健司 加納 | Kyoto University (original) (raw)

Papers by 健司 加納

Chemical & Pharmaceutical Bulletin, 1987

In connection with the carcinogenic activity of 4-(hydroxyamino)quinoline N-oxide (4HAQO), voltam... more In connection with the carcinogenic activity of 4-(hydroxyamino)quinoline N-oxide (4HAQO), voltammetric studies of the oxidation processes of 4HAQO and related substances were carried out in aqueous solutions. It was verified that 4HAQO forms a reversible redox couple with 4nitrosoquinoline N-oxide (4NOQO) through an intermediate free radical. The reversible reactions in these redox couples were evaluated quantitatively, and the formation constant of the intermediate free radical was calculated. The pH dependence of the above standard redox potential gave the pKa values, which agreed quite well with the data measured by ultraviolet spectral methods. The molecular structures of species formed by proton addition or dissociation were investigated by analyses of the pKa values and the electronic spectra, and by their molecular orbital calculations. The N-oxide type structure was considered to be a main species in aqueous solutions of 4HAQO and its analogues.

Analytical Sciences, 2021

A liquid-membrane type nitrate-selective electrode was improved to lower the influence of contami... more A liquid-membrane type nitrate-selective electrode was improved to lower the influence of contaminants by modifying its inner electrode system from Ag | AgCl | Clto Ag | Ag +. The NO3-selective electrode displayed a linear response to the concentration of NO3with a Nernstian slope of-53 ± 1 mV decade-1 , in the concentration region between 10-5 and 2 mol dm-3 (M). The NO3detection limit was about 10-5 M. The electrochemical response of this electrode was stable for more than 30 days. The deterioration in responding characteristics due to the coexistence of Clwas suppressed by use of the Ag | Ag + redox couple in the absence of Clinside the NO3-selective electrode.

Analytical Sciences, 2020

In order to improve plant factories, an appropriate control system on fertilization is urgently r... more In order to improve plant factories, an appropriate control system on fertilization is urgently required. An automatic management system to control nutrient concentration was constructed using a programmable logic controller (PLC) and ion selective electrodes (ISEs) of nitrate, phosphate, and potassium ion. The concentration of nutrient components in a culture solution was monitored using these ISEs. When the concentration of the nutrient components diminished to the threshold set as an optimum condition (0.1-2.0 mM), an appropriate amount of a concentrated solution of each nutrient component was added to the culture solution using solenoid valves connected with the PLC. The present cultivation system was simply constructed without any computers and pumps. Three kinds of automatic control systems simultaneously worked and did not influence each other.

Japanese Journal of Pesticide Science, 2014

Analytical Sciences, 2019

A phosphate ion-selective electrode using molybdenum metal was constructed. The modified molybden... more A phosphate ion-selective electrode using molybdenum metal was constructed. The modified molybdenum electrode responded to HPO4 2in the presence of molybdenum dioxide and molybdophosphate (PMo12O40 3-) on the surface. The electrode exhibited a linear response to HPO4 2in the concentration range between 1.0 × 10-5 and 1.0 × 10-1 M (mol dm-3) in the pH range from 8.0 to 9.5 with a detection limit of 1.0 × 10-6 M. The sensor showed near Nernstian characteristics (27.8 ± 0.5 mV dec-1) at pH 9.0. Since the responding potential was attributed to the activity of HPO4 2-, the potential at a given concentration of phosphate depended on the pH. The electrode indicated a good selectivity with respect to other common anions such as NO3-, SO4 2-, Cl-, HCO3and CH3COO-. The modified molybdenum electrode can be continuously used for over a 1 month with good reproducibility. The feasibility of the electrochemical sensor was proved by successful for the detection of phosphate in real samples.

Electrochemistry Communications, 2019

A pH sensor was fabricated using a modified hydrogen-storage palladium electrode. The Pd electrod... more A pH sensor was fabricated using a modified hydrogen-storage palladium electrode. The Pd electrode stores H 2 generated electrochemically at suitable potentials. After the Pd electrode had become coated with palladium hydride (PdH x), the resting potential of the modified Pd electrode responded to changes in the pH with a near-Nernstian response of −56.2 ± 0.2 mV pH −1 in the range from pH 1 to pH 13. Although such Pd electrodes are usually unstable due to the release of H 2 , their stability could be dramatically increased by covering with a Teflon tube. The Pd electrode can be easily regenerated by electrolysis. As H 2 gas is spontaneously released from the modified Pd electrode, the partial pressure of H 2 gas on the surface of the Pd electrode is almost constant (H 2 gas is almost saturated in the vicinity of the electrode). Accordingly, the potential is assumed to be determined by the pH value of the aqueous solution based on the redox potential of the H 2 |H + couple. When the pH value of the solution is almost constant, the modified Pd electrode can act as a reference electrode without any leakage of the inner electrolyte that occurs with Ag|AgCl|sat. KCl electrodes.

Analytical Sciences, 2019

An automatic management system for nutrient solutions was constructed using a programmable logic ... more An automatic management system for nutrient solutions was constructed using a programmable logic controller (PLC) and a K +-ion selective electrode (K +-ISE). The concentration of K + was monitored by the K +-ISE. When the concentration of K + fell to the threshold limit, an appropriate amount of a concentrated K + solution was added to the hydroponic solution. The volume was also maintained at a constant level by addition of water. This system can be constructed simply and inexpensively without any computers and pumps.

Journal of the agricultural chemical society of Japan, 1992

ACS Catalysis, 2017

A high power mediated electron transfer-type formate (HCOO −)/dioxygen (O 2) biofuel cell is repo... more A high power mediated electron transfer-type formate (HCOO −)/dioxygen (O 2) biofuel cell is reported herein. The cell utilizes a Ketjen Black-modified waterproof carbon cloth as the electrode material. The bioanode comprises tungsten-containing formate dehydrogenase and a viologen-functionalized polymer, whereas the biocathode comprises bilirubin oxidase and 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonate). In addition, a gas-diffusion-type system was employed for the biocathode to realize high speed O 2 supply. These electrodes exhibited a large current density of 20 mA cm −2 in the quiescent steady state for both HCOO − oxidation and O 2 reduction. Finally, these electrodes were coupled to construct an HCOO − /O 2 biofuel cell without a separator. The Page 1 of 25 ACS Paragon Plus Environment ACS Catalysis 2 cell exhibited a maximum power density of 12 mW cm −2 at a cell voltage of 0.78 V under quiescent conditions and an open-circuit voltage of 1.2 V. We show the great potential of HCOO − for the fuel of biofuel cells.

Analytical sciences : the international journal of the Japan Society for Analytical Chemistry, 2016

Ion transport through a single channel of gramicidin A (GA) within the bilayer lipid membrane (BL... more Ion transport through a single channel of gramicidin A (GA) within the bilayer lipid membrane (BLM) between two aqueous phases (W1 and W2) has been analyzed based on the electroneutrality principle. The single-channel current increases in proportion to the magnitude of the applied membrane potential and is also dependent on the permeability coefficients of electrolyte ions (K(+) and Cl(-)). By varying the ratio of the concentration of KCl in W1 to that in W2, the ratio of the diffusion coefficient of K(+) in the BLM to that of Cl(-) in the BLM can be evaluated.

Review of Polarography, 2012

Review of Polarography, 2014

Agricultural and Biological Chemistry, 1984

A polarographic method based on the Brdicka current (the polarographic catalytic hydrogen evoluti... more A polarographic method based on the Brdicka current (the polarographic catalytic hydrogen evolution current produced by proteins in the presence of cobalt salts) was applied to direct titration of subtilisin BPN' (S.BPN') with plasminostreptin (PS) at a concentration level of IO-8 M. The first and second dissociation constants of the S.BPN'-PS complex were determined by fitting theoretical curves to the titration data, in which the multiple equilibria involving microscopically distinct forms of S.BPN'-PS complex were taken into account. The intrinsic free energy change in the first binding of S.BPN' to dimeric PS was larger than that in the second binding. The dependence of the microscopic dissociation constants of S.BPN'-PS complex on pH indicates the participation of ionizable groups of pK. 8.0 and 9.4 in the complex formation. The repUlsive effect between negatively charged molecules of S.BPN' and PS in the complex formation at elevated pH is suggested.

Review of Polarography, 2011

Phytochemistry, 2012

Abscisic acid (ABA, 1), a plant hormone, has electrophilicity derived almost entirely from the si... more Abscisic acid (ABA, 1), a plant hormone, has electrophilicity derived almost entirely from the side chain, 3-methylpenta-2,4-dienoic acid. We have investigated the electrochemical property of ABA by analysis of its cathodic reaction. ABA methyl ester (1-Me) was reduced at a peak potential of-1.6 V to give a unique and unstable bicyclic compound (5-Me) as a major product at pH 3 and 7. This finding showed that an electron was absorbed in the conjugated dienecarboxyl group, and that C-5 with a high electron density was bound to C-2' through an intramolecular nucleophilic addition. At pH 10, in addition to 5-Me, a compound 4-Me was formed by isomerization of 5-Me under an alkaline condition. For a cathodic reaction of ABA at pH 3 and 7, compound 5 was a major product as well as in the case of ABA methyl ester. However, at pH 10, a dimer (6) with an epoxy group, 1'-deoxy-ABA (7) and other compounds were formed instead of compounds 4 and 5. Compounds 4 and 5 were biologically inactive, suggesting the importance of the electrophilic side chain of ABA for the biological activity.

Journal of Biological Chemistry, 2003

DsbB is an Escherichia coli plasma membrane protein that reoxidizes the Cys 30-Pro-His-Cys 33 act... more DsbB is an Escherichia coli plasma membrane protein that reoxidizes the Cys 30-Pro-His-Cys 33 active site of DsbA, the primary dithiol oxidant in the periplasm. Here we describe a novel activity of DsbB to induce an electronic transition of the bound ubiquinone molecule. This transition was characterized by a striking emergence of an absorbance peak at 500 nm giving rise to a visible pink color. The ubiquinone red-shift was observed stably for the DsbA(C33S)-DsbB complex as well as transiently by stopped flow rapid scanning spectroscopy during the reaction between wild-type DsbA and DsbB. Mutation and reconstitution experiments established that the unpaired Cys at position 44 of DsbB is primarily responsible for the chromogenic transition of ubiquinone, and this property correlates with the functional arrangement of amino acid residues in the neighborhood of Cys 44. We propose that the Cys 44-induced anomaly in ubiquinone represents its activated state, which drives the DsbB-mediated electron transfer.

Chemical & Pharmaceutical Bulletin, 1987

In connection with the carcinogenic activity of 4-(hydroxyamino)quinoline N-oxide (4HAQO), voltam... more In connection with the carcinogenic activity of 4-(hydroxyamino)quinoline N-oxide (4HAQO), voltammetric studies of the oxidation processes of 4HAQO and related substances were carried out in aqueous solutions. It was verified that 4HAQO forms a reversible redox couple with 4nitrosoquinoline N-oxide (4NOQO) through an intermediate free radical. The reversible reactions in these redox couples were evaluated quantitatively, and the formation constant of the intermediate free radical was calculated. The pH dependence of the above standard redox potential gave the pKa values, which agreed quite well with the data measured by ultraviolet spectral methods. The molecular structures of species formed by proton addition or dissociation were investigated by analyses of the pKa values and the electronic spectra, and by their molecular orbital calculations. The N-oxide type structure was considered to be a main species in aqueous solutions of 4HAQO and its analogues.

Analytical Sciences, 2021

A liquid-membrane type nitrate-selective electrode was improved to lower the influence of contami... more A liquid-membrane type nitrate-selective electrode was improved to lower the influence of contaminants by modifying its inner electrode system from Ag | AgCl | Clto Ag | Ag +. The NO3-selective electrode displayed a linear response to the concentration of NO3with a Nernstian slope of-53 ± 1 mV decade-1 , in the concentration region between 10-5 and 2 mol dm-3 (M). The NO3detection limit was about 10-5 M. The electrochemical response of this electrode was stable for more than 30 days. The deterioration in responding characteristics due to the coexistence of Clwas suppressed by use of the Ag | Ag + redox couple in the absence of Clinside the NO3-selective electrode.

Analytical Sciences, 2020

In order to improve plant factories, an appropriate control system on fertilization is urgently r... more In order to improve plant factories, an appropriate control system on fertilization is urgently required. An automatic management system to control nutrient concentration was constructed using a programmable logic controller (PLC) and ion selective electrodes (ISEs) of nitrate, phosphate, and potassium ion. The concentration of nutrient components in a culture solution was monitored using these ISEs. When the concentration of the nutrient components diminished to the threshold set as an optimum condition (0.1-2.0 mM), an appropriate amount of a concentrated solution of each nutrient component was added to the culture solution using solenoid valves connected with the PLC. The present cultivation system was simply constructed without any computers and pumps. Three kinds of automatic control systems simultaneously worked and did not influence each other.

Japanese Journal of Pesticide Science, 2014

Analytical Sciences, 2019

A phosphate ion-selective electrode using molybdenum metal was constructed. The modified molybden... more A phosphate ion-selective electrode using molybdenum metal was constructed. The modified molybdenum electrode responded to HPO4 2in the presence of molybdenum dioxide and molybdophosphate (PMo12O40 3-) on the surface. The electrode exhibited a linear response to HPO4 2in the concentration range between 1.0 × 10-5 and 1.0 × 10-1 M (mol dm-3) in the pH range from 8.0 to 9.5 with a detection limit of 1.0 × 10-6 M. The sensor showed near Nernstian characteristics (27.8 ± 0.5 mV dec-1) at pH 9.0. Since the responding potential was attributed to the activity of HPO4 2-, the potential at a given concentration of phosphate depended on the pH. The electrode indicated a good selectivity with respect to other common anions such as NO3-, SO4 2-, Cl-, HCO3and CH3COO-. The modified molybdenum electrode can be continuously used for over a 1 month with good reproducibility. The feasibility of the electrochemical sensor was proved by successful for the detection of phosphate in real samples.

Electrochemistry Communications, 2019

A pH sensor was fabricated using a modified hydrogen-storage palladium electrode. The Pd electrod... more A pH sensor was fabricated using a modified hydrogen-storage palladium electrode. The Pd electrode stores H 2 generated electrochemically at suitable potentials. After the Pd electrode had become coated with palladium hydride (PdH x), the resting potential of the modified Pd electrode responded to changes in the pH with a near-Nernstian response of −56.2 ± 0.2 mV pH −1 in the range from pH 1 to pH 13. Although such Pd electrodes are usually unstable due to the release of H 2 , their stability could be dramatically increased by covering with a Teflon tube. The Pd electrode can be easily regenerated by electrolysis. As H 2 gas is spontaneously released from the modified Pd electrode, the partial pressure of H 2 gas on the surface of the Pd electrode is almost constant (H 2 gas is almost saturated in the vicinity of the electrode). Accordingly, the potential is assumed to be determined by the pH value of the aqueous solution based on the redox potential of the H 2 |H + couple. When the pH value of the solution is almost constant, the modified Pd electrode can act as a reference electrode without any leakage of the inner electrolyte that occurs with Ag|AgCl|sat. KCl electrodes.

Analytical Sciences, 2019

An automatic management system for nutrient solutions was constructed using a programmable logic ... more An automatic management system for nutrient solutions was constructed using a programmable logic controller (PLC) and a K +-ion selective electrode (K +-ISE). The concentration of K + was monitored by the K +-ISE. When the concentration of K + fell to the threshold limit, an appropriate amount of a concentrated K + solution was added to the hydroponic solution. The volume was also maintained at a constant level by addition of water. This system can be constructed simply and inexpensively without any computers and pumps.

Journal of the agricultural chemical society of Japan, 1992

ACS Catalysis, 2017

A high power mediated electron transfer-type formate (HCOO −)/dioxygen (O 2) biofuel cell is repo... more A high power mediated electron transfer-type formate (HCOO −)/dioxygen (O 2) biofuel cell is reported herein. The cell utilizes a Ketjen Black-modified waterproof carbon cloth as the electrode material. The bioanode comprises tungsten-containing formate dehydrogenase and a viologen-functionalized polymer, whereas the biocathode comprises bilirubin oxidase and 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonate). In addition, a gas-diffusion-type system was employed for the biocathode to realize high speed O 2 supply. These electrodes exhibited a large current density of 20 mA cm −2 in the quiescent steady state for both HCOO − oxidation and O 2 reduction. Finally, these electrodes were coupled to construct an HCOO − /O 2 biofuel cell without a separator. The Page 1 of 25 ACS Paragon Plus Environment ACS Catalysis 2 cell exhibited a maximum power density of 12 mW cm −2 at a cell voltage of 0.78 V under quiescent conditions and an open-circuit voltage of 1.2 V. We show the great potential of HCOO − for the fuel of biofuel cells.

Analytical sciences : the international journal of the Japan Society for Analytical Chemistry, 2016

Ion transport through a single channel of gramicidin A (GA) within the bilayer lipid membrane (BL... more Ion transport through a single channel of gramicidin A (GA) within the bilayer lipid membrane (BLM) between two aqueous phases (W1 and W2) has been analyzed based on the electroneutrality principle. The single-channel current increases in proportion to the magnitude of the applied membrane potential and is also dependent on the permeability coefficients of electrolyte ions (K(+) and Cl(-)). By varying the ratio of the concentration of KCl in W1 to that in W2, the ratio of the diffusion coefficient of K(+) in the BLM to that of Cl(-) in the BLM can be evaluated.

Review of Polarography, 2012

Review of Polarography, 2014

Agricultural and Biological Chemistry, 1984

A polarographic method based on the Brdicka current (the polarographic catalytic hydrogen evoluti... more A polarographic method based on the Brdicka current (the polarographic catalytic hydrogen evolution current produced by proteins in the presence of cobalt salts) was applied to direct titration of subtilisin BPN' (S.BPN') with plasminostreptin (PS) at a concentration level of IO-8 M. The first and second dissociation constants of the S.BPN'-PS complex were determined by fitting theoretical curves to the titration data, in which the multiple equilibria involving microscopically distinct forms of S.BPN'-PS complex were taken into account. The intrinsic free energy change in the first binding of S.BPN' to dimeric PS was larger than that in the second binding. The dependence of the microscopic dissociation constants of S.BPN'-PS complex on pH indicates the participation of ionizable groups of pK. 8.0 and 9.4 in the complex formation. The repUlsive effect between negatively charged molecules of S.BPN' and PS in the complex formation at elevated pH is suggested.

Review of Polarography, 2011

Phytochemistry, 2012

Abscisic acid (ABA, 1), a plant hormone, has electrophilicity derived almost entirely from the si... more Abscisic acid (ABA, 1), a plant hormone, has electrophilicity derived almost entirely from the side chain, 3-methylpenta-2,4-dienoic acid. We have investigated the electrochemical property of ABA by analysis of its cathodic reaction. ABA methyl ester (1-Me) was reduced at a peak potential of-1.6 V to give a unique and unstable bicyclic compound (5-Me) as a major product at pH 3 and 7. This finding showed that an electron was absorbed in the conjugated dienecarboxyl group, and that C-5 with a high electron density was bound to C-2' through an intramolecular nucleophilic addition. At pH 10, in addition to 5-Me, a compound 4-Me was formed by isomerization of 5-Me under an alkaline condition. For a cathodic reaction of ABA at pH 3 and 7, compound 5 was a major product as well as in the case of ABA methyl ester. However, at pH 10, a dimer (6) with an epoxy group, 1'-deoxy-ABA (7) and other compounds were formed instead of compounds 4 and 5. Compounds 4 and 5 were biologically inactive, suggesting the importance of the electrophilic side chain of ABA for the biological activity.

Journal of Biological Chemistry, 2003

DsbB is an Escherichia coli plasma membrane protein that reoxidizes the Cys 30-Pro-His-Cys 33 act... more DsbB is an Escherichia coli plasma membrane protein that reoxidizes the Cys 30-Pro-His-Cys 33 active site of DsbA, the primary dithiol oxidant in the periplasm. Here we describe a novel activity of DsbB to induce an electronic transition of the bound ubiquinone molecule. This transition was characterized by a striking emergence of an absorbance peak at 500 nm giving rise to a visible pink color. The ubiquinone red-shift was observed stably for the DsbA(C33S)-DsbB complex as well as transiently by stopped flow rapid scanning spectroscopy during the reaction between wild-type DsbA and DsbB. Mutation and reconstitution experiments established that the unpaired Cys at position 44 of DsbB is primarily responsible for the chromogenic transition of ubiquinone, and this property correlates with the functional arrangement of amino acid residues in the neighborhood of Cys 44. We propose that the Cys 44-induced anomaly in ubiquinone represents its activated state, which drives the DsbB-mediated electron transfer.