Faculty Profiles - SHIMANOUCHI Toshinori

Papers - SHIMANOUCHI Toshinori

Division display 141 - 160 of about 166 ／ All the affair displays >>

Immobilization of liposomes onto quartz crystal microbalance to detect interaction between liposomes and proteins

S Morita, M Nukui, R Kuboi

JOURNAL OF COLLOID AND INTERFACE SCIENCE 298 ( 2 ) 672 - 678 2006.6

Language：English Publishing type：Research paper (scientific journal) Publisher：ACADEMIC PRESS INC ELSEVIER SCIENCE

To study the interaction between liposomes and proteins, intact liposomes were immobilized on a metal planar support by chemical binding and/or bioaffinity using a quartz crystal microbalance (QCM). A large decrease in the resonance frequency of quartz crystal was observed when the QCM, modified by a self-assembled monolayer (SAM) of carboxythiol, was added to liposome solutions. The stable chemical immobilization of intact liposomes onto SAM was judged according to the degree with which adsorbed mass depended on the prepared size of liposomes, as well as on the activation time of SAMs when amino-coupling was introduced, where the liposome coverage of electrodes was 69 +/- 8% in optimal conditions. When avidin-biotin binding was used on amino-coupling liposome layers, liposome immobilization finally reached 168% coverage of the electrode surface. Denatured protein was also successfully detected according to the change in the frequency of the liposome-immobilized QCM. The adsorbed mass of denatured carbonic anhydrase from bovine onto immobilized liposomes showed a characteristic peak at a concentration of guanidine hydrochloride that corresponded to a molten globule-like state of the protein, although the mass adsorbed onto deactivated SAM increased monotonously. (c) 2005 Elsevier Inc. All rights reserved.

DOI： 10.1016/j.jcis.2005.12.043

Evaluation of temperature and guanidine hydrochloride-induced protein-liposome interactions by using immobilized liposome chromatography

N Yoshimoto, M Yoshimoto, K Yasuhara, T Shimanouchi, H Umakoshi, R Kuboi

BIOCHEMICAL ENGINEERING JOURNAL 29 ( 3 ) 174 - 181 2006.4

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE SA

Hydrophobic interactions between nine model proteins and net-neutral lipid bilayer membranes (liposomes) under stress conditions were quantitatively examined by using immobilized liposome chromatography (ILC). Small or large unilamellar liposomes were composed of 1-palinitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) and immobilized in a gel matrix by utilizing covalent coupling between amino-containing lipids and activated gel beads or avidin-biotin biospecific binding. Retardation of bovine carbonic anhydrase (CAB) in ILC was pronounced at particular temperatures (50 and 60 degrees C) where the local hydrophobicity of theses protein molecules becomes sufficiently large. Protein-induced leakage of a hydrophilic dye (calcein) from immobilized liposomes interior was also drastically enhanced at particular temperatures where large retardation was observed. For other proteins examined, similar results were also observed. The specific capacity factor of the proteins characteristic for the ILC and the amount of calcein released from immobilized liposomes were successfully expressed as a function of the product of the local hydrophobicities of proteins and liposomes, regardless of protein species and the type of the stress conditions applied (denaturant and heating). These findings indicate that lipid membranes have an ability to non-specifically recognize local hydrophobicities of proteins to form stress-mediated supramolecular assemblies with proteins, which may have potential applications in bioprocesses such as protein refolding and separation. ILC was thus found to be a very useful method for the quantitative detection of dynarnic protein-liposome interactions triggered by stress conditions. (c) 2005 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.bej.2005.08.030

Evaluation of carboxylic acid-induced conformational transitions of beta-lactoglobulin: Comparison of the alcohol effects on beta-lactoglobulin

