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Volume 37 (2012)
- Issue 6 Pages 264-
- Issue 5 Pages 212-
- Issue 4 Pages 164-
- Issue 3 Pages 108-
- Issue 2 Pages 59-
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Volume 37, Issue 4
Displaying 1-9 of 9 articles from this issue
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Special Topic : Behavior of Lipids in the Biomembrane
Review Article
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Moritoshi Sato2012 Volume 37 Issue 4 Pages 164-167
Published: 2012
Released on J-STAGE: September 13, 2014
JOURNAL OPEN ACCESSFluorescence imaging could be the most powerful technique available for observing spatial and temporal dynamics of molecular processes in living cells, if fluorescent probes for the relevant molecular processes become available. We have been developing fluorescent probes for a variety of cellular signaling processes, including second messengers and protein phosphorylations. Using the probes, we have visualized spatial and temporal dynamics of these molecular events in single living cells. The present fluorescent probes are becoming an indispensable tool for understanding the complex mechanism of the signal transduction in living cells. In this review, fluorescent probes to visualize subcellular dynamics of lipid messngers are described.View full abstractDownload PDF (662K) -
Toshiaki Miki, Mizuho Kaneda, Kohji Kasahara2012 Volume 37 Issue 4 Pages 168-173
Published: 2012
Released on J-STAGE: September 13, 2014
JOURNAL OPEN ACCESSThe association of gangliosides with specific proteins in the central nervous system was examined by co-immunoprecipitation with an anti-ganglioside antibody. The monoclonal antibody to the ganglioside GD3 immunoprecipitated the α-subunit of a heterotrimeric G protein, Go (Goα) from the rat cerebellum. Using sucrose density gradient analysis, Goα, but not Gβγ, was observed in detergent-resistant membrane (DRM) raft fractions, after the addition of GTPγS. On the other hand, both Goα and Gβγwere excluded from the DRM raft fractions in the presence of GDPβS. Only Goα was observed in the DRM fractions from the cerebellum on postnatal day 7, but not from that in adult. After pertussis toxin treatment, Goα was not observed in the DRM fractions, even from the cerebellum on postnatal day 7. These results indicate the activation-dependent translocation of Goα into the DRM rafts. Furthermore, treatment with stromal cell-derived factor-1α stimulated [35S]GTPγS binding to Goα, and caused Goα translocation to the DRM fractions, leading to growth cone collapse of cerebellar granule neurons. These results demonstrate involvement of signal - dependent Goα translocation to DRM in the growth cone behavior of cerebellar granule neurons.View full abstractDownload PDF (718K)
Lecture Note
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Jun Suzuki, Shigekazu Nagata2012 Volume 37 Issue 4 Pages 174-178
Published: 2012
Released on J-STAGE: September 13, 2014
JOURNAL RESTRICTED ACCESSPhospholipids on plasma membranes are asymmetrically distributed between inner and outer leaflets. ATPdependent flippases or aminophospholipid translocases regulate the asymmetry of phospholipids, especially the inner location of phosphatidylserine (PS), while calcium-dependent scramblases disrupt this asymmetry, and as a result of that, PS is exposed on the cell surface. PS exposure is biologically important in clearance of apoptotic cells and platelet clotting. However, it is unknown how PS is exposed on the cell surface. In this talk, I will discuss how PS is exposed on the cell surface.View full abstractDownload PDF (747K) -
Sumie Manno2012 Volume 37 Issue 4 Pages 179-182
Published: 2012
Released on J-STAGE: September 13, 2014
JOURNAL RESTRICTED ACCESSPhospholipids (PLs) in erythrocyte membranes are asymmetrically distributed in the bilayer; amino PLs such as PS and PE reside exclusively in the inner leaflet and the outer leaflet is thus enriched with neutral PLs such as PC and SM. The localization of PS and PE is principally maintained by an activity of ATP-dependent Flippase. However, the asymmetric distribution is abolished by PL scrambling at critical cellular events like cell senescence. A detailed mechanism of PL scrambling is yet to be understood. Phospholipid scramblase 1 (PLSCR1), a 37 kDa transmembrane protein, has been reported to be responsible for Ca2+-dependent, PL nonselective bidirectional movement between the outer and inner leaflets. Based on the fact that this protein is present in cholesterol-rich raft I examined the effect of cholesterol on scrambling activity. In the present symposium using human erythrocyte membranes and liposomes reconstituted with purified PLSCR1 or its transmembrane peptides I could show that (1) cholesterol removal from erythrocyte membranes resulted in PS exposure to the outer leaflet in Ca2+-independent manner and (2) presence of cholesterol in the reconstituted liposomes suppressed scrambling activity. These results strongly suggest that cholesterol inhibits scrambling activity of PLSCR1 in human erythrocytes.View full abstractDownload PDF (718K)
Special Topic : Soft interfaces Linked between Synthetic Membranes and Biomembranes
Review Article
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Mizuo Maeda2012 Volume 37 Issue 4 Pages 183-188
Published: 2012
Released on J-STAGE: September 13, 2014
JOURNAL OPEN ACCESSWe have studied unique functions of DNA-modified nanoparticles, which disperse in an aqueous medium due to electrostatic repulsion between anionic phosphate groups in the DNA backbone. Interestingly, when complementary single-stranded DNA, whose base number is identical to that of the DNA on the surface, is added to the dispersion of DNA nanoparticles to form the fully matched double helix on the surface, the DNA nanoparticles become unstable and spontaneously form aggregates in a non-crosslinking manner. Furthermore, we have found that the doublestranded DNA-carrying nanoparticles acquire high colloidal stability to disperse in an aqueous medium when a terminal single-base mismatch exists at the interface between the DNA corona and the disperse medium. Exploiting the unique colloidal behavior of the DNA nanoparticles, we have devised a facile single-nucleotide polymorphism genotyping method. We applied the SPR imaging technique on microfluidic devices to the detection of the nanoparticles aggregation.View full abstractDownload PDF (839K) -
Madoka Takai, Kyosuke Nii2012 Volume 37 Issue 4 Pages 189-194
Published: 2012
Released on J-STAGE: September 13, 2014
JOURNAL OPEN ACCESSWe prepared the biocompatible phospholipid polymer, poly [2-methacryloyloxyethyl phosphorylcholine (MPC)-co-3-(methacryloyloxy)propyltris (trimethylsilyloxy) silane (MPTSSi)]: PMMSi for the surface modification in microchannel of PDMS bioanalytical devices. The protein adsorption was resisted and electro-osmotic flow (EOF) was reduced on the PMMSi coated PDMS surface. The repeatable precision on electrophoresis was obtained, so it is expected the PMMSi coated interface is suitable for micro-bioanlysis.View full abstractDownload PDF (813K) -
Functions Inspired by BiomembranesJun Matsui, Tokuji Miyashita2012 Volume 37 Issue 4 Pages 195-199
Published: 2012
Released on J-STAGE: September 13, 2014
JOURNAL OPEN ACCESSSeveral optical and electrical functional materials have been prepared by hierarchical assembly of “polymer nanosheets”. “Polymer nanosheets” consisting of amphiphilic polyalkylacrylamides are described as ultrathin polymer Langmuir-Blodgett films through two-dimensional hydrogen networks between polymer backbones. Several functional polymer nanosheets, those contain organic dye or redox active molecules have been prepared by the copolymerization method. These polymer nanosheets were hierarchically assembled onto as solid substrate based on the redox potentials of the functional molecules. We demonstrated that the potential diagrams in the hierarchically assembled film can be easily controlled by the selection of the functional molecules and the deposition order of the functional polymer nanosheets. Furthermore, the hierarchical assembled films were applied to fabricate molecular memory, switch and logic gate functions.View full abstractDownload PDF (834K) -
Makoto Sakai, Masaaki Fujii2012 Volume 37 Issue 4 Pages 200-205
Published: 2012
Released on J-STAGE: September 13, 2014
JOURNAL OPEN ACCESSIR spectroscopy is powerful method to study structure of molecule based on vibrational spectrum. However, its application to microscope did not show large progresses so much. The largest difficulty is the lower resolution of IR microscope due to the longer wavelength of IR light, and it is limited at several μm. To overcome this limitation, we developed a novel IR microscope based on vibrational sum-frequency generation (VSFG). VSFG is a non-linear optical process and we irradiate visible and IR beams on the sample. If IR beam is resonant to vibrational mode of target molecule, VSFG signal photon whose frequency is equal to sum-frequency of the two pump beams will be strongly generated. Therefore, we can detect IR absorption of the molecule by monitoring VSFG and IR spectrum can be obtained by scanning IR wavelength. Because VSFG signal has visible wavelength, IR absorption can be imaged at the resolution of visible light (several 100 nm).View full abstractDownload PDF (997K)
Products Spotlight
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Tetsuro Yoshimura, Masatoshi Hashimoto2012 Volume 37 Issue 4 Pages 206-208
Published: 2012
Released on J-STAGE: September 13, 2014
JOURNAL RESTRICTED ACCESSRecently, we developed simple vortex-mixing procedures for preparation of MLV, LUV, SUV and GUV, and succeeded in constructing “automated multi-functional liposome manufacturing equipment” adopting these novel procedures. This unique, easy-to-operate device possesses conventional vortex-mixing and ultrasonic parts and allows even unskilled users to prepare desired types of liposomes overnight with a single touch of a button. In addition to MLV, LUV, SUV and GUV, various functional liposomes, such as charged liposomes, sensitized liposomes, surfacemodified liposomes, and reconstituted liposomes, can be prepared. Comprising conventional parts, the fully automated machine operates under oxygen-/germ-free conditions and is also applicable for concentration of a solute in a solution by removal of organic solvent, biochemical reactions (as bioreactors), ultrasonic disruption of bacteria, etc.View full abstractDownload PDF (694K)
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