• Title/Summary/Keyword: Membrane Protein

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Effects of Dopamine.HCI on Structural Parameters of Bovine Brain Membranes

  • Bae, Moon-Kyoung;Huh, Min-Hoi;Lee, Seung-Woo;Kang, Hyun-Gu;Pyun, Jae-Ho;Kwak, Myeong-Hee;Jang, Hye-Ock;Yun, Il
    • Archives of Pharmacal Research
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    • v.27 no.6
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    • pp.653-661
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    • 2004
  • Fluorescence probes located in different membrane regions were used to evaluate the effect of dopamine$.$HCI on the structural parameters (transbilayer lateral mobility, annular lipid fluidity, protein distribution, and thickness of the lipid bilayer) of synaptosomal plasma membrane vesicles (SPMV), which were obtained from the bovine cerebral cortex. An experimental procedure was used based on selective quenching of 1,3-di(1-pyrenyl)propane (Py-3-Py) by trinitrophenyl groups, and radiationless energy transfer from the tryptophan of membrane pro-teins to Py-3-Py and energy transfer from Py-3-Py monomers to 1-anilinonaphthalene-8-sulfonic acid (ANS) was also utilized. Dopamine$.$HCI increased both the bulk lateral mobility and annular lipid fluidity, and it had a greater fluidizing effect on the inner monolayer than on the outer monolayer. Furthermore, the drug had a clustering effect on membrane proteins.

Effects of Glucose Degradation Products on Human Peritoneal Mesothelial Cells (포도당분해산물이 사람 복막중피세포 활성화에 미치는 영향)

  • Song, Jae-Sook;Lee, Kyung-Lim;Ha, Hunjoo
    • Microbiology and Biotechnology Letters
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    • v.33 no.4
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    • pp.308-314
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    • 2005
  • Both high glucose and glucose degradation products (GDP) have been implicated in alterations of peritoneal membrane structure and function during long-term peritoneal dialysis (PD). The present study examined the role of GDP including methylglyoxal (MGO), acetaldehyde, and 3,4-dideoxyglucosone (3,4-DGE) in HPMC activation with respect to membrane hyperpermeability or fibrosis. The role of reactive oxygen species (ROS) and activation of protein kinase C (PKC) in GDP-induced HPMC activation were also examined. Using M199 culture medium as control, growth arrested and synchronized HPMC were continuously stimulated by MGO, acetaldehyde, and 3,4-DGE for 48 hours. Vascular endothelial growth factor (VEGF) was quantified as a marker of peritoneal membrane hyperpermeability and fibronectin and heat shock protein 47 (hsp47) as markers of fibrosis. Involvement of ROS and PKC was examined by the inhibitory effect of N-acetylcystein (NAC) or calphostin C, respectively. MGO significantly increased VEGF (1.9-fold), fibronectin (1.5-fold), and hsp47 (1.3-fold) secretion compared with control M199. NAC and calphostin C effectively inhibited MGO-induced VEGF upregulation. Acetaldehyde stimulated and 3,4-DGE inhibited VEGF secretion. Fibronectin secretion and hsp47 expression in HPMC were not affected by acetaldehyde or 3,4-DGE In conclusion, MGO upregulated VEGF and fibronectin secretion and hsp47 expression in HPMC, and PKC as well as ROS mediate MGO-induced VEGF secretion by HPMC. This implies that PKC activation and ROS generation by GDP may constitute important signals for activation of HPMC leading to progressive membrane hyperpermeability and accumulation of extracellular matrix and eventual peritoneal fibrosis.

Regulation of an Outer Membrane Protein, OmpW, Expression and Its Biological Function in Salmonell typhimurium (Salmonella typhimurium 외막 단백질 OmpW의 발현조절 및 기능에 관한 연구)

  • Yoo, Ah-Young;Yu, Jong-Earn;Yang, Ji-Seon;Kim, Young-Hee;Bae, Chang-Ho;Oh, Jeong-Il;Kang, Ho-Young
    • Journal of Life Science
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    • v.18 no.11
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    • pp.1606-1611
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    • 2008
  • Outer membrane proteins (OMPs) expressed in the Gram negative bacteria such as Salmonella play multiple functions including material transports, adhesive factors and reception of external signals. This study has been focused on an OmpW protein known as a protein required to form a hydrophobic porin in outer membrane. We have constructed a S. typhimurium CK10 mutant deleting an ompW gene on chromosome. The CK10 strain was more tolerant to SDS than the wild-type strain did. As increase of salt concentration in the culture media, significantly decreased amount of OmpW protein in cells were detected. The maximum OmpW protein was expressed in the absence of salt supplement. However, the growth of CK10 strain was indistinguishable compared to that of the wild-type strain at the variable osmotic conditions. The biological role of differential OmpW expression in response to osmotic conditions remains to be investigated.

Analysis of lysosomal membrane proteins exposed to melanin in HeLa cells

  • Bang, Seung Hyuck;Park, Dong Jun;Kim, Yang-Hoon;Min, Jiho
    • Environmental Analysis Health and Toxicology
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    • v.31
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    • pp.9.1-9.5
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    • 2016
  • Objectives There have been developed to use targeting ability for antimicrobial, anticancerous, gene therapy and cosmetics through analysis of various membrane proteins isolated from cell organelles. Methods It was examined about the lysosomal membrane protein extracted from lysosome isolated from HeLa cell treated by 100 ppm melanin for 24 hours in order to find associated with targeting ability to melanin using by 2-dimensional electrophoresis. Results The result showed 14 up-regulated (1.5-fold) and 13 down-regulated (2.0-fold) spots in relation to melanin exposure. Conclusions It has been found that lysosomal membrane proteins are associated with melanin to decolorize and quantity through cellular activation of lysosome.

Development of Research into Autophagic Lysosome Reformation

  • Chen, Yang;Yu, Li
    • Molecules and Cells
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    • v.41 no.1
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    • pp.45-49
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    • 2018
  • Autophagy is a lysosome-dependent degradation process that is essential for maintaining cellular homeostasis. In recent years, more studies have focused on the late stages of autophagy. Our group discovered and studied the terminal step of autophagy, namely autophagic lysosome reformation (ALR). ALR is the process that regenerates functional lysosomes from autolysosomes, thus maintaining lysosome homeostasis. ALR involves clathrin-mediated membrane budding from autolysosomes, elongation of membrane tubules along microtubules with the pulling force provided by the motor protein KIF5B, proto-lysosome scission by dynamin 2, and finally maturation of proto-lysosomes to functional lysosomes. In this review, we will summarize progress in unveiling the molecular mechanisms underlying ALR and its potential pathophysiological roles.

Fabrication and characterization of polysulfone ultrafiltration membrane using polyethylene glycol and tartaric acid: morphology and performance in protein separation

  • Sharma, N.;Purkait, M.K.
    • Membrane and Water Treatment
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    • v.8 no.6
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    • pp.591-612
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    • 2017
  • Increase in the hydrophilicity (HPCT) of polysulfone (PS) membrane and subsequently decrease in fouling can be achieved by surface modification of PS based membranes. Therefore, in this work, ultrafiltration membranes with increased HPCT were prepared using the enantiomeric tartaric acid (D-TA) and racemic tartaric acid (DL-TA). Phase inversion technique was used for the preparation of polyethylene glycol and TA blended PS membrane. Morphological analysis of the fabricated membranes was done by scanning electron microscope and atomic force microscopy. Bovine serum albumin (BSA) solution was taken for finding the permeation and rejection behavior of prepared membranes. Maximum BSA rejection was increased by 70.5% for the modified membrane.