BK Lee, T Shimanouchi, H Umakoshi, R Kuboi

BIOCHEMICAL ENGINEERING JOURNAL 28 ( 1 ) 79 - 86 2006.2

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE SA

Conformational transitions of bovine P-lactoglobulin A (beta-LG) induced by carboxylic acid were systematically studied by steady-state tryptophan (Trp) fluorescence. The behavior of beta-LG denaturation depends upon the species and concentration of carboxylic acid, as well as on the pH of solutions. The order of the effectiveness of the respective carboxylic acids was described as follows: MeCOOH < EtCOOH < PrCOOH < ClEtCOOH < TFA < iBuCOOH < nBuCOOH < PFPA. The conformational chan-e of beta-LG through the carboxylic acid-induced transitions of the beta-LG conformation were analyzed assuming a two-state mechanism between unfold and native states in order to obtain the m value, a measure of the dependence of the free energy change on the concentration of carboxylic acid. The m values of various carboxylic acids were compared with those of various alcohols based on the role of each group constituting the carboxylic acid and alcohol molecules, namely, the hydrocarbon group, hydroxyl group, halogen substituents, and the carboxyl group. Among these groups, the hydrophobic hydrocarbon groups and halogen substituents contributed positively to the in value, whereas the hydrophilic carboxyl and hydroxyl group contributed negatively. The present results can therefore be interpreted as a simple correlation based on the accessible surface area (ASA) of each groups of carboxylic acids and alcohols. These results suggest that the conformational transition of the protein due to the addition of carboxylic acids and alcohols can be explained both by hydrophobicity as well as clustering effects of each carboxylic acid and alcohol molecule. (c) 2005 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.bej.2005.08.040

Heat-enhanced production of chitosanase from Streptomyces griseus in the presence of liposome

KX Ngo, H Umakoshi, T Shimanouchi, HS Jung, S Morita, R Kuboi

JOURNAL OF BIOSCIENCE AND BIOENGINEERING 100 ( 5 ) 495 - 501 2005.11

Language：English Publishing type：Research paper (scientific journal) Publisher：SOC BIOSCIENCE BIOENGINEERING JAPAN

The effects of heat stress and liposome treatment on the growth of Streplomyces griseus cells and chitosanase production were investigated on the basis of using the designed strategy of a stress-mediated bioprocess. The effective conditions for increasing the interaction between chitosanase and the 1-palmitoyl-2-oleoyl-3-phosphocholine (POPC) liposome under heat stress condition were determined on the basis of the results of circular dichroism (CD) and dielectric dispersion analysis (DDA). Under these effective conditions, S. griseus cells were cultivated for the effective production of chitosanase. The results obtained from both CD spectra and DDA showed that heat stress enhances the interaction of the POPC liposomes and chitosanase. The strongest interaction between them could be obtained in the specific temperature range of 40-45 degrees C. The enhancement of the target chitosanase production was conducted under heat stress at WC in the presence and absence of the POPC liposomes. The growth rates of S. griseus cells in the cases of heat (41 degrees C) and heat (41 degrees C)/POPC treatments were respectively 1.2 and 1.4 times higher than that obtained under the control condition. In the heat (41 degrees C) and heat (41 degrees C)/POPC treatments, chitosanase activity increased to 1.8 and 2 times, respectively, higher than that obtained under the control condition. Heat stress and the addition of the POPC liposomes could therefore be utilized to induce the potential functions of bacterial cells for the enhancement of the final target production.

DOI： 10.1263/jbb.100.495

Oxidation of cholesterol catalyzed by amyloid beta-peptide (A beta)-Cu complex on lipid membrane

N Yoshimoto, M Tasaki, T Shimanouchi, H Umakoshi, R Kuboi

JOURNAL OF BIOSCIENCE AND BIOENGINEERING 100 ( 4 ) 455 - 459 2005.10

Language：English Publishing type：Research paper (scientific journal) Publisher：SOC BIOSCIENCE BIOENGINEERING JAPAN

A catalytic reaction of H2O2 production by an amyloid beta-peptide (A beta)-Cu complex with cholesterol incorporated in a liposome was kinetically analyzed. The Michaelis-Menten model was applied to the H2O2 production reaction using cholesterol as the substrate catalyzed by the A beta-Cu complex. The K-m value for the A beta-Cu complex catalytic reaction with cholesterol-containing 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) liposomes (K-m=0.436 mu M for A beta(1-40); K-m=0.641 mu M for A beta(1-42)) was found to be smaller than that with cholesterol-containing 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) liposomes (K-m=0.585 mu M for A beta(1-40), K-m=0.890 mu M for A beta(1-42)). The results imply that membrane properties could play an important role in the interactions of the A beta-Cu complex with cholesterol in these liposomes. Considering the physical states of the cholesterol/POPC (liquid disordered phase) and cholesterol/DPPC (liquid ordered phase) liposomes in the present reaction conditions, the data obtained suggests that the H2O2-gencrating activity of the A beta-Cu complex, accompanied by oxidation of membrane-incorporated cholesterol, could be effected by the phase of the liposome membranes.

