• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
• /
• pp.375-375
• /
• 2012

Graphene is a sp2-hybridized carbon sheet with an atomic-level thickness and a wide range of graphene applications has been intensely investigated due to its unique electrical, optical, and mechanical properties. In particular, hybrid graphene structures combined with various nanomaterials have been studied in energy- and sensor-based applications due to the high conductivity, large surface area and enhanced reactivity of the nanostructures. Conventional metal-catalytic growth method, however, makes useful applications difficult since a transfer process, used to separate graphene from the metal substrate, should be required. Recently several papers have been published on direct graphene growth on the two dimensional planar substrates, but it is necessary to explore a direct growth of hierarchical nanostructures for the future graphene applications. In this study, uniform graphene layers were successfully synthesized on highly dense dielectric nanowires (NWs) without any external catalysts. We also demonstrated that the graphene morphology on NWs can be controlled by the growth parameters, such as temperature or partial pressure in chemical vapor deposition (CVD) system. This direct growth method can be readily applied to the fabrication of nanoscale graphene electrode with designed structures because a wide range of nanostructured template is available. In addition, we believe that the direct growth growth approach and morphological control of graphene are promising for the advanced graphene applications such as super capacitors or bio-sensors.

• BMB Reports
• /
• 제40권4호
• /
• pp.539-546
• /
• 2007

The lysozymes encoded by bacteriophage T7 and K11 are both bifunctional enzymes sharing an extensive sequence homology (75%). The constructions of chimeric lysozymes were carried out by swapping the N-terminal and C-terminal domains between phage T7 and K11 lysozymes. This technique generated two chimeras, T7K11-lysozyme (N-terminal T7 domain and C-terminal K11 domain) and K11T7-lysozyme (N-terminal K11 domain and C-terminal T7 domain), which are both enzymatically active. The amidase activity of T7K11-lysozyme is comparable with the parental enzymes while K11T7-lysozyme exhibits an activity that is approximately 45% greater than the wild-type lysozymes. Moreover, these chimeric constructs have optimum pH of 7.2-7.4 similar to the parental lysozymes but exhibit greater thermal stabilities. On the other hand, the chimeras inhibit transcription comparable with the parental lysozymes depending on the source of their N-terminals. Taken together, our results indicated that domain swapping technique localizes the N-terminal region as the domain responsible for the transcription inhibition specificity of the wild type T7 and K11 lysozymes. Furthermore, we were able to develop a simple and rapid purification scheme in purifying both the wild-type and chimeric lysozymes.

• Journal of Microbiology and Biotechnology
• /
• 제13권4호
• /
• pp.613-619
• /
• 2003

The polyketide backbone of rifamycin B is assembled by the type I rifamycin polyketide synthase (PKS) encoded by the rifA-rifE genes. In order to produce novel analogs of rifamycin via engineering of the PKS genes, inactivation of the ${\beta}-ketoacyl:acyl$ carrier protein reductase (KR) domain in module 8 of rifD, by site-specific mutagenesis of the NADPH binding site, was attempted. Module 8 contains a nonfunctional dehydratase (DH) domain and a functional KR domain that is involved in the reduction of the ${\beta}-carbonyl$ group, resulting in the C-21 hydroxyl of rifamycin B. This mutant strain produced linear polyketides, from tetraketide to octaketide, which were also produced by a rifD-disruption mutant as a consequence of premature termination of the polyketide assembly. Another attempt to replace the DH domain of module 7, which has been considered nonfunctional, with a functional homolog derived from module 7 of rapamycin-producing PKS also resulted in the production of linear polyketides, including the heptaketide intermediate and its precursors. Premature release of the carbon chain assembly intermediates is an unusual property of the rifamycin PKS. that is not seen in other PKSs such as the erythromycin PKS.

• 충청수학회지
• /
• 제22권2호
• /
• pp.201-209
• /
• 2009

In this paper, we prove the stability of the functional equation $$\sum_{i=0}^3_3C_i(-1)^{3-i}f(ix+y)=0$$ in the sense of Th.M.Rassias on the punctured domain. Also, we investigate the superstability of the functional equation.

