• Journal of Microbiology and Biotechnology
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• 제25권8호
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• pp.1380-1389
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• 2015

Prx1, an AhpF-dependent 2-Cys peroxiredoxin (Prx), was previously identified in Vibrio vulnificus, a facultative aerobic pathogen. In the present study, transcription of the V. vulnificus prx1ahpF genes, which are adjacently located on the chromosome, was evaluated by analyzing the promoter and intergenic region of the two genes. Northern blot analyses revealed that transcription of prx1ahpF results in two transcripts, the prx1 and prx1ahpF transcripts. Primer extension analysis and a point mutational analysis of the promoter region showed that the two transcripts are generated from a single promoter. In addition, the 3' end of the prx1 transcript at the prx1ahpF intergenic region was determined by a 3'RACE assay. These results suggested that the prx1ahpF genes are transcribed as an operon, and the prx1 transcript was produced by transcriptional termination in the intergenic region. RNA secondary structure prediction of the prx1ahpF intergenic region singled out a stem-loop structure without poly(U) tract, and a deletion analysis of the intergenic region showed that the atypical stem-loop structure acts as the transcriptional attenuator to result in the prx1 and prx1ahpF transcripts. The combined results demonstrate that the differential expression of prx1 and ahpF is accomplished by the cis-acting transcriptional attenuator located between the two genes and thereby leads to the production of a high level of Prx1 and a low level of AhpF.

• Bulletin of the Korean Chemical Society
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• 제33권2호
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• pp.583-588
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• 2012

Functional interaction between Drosophila orphan receptor FTZ-F1 (NR5A3) and a segmentation gene product fushi tarazu (FTZ) is crucial for regulating genes related to define the identities of alternate segmental regions in the Drosophila embryo. FTZ binding to the ligand-binding domain (LBD) of FTZ-F1 is of essence in activating its transcription process. We determined solution structures of the cofactor peptide ($FTZ^{PEP}$) derived from FTZ by NMR spectroscopy. The cofactor peptide showed a nascent helical conformation in aqueous solution, however, the helicity was increased in the presence of TFE. Furthermore, $FTZ^{PEP}$ formed ${\alpha}$-helical conformation upon FTZ-F1 binding, which provides a receptor bound structure of $FTZ^{PEP}$. The solution structure of $FTZ^{PEP}$ in the presence of FTZ-F1 displays a long stretch of the ${\alpha}$-helix with a bend in the middle of helix.

• Computers and Concrete
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• 제29권4호
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• pp.209-217
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• 2022

In order to analyze the static and dynamic structural characteristics of the Obermeyer gate under overflow conditions, the force characteristics and vibration characteristics of the shield plate structure are studied based on the fluid-solid coupling theory. In this paper, the effects of the flow rate, airbag pressure and overflow water level on the structural performance of shield plate of air shield dam are explored through the method of controlling variables. The results show that the maximum equivalent stress and total deformation of the shield plate decrease first and then increase with the flow velocity. In addition, they are positively correlated with the airbag pressure. What's more, we find that the maximum equivalent stress of the shield plate decreases first and then increases with the overflow water level, and the total deformation of the shield plate decreases with the overflow water level. What's more importantly, the natural frequency of the shield structure of the Obermeyer gate is concentrated at 50 Hz and 100 Hz, so there is still the possibility of resonance. Once the resonance occurs, the free edge of the shield vibrates back and forth. This work may provide a theoretical reference for the safe and stable operation of the shield of the Obermeyer gate.

• 말소리와 음성과학
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• 제2권4호
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• pp.29-37
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• 2010

Previous studies have investigated a between-category relationship of multiple acoustic cues for a laryngeal contrast by examining the distributions of VOT, f0 and H1-H2. The current study examined within-category correlations between cues comprising stops by Korean- and English-speaking adults and children to understand how children master the internal structure of stop phonation types in two languages. Word-initial stops were collected from about 70 children and 15 adults speaking English and Korean, and were analyzed in terms of VOT, f0 and H1-H2 to compute correlation coefficients. Findings in adults' productions included a gender-differentiated cue-correlation pattern associated with H1-H2 in Korean tense stops and a trading relationship between f0 and VOT in Korean lax and aspirated stops and English voiced and voiceless stops. Children did not necessarily have adult-like cue-correlation patterns even in early-acquired categories, suggesting that the mastery of intra-category structure of phonation type might occur later than inter-category structure.

• 생명과학회지
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• 제12권4호
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• pp.464-468
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• 2002

대장균 트립토판 중합효소(tryptophan synthase) $\alpha$ 소단 위체의 96번, 139번 과 258번 자리를 돌연변이 시킨 이중 돌연변이체 P96L/F139W, P6L/F258W와 삼중 돌연변이체 P96L/F139W/F258W의 효소 활성도와 형광 분광계를 이용한 분광학적 성질을 조사하였다. 이중 돌연변이체의 효소 활성도는 야생형과 유사하나 삼중 돌연변이체는 40% 감소된 활성도를 가진다. P96L/F139W 와 P96L/F258W의 형광세기는 야생형에 비해 감소하였으나 P96L/F139W/F258W는 야생형에 비해 증가하였다. 효소 활성도와 형광 결과는 96번의 치환이 8번 알파구조와 4번 베타 구조와 4번 알파구조 사이의 loop의 안정성에 영향을 준 것을 나타낸다. 이 결과로부터 P96L/F139W/F258W는 야생형과 다른 3차 구조를 가지나 139번과 258면 주위는 더 조밀한 구조를 가지고 있다는 것을 보여준다.

