• 대한화학회지
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• 제38권10호
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• pp.710-718
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• 1994

본 연구에서는 ${\alpha}$-aminoisobutyric acid (Aib)와 alanine (Ala)이 교대로 결합된 올리고펩티드(Buo-(Ala-Aib)$_n$-oMe:여기서 Buo는 t-butoxy를 oMe는 methoxy를 의미한다)의 구조적인 전이현상을 적절하게 설명할 수 있는 통계 열역학적인 이론을 제시하고자 한다. Poly $\alpha-aminoisobutyric$ acid는 $3_{10}$ 나선 구조를 가지며 polyalanine은 $\alpha$ 나선구조를 가진다. 올리고펩티드(Buo-(Ala-Aib)$_n$-oMe)의 사슬 길이를 N = 4(N = 2n)에서부터 증가시킬 때, $3_{10}$ 나선구조에서 $\alpha$ 나선구조로의 전이는 사슬길이가 N = 8일 때 일어난다. 올리고 펩티드는 수용액에서 코일 구조로만 있으나, 유기용매(예를 들면, $CD_3$CN)에서는 여러가지 구조가 있을 수 있기 때문에, 코일구조만으로 된 것, 코일과 $3_{10}$ 나선구조로 된 것, 코일과 $\alpha$ 나선구조로 된 것을 zipper 모형을 사용하여 전이현상을 설명하였다. Zimm-Bragg변수인 $\alpha$와 $\xi$는 실험적인 값에 의거하였다. 각각 그 값은 $\sigma_T$ = 0.00011이고, ${\sigma}_T$ = 0.0060이며, $\xi_A$ = 10.1, $\xi_T$ = 3.90이 된다(첨자 A와 T는 각각 $\alpha$ 나선, $3_{10}$을 의미한다.) 일반적으로 사슬 전체길이를 N이라 하면 $\alpha$ 나선내에서의 나선내 수소 결합수는 N-2, N-3, N-4, ${\cdots}$, 3, 2, 1등이 있을 수 있으며, $3_{10}$ 나선에서는 N-1, N-2, N-3, N-4, ${\cdots}$, 3, 2, 1등이 있을 수 있다. 그러나 $\xi_A$와 $\xi_T$가 1보다 큰 값을 가지기 때문에, 긴 나선으로 된 사슬로 존재하는 것이 상대적으로 많다.

• 한국균학회소식:학술대회논문집
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• 한국균학회 2015년도 춘계학술대회 및 임시총회
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• pp.61-61
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• 2015

Rice blast, caused by the fungal pathogen Magnaporthe oryzae, is one of the most destructive diseases of rice worldwide. The rice - M. oryzae pathosystem has become a model in the study of plant - fungal interactions due to its economic importance and accumulating knowledge. During the evolutionary arms race with M. oryzae, rice plants evolved a repertoire of Resistance (R) genes to protect themselves from diseases in a gene-for-gene fashion. M. oryzae secretes a battery of small effector proteins to manipulate host functions for its successful infection, and some of them are recognized by host R proteins as avirulence effectors (AVR), which turns on strong immunity. Therefore, the analysis of interactions between AVRs and their cognate R proteins provide crucial insights into the molecular basis of plant - fungal interactions. Rice blast resistance genes Pik, Pia, Pii comprise pairs of protein-coding ORFs, Pik-1 and Pik-2, RGA4 and RGA5, Pii-1 and Pii-2, respectively. In all three cases, the paired genes are tightly linked and oriented to the opposite directions. In the AVR-Pik/Pik interaction, it has been unraveled that AVR-Pik binds to the N-terminal coiled-coil domain of Pik-1. RGA4 and RGA5 are necessary and sufficient to mediate Pia resistance and recognize the M. oryzae effectors AVR-Pia and AVR1-CO39. A domain at the C-terminus of RGA5 characterized by a heavy metal associated domain was identified as the AVR-binding domain of RGA5. Similarly, physical interactions among Pii-1, Pii-2 and AVR-Pii are being analyzed.

• Journal of Life Science
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• 제11권1호
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• pp.1-6
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• 2001

In order to determine the role of the carboxyl terminal amino acid residues of unacetylated ${\alpha}$-tropomyosin in actin affinity two mutant tropomyosins were constructed by site-directed mutagenesis. TM16 was identical to the striated tropomyosin except that three amino acids in the carboxyl terminal end were altered to $^{282}TNM^{284}$ while in TM17 $^{282}TSI^{284}$ of the striated was replaced with$^{282}NSM^{284}$. TM16 and TM17 were overproduced in Escherichia coli and analyzed for actin affinity by comparing actin affinities of the striated and TM11 $^{282}NNM^{284}$). The apparent binding constants (Kapp) of unacetylated tropomyosins to actin were $5.1{\times}10^4M^{-1}$ for the striated, $1.1{\times}10^5M^{-1}$ for TM11, $1.09{\times}10^5M^{-1}$ for TM16, and $1.03{\times}10^5M^{-1}$ for TM17, respectively. Since the actin affinities of TM11, TM16, and TM17 were very similar, this result suggested that amino acid residues 282 and 283 were insignificant for acting affinity of unacetylated $\alpha$-tropomyosin. However, they all exhibited higher actin affinities than that of the striated, suggesting that Met residue at the carboxyl terminus of unacetylated smooth tropomyosin was rather important for actin affinity, presumably due to the nucleophilic nature of sulfur atom in Met residue.

• 한국전산유체공학회지
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• 제9권3호
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• pp.49-56
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• 2004

A heated and expanded helium is used to pressurize liquid propellants in propellant tanks of propulsion system of liquid propellant launch vehicles. To produce a heated and expanded helium, an hot-gas heat exchanger is used by utilizing heat source from an exhausted gas, which was generated in a gas generator to operate turbine of turbo-pump and dumped out through an exhaust duct of engine. Both experimental and numerical approaches of hot-gas heat exchanger design were conducted in the present study. Experimentally, siliconites - electrical resistance types - were used to simulate the full heat condition instead of an exhausted gas. Cryogenic heat exchangers, which were immersed in a liquid nitrogen pool, were used to feed cryogenic gaseous helium in a hot-gas heat exchanger. Numerical simulation was made using commercially utilized solver - Fluent V.6.0 - to validate experimental results. Helically coiled stainless steel pipe and stainless steel exhausted duct were consisted of tetrahedron unstructured mesh. Helium was a working fluid Inside helical heat coil and regarded as an ideal gas. Realizable k-』 turbulent modeling was adopted to take turbulent mixing effects in consideration. Comparisons between experimental results and numerical solutions are Presented. It is observed that a resulted hot-gas heat exchanger design is reliable based on the comparison of both results.

• BMB Reports
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• 제40권6호
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• pp.973-978
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• 2007

Septins are a family of conserved cytoskeletal GTPase forming heteropolymeric filamentous structure in interphase cells, however, the mechanism of assembly are largely unknown. Here we described the characterization of SEPT12, sharing closest homology to SEPT3 and SEPT9. It was revealed that subcelluar localization of SEPT12 varied at interphase and mitotic phase. While SEPT12 formed filamentous structures at interphase, it was localized to the central spindle and to midbody during anaphase and cytokinesis, respectively. In addition, we found that SEPT12 can interact with SEPT6 in vitro and in vivo, and this interaction was independent of the coiled coil domain of SEPT6. Further, co-expression of SEPT12 altered the filamentous structure of SEPT6 in Hela cells. Therefore, our result showed that the interaction between different septins may affect the septin filament structure.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1995년도 제3회 추계심포지움
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• pp.107-113
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• 1995

