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Predecessor
Volume 61, Issue 10
Displaying 1-7 of 7 articles from this issue
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Yoshihiro ITO, Tetsuya YAMAUCHI, Kaoru OMURA2004 Volume 61 Issue 10 Pages 501-510
Published: October 25, 2004
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSWe have developed a photo-immobilization method for preparation of micro-array biochips. If one uses the photo-immobilization method, one may easily immobilize various types of organic molecules by the same procedure. In addition, by using biomimetic polymers as matrices, one can reduce non-specific interactions with biocomponents. Various proteins, antibodies, and cells were micro-arrayed and the interactions with proteins, antibodies, and cells were investigated. This type of micro-array biochip will be important not only for academic applications such as genomics, proteomics, and cellomics, but also for clinical analyses.View full abstractDownload PDF (13252K) -
A New Method for the Immobilization of the Proteins Utilizing a HydrogelShun-ichi TAMARU, Itaru HAMACHI2004 Volume 61 Issue 10 Pages 511-522
Published: October 25, 2004
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSBecause a rapid and high throughput assay system for proteins and peptides is useful to understand the biological events, the development of a sophisticated protein microarray is one of the significant subjects in the recent nano-biochemistry. Unlike DNA arrays, the instability of proteins under dry conditions is problematic. Here, semi-wet protein/peptide arrays using a supramolecular hydrogel are introduced as a new nano-bio device. In this method, proteins and/or peptides are three-dimensionally immobilized on a plate surface with a water-rich environment. For one to mount proteins or peptides on a plate surface, no chemical modifications are required. Aqueous cavities formed of the hydrogel fibers are suitable for a protein and a peptide to function their original activity without denaturation. This semi-wet array system is expected to be widely applicable for proteomics and pharmaceutical research.View full abstractDownload PDF (16481K) -
Kiyoshi NOKIHARA, Takafumi OHYAMA, Kenji USUI, Koichi YONEMURA, Kin-ya ...2004 Volume 61 Issue 10 Pages 523-532
Published: October 25, 2004
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSNovel high-throughput technologies, which can replace conventional electrophoresis and mass spectroscopic analyses, are in great demand for understanding the structure-function relationships of proteins. For a practical protein-detection system, arrays with immobilized designed synthetic peptides have been constructed. Peptides were labeled with fluorescent dyes in order to achieve high sensitivity. Two different types of prototype-arrayer have been constructed: one has a micro-dispensing system and the other a spot-printing system. Combinatorial peptide libraries, which consisted of β-loop, β-strand and α-helical peptides, were constructed by improved highly efficient solid-phase synthesis. Labeled peptides were covalently immobilized on solid supports such as precision glass plates. Various proteins were characterized with these peptide-arrays using a fluorescent scanner to give the“protein fingerprint”which is characteristic of the individual proteins. The results of the present prototype system demonstrate the practicality of protein-chips as a new generation of biochips.View full abstractDownload PDF (9724K) -
Hiroyasu YAMAGUCHI, Akira HARADA2004 Volume 61 Issue 10 Pages 533-540
Published: October 25, 2004
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSAn amplification method of the detection signals for a target molecule has been devised by using the signal enhancement in the supramolecular assembly of antibodies with divalent antigens. Target substrate added to the flow cell of biosensors based on surface plasmon resonance (SPR) can be detected quantitatively by monitoring the total amount of the antibody bound to the surface of the sensor chip. The sensitivity of this system was found to be two orders higher than that of the simple addition of target substrate to the antibody immobilized on the surface of the sensor chip. The complexes of the antibody with trivalent antigens formed a dendritic network structure and enhanced the response signal intensities on the SPR biosensor. Dendritic antibody supramolecules were designed and prepared by using IgM as a core and chemically modified IgG as branches. Many binding sites of IgG were arranged radially on the surface of single molecule. The resulting artificial antibodies bound antigens more selectively than IgM and more strongly than IgG. Antibodies attached to the surface of gold nanoparticles were also prepared. They were found to be useful as a functional material for the amplification of detection signals of target molecules in SPR sensors and enzyme-linked immunosorbent assay.View full abstractDownload PDF (3924K) -
Construction of Intermolecular Communication System on “Cerasome” as an Organic-Inorganic NanohybridYoshihiro SASAKI, Maki YAMADA, Takashi TERASHIMA, Jian-Feng WANG, Mine ...2004 Volume 61 Issue 10 Pages 541-546
Published: October 25, 2004
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSA molecular communication system exhibiting signal transduction behavior was constructed on Cerasome, which is an organic-inorganic hybrid vesicle used as a biomembrane model. The Cerasome formed with a synthetic peptide lipid bearing atriethoxysilyl and a quaternary ammonium group on the head moiety showed extremely high morphological stability against a cationic surfactant. A molecular device, was needed to control enzymatic activity on the Cerasome through functional connection of molecular recognition by a membrane-binding artificial receptor and signal amplification by the enzyme. Suchudevice was prepared and its supramolecular functions were evaluated. Marked signal transduction behavior was observed in the Cerasome system containing a steroidal receptor with an amino group, pyridoxal 5′-phosphate as an external signal, Cu (II) ion as a mediator species, and L-lactate dehydrogenase as an amplifier of chemical signals.View full abstractDownload PDF (4313K) -
Junji WATANABE, Kazuhiko ISHIHARA2004 Volume 61 Issue 10 Pages 547-554
Published: October 25, 2004
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSBio-conjugate nanoparticles were prepared by combination of a phospholipid polymer shell and a polystyrene core. Active ester groups for bio-conjugation and phospholipid polar groups were incorporated into the phospholipid polymer backbone by using a novel active ester monomer and 2-methacryloyloxyethyl phosphorylcholine. The active ester groups and the phospholipid polar groups were located on the nanoparticle surface. The reaction of the active ester groups with enzyme was roughly 40% at 4°C and 25°C. The activity of the enzyme immobilized at 4°C was found to be higher than that immobilization at 25°C. For the sequential enzymatic reaction, choline oxidase and peroxidase were immobilized onto the nanoparticles. Choline chloride and tetramethyl benzidine were added as substrates to the nanoparticle suspension. The choline chloride was oxidized by the choline oxidase, and hydrogen peroxide was formed as a degradation product. The hydrogen peroxide was used for the subsequent enzymatic oxidation of tetramethyl benzidine. If hydrogen peroxidewas free to diffuse between the choline oxidase and the peroxidase, a sequential enzymatic reaction would be observed. The enzymatic reaction on the nanoparticles was found to be significantly more efficient than that by the enzyme mixture. This result indicates that the diffusion of the degradation products and localization of immobilized enzymes are dominant factors for the reaction. The nanoparticles are thus promising materials for a highsensitivity diagnosis carrier.View full abstractDownload PDF (6903K) -
Madoka TAKAI, Satomi SHINBASHI, Hiroki OGAWA, Masao NAGAI, Kazuhiko IS ...2004 Volume 61 Issue 10 Pages 555-560
Published: October 25, 2004
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSA microglucose sensor for healthcare chip that allows multi-item measurement in an infinitesimal trace of blood (less than one μL) has been developed. The causes of instability (including a low sensitivity and a low accuracy) in microglucose sensor with a small electrode of 300 μm in diameter have been determined to include dispersibility of ferrocene, amount of immobilized GOD, and plasma-protein absorption on sensor surface. To improve the sensitivity and accuracy, we studied these parameters. High packing density of ferrocene particles on carbon electrode has improved piece-to-piece variations of sensor characteristics. Measurements up to 50 mmol dm-3 of glucose have been achieved by combination of ferrocene particles with a hydrophobic polymer such as a poly vinyl group. Lamination of poly-ion-complex was a good immobilization method for increasing immobilized enzyme. It led to the increase of the sensitivity and accuracy due to increasing response current. Sensitivity in plasmas has drastically improved by suppression of plasma-protein absorptions on sensor surface using biocompatible MPC-co-BMA polymer coatings.View full abstractDownload PDF (9007K)
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