• 한국염색가공학회지
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• 제11권2호
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• pp.9-18
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• 1999

In order to establish fundamental data for the betterment of Polyester microfiber fabric handle, a study by using fixed warp of ITY yarn samples with P/F, DTY, and ITY weft yarns was performed. For this purpose the samples of total 27 kinds were prepared. That is, each sample yarn was twisted in three ways and for each twisted yarn the fabric structures were modified in three ways, plain, twill, and satin. The examination was done by focusing on the point of the change of handles and the characteristics of the mechanical properties of the samples with the change of yarn and the fabric structure. The handles and the mechanical properties were examined with the KES-F system suggested by Kawabata. The results were as follows : 1. WT and MIU increased with increasing the twist. By comparing WT and MIU by yarn, DTY was higher than P/F. It appeared that twill and satin were higher than plain. 2. The bending rigidity change in DTY with increasing the twist was not significant, however in P/F it appeared apparently decreased with increasing the tlvist. Also, it appeared that when using P/F as weft the bending rigidity was higher than when using DTY and the twill structure appeared higher than the satin structure. 3. In shear force the increasing rates of plain and the twill were higher than satin. When DTY and P/F were used as weft, the shear force was higher in ITY and DTY than in P/F case. 4. Koshi appeared higher in the order of plain, twill and satin. When DTY and P/F were used as the weft Koshi increased with increasing the twist in plain, however in twill and satin it appeared to decrease. In hand value ITY(=7.5) appea.ed to be highe. than DTY and P/F(=6.5). 5. In all cases Shinayakasa decreased with increasing the twist. The hand values observed that satin was =4, twill was =3, and plain was =1.5. 6. Fukurami showed no significant change with increasing the twist in DTY, however in P/F and ITY it decreased.

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.305-305
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• 2006

The molecular structure and dynamics of inclusion compounds (ICs) consisting of n-perfluoroalkane (PFA) guests and ${\Box}-cyclodextrin$ (${\Box}-CD$) host were investigated using $^{19}F$ magic angle spinning (MAS) and $^{1}H{\to}^{19}F$ cross polarization (CP) / MAS NMR spectroscopy with the aid of thermal analyses, FT-IR spectroscopy, X-ray diffraction, and $^{1}H{\to}^{19}F$ CP/MAS technique revealed that $C_{9}F_{20}$ molecules included in ${\Box}-CD$ undergo vigorous molecular motion and partly come out of the ${\Box}-CD$ channel above $80^{\circ}C$. In case of $C_{20}F_{42}/{\Box}-CD$, an exothermic peak is observed by differential scanning calorimetry (DSC) at ca. $40^{\circ}C$ which suggests that ${\Box}-CD$ molecules become mobile and commence rearrangements that form more ordered structures at higher temperatures.

• 한국세라믹학회지
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• 제48권6호
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• pp.625-629
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• 2011

In this study, we show that by anodization of Nb in NaF electrolytes microcone niobium oxide layers can be formed under a range of experimental conditions. It is found that a single NaF electrolyte leads to the formation of microcones. At 1 M NaF, 40 V, 1 h, well-ordered microcones were generated on Nb discs. XRD results show that the initially formed anodic oxide is amorphous, but an amorphous to crystalline transition occurs during anodization. For the formation of favorable microcones, it is considered that proper parameters such as electrolyte concentration, voltage, anodizing time are necessary according to the kind of electrolytes.

• 한국미생물·생명공학회지
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• 제24권5호
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• pp.574-578
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• 1996

In the course of screening for the antifungal compounds against Candida albicans, an antifungal compound (F1480) was isolated from the culture broth of Aspergillus candidus F1484. Isolation and purification of compound F1484 were performed using ethyl acetate extraction, silica gel column chromatography, ODS column chromatography, and preparative HPLC. The structure of compound F1484 was determined by the spectroscopic analyses of EI-MS, $^{13}$C, $^{1}$H-NMR, DEPT, HMQC, and HMBC. This compound appeared to have a structure of antifungal agent, chloroflavonin. In addition to antifungal activities against the yeast phase of Candida species, compound F1484 showed cytotoxic effect against various human tumor cell lines.

• Journal of Microbiology and Biotechnology
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• 제22권1호
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• pp.34-45
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• 2012

A thermophilic Bacillus stearothermophilus F1 produces an extremely thermostable serine protease. The F1 protease sequence was used to predict its three-dimensional (3D) structure to provide better insights into the relationship between the protein structure and biological function and to identify opportunities for protein engineering. The final model was evaluated to ensure its accuracy using three independent methods: Procheck, Verify3D, and Errat. The predicted 3D structure of F1 protease was compared with the crystal structure of serine proteases from mesophilic bacteria and archaea, and led to the identification of features that were related to protein stabilization. Higher thermostability correlated with an increased number of residues that were involved in ion pairs or networks of ion pairs. Therefore, the mutants W200R and D58S were designed using site-directed mutagenesis to investigate F1 protease stability. The effects of addition and disruption of ion pair networks on the activity and various stabilities of mutant F1 proteases were compared with those of the wild-type F1 protease.