• Genomics & Informatics
• /
• 제12권3호
• /
• pp.105-113
• /
• 2014

A subset of mammalian genes differ functionally between two alleles due to genomic imprinting, and seven such genes (Peg3, Usp29, APeg3, Zfp264, Zim1, Zim2, Zim3) are localized within the 500-kb genomic interval of the human and mouse genomes, constituting the Peg3 imprinted domain. This Peg3 domain shares several features with the other imprinted domains, including an evolutionarily conserved domain structure, along with transcriptional co-regulation through shared cis regulatory elements, as well as functional roles in controlling fetal growth rates and maternal-caring behaviors. The Peg3 domain also displays some unique features, including YY1-mediated regulation of transcription and imprinting; conversion and adaptation of several protein-coding members as ncRNA genes during evolution; and its close connection to human cancers through the potential tumor suppressor functions of Peg3 and Usp29. In this review, we summarize and discuss these features of the Peg3 domain.

• 대한한방내과학회지
• /
• 제29권2호
• /
• pp.443-455
• /
• 2008

Objectives : This study was designed to research whether HRV can yield a suitable diagnosis for activity of autonomic nerve system on functional dyspepsia. Methods : The testing of HRV was carried out at the Oriental Medical Center of Dong-Eui University with the participation of 28 functional dyspepsia patients, 25 dyspepsia caused by organic disease patients and 33 control group people. We checked HRV of the three groups for 5 minutes and compared HRV index(frequency domain analysis: HF, LF, VLF, LF/HF Ratio, TP) between groups. Results were as follows : 1. In the frequency domain analysis, HF, LF, VLF, and TP were significantly lower than the control group in the functional dyspepsia patients and dyspepsia caused by organic disease groups. HF, LF, VLF, LF/HF ratio, and TP were not significantly different between functional dyspepsia group and dyspepsia caused by organic disease group. 2. Age in dyspepsia patient group was significantly higher than in the control group. 3. In the frequency domain analysis, LF, VLF, and TP were significantly lower in the functional dyspepsia group than the control group in age 20-30 years. HF, LF, VLF, LF/HF ratio, and TP were not significantly different between the control group and dyspepsia caused by organic disease group in ages 20-30 years. HF, LF, VLF, LF/HF ratio, and TP were not significantly different between functional dyspepsia group and dyspepsia caused by organic disease group in age 20-30 years. Conclusion : According to this study, autonomic nerve system and parasympathetic nerve system decreased more in the functional dyspepsia patient group compared with the control group.

• 한국생물물리학회:학술대회논문집
• /
• 한국생물물리학회 2003년도 정기총회 및 학술발표회
• /
• pp.45-45
• /
• 2003

We isolated a novel ankyrin-repeat containing protein, rSIAP (rSlo Interacting Ankyrin-repeat Protein), as an interacting protein to the cytosolic domain of the alpha-subunit of rat large-conductance Ca$\^$2+/-activated K$\^$+/ channel (rSlo) by yeast two-hybrid screening. Affinity pull-down assay showed the direct and specific interaction between rSIAP and rSlo domain. The channel-binding proteins can be classified into several categories according to their functional effects on the channel proteins, i.e. signaling adaptors, scaffolding net, molecular tuners, molecular chaperones, etc. To obtain initial clues on its functional roles, we investigated the cellular localization of rSIAP using immunofluorescent staining. The results showed the possible co-localization of rSlo and rSIAP protein near the plasma membrane, when co-expressed in CHO cells. We then investigated the functional effects of rSIAP on the rSlo channel using electrophysiological means. The co-expression of rSIAP accelerated the activation of rSlo channel. These effects were initiated at the micromolar [Ca$\^$2+/]$\_$i/ and gradually increased as [Ca$\^$2+/]$\_$i/ raised. Interestingly, rSIAP decreased the inactivation kinetics of rSlo channel at micromolar [Ca$\^$2+/]$\_$i/, while the rate was accelerated at sub-micromolar [Ca$\^$2+/]$\_$i/. These results suggest that rSIAP may modulate the activity of native BK$\_$Ca/ channel by altering its gating kinetics depending on [Ca$\^$2+/]$\_$i/. To localize critical regions involved in protein-protein interaction between rSlo and rSIAP, a series of sub-domain constructs were generated. We are currently investigating sub-domain interaction using both of yeast two-hybrid method and in vitro binding assay.