Basement membrane laminin is a multidomain glycoprotein that interacts with itself, heparin and cells. The distal long arm plays major cell and heparin interactive roles. The long arm consists of three subunits (A, B1, B2) joined in a coiled-coil rod attached to a terminal A chain globule (G). The globule is in turn subdivided into five subdomains (Gl-5). In order to analyze the functions of this region, recombinant G domains (rG, rAiG, rG5, rGΔ2980-3028) were expressed in Sf9 insect cells using a baculovirus expression vector. A hybrid molecule (B-rAiG), consisting of recombinant A chain(rAiG) and the authentic B chains (E8-B)was assembled in vitro. The intercalation of rAiG into E8-B chains suppressed a heparin binding activity identified in subdomain Gl-2. By the peptide napping and ligand blotting, the relative affinity of each subeomain to heparin was assigned as Gl> G2= G4> G5> G3, such that G1 bound strongly and G3 not at all. The active heparin binding site of G domain in intact laminin appears to be located in G4 and proximal G5. Cell binding was examined using fibrosarcoma Cells. Cells adhered to E8, B-rAiG, rAiG and rG, did not bind on denatured substrates, poorly bound to the mixture of E8-B and rG. Anti-${\alpha}$6 and anti-${\beta}$1 integrin subunit separately blocked cell adhesion on E8 and B-rAiG, but not on rAiG. Heparin inhibited cell adhesion on rAiG, partially on B-rAiG, and not on E8. In conclusion, 1) There are active and cryptic cell and heparin binding activities in G domain. 2) Triple-helix assembly inactivates cell and heparin binding activities and restores u6131 dependent cell binding activities.

• Asian-Australasian Journal of Animal Sciences
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• 제23권12호
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• pp.1543-1551
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• 2010

A major aim of cattle genome research is to identify candidate genes associated with meat quantity and quality through QTL analysis for application in the livestock industry. Therefore, this study focused on discovery of useful SNPs within the LOC534614 gene, containing 12273_165 SNP which is located on the same site as the QTL on chromosome 6, and evaluation of the association between SNP and body weight and cold carcass weight in Hanwoo (Korean cattle) As a result of a BLAST search of the NCBI web site, we discovered that the mRNA sequence of the LOC534614 gene was similar to that of the coiled-coil domain containing 158 (CCDC158) for dog and human. According to the direct DNA sequence from the CCDC158 gene, we identified 19 polymorphic SNPs within exons and their flanking regions. Among them, 17 polymorphic SNPs were selected for genotyping in Hanwoo (n = 476) and seventeen marker haplotypes containing 12273_165 SNP (frequency >0.1) were identified. As a result of the association between 17 polymorphic SNPs and Hanwoo (n = 476), g.8778G>A SNP in exon 6 was found to be a non-synonymous SNP, and was significantly associated with body weight and cold carcass weight (p<0.05). We discovered 19 polymorphic SNPs in the CCDC158 gene on the QTL region of BTA 6 in Hanwoo and identified that the g.8778G>A SNP was significantly associated with body weight and cold carcass weight (p<0.05), which causes an amino acid variation from valine to methionine. Furthermore, statistical analysis demonstrated that the CCDC158 gene is strongly associated with body weight and cold carcass weight in Hanwoo. In this regard, the g.8778G>A SNP in the CCDC158 gene can be useful as a positional candidate for body weight and cold carcass weight for marker-assisted selection in Hanwoo.

• Asian Pacific Journal of Cancer Prevention
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• 제16권3호
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• pp.1011-1018
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• 2015

