• 제목/요약/키워드: membrane proteins

검색결과 1,002건 처리시간 0.026초

Home-built Solid-state NMR Probe for Membrane Protein Studies

  • Kim, Yong-Ae;Hwang, Jung-Hyun;Park, Jae-Joon
    • Bulletin of the Korean Chemical Society
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    • 제24권9호
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    • pp.1281-1283
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    • 2003
  • Proteins in highly oriented lipid bilayer samples are useful to study membrane protein structure determination. Planar lipid bilayers aligned and supported on glass slide were prepared. These stack of glass slide with planar lipid bilayers are not well fit for commercial solid-state NMR probe with round coil. Therefore, homebuilt solid-state NMR probe was built and used for a stack of thin glass plates and RF coil is wrapping directly around the flat square sample. The overall filling factor of the coil is much better and the large surface area enhances the extent to orientation by providing uniform environments for the phospholipids and the high ratio of circumference to area reduces edge effects. $^1H\;and\;^{15}N$ double resonance probe for 400 MHz NMR (9.4T) with a flat coil (coil size: 11 mm ${\times}$ 20 mm ${\times}$ 4 mm) is constructed and tested.

Multiple Antibiotic Resistance in Pseudomonas putida Associated with Overproduction of a Membrane Protein

  • JUNG NAM KIM;HO GUN RHIE
    • 한국환경독성학회:학술대회논문집
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    • 한국환경독성학회 2001년도 춘계심포지움 및 학술발표회
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    • pp.140-140
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    • 2001
  • Porins are major outer membrane proteins which produce non-specific aqueous channels across the membrane that permit the diffusion into the bacterial cells of hydrophilic compounds including sugars, amino acids, and antibiotics. In some gram-negative organisms, antibiotic resistance can be induced by mutational loss of channel that causes a decrease in outer membrane permeability. (omitted)

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Cucurbita pepo에서 분리한 Light Membrane Vesicle의 ATPase와 Phosphatase의 정제 및 특성 (Purification and Characterization of ATPase and Phosphatase of Light Membrane Vesicles Isolated from Cucurbita pepo)

  • 오승은
    • Journal of Plant Biology
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    • 제33권4호
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    • pp.325-332
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    • 1990
  • Light membrane vesicles were isolated from the zucchini hypocotyl by floatation on ficoll density gradients and the proteins were solubilized with Triton X100. Three ATP-hydrolyzing enzymes were partially purified by ion-exchange and gel filtration chromatography and isoelectric focusing. There are plasma membrane-type ATPase whose activity was inhibited by vanadate but not by nitrate, tonoplast-type ATPase which was sensitive to nitrate but insensitive to vanadate and one having a phosphatase activity with a pI value different from that of an acid phosphatase. A fraction was obtained after DEAE-ion-exchange chromatography crossreacting with polyclonal antibodies against Ca2+ -ATPase from human erythrocytes.

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Proteomic Analysis of the Increased Proteins in Peroxiredoxin II Deficient RBCs

  • Yang, Hee-Young;Lee, Tae-Hoon
    • Reproductive and Developmental Biology
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    • 제36권1호
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    • pp.55-64
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    • 2012
  • Peroxiredoxin II (Prdx II; a typical 2-Cys Prdx) has been originally isolated from erythrocytes, and its structure and peroxidase activity have been adequately studied. Prdx II has been reported to protect a wide range of cellular environments as antioxidant enzyme, and its dysfunctions may be implicated in a variety of disease states associated with oxidative stress, including cancer and aging-associated pathologies. But, the precise mechanism is still obscure in various aspects of aging containing ovarian aging. Identification and relative quantification of the increased proteins affected by Prdx II deficiency may help identify novel signaling mechanisms that are important for oxidative stress-related diseases. To identify the increased proteins in Prdx $II^{-/-}$ mice, we performed RBC comparative proteome analysis in membrane fraction and cytosolic fractions by nano-UPLC-$MS^E$ shotgun proteomics. We found the increased 86 proteins in membrane (32 proteins) and cytosolic (54 proteins) fractions, and analyzed comparative expression pattern in healthy RBCs of Prdx $II^{+/+}$ mice, healthy RBCs of Prdx $II^{-/-}$ mice, and abnormal RBCs of Prdx $II^{-/-}$ mice. These proteins belonged to cellular functions related with RBC lifespan maintain, such as cellular morphology and assembly, cell-cell interaction, metabolism, and stress-induced signaling. Moreover, protein networks among the increased proteins were analyzed to associate with various diseases. Taken together, RBC proteome may provide clues to understand the clue about redox-imbalanced diseases.