• 한국정보과학회논문지:소프트웨어및응용
• /
• 제31권12호
• /
• pp.1602-1610
• /
• 2004

다양한 유전체 프로젝트로 말미암아 엄청난 서열 데이타들이 쏟아지고, 이에 따라 핵산 및 단백질 수준의 서열 데이타 분석이 매우 중요하게 인식되고 있다. 특히 최근에는 단백질이 단순하게 개별적인 기능을 가진 독립적인 요소가 아닌 전체 단백질 상호작용 네트워크 상에서 다른 객체들과 유기적인 관계를 갖으며 나름대로의 중요한 역할을 수행하고 있다는 점에 초점을 맞추어 연구가 진행되고 있다. 특히 단백질 상호작용 관계 분석을 위해서는 실제로 상호작용이 일어나는 도메인 모듈 정보가 아주 중요하게 작용하는데, 본 논문에서는 이러한 점을 고려하여 우리가 개발한 단백질 기능 및 상호작용 분석을 위한 PIVS(Protein-protein interaction Inference and Visualization System)에 대해 소개하고 있다 PIVS는 기존의 단백질 상호작용 데이타베이스들을 합쳐서 통합 데이타베이스를 생성하고, 다양한 전처리 과정으로 통합 데이타베이스 서열의 기능 및 주석 정보를 추출하여 로컬 데이타베이스화 하였다. 그리고 특히 단백질 상호작용 관계 분석을 위해 중요하게 작용하는 도메인 모듈 정보들을 추출하여 로컬 데이터베이스를 구축하였고, 기존의 단백질 상호작용 관계 데이타를 이용하석 도메인 사이의 상호작용 관계 정보도 수집하여 분석하였다. PIVS는 단백질의 종합적인 분석 정보, 즉, 기능 및 주석, 도메인, 상호작용 관계 정보 등을 손쉽고 편리하게 얻고자 하는 사용자에게 매우 유용하게 사용될 수 있을 것이다.

• IMMUNE NETWORK
• /
• 제10권2호
• /
• pp.35-45
• /
• 2010

Background: Expression of recombinant antibodies and their derivatives fused with other functional molecules such as alkaline phosphatase in Escherichia coli is important in the development of molecular diagnostic reagents for biomedical research. Methods: We investigated the possibility of applying a well-known Fos-Jun zipper to dimerize $V_H$ and $V_L$ fragments originated from the Fab clone (SP 112) that recognizes pyruvate dehydrogenase complex-E2 (PDC-E2), and demonstrated that the functional zipFv-112 and its alkaline phosphatase fusion molecules (zipFv-AP) can be produced in the cytoplasm of Origami(DE3) trxB gor mutant E. coli strain. Results: The zipFv-AP fusion molecules exhibited higher antigen-binding signals than the zipFv up to a 10-fold under the same experimental conditions. However, conformation of the zipFv-AP seemed to be influenced by the location of an AP domain at the C-terminus of $V_H$ or $V_L$ domain [zipFv-112(H-AP) or zipFv-112(L-AP)], and inclusion of an AraC DNA binding domain at the C-terminus of VH of the zipFv-112(L-AP), termed zipFv-112(H-AD/L-AP), was also beneficial. Cytoplasmic co-expression of disulfide-binding isomerase C (DsbC) helped proper folding of the zipFv-112(H-AD/L-AP) but not significantly. Conclusion: We believe that our zipFv constructs may serve as an excellent antibody format bi-functional antibody fragments that can be produced stably in the cytoplasm of E. coli.