This study was conducted to investigate the plasma phosphoproteome and differential plasma phosphoproteins in cases of of Opisthorchis viverrini (OV)-related cholangiocarcinoma (CCA). Plasma phosphoproteomes from CCA patients (10) and non-CCA subjects (5 each for healthy subjects and OV infection) were investigated using gel-based and solution-based LC-MS/MS. Phosphoproteins in plasma samples were enriched and analyzed by LC-MS/MS. STRAP, PANTHER, iPath, and MeV programs were applied for the identification of their functions, signaling and metabolic pathways; and for the discrimination of potential biomarkers in CCA patients and non-CCA subjects, respectively. A total of 90 and 60 plasma phosphoproteins were identified by gel-based and solution-based LC-MS/MS, respectively. Most of the phosphoproteins were cytosol proteins which play roles in several cellular processes, signaling pathways, and metabolic pathways (STRAP, PANTHER, and iPath analysis). The absence of serine/arginine repetitive matrix protein 3 (A6NNA2), tubulin tyrosine ligase-like family, member 6, and biorientation of chromosomes in cell division protein 1-like (Q8NFC6) in plasma phosphoprotein were identified as potential biomarkers for the differentiation of healthy subjects from patients with CCA and OV infection. To differentiate CCA from OV infection, the absence of both serine/threonine-protein phosphatase 2A 56 kDa regulatory subunit beta isoform and coiled-coil domain-containing protein 126 precursor (Q96EE4) were then applied. A combination of 5 phosphoproteins may new alternative choices for CCA diagnosis.

• 대한물리치료과학회지
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• 제11권1호
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• pp.20-27
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• 2004

It is widely accepted that smooth muscle contraction is triggered by intracellular $Ca^{2+}$ ($[Ca^{2+}]_i$) released from intracellular $Ca^{2+}$ stores such as sarcoplasmic reticulum (SR) and from the extracellular space, The increased $[Ca^{2+}]_i$ can phosphorylate the 20-kDa myosin light chain ($MLC_{20}$) by activating MLC kinase (MLCK), and this initiates smooth muscle contraction. In addition to the $[Ca^{2+}]_i$-MLCK-tension pathway, a number of intracellular signal molecules, including mitogen-activated protein kinase (MAPK), protein kinase C (PKC), phosphatidylinositol 3-kinase (PI3K), and Rho-associated coiled coil-forming protein kinase (ROCK), play important roles in the regulation of smooth muscle contraction. However, the mechanisms regulating contraction of caldesmon (CaD), actin-binding protein, are not entirely elucidated in the presence of $Ca^{2+}$. It is known that CaD tightly interacts with actin and inhibits actomyosin ATPase activity. Therefore, the purpose of the present study was to investigate the roles of $Ca^{2+}$-dependent CaD in smooth muscle contraction. Endothelin-1 (ET-1), G-protein coupled receptor agonist and vasoconstrictor, increased both vascular smooth contraction and phosphorylation of CaD in the presence of $Ca^{2+}$. These results suggest that ET-1 induces contraction and phosphorylation of CaD in rat aortic smooth muscle, which may he mediated by the increase of $[Ca^{2+}]_i$.

• The Plant Pathology Journal
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• 제30권3호
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• pp.254-260
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• 2014

Potato Rpi-blb2 encodes a protein with a coiled-coil-nucleotide binding site and leucine-rich repeat (CC-NBSLRR) motif that recognizes the Phytophthora infestans AVRblb2 effector and triggers hypersensitive cell death (HCD). To better understand the components required for Rpi-blb2-mediated HCD in plants, we used virus-induced gene silencing to repress candidate genes in Rpi-blb2-transgenic Nicotiana benthamiana plants and assayed the plants for AVRblb2 effector. Rpi-blb2 triggers HCD through NbSGT1-mediated pathways, but not NbEDS1- or NbNDR1-mediated pathways. In addition, the role of salicylic acid (SA), jasmonic acid (JA), and ethylene (ET) in Rpi-blb2-mediated HCD were analyzed by monitoring of the responses of NbICS1-, NbCOI1-, or NbEIN2-silenced or Rpi-blb2::NahG-transgenic plants. Rpi-blb2-mediated HCD in response to AVRblb2 was not associated with SA accumulation. Thus, SA affects Rpi-blb2-mediated resistance against P. infestans, but not Rpi-blb2-mediated HCD in response to AVRblb2. Additionally, JA and ET signaling were not required for Rpi-blb2-mediated HCD in N. benthamiana. Taken together, these findings suggest that NbSGT1 is a unique positive regulator of Rpi-blb2-mediated HCD in response to AVRblb2, but EDS1, NDR1, SA, JA, and ET are not required.