and Asp with hydrophobic aromatic residues at position 16 and 18 of HP (2-20) caused increase in antibiotic activity without hemolytic effect. Substitution of Gin and Asp with Trp and Try increased antibiotic activity of HP (220) twice more compared to substitution with Phe. The tertiary structures of Anal 6 and Anal 7 in SDS micelles has been investigated using NMR spectroscopy. The structures revealed that substitutions of the aromatic residues at C-terminus resulted in longer and well defined alpha-helix and improved their antibacterial activities

• Journal of Magnetics
• /
• v.17 no.4
• /
• pp.302-307
• /
• 2012

We have designed, fabricated and tested an integrated microfluidic chip with a Planar Hall Effect (PHE) sensor. The sensor was constructed by sequentially sputtering Ta/NiFe/Cu/NiFe/IrMn/Ta onto glass. The microfluidic channel was fabricated with poly(dimethylsiloxane) (PDMS) using soft lithography. Magnetic nanoparticles suspended in hexadecane were used as ferrofluid, of which the saturation magnetisation was 3.4 emu/cc. Droplets of ferrofluid were generated in a T-junction of a microfluidic channel after hydrophilic modification of the PDMS. The size and interval of the droplets were regulated by pressure on the ferrofluid channel inlet. The PHE sensor detected the flowing droplets of ferrofluid, as expected from simulation results. The shape of the signal was dependent on both the distance of the magnetic droplet from the sensor and the droplet length. The sensor was able to detect a magnetic moment of $2{\times}10^{-10}$ emu at a distance of 10 ${\mu}m$. This study provides an enhanced understanding of the magnetic parameters of ferrofluid in a microfluidic channel using a PHE sensor and will be used for a sample inlet module inside of integrated magnetic lab-on-a-chip systems for the analysis of biomolecules.

• Proceedings of the SAREK Conference
• /
• 2009.06a
• /
• pp.1096-1101
• /
• 2009

The plate heat exchanger(PHE) in heat pump has two flow streams of the refrigerant and water. The flow direction of the refrigerant, unlike that of water, can be changed by a 4-way valve depending on operating condition. Therefore the flow arrangement is a parallel flow for heating and a counter flow for cooling, respectively. In this study, the effects of the flow direction of the water on the heat transfer rate are investigated experimentally. The experiments are carried out for brazed plate heat exchangers under a parallel and counter flow conditions in evaporation and condensation. The experimental parameters in this study include the mass flux of the refrigerant 410A from 3 to $14\;kg/m^2s$ and the flow patterns for the pressure of PHE fixed at 0.97 and 2.46 MPa. The results show that both the heat transfer rate and frictional pressure drop across the PHE increase with the mass flux. The heat transfer rate of the refrigerant 410A for evaporation show great sensitivity to flow direction of the water. The heat transfer rate for evaporation with a counter flow are 5-30% higher than that with a parallel flow.

• Proceedings of the Korean Vacuum Society Conference
• /
• 1999.07a
• /
• pp.198-198
• /
• 1999

본 연구는 진공상태에서 단단한 물질로 된 diamond stylus로 단결정 MgO 표면에 마모(abrasion)가 할 때 발생되는 Photon emission(PHE), electron emission(EE), 마찰력을 시간의 함수로 동시에 측정하였다. 마모가 일어나는 동안 PHE 와 EE을 시간의 함수로 측정하면 마찰력 신호(signal)와 일치하지 않고 강한 fluctuation을 보여주고 있다. 마모를 가할 때 PHE와 EE의 signal은 wear 실험이 지속되는 동안은 force signal과 관계가 있다. 그러나 변형과 마찰력의 시간의 함수에는 관계하지 않음을 알 수 있다. 본 실험에서 사용된 실험장치는 PhE, EE, frictional force을 동시에 실할 수 있는 장치이다. 광자방출 실험은 공기 중에서도 할 수 있으나 전자방출은 진공에서 얻을 수 있으므로 1$\times$10-4pa하에서 실험하였다. 전자방출은 Channel electron multiplier(bias-100V)로 검출하였고, 광자 에너지는 Gencom photomultiplier를 사용하여 180~600nm의 photon을 측정하였다. 마모는 탐색기에 관계되는 접촉점의 움직임에 관계없이 실험하였다. 시료의 처리과정과 load속도에 따른 PhE, EE, data의 방출은 시료의 표면 상태에 따라 좌우되었다. cleaved 표면은 polished 표면보다 강한 emission을 나타내었다. 이것은 마찰이 표면 상태에 의존됨을 볼 수 있었다. 속도에 따라 emission이 증가하다가 ~0.5m/s이상에서 포화상태에 도달하였다. emission 측정은 열처리한 시료와 열처리 안한 시료를 비교하였다. 발광도(luminescence)는 주로 변형(deformation)에 의해 생겼으며, 전자 방출은 벽개(fracture)에 의해 발생됨을 알 수 있었다. 측정한 3개의 signal을 시간에 따라 분석하면 stick-slip-like 현상을 볼 수 있었다. 이것으로 보아 stick은 변형에 의해 생기고 ms 후에 벽개 현상이 발생됨을 볼 수 있다. 이러한 방출 현상은 마모시 일어나는 세라믹의 급격한 벽개 과정을 이해하는 데 많은 도움을 주었다. PhE와 EE signal은 다이아몬드 stylus로 단결정 MgO 기판에 마모를 가할 때 ms 단위로 검출 할 수 있었다. 방출과 마찰력은 표면조건, load, stylus velocity에 따라 변하였다. 마찰력, PhE, EE의 시간에 따른 분석에서 PhE는 변형 과정에 민감하며, EE는 stylus velocity에 의존하였다. 본 연구의 MgO 마찰 실험에서 표면 변화에 대한 정보를 얻을 수 있었다.

• Asian Pacific Journal of Cancer Prevention
• /
• v.13 no.7
• /
• pp.3047-3052
• /
• 2012

The enzyme encoded by the MGMT gene is involved in the repair of alkylated lesions formed in DNA by carcinogenic nitrosamines. Since dietary items consumed by the Kashmiri population contain high concentrations of these agents, it is biologically plausible that MGMT polymorphic variants may be associated with their risk of esophageal cancer. The present study was performed to assess whether non-synonymous SNPS at codon Leu84Phe and codon Ileu143Val of the MGMT gene, close to the active site of the protein, might be linked to predisposition of Kashmiris to esophageal cancer. Genotyping was carried out by polymerase chain reaction-restriction fragment length polymorphism on 92 cases and 77 healthy controls. Codon 84 and codon 143 SNPs of the MGMT gene were not associated with any increase in risk. While the frequency of the Phe allele at codon 84 in cases was (0.16), slightly higher than controls (0.12), the difference was not statistically significant. Similarly, the frequency of Valine allele in cases at codon 143 (0.08) and controls (0.09) was nearly equal. Moreover, no significant association of MGMT genotypes with the clinicopatholgic variables of esophageal cancer patients was observed. In conclusion, MGMT variants at codon 84 and codon143 may not be involved in the susceptibility of the Kashmiri population to esophageal cancer.

• Biomolecules & Therapeutics
• /
• v.2 no.4
• /
• pp.303-309
• /
• 1994

The analysis of membrane receptors for hormones and neurotransmitters has progressed considerably by pharmacological and biochemical means and more recently through the use of specific antibodies. Two kinds of antibodies could be produced, one is from synthetic peptides and the other from proteins such as purified receptor. Anti-peptide antibodies gave some advantages; epitope is evident and also receptor purification in quantity is not prerequisite. It can be also applied to the study of receptor structure-activity relationship. The purpose of the present study was 1) to produce and characterize a polyclonal antibody against a synthetic $\beta$2-adrenergic receptor peptide(Phe-Gly-Asn-Phe-Trp-Cys-Phe-Trp-Thr-Ser-Ile-Asp-Val-Leu) and 2) to determine the effects of this antibody on the $\beta$-adrenergic receptor ligand interaction. The peptide sequence contains an amino acid residue such as Asp-113 which was identified as one of important component for receptor-ligand interaction in site-directed mutagenesis studies. Production of antibody was performed by immunization of rabbits through popliteal lymph node with the peptide coupled with Keyhole Limpet Hemocyanin (KLH). The titer of antibody against this peptide was 1 : 1000. The anti-peptide antibody was able to detect a 67 kDa protein band in western blot corresponding to the molecular weight of the $\beta$-adrenergic receptor in partially purified receptor fraction derived from guinea pig lung. The antisera inhibited the specific binding of [$^3$H]dihydroalprenolol to $\beta$-adrenergic receptor in a concentration-dependent manner. The results from this study suggest that the peptide sequence selected in the present study is important for the receptor ligand interaction.