DOI： 10.1263/jbb.100.455

Liposome-assisted activity of superoxide dismutase under oxidative stress

H Nagami, N Yoshimoto, H Umakoshi, T Shimanouchi, R Kuboi

JOURNAL OF BIOSCIENCE AND BIOENGINEERING 99 ( 4 ) 423 - 428 2005.4

Language：English Publishing type：Research paper (scientific journal) Publisher：SOC BIOSCIENCE BIOENGINEERING JAPAN

A biological membrane is the front line of defense for cells against various environmental stresses such as heat and reactive oxygen species (ROS) and is expected to play an important role in the antioxidant system with antioxidant enzymes, similarly to its chaperone-like function in cooperation with heat shock proteins. The oxidative stress response of superoxide dismutase (SOD), which is known to catalyze the dismutation of O-2(-) to H2O2 was investigated in the presence of artificial membranes, liposomes, in order to obtain fundamental information on the biological ROS scavenging system. SOD lost its activity in the presence of H2O, and was found to have two loops including one which contains an a-helix which presents the substrate O-2(-) to the activity center of SOD (Cu(II)). From circular dichroism analysis of SOD in the presence of H2O2, the contents of the a-helix in SOD were found to decrease in correspondence with the inactivation and conformational change of SOD, suggesting that the conformation of the a-helix loops affects SOD activity. In the presence of liposomes composed of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC), SOD was not inactivated in the presence of H2O2 although the contents of its a-helix structure were decreased. The oxidized SOD was found to interact with the liposome surface under oxidative stress using dielectric dispersion analysis. Based on these results, a possible mechanism of SOD protection against ROS on liposomes was presented.

DOI： 10.1263/jbb.99.423

PBL Education for the 2nd Year Undergraduate Students in Chemical Engineering and Continuous Outcomes Assessment

KUBOI Ryoichi, SHIMADA Wataru, EGASHIRA Yasuyuki, EBITANI Kohki, KINO-OKA Masahiro, TAKAHASHI Hideaki, SATO Hiroshi, UMAKOSHI Hiroshi, SHIRAISHI Yasuhiro, SHIBA Sadataka, SHIMAUCHI Hisanori

Journal of JSEE 53, 52-57/, ( 6 ) 52 - 57 2005

Language：Japanese Publisher：Japanese Society for Engineering Education

A Project-Based Learning (PBL) program has been examined for the 2nd year students who spontaneously set the project themes. The questionnaires to the same students who had taken the PBL course were carried out just after promotion to the 4th year as well as just before graduation. The results demonstrated the effectiveness of the PBL program and the usefulness of the PBL continuous assessment of the outcomes.

DOI： 10.4307/jsee.53.6_52

Variable SOD-like activity of liposome modified with Mn(II)-porphyrin derivative complex

H Nagami, H Umakoshi, T Shimanouchi, R Kuboi

BIOCHEMICAL ENGINEERING JOURNAL 21 ( 3 ) 221 - 227 2004.11

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE SA

A novel artificial superoxide dismutase (SOD), which can vary its activity in response to oxidative stress, was developed by using the liposome modified with a metal-functional ligand complex. A lipophilic chloro-(5,10,15,20-tetrakis[1-hexadecylpyridinium-4-yl]-21H,23H-porphyrin) (HPyP) was selected as the functional ligand to modify the liposome surface. The effects of the molar ratio of the HPyP and metal ion in the liposome membrane on two kinds of SOD-like functions, i.e. SOD activity and the antioxidative function against phospholipid composed of liposome was investigated by varying the membrane properties of liposomes. The modification of liposome with HPyP complex resulted in conflicting functions, such as an inhibitive and a promotional function during the induction of the antioxidation function against phospholipid, depending on the molar content of HPyP. The Mn(II)-HPyP complex can efficiently convert O-2(-) to H2O2 and O-2 at low HPyP content, while the efficiency of the SOD activity of Mn(II)-HPyP was significantly reduced due to the cluster formation of Mn(II)-HPyP complex in the liposome at a HPyP content exceeding 1 mol%. It was considered that the cluster formation of the Mn(II)-HPyP complex in the liposome may decrease the reactivity of the active center of the disproportional reaction of Mn(II)-HPyP since the complex was buried into the aggregate of Mn(II)-HPyP itself. (C) 2004 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.bej.2004.05.006

Comparison of the extraction behavior of metal ions by metal affinity ligands in an organic-aqueous two-phase system and in a liposome system

H Nagami, H Umakoshi, T Shimanouchi, R Kuboi, Y Baba

SOLVENT EXTRACTION RESEARCH AND DEVELOPMENT-JAPAN 11 159 - 165 2004

Language：English Publishing type：Research paper (scientific journal) Publisher：JAPAN ASSOC SOLVENT EXTRACTION

The interaction of various metal ions with simple metal affinity ligands, 3(hexadecylthio)propionic acid (HTP) and 2-(hexadecylthio)benzoic acid (HTB), was investigated in an organic/aqueous two-phase system and in a liposome system. Both ligands exhibited a high silver(I) affinity at low pH in the organic/aqueous two phase system but low selectivity in the extraction of other transition metal ions such as Cu(II), Ni(II), Co(II), Zn(II), Cd(II), and Hg(II) above pH 6. On the other hand, remarkably different behavior for metal adsorption was observed in the liposome system with HTP and HTB. HTB lost the ability to interact with metal ions when modified on the liposome surface. This may be attributed to the formation of a hydrogen bond between the carboxyl group of the HTB and the phosphate group of the phospholipid. The HTP-modified liposome effectively adsorbed metal ions of the zinc family, such as Zn(II) and Cd(II), which could interact with the phosphate group of phospholipid, and also adsorbed those transition metal ions, which could be extracted in the organic/aqueous two-phase system. This may be caused by two functions of the liposome, i.e., a gate function for metal ions at the surface of the HTP-modified liposome and additional stabilization by interaction between Cu(II) and the phosphate group of the phospholipid.

Development of PPy films doped with thiol-SAM-Cu particles for NH3 gas sensing

T Shimanouchi, S Morita, HS Jung, Y Sakurai, Y Suzuki, R Kuboi

SENSORS AND MATERIALS 16 ( 5 ) 255 - 265 2004

Language：English Publishing type：Research paper (scientific journal) Publisher：MYU, SCIENTIFIC PUBLISHING DIVISION

We have developed a high-sensitivity polypyrrole (PPy) film with a porous structure using a simple and easy method of doping thiol self-assembled monolayer (SAM)-Cu particles into a PPy film. The thiol-Cu-SAM particles were doped by the adsorption of thioxylenol or decanethiol into the porous PPy film surface, resulting in an improvement in sensitivity of the film to NH3. Owing to the addition of thiol-Cu-SAM particles formed using various 4-tent-butylcalix-6-arene thiol derivatives, the sensitivity correspondingly decreased. In particular, for the case of poly(propylene oxide)-calix-6-arenethiol, a marked decrease in sensitivity was observed. Using this composite nanomaterial, we found that the detection limit for NH3 increased to concentration levels of several ppm. We present a novel preparation method for these sensor films aimed at controlling their porosity and sensitivity.

Detection of protein conformation under stress conditions using liposomes as sensor materials

R Kuboi, T Shimanouchi, M Yoshimoto, H Umakoshi

SENSORS AND MATERIALS 16 ( 5 ) 241 - 254 2004

Language：English Publishing type：Research paper (scientific journal) Publisher：MYU, SCIENTIFIC PUBLISHING DIVISION

Calcein release from liposomes was analyzed kinetically in the presence of various proteins under the stress condition. In the case of bovine carbonic anhydrase (CAB), a significant release of calcein was observed at pH 4. The conformational change of CAB from the native to the molten-globule (MG) state was confirmed using an aqueous two-phase partitioning method and immobilized liposome chromatography. The CAB-liposome interaction was maximum at a specific pH (4.0), where the CAB conformation was an MG-like state. The results may show that the hydrophobic interaction between CAB and liposomes enhances the perturbation of the liposome membrane, leading to a significant release of calcein from liposomes. These phenomena depended not only on the characteristics of proteins (local hydrophobicity, LHpr) but also on the dynamic properties of liposomes (membrane fluidity). These results obtained with CAB may be extended to other proteins. The manner of protein-induced calcein release was classified into at least two types. Calcein release due to the addition of proteins having either disulfide bonds or being rich in beta-sheet structure was not observed. On the contrary, a significant release of calcein was observed in the case of a reduced protein with a cleaved disulfide bond and in the case of a protein with relatively a low content of beta-sheet structure. These findings suggest that a liposome containing calcein can be used as an effective sensor element for the detection of proteins having large structural fluctuations.

Novel fabrication of conductive polymers contained micro-array gas sensitive films using a micromanipulation method

HS Jung, T Shimanouchi, S Morita, R Kuboi

ELECTROANALYSIS 15 ( 18 ) 1453 - 1459 2003.10

Language：English Publishing type：Research paper (scientific journal) Publisher：WILEY-V C H VERLAG GMBH

A novel method for fabricating a micro gas sensor film on an indium tin oxide (ITO) electrode patterned using micromachining technology was developed. A micromanipulation system equipped with a counter electrode (Au; circle divide10 pm) and a microsyringe, which was connected to a microinjection system, was first constructed. With this system, micro gas sensor arrays could be successfully prepared on ITO electrodes. Two kinds of micro gas sensor films were prepared, based on polythiophene (PTh) and poly(3-n-dodecylthiophene) (PD). The response behavior of conventional PTh and micro-PTh films against NH3 at three different operating temperatures (25, 40 and 60degreesC) was investigated by measuring the resistance of the film. With the micro-PTh film, a reversible response was observed against NH3 when measured at 40 and 60degreesC. In addition, the responsive characteristics of the microsensor films against different testing gases were examined at the three operating temperatures. The resistance of the microsensor films of PTh and PD changed considerably, depending on the type of testing gas, allowing these sensor films to be used for the detection of various gases. Furthermore, the microsensor films had a high stability compared with conventional films prepared from the same polymer.

DOI： 10.1002/elan.200302660

Characterization of the surface properties of chitosanase under heat stress condition using aqueous two-phase systems and an immobilized-liposome sensor system

HS Jung, H Umakoshi, SY Son, T Shimanouchi, R Kuboi

SOLVENT EXTRACTION RESEARCH AND DEVELOPMENT-JAPAN 10 123 - 132 2003

Language：English Publishing type：Research paper (scientific journal) Publisher：JAPAN ASSOC SOLVENT EXTRACTION

The surface properties of chitosanase from Storeptomyces griseus were characterized under heat stress conditions by using aqueous two-phase systems and by using an immobilized-liposome sensor. The surface net (HFS) and local hydrophobicities (LH), were first characterized by using the poly (ethylene glycol) (PEG)/dextran 100-200k (Dex) aqueous two-phase system at various temperatures (25similar to50degreesC). The LH values of dithiothreitol (DTT)-treated chitosanase showed a maximum at a specific temperature (45degreesC) while the HFS values gradually increased with increasing temperature from 40 to 50degreesC. At the same temperature conditions as above, the surface properties of chitosanase were also analyzed by using a sensor tip immobilized-liposome electrode. Similarly in the case of the variation of LH but not HFS, the detected signal (maxima in electric current) was maximized at 45degreesC, and a linear correlation between the LH values and the signal values of the new immobilized-liposome sensor system was obtained. It was thus found that the new sensor system was effective for the characterization of the surface properties and LH values, of proteins, as well as the aqueous two-phase system method.

Detection of a heat stress-mediated interaction between protein and phospholipid membrane using dielectric measurement

Seiichi Morita, Toshinori Shimanouchi, Masashi Sasaki, Hiroshi Umakoshi, Ryoichi Kuboi

Journal of Bioscience and Bioengineering 95 ( 3 ) 252 - 256 2003

Language：English Publishing type：Research paper (scientific journal) Publisher：Society of Fermentation and Bioengineering

The dielectric response of lipid bilayer membrane vesicles (liposomes) prepared using either phosphatidylcholine from egg (EPC) or 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) was analyzed at a frequency range of 0.1 to 100 MHz. A marked dielectric dispersion for EPC and POPC liposome suspensions was observed above 1 MHz. An appropriate analysis of the dielectric dispersion curve was performed using the Cole-Cole equation and the Debye equation and was found to provide a method for the determination of dielectric parameters. Among the dielectric parameters, the characteristic frequency of a second dispersion around 50 MHz varied corresponding with changes in the test conditions. Of particular note is that an anomalous change in the characteristic frequency in the presence of protein corresponded to the degree of hydrophobic interaction between proteins and liposomes. The value of the frequency around 50 MHz, as well as the decrease in permittivity over the frequency range tested, are indicators of the interaction between proteins and liposomes.

DOI： 10.1263/jbb.95.252

Characterization and control of stimuli-induced membrane fusion of liposomes in the presence of proteins and stimuli responsive polymers

MM Felix, H Umakoshi, T Shimanouchi, M Yoshimoto, R Kuboi

BIOCHEMICAL ENGINEERING JOURNAL 12 ( 1 ) 7 - 19 2002.10

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE SA

The process of fusion of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) liposomes in the presence of stimuli responsive copolymers (poly(N-isopropylacrylaniide-co-methacrylic acid) and poly(N-isopropylacrylamide-co-methacrylic acid-co-octadecylacrylamide)) or proteins ((x-chymotrypsin (alpha-CT), bovine carbonic anhydrase (CAB), and p-galactosidase (p-gal)) was quantitatively characterized under the stimuli by varying pH and temperature. After the liposomes were exposed to the specific pH and heat stimuli in the presence of the stimuli responsive polymers or proteins, the percentage of the fusion was determined by using two kinds of liposomes entrapping cobalt-calcein and EDTA (cobalt-calcein method). In the presence of stimuli responsive copolymers, the percentage of fusion was increased to 20% above the phase transition condition of the copolymer (above 37 degreesC and below pH 5.7). The percentage of fusion in the presence of proteins was varied under the stimuli, depending on the type of proteins. In the case of the alpha-CT, the maximal percentage of fusion was only 8%. The addition of the CAB and p-gal improved the percentage of fusion to 15 and 20%, respectively, by selecting the optimal stimuli conditions. Although some disagreements were observed in the region of strong acidic conditions, it was found that the increase of the percentage of fusion was well corresponding with the increase of the membrane fluidity of the POPC liposome, followed by the increase of the local hydrophobicity of proteins or copolymers under the stimuli. Based on the above results, a possible model for the stimuli-induced fusion of POPC liposome membranes was finally presented. (C) 2002 Elsevier Science B.V. All rights reserved.

DOI： 10.1016/S1369-703X(02)00014-1

Novel array-type gas sensors using conducting polymers, and their performance for gas identification

Y Sakurai, HS Jung, T Shimanouchi, T Inoguchi, S Morita, R Kuboi, K Natsukawa

SENSORS AND ACTUATORS B-CHEMICAL 83 ( 1-3 ) 270 - 275 2002.3

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE SA

Novel gas sensor devices have been developed using polythiophene (pTh) film and poly(3-n-dodecylthiophene) (pDpTh.) film coated over pTh film. These polymer films were electrochemically deposited and doped by cyclic voltammetry on thin-film electrodes where the isolation gap was formed by a micromachining process. We examined the response characteristics of the conducting polymer films against various sample gases over a range of temperatures of the sensitive layer. The resistance changes of both sensitive layers of pTh and pDpTh were highly dependent on the kind of layer. In particular, pTh film responded to ammonia gas and pDpTh films clearly responded to hydrophobic gases, such as chloroform, methane and ethanol. The response of these films to several gases was analyzed with a pattern recognition (PARC) algorithm. It was found that our simple gas sensor device could discriminate between the gases that were used here. (C) 2002 Elsevier Science B.V. All rights reserved.

DOI： 10.1016/S0925-4005(01)01069-3

Evaluation of interaction between liposome membranes induced by stimuli responsive polymer and protein

Matundu Menayame Félix, Hirosh Umakoshi, Toshinor Shimanouchi, Makot Yoshimoto, Ryoich Kuboi

Journal of Bioscience and Bioengineering 93 ( 5 ) 498 - 501 2002

Language：English Publishing type：Research paper (scientific journal) Publisher：Society of Fermentation and Bioengineering

Immobilized liposome chromatography was utilized as a novel method for the quantitative evaluation of the interaction between liposome membranes. The capacity factors evaluated from the elution profile showed that interaction between 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) liposome membranes occurred in the presence of a stimuli responsive polymer and protein under specific stimulus conditions. The occurrence of such interaction was supported by experimental results for POPC liposome membrane fusion under corresponding stimuli conditions.

DOI： 10.1016/S1389-1723(02)80098-6

Characterization of stimuli-induced membrane fusion of liposomes

Matundu Menayame Félix, Toshinori Shimanouchi, Hiroshi Umakoshi, Makoto Yoshimoto, Ryoichi Kuboi

Kagaku Kogaku Ronbunshu 28 ( 4 ) 481 - 484 2002

Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Society of Chemical Engineers

The phenomena of aggregation and fusion of liposome membranes under the stimuli conditions (heat and pH) were shown to be triggered by the conformational change of the stimuli-responsive polymers and proteins. It is found that the percentage of liposome fusion and the liposome size under the specific stimuli condition were well corresponding with the capacity factor obtained from the peak shift of the elution profile on the immobilized liposome chromatography.

DOI： 10.1252/kakoronbunshu.28.481

Highly sensitive and selective gas sensors using the polythiophen derivatives controlled the temperature Reviewed

Y Sakurai, HS Jung, T Inoguchi, T Shimanouchi, M Umakoshi, R Kuboi, K Natsukawa

TRANSDUCERS '01: EUROSENSORS XV, DIGEST OF TECHNICAL PAPERS, VOLS 1 AND 2 1696 - 1699 2001

Language：English Publishing type：Research paper (international conference proceedings) Publisher：SPRINGER-VERLAG BERLIN

The advanced odor gas sensor devices were developed using the polythiophene derivatives. These polymers have been found to sense gases and vapours by monitoring the change in resistance on exposure of the polymer to the gas sample. These polymer films were electrochemically deposited and doped by cyclic voltammetry on thin-film electrodes where the isolation gap was formed by the micro-machining process. The breakthrough resulted in sensor devices with unique benefits, such as the very high selectivity and the operation possibility at ambient temperatures (steady and nonsteady state).

Immobilized liposome chromatography for refolding and purification of protein

Makoto Yoshimoto, Toshinori Shimanouchi, Hiroshi Umakoshi, Ryoichi Kuboi

Journal of Chromatography B: Biomedical Sciences and Applications 743 ( 1-2 ) 93 - 99 2000.6

Language：English Publishing type：Research paper (scientific journal)

Small unilamellar liposomes were utilized as a kind of aqueous two-phase system and artificial chaperone which specifically recognize protein conformation with fluctuated structure. Liposomes showed highly selective binding ability to conformationally changed proteins treated with various concentrations of guanidinium hydrochloride, as evaluated by immobilized liposome chromatography (ILC). In refolding of proteins, liposomes bound to refolding intermediate of proteins and prevented them from forming intermolecular aggregates. Refolding of bovine carbonic anhydrase, lysozyme and ribonuclease A was significantly improved in the presence of liposomes. Furthermore, by utilizing ILC, refolding of proteins was also successfully and simply carried out with considerable high reactivation yield. © 2000 Elsevier Science B.V.

DOI： 10.1016/S0378-4347(00)00051-7

　 PREV - NEXT 　

1
2
3
4
5
6
7
8
9