성장기 소의 등심에 발현되는 단백질들의 분리 및 동정 (Isolation and Identification of Proteins Increasingly Expressed in Beef Loin on Maturation)

  • 황선일;임진규
    • Applied Biological Chemistry
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    • 제42권1호
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    • pp.39-44
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    • 1999
  • 각각 다른 성장기의 한우 등심에서 추출한 단백질을 이차원 전기영동법으로 분리하여 젤 상의 단백질 전개 양상을 비교하였다. 성장 0, 6, 12, 24 개월령의 한우 등심 단백질들을 길이 16 cm 튜브젤에서 등전점에 따라 분리하고, 이차원적으로 $18{\times}20$ cm, 12% SDS-polyacrylamide gel 전기영동 하여 단백질을 분리하였다. 등전점 3.0에서 9.0 그리고 분자량 15,000에서 100,000 Da 사이의 단백질들이 분리되어 Silver 염색법으로 명확히 구분할 수 있었다. 흥미롭게, 성장과정에서 단백질 발현이 증가했거나 감소한 단백질들은 저분자 단백질들 이었다. 성장 과정 중 증가된 단백질들을 분리하기 위해 수용성 단백질들을 조직으로부터 1% Triton X-100 으로 추출하였다. 그리고 이를 30%와 50% 황산암모니아로 분획하였다. 이와 같이하여 각 단백질들의 분리조건을 결정하였다. 이들 조건을 이용하여 발현이 증가된 단백질들을 분리하고 PVDF membrane에 옮겨서 아미노산 서열을 결정하여 단백질을 규명하였다.

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Effect of lactoferrin on ram sperm motility after cryopreservation

  • Su, Jie;Wang, Caiyun;Song, Yongli;Yang, Yanyan;Cao, Guifang
    • Animal Bioscience
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    • 제35권9호
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    • pp.1351-1359
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    • 2022
  • Objective: The objective of this study was to analyse the differentially abundant proteins caused by freeze-thawing of ram sperm and explore candidate proteins of interest for their ability to improve ram sperm cryopreservation outcomes in vitro. Methods: Sperm were from three mature Dorper. Fresh and frozen sperm proteins were extracted, and the differentially abundant proteins were analysed by mass spectrometry. Among these proteins, lactoferrin (LTF) was selected to be added before cryopreservation. Next, sperm samples were diluted in Tris extender, with the addition of 0, 10, 100, 500, and 1,000 ㎍/mL of LTF. After thawing, sperm quality was evaluated by motility, plasma membrane integrity, mitochondrial activity and reactive oxygen species (ROS). Results: Cryopreservation significantly altered the abundance of 40 proteins; the abundance of 16 proteins was increased, while that of 24 proteins was decreased. Next, LTF was added to Tris extender applied to ram sperm. The results showed that sperm motility and plasma membrane integrity were significantly improved (p<0.05) by supplementation with 10 ㎍/mL LTF compared to those in the control group. There was no significant difference in mitochondrial activity between the 0 ㎍/mL group and other groups (p>0.05). Supplementation of the cryoprotective extender with 10 ㎍/mL LTF led to decreased ROS levels compared with those in the control and other groups (p<0.05). Conclusion: The LTF is an important protein during cryopreservation, and the addition of 10 ㎍/mL LTF to a cryoprotective extender can significantly improve the function of frozen ram sperm.

계면 활성제 처리에 의한 세균 세포막의 변화에 관한 연구 (The effect of some detergents on the changes of bacterial membrane)

  • 이종삼;이호용;조기승;조선희;장성열;최영길
    • 미생물학회지
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    • 제21권3호
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    • pp.115-126
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    • 1983
  • The results that the effect of 6 detergents on the structural changes and biochemical composition of bacterial membrane of Escherichia coli and Bacillus cereus are as follows ; 1. Population growth of the bacteria was increased in case of the treatment with palmitoyl carnitine and sodium deoxy cholate but was increased in case of the treatment with palmitoyl carnitine and sodium deoxy cholate but was decreased by sodium dodecyl sulfate and palmitoyl choline, in E.coli and was decreased by palmitoyl carnitine and palmitoyl choline at the low concentration, in B. cereus. 2. The electron micrograph showed that cell wall lysis or cell collapse were observed in the treatment of sodium dodecyl sulfate and palmitoyl choline, and also cell wall was condensed by triton X-100 and sodium deoxy cholate, in E.coli. And in B. cereus, endospore formation of the bacteria was stimulated by palmitoyl choline, and cell lysis or structural changes of the membrane were observed in the treatment of sodium dodecyl sulfate, sodium cholate, and triton X-100, respectively. 3. As to the effect of detergent on the biochemical composition of biomembrane, the content of carnitine, in E.coli, and B.cereus, the content of structural protein and phospholipid were decreased by treatment of sodium dodecyl sulfate and structural protein was denatured by palmitoyl choline. 4. The profile of membrane protein revealed that the bacterial membrane were composed of various proteins. By dint of this result, some of membrane proteins were solubilized or changed to small molecules by the treatment of sodium dodecyl sulfate and palmitoyl choline, in E.coli and membrane protein of the biomembrane by treatment of sodium dodecyl sulfate, sodium deoxy cholate, palmitoyl choline, and palmitoyl carnitine were confirmed to be different profile as compared with those of the control, in B. cereus. Therefore, it is suggested that sodium dfodecyl sulfate and palmitoyl choline soulbilized biomembranes or inhibited membrane transport and that palmitoyl carnitine and sodium deoxy cholate were used as an energy source or stimulating the membrane transport, in E.coli. And, it is suggested that all of detergents were inhibited biomembrane synthesis, expet saponin, in B.cereus.

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Functional annotation of uncharacterized proteins from Fusobacterium nucleatum: identification of virulence factors

  • Kanchan Rauthan;Saranya Joshi;Lokesh Kumar;Divya Goel;Sudhir Kumar
    • Genomics & Informatics
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    • 제21권2호
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    • pp.21.1-21.14
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    • 2023
  • Fusobacterium nucleatum is a gram-negative bacteria associated with diverse infections like appendicitis and colorectal cancer. It mainly attacks the epithelial cells in the oral cavity and throat of the infected individual. It has a single circular genome of 2.7 Mb. Many proteins in F. nucleatum genome are listed as "Uncharacterized." Annotation of these proteins is crucial for obtaining new facts about the pathogen and deciphering the gene regulation, functions, and pathways along with discovery of novel target proteins. In the light of new genomic information, an armoury of bioinformatic tools were used for predicting the physicochemical parameters, domain and motif search, pattern search, and localization of the uncharacterized proteins. The programs such as receiver operating characteristics determine the efficacy of the databases that have been employed for prediction of different parameters at 83.6%. Functions were successfully assigned to 46 uncharacterized proteins which included enzymes, transporter proteins, membrane proteins, binding proteins, etc. Apart from the function prediction, the proteins were also subjected to string analysis to reveal the interacting partners. The annotated proteins were also put through homology-based structure prediction and modeling using Swiss PDB and Phyre2 servers. Two probable virulent factors were also identified which could be investigated further for potential drug-related studies. The assigning of functions to uncharacterized proteins has shown that some of these proteins are important for cell survival inside the host and can act as effective drug targets.

Heat Shock Proteins: A Review of the Molecular Chaperones for Plant Immunity

  • Park, Chang-Jin;Seo, Young-Su
    • The Plant Pathology Journal
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    • 제31권4호
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    • pp.323-333
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    • 2015
  • As sessile organisms, plants are exposed to persistently changing stresses and have to be able to interpret and respond to them. The stresses, drought, salinity, chemicals, cold and hot temperatures, and various pathogen attacks have interconnected effects on plants, resulting in the disruption of protein homeostasis. Maintenance of proteins in their functional native conformations and preventing aggregation of non-native proteins are important for cell survival under stress. Heat shock proteins (HSPs) functioning as molecular chaperones are the key components responsible for protein folding, assembly, translocation, and degradation under stress conditions and in many normal cellular processes. Plants respond to pathogen invasion using two different innate immune responses mediated by pattern recognition receptors (PRRs) or resistance (R) proteins. HSPs play an indispensable role as molecular chaperones in the quality control of plasma membrane-resident PRRs and intracellular R proteins against potential invaders. Here, we specifically discuss the functional involvement of cytosolic and endoplasmic reticulum (ER) HSPs/chaperones in plant immunity to obtain an integrated understanding of the immune responses in plant cells.

Shotgun analysis on the peritrophic membrane of the silkworm Bombyx mori

  • Zhong, Xiaowu;Zhang, Liping;Zou, Yong;Yi, Qiying;Zhao, Ping;Xia, Qingyou;Xiang, Zhonghuai
    • BMB Reports
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    • 제45권11호
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    • pp.665-670
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    • 2012
  • The insect midgut epithelium is generally lined with a unique chitin and protein structure, the peritrophic membrane (PM), which facilitates food digestion and protects the gut epithelium. We used gel electrophoresis and mass spectrometry to identify the extracted proteins from the silkworm PM to obtain an in-depth understanding of the biological function of the silkworm PM components. A total of 305 proteins, with molecular weights ranging from 8.02 kDa to 788.52 kDa and the isoelectric points ranging from 3.39 to 12.91, were successfully identified. We also found several major classes of PM proteins, i.e. PM chitin-binding protein, invertebrate intestinal mucin, and chitin deacetylase. The protein profile provides a basis for further study of the physiological events in the PM of Bombyx mori.