• 제목/요약/키워드: membrane characterization

검색결과 687건 처리시간 0.023초

Structural and Functional Characterization of CRAMP-18 Derived from a Cathelicidin-Related Antimicrobial Peptide CRAMP

  • Park, Kyong-Soo;Shin, Song-Yub;Hahm, Kyung-Soo;Kim, Yang-Mee
    • Bulletin of the Korean Chemical Society
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    • 제24권10호
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    • pp.1478-1484
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    • 2003
  • CRAMP was identified from a cDNA clone derived from a mouse femoral marrow cells as a member of cathelicidin-derived antimicrobial peptide. Tertiary structure of CRAMP in TFE/$H_2O$ (1 : 1, v/v) solution has been determined by NMR spectroscopy previously and consists of two amphipathic $\alpha-helices$ from Leu4 to Lys10 and from Gly16 to Leu33. These two helices are connected by a flexible region from Gly11 to Gly16. Analysis of series of fragments composed of various portion of CRAMP revealed that an 18-residue fragment with the sequence from Gly16 to Leu33 (CRAMP-18) was found to retain antibacterial activity without cytotoxicity. The effects of two Phe residues at positions 14 and 15 of CRAMP-18 on structure, antibacterial activity, and interaction with lipid membranes were investigated by $Phe^{14,15}$ ${\rightarrow}$ Ala substitution (CRAMP-18-A) in the present study. Substitution of Phe with Ala in CRAMP-18 caused a significant reduction on antibacterial and membrane-disrupting activities. Tertiary structures of CRAMP-18 in 50% TFE/$H_2O$ (1 : 1, v : v) solution shows amphipathic ${\alpha}$-helix, from $Glu^2{\;}to{\;}Leu^{18}$, while CRAMP-18-A has relatively short amphipathic ${\alpha}$-helix from $Leu^4{\;}to{\;}Ala^{15}$. These results suggest that the hydrophobic property of $Phe^{14}{\;}and{\;}Phe^15$ in CRAMP-18 is essential for its antibacterial activity, ${\alpha}$-helical structure, and interactions with phospholipid membranes.

미국흰불나방 지방체에서 저장단백질-1의 수용체의 특성과 부분정제 (Characterization and Partial Purification of Storage Protein-i Receptor in the Fat Body of Hyphantria cunea)

  • 채권석;여성문;김학렬
    • 한국동물학회지
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    • 제38권4호
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    • pp.490-497
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    • 1995
  • 미국흰불나방 의지방체 조직을 [35S]-메타이오닌이 포하된 배지에서 조직배양한 결과, 저장단백질-1(SP-1)의 전용기부터 용 1일 사이에 지방체로 흡수됨을 알았다. CHAPS, Triton X-100 등의 계면활성제를 농도별로 처리하여 막단백질의 용해도를 스크리닝한 뒤, anti-SP-1 polyclonal 항체를 쓴 Western blotting과 ligand blotting, 그리고 in vitro reductive methylation으로 14C을 표지한 저장단백질-1을 사용한 fluorography 등으로 1개의 수용체 밴드를 확인하였다. 1% Triton X-100으로 용해시킨 부분정제하였고, SDS-PAGE에 의해서 분자량을 측정한 결과 약 80 kDa로 나타났고 isoelectric focusing 시행 결과 등전점은 약 6.1로 계산되었다. 수용체 분자는 환원조건과 비환원조건의 차이와 전기영동 중의 온도에 따라서 SDS-PAGE상의 뚜렷한 밴드 양상의 차이를 나타내었다.

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도파민 수송체의 기능적 특성 및 발현에 관한 연구 (Functional Characterization and Regional Expression of Dopamine Transporter)

  • 이상훈;이송득;성기욱;이동섭;이용성;고재경
    • 약학회지
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    • 제39권2호
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    • pp.161-168
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    • 1995
  • Brain dopamine systems play a central role in the control of movement, hormone release, and many complex behavior. The action of dopamine at its synapse is terminated predominately by high affinity reuptake into presynaptic terminals by dopamine transporter (DAT). The dopamine transporter(DAT) is membrane protein localized to dopamine-containing nerve terminals and closely related with cocaine abuse, Parkinsonism, and schizophrenia. In present study, the recombinant plasmid pRc/CMV-DAT, constructed by subcloning of a cDNA encoding a bovine DAT into eukaryotic expression vector pRc/CMV, was stably transfected into CV-1 cells(monkey kidney cell line). The DAT activities in the cell lines selected by Geneticin$^{R}$ were determined by measuring the uptake of $[^3H]$-dopamine. The transfected cell lines showed 30-50 fold higher activities than untransfected CV-1 cell line, and this result implies that DAT is well expressed and localized in transfected cells. The transfected cells accumulated $[^3H]$-dopamine in a dose-dependent manner with a $K_{m}$ of 991.6nM. Even though high doses of norepinephrine, epinephrine, serotonin, and choline neurotransmitters inhibited the uptake of $[^3H]$-dopamine, DAT in transfected cell line was proven to be much more specific to dopamine. The psychotropic drugs such as GBR12909, CFT, normifensine, clomipramine, desipramine, and imipramine inhibited significantly the dopamine uptake in tissue culture cells stably transfected with DAT cDNA. Radioactive in situ hybridization was done to map the cellular localization of DAT mRNA-containing cells in the adult rat central nervous system. The strong hybridization signals were detected only in the substantia nigra pars compacta and ventral tegmental area. The restricted anatomical localization of DAT mRNA-containing cells confirms the DAT as a presynaptic marker of dopamine-containing cells in the rat brain.

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애기장대 AtPGR 단백질의 병 저항성에 관한 생리적 특성 분석 (Physiological Characterization of an AtPGR from Arabidopsis Involved in Pathogen Resistance)

  • 정문수;김철수
    • 생명과학회지
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    • 제21권9호
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    • pp.1295-1300
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    • 2011
  • 식물체에서 당 조절 인자의 병 저항성 생리적 특성을 살펴보길 위하여, 원형질막에 존재하는 glucose 조절인자인 애기장대 AtPGR 유전자의 과발현 및 RNAi 형질전환체를 사용하였다[3]. AtPGR 유전자는 병원균 처리에 의하여 전사 발현양이 증가하였을 뿐만 아니라, JA와 SA 처리 시에도 AtPGR 전사 발현양이 증가함을 확인하였다. 과발현 형질전환체를 이용하여 병 저항성을 살펴본 결과, AtPGR 유전자는 병원균에 대해 저항성을 유도함을 알수 있었다. 또한 병원균 유도 증가 유전자로 알려진 PDF1.2 및 PR1 유전자 발현 양상을 qPCR을 통해 살펴본 결과, AtPGR 유전자는 PDF1.2 유전자를 SA 경로 하에서는 증가시키는 반면, JA 경로 하에서는 발현 증가량을 감소시키는 경향이 있음을 나타내었고, PR1 유전자의 발현은 JA 경로를 통해 조절할 것으로 생각되어진다. 이러한 결과를 바탕으로, AtPGR 유전자는 glucose 뿐만 아니라 병원균 반응에도 관련되어져 있음을 알 수 있다.

고분자연료전지용 설폰산화 폴리아릴렌에테르설폰 멀티블록공중합체의 합성 및 특성 분석 (Synthesis and Characterization of Sulfonated Poly (Arylene ether Sulfone) Multi-Block Copolymer for PEMFC Application)

  • 안진주;최영우;양태현;김창수;배병찬
    • 한국수소및신에너지학회논문집
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    • 제23권5호
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    • pp.461-467
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    • 2012
  • Multi-block sulfonated poly (arylene ether sulfone) (SPES) membranes were synthesized by post-sulfonation and its properties characterized. Two types of oligomers, F-terminated and OH-terminated telechelic oligomers, were synthesized by controlling the feed ratio of dihydroxyl- and difluoro-monomers. Their number of repeating unit (X and Y) was analyzed by GPC and $^1H$ NMR. Copolymerization with F-terminated and OH-terminated telechelic oligomers via nucleophilic aromatic substitution, gave high-molecular-weight multi-block PESs. Each block length was controlled to have different values with X5Y10, X10Y10, X20Y10 and X20Y20. Successful polymerization and its successful sulfonation was confirmed by GPC and $^1H$ NMR. RH dependence of proton conductivity of multi-block SPES membranes was comparable to that of Nafion 212 at high RH conditions.

Separation and Characterization of Spikelet Proteins at Young Microspore Stage in Rice

  • Woo, Sun-Hee;Kim, Tae-Seon;Cho, Seong-Woo;Ahn, Jung-Gu;Chung, Keun-Yook;Lee, Byung-Moo;Cho, Yong-Gu;Kim, Hong-Sig;Song, Beom-Heon;Lee, Chul-Won;Jong, Seung-Keun
    • 한국작물학회지
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    • 제51권1호
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    • pp.66-72
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    • 2006
  • Spikelet proteins expressed at the young microspore stage in rice were separated and analysed by two-dimensional polyacrylamide gel electrophoresis (2DE). The separated proteins were electro blotted onto a polyvinylidene difluoride (PVDF) membrane, and 50 proteins were analyzed by a gas-phase protein sequencer. The N-terminal amino acid sequences of 20 out of 50 proteins were determined. N-terminal regions of the remaining proteins could not be sequenced because of blocking. The internal amino acid sequences of proteins were determined by sequence analysis of peptides obtained by the Cleveland peptide mapping method. Results revealed the presence of the photosynthetic apparatus at rice young microspore stage. Major proteins identified in this study could be used as a marker for various studies on physiological stresses.

Production rind Characterization of the Polyclonal Anti-peptide Antibody for $\beta$-adrenergic Receptor

  • Kim, Hee-Jin;Shin, Chan-Young;Sang Bong lee;Ko, Kwang-Ho
    • Biomolecules & Therapeutics
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    • 제2권4호
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    • pp.303-309
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    • 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.

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Expression analysis and characterization of rice oligopeptide transport gene (OsOPT10) that contributes to salt stress tolerance

  • Jung, Yu-Jin;Lee, In-Hye;Han, Kyung-Hee;Son, Cho-Yee;Cho, Yong-Gu;Lee, Myung-Chul;Kang, Kwon-Kyoo
    • Journal of Plant Biotechnology
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    • 제37권4호
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    • pp.483-493
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    • 2010
  • Knock-out of a gene by insertional mutagenesis is a direct way to address its function through the mutant phenotype. Among ca. 15,000 gene-trapped Ds insertion lines of rice, we identified one line from selected sensitive lines in highly salt stress. We conducted gene tagging by TAIL-PCR, and DNA gel blot analysis from salt sensitive mutant. A gene encoding an oligopeptide transporter (OPT family) homologue was disrupted by the insertion of a Ds transposon into the OsOPT10 gene that was located shot arm of chromosome 8. The OsOPT10 gene (NP_001062118.) has 6 exons and encodes a protein (752 aa) containing the OPT family domain. RT-PCR analysis showed that the expression of OsOPT10 gene was rapidly and strongly induced by stresses such as high-salinity (250 mM), osmotic, drought, $100\;{\mu}M$ ABA. The subcellular localization assay indicated that OsOPT10 was localized specifically in the plasma membrane. Overexpression of OsOPT10 in Arabidopsis thaliana and rice conferred tolerance of transgenic plants to salt stress. Further we found expression levels of some stress related genes were inhibited in OsOPT10 transgenic plants. These results suggested that OsOPT10 might play crucial but differential roles in plant responses to various abiotic stresses.

신경정신 의학분야의 방사성동위원소 표지 cDNA 마이크로어레이 (Radioactive cDNA microarray in Neurospsychiatry)

  • 최재걸;신경호;이민수;김명곤
    • 대한핵의학회지
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    • 제37권1호
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    • pp.43-52
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    • 2003
  • Microarray technology allows the simultaneous analysis of gene expression patterns of thousands of genes, in a systematic fashion, under a similar set of experimental conditions, thus making the data highly comparable. In some cases arrays are used simply as a primary screen loading to downstream molecular characterization of individual gene candidates. In other cases, the goal of expression profiling is to begin to identify complex regulatory networks underlying developmental processes and disease states. Microarrays were originally used with ceil lines or other simple model systems. More recently, microarrays have been used in the analysis of more complex biological tissues including neural systems and the brain. The application of cDNA arrays in neuropsychiatry has lagged behind other fields for a number of reasons. These include a requirement for a large amount of input probe RNA In fluorescent-glass based array systems and the cellular complexity introduced by multicellular brain and neural tissues. An additional factor that impacts the general use of microarrays in neuropsychiatry is the lack of availability of sequenced clone sets from model systems. While human cDNA clones have been widely available, high qualify rat, mouse, and drosophilae, among others are just becoming widely available. A final factor in the application of cDNA microarrays in neuropsychiatry is cost of commercial arrays. As academic microarray facilitates become more commonplace custom made arrays will become more widely available at a lower cost allowing more widespread applications. in summary, microarray technology is rapidly having an impact on many areas of biomedical research. Radioisotope-nylon based microarrays offer alternatives that may in some cases be more sensitive, flexible, inexpensive, and universal as compared to other array formats, such as fluorescent-glass arrays. In some situations of limited RNA or exotic species, radioactive membrane microarrays may be the most practical experimental approach in studying psychiatric and neurodegenerative disorders, and other complex questions in the brain.

Improved Purification of Thermophilic FoF1-ATP Synthase c-Subunit Rings and Solid-State NMR Characterization of Them in Different Lipid Membranes

  • Bak, Suyeon;Kang, Su-Jin;Suzuki, Toshiharu;Yoshida, Masasuke;Fujiwara, Toshimichi;Akutsu, Hideo
    • 한국자기공명학회논문지
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    • 제17권2호
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    • pp.67-75
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    • 2013
  • ATP synthase produces ATP, a major energy source for metabolic processes in organisms, from ADP and inorganic phosphate in cellular membranes. ATP synthase is known as a rotary motor, in which the c-subunit ring functions as a rotor. In this work, we have tried to develop a more general preparation procedure of thermophilic $F_oc$-ring ($TF_oc$-ring) for NMR measurements. The expression of $TF_oF_1$ is easily affected by various experimental conditions such as temperature, shape and size of a flask, a volume of medium, and shaking rate of an incubator. Accordingly, we have tried to optimize the expression conditions of $TF_oF_1$. $TF_oc$-rings were purified from $TF_oF_1$ according to a reported method. We modified purification procedures to improve purity and yield of $TF_oc$. On top of them, we found a new combination of detergents for the purification at anion-exchange column chromatography. To examine the effect of lipid environments on the structure, the $TF_oc$-rings were reconstituted into two kinds of lipid bilayers, namely, saturated and unsaturated lipid ones. Then, we have compared characteristics of the $TF_oc$-ring structures in these membranes with solid-state NMR.