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H Watari

Publications and source records attributed to H Watari.

At least 127 records · Page 7Linked to original sources
PubMed1982

Thermodynamic characterization of hog kidney D-amino acid oxidase apoenzyme in concentrated guanidine hydrochloride solution. Preferential interaction with the solvent components and the molecular weight of the monomeric unit.

This paper describes the physical characterization of the monomeric unit of hog kidney D-amino acid oxidase apoenzyme in 6 M guanidine hydrochloride (GuHCl) solution by means of differential refractometry, densimetry, light scattering, equilibrium sedimentation, and high-speed gel filtration chromatography. In 6 M GuHCl solution, the oxidase interacts preferentially with GuHCl: the values of the preferential interaction parameter are 0.11 +/- 0.03 (S.D.) g/g of protein by densimetry and 0.14 +/- 0.04 g/g of protein by refractometry. The volume change, delta V, of the oxidase on transfer from the native to the denatured state is -350 ml/mol. The molecular weight of the monomeric apoenzyme is 39,600 +/- 1,700 by light scattering and 38,000 +/- 1,200 by high-speed equilibrium sedimentation. The values of the molecular weight estimated by the empirical methods, i.e., sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis and high-speed gel filtration chromatography in 6 M GuHCl, agree well with those obtained by the thermodynamic methods mentioned above. These results confirm definitely that the complex of the apoenzyme with SDS normally behaves in the same manner as those of standard proteins in SDS-gel electrophoresis. This is also supported in this study by the analysis of the electrophoretic data at several gel concentrations by Ferguson plots. The molecular weight of quasi-D-amino acid oxidase apoenzyme was also examined by the empirical methods.

Animals↗
PubMed1982

A study of the deformability of red blood cells of a teleost fish, the yellowtail (Seriola quinqueradiata), and a comparison with human erythrocytes.

The blood of a carangid fish, the yellowtail (Seriola quinqueradiata) has been studied with particular reference to the deformability properties of the red blood cells. The rate at which blood flows through a Nuclepore filter containing 5 micrometers pores has been determined under the same conditions that have been used with human blood. Marked differences were found in the flow of yellowtail blood which depended on the particular way in which the blood had been sampled. Such differences seem to be due to a sensitivity of fish red blood cells to their environmental conditions. Blood flow through filters is temperature-dependent, the rate increasing with a rise in temperature. Measurements made at 37 degrees C gave values which were similar to those normally obtained for human red blood cells, in spite of their greater dimensions (10.4 x 6.8 x 3.4 micrometers), and nucleated nature. It was also found that the blood flow rate of human blood was slower than that of yellowtail blood when measured at the normal environmental temperatures (15 degrees C) for these fish.

Animals↗
PubMed1981

Resonance Raman study of D-amino acid oxidase-inhibitor complexes.

The resonance Raman (RR) spectra of the complexes of D-amino acid oxidase (DAO) with benzoate derivatives were measured. The RR spectra of complexes of DAO with benzoate derivatives excited at 514.5 nm are similar to one another and also similar to that of oxidized flavin. In the cases of DAO-o-NH2-benzoate and DAO-o-OH-benzoate complexes, however, the line at 568 or 565 cm-1, derived from the benzoate derivative, was intensified. In the case of DAO-o-NH2-benzoate complex, which has an intense charge-transfer absorption band, the resonance enhancement of the Raman lines at 1583 and 568 cm-1 in the RR spectrum excited at 632.8 nm is striking. The former line is known to involve the vibrational displacements of the N(5) and C(4a) atoms of isoalloxazine and the latter is considered to be derived from a ring deformation mode of o-NH2-benzoate. This suggests that the o-NH2-benzoate molecule lies along the N(5)-C(4a) bond and parallel to the flavin face. A Raman line derived from o-OH-benzoate in the RR spectrum of DAO-o-OH-benzoate complex excited at 514.5 nm was detected. This result supports the view that the complex has a charge-transfer band, as has been pointed out by Massey and Ganther. Also, the spectrum of quasi-DAO-o-OH-benzoate complex is identical with that of the complex of DAO, suggesting that the active sites of these two enzymes have similar structures.

Aminobenzoates↗
PubMed1980

A study of the absorption, circular dichroism and magnetic circular dichroism spectra of a flavin derivative. The pi-electronic structure of 8-amino-8-demethyl-D-riboflavin.

The absorption, CD and MCD spectra of 8-amino-8-demethyl-D-riboflavin, which showed novel spectral properties, were measured in the spectral region from 220 nm to 540 nm and the spectra obtained were analyzed in terms of Gaussian wave number curves (from band I to band X). Semi-empirical calculations of the Pariser-Parr-Pople Hamiltonian were performed to investigate the novel spectral properties and the reactivity at the 5-position. The theoretical results as well as the experimental results showed that the novel spectral properties were a result of amino substitution at the 8-position.

Chemical Phenomena↗
PubMed1980

31P nuclear magnetic resonance study on perfused brain slices of guinea pig.

31P-NMR measurements of brain slices of guinea pig were successfully carried out for the first time with a new perfusion and spinning technique. The 31P-NMR spectrum showed resonance lines of phosphocreatine, fructose-6-phosphate, ATP, and inorganic phosphate. In the time course of the 31P-NMR spectra, the concentrations of phosphocreatine and fructose-6-phosphate, which were estimated from the initial spectrum, were 4.3 and 1.1 mumol/g of fresh tissue, respectively, and the estimates from the following ones showed that the concentration of phosphocreatine decreased to 2.7 mumol/g of fresh tissue while that of fructose-6-phosphate did not change significantly throughout the measurements.

Adenosine Triphosphate↗
PubMed1980

Studies on the reaction of D-amino acid oxidase with beta-cyano-D-alanine. Observation of an intermediary stable charge transfer complex.

The reaction of D-amino acid oxidase [EC 1.4.3.3] (DAO) from porcine kidney with beta-cyano-D-alanine (D-BCNA) was studied. DAO was found to catalyze elimination of the cyano group as well as oxidation of D-BCNA. During the course of the reaction in the presence of excess oxygen, an intermediate was observed which exhibited a characteristic absorption spectrum with a broad charge transfer band in the longer wavelength region. The CD spectrum of this intermediate resembles that of DAO-anthranilate complex. The rate of oxygen consumption in the aerobic reaction decreased with time, suggesting product inhibition due to complex formation between the enzyme and the product. Anaerobic addition of D-BCNA reduced the enzyme to its fully reduced state, the CD spectrum of which closely resembles that of the enzyme reduced by excess D-alanine. When an appropriate amount of D-BCNA was added to the enzyme under air, the charge transfer complex was observed immediately, and underwent a change to the reduced state as the oxygen was consumed. The binding strength in the charge transfer complex was found to be comparable to that in DAO-benzoate complex. The accumulating product in the oxidation of D-BCNA had a strong absorption at 285 nm. The aerobic reaction of beta-cyano-L-alanine (L-BCNA) with snake venom L-amino acid oxidase (LAO) produced the same product with an absorption at 285 nm as the reaction of DAO with D-BCNA. The product obtained in the reaction with LAO was found to form the same charge transfer complex with DAO. We tentatively identified this product as alpha-amino-beta-cyanoacrylate and the charge transfer complex as the complex of alpha-amino-alpha-cyanoacrylate with the oxidized enzyme. A hypothetical reaction pathway based on the present finding is proposed. Addition of L-BCNA to the enzyme produced an absorption spectrum very similar to that of the DAO-benzoate complex without oxidation or elimination. L-BCNA was found to be a competitive inhibitor of the oxidation of D-alanine.

Alanine↗
PubMed1980

Vibrational modes of flavin bound to riboflavin binding protein from egg white. Resonance Raman spectra of lumiflavin and 8-substituted riboflavin.

The resonance Raman (RR) spectra of 8-halogenated-riboflavin, 8-demethyl-riboflavin(8-H-RF), 8-amino-riboflavin(8-NH2-RF), 8-methoxy-riboflavin(8-OCH3-RF), lumiflavin, and 3-methyl-lumiflavin were observed. The Raman lines with the highest frequency are at 1624, 1620, and 1615 cm-1 for 8-chloro-riboflavin, 8-bromo-riboflavin, and 8-iodo-riboflavin, respectively. This systematic shift confirms that the 1631 cm-1 line of riboflavin is derived from the benzene part of isoalloxazine. Substitution at the 8-position by an amino or methoxy group, which has a large influence on the electronic structure of isoalloxazine, changes the RR spectrum markedly in comparison with that of 8-halogenated riboflavin. The 1583 cm-1 line of riboflavin, which involves the vibrational displacement of N(5) and C(4a) atoms of isoalloxazine, is shifted to the low frequency side by substitution at the 8-position with an amino or methoxy group. The corresponding line of 8-H-RF, on the contrary, shifts to the high frequency side. The RR spectrum of lumiflavin is very different from that of riboflavin in the range from 1200 to 1300 cm-1. Although the pi-electronic structure is little affected by the substitution at the 10-position, the Raman spectrum of lumiflavin in this region is very sensitive.

Binding Sites↗
PubMed1980

Resonance Raman spectra of semiquinone forms of flavins bound to riboflavin binding protein.

The resonance Raman (RR) spectra of semiquinones of complexes of riboflavin or 8-methoxyriboflavin (8-OCH3-RF) with riboflavin binding protein (RBP) were observed. The RR spectrum of neutral semiquinone of riboflavin-RBP complex in H2O solution has an intense line at 1617 cm-1, not observed for oxidized riboflavin bound to RBP. The line at 1617 cm-1 does not shift in D2O solution. The absorption spectrum of semiquinone of 8-OCH3-RF bound to RBP has maxima at 586, 396, and 344 nm, and the RR spectrum doublet lines at 1623 and 1615 cm-1. In D2O solution, the 1623 cm-1 line does not shift, but the 1615 cm-1 line shifts to 1604 cm-1. The line around 1620 cm-1 for the flavin semiquinone will be useful in the determination of the redox state of flavin.

Binding Sites↗
PubMed1980

Circular dichroism studies on flavoproteins containing covalently bound coenzymes.

Absorption and circular dichroism spectra of cholesterol oxidase from Schizophyllum commune and choline oxidase from Alcaligenes sp. were measured and compared. The prosthetic group of cholesterol oxidase is 8 alpha-[N(1)-histidyl]-FAD (1, 2), while that of choline oxidase is 8 alpha-[N(3)-histidyl]-FAD (3). In the CD spectra of the two enzymes in either the oxidized or reduced state, the corresponding bands in the visible region are of approximately the same intensity and shape but of opposite sign. A notable feature in the CD spectra of the two enzymes after light irradiation is the appearance of a CD band in the longer wavelength region (550-650 nm) and the opposite signs of the CD band in this region in the two enzymes. The similarity of the shape and intensity of the CD spectra of the two enzymes suggests that the environments surrounding the flavin moieties are very similar, and the sign reversal of the CD bands suggests that the mutual orientations between the transition moment of flavin and that of its environment differ in the two enzymes.

3-Hydroxysteroid Dehydrogenases↗
PubMed1980

[Laboratory and clinical studies on cefoperazone in pediatrics treatment (author's transl)].

Laboratory and clinical studies of cefoperazone (CPZ), a new semisynthetic cephalosporin, were investigated and following results were obtained. (1) Blood level: CPZ was given intravenous dose of 25 mg/kg and 50 mg/kg to each 3 children. In the former, the blood level of 15 minutes after injection was 194.2 mcg/ml on average and the half life was 106.2 minutes. In the latter, the blood level was 320.0 mcg/ml on average and half life was 102.2 minutes. (2) Urinary concentration: In the cases of the dose of 25 mg/kg, 35.9% of CPZ was recovered on average from the urine within 6 hours after injection, and the urinary concentration reached to 2,148.6 mcg/ml (0 approximately 2 hours). And in the cases of the dose of 50 mcg/kg, the recovery rate in urine was 43.6%, and the urinary concentration was 3,008.3 mcg/ml. (3) Cerebrospinal fluid level: CSF level was determined in a patient with bacterial meningitis by S. pneumoniae. Ninety mg/kg of CPZ were given intravenous injection. After 60 minutes CSF level was 3.35 mcg/ml, and after 80 minutes the blood level was 192.0 mcg/ml. (4) Bacteriological evaluation: Against 164 strains isolated clinical specimens, the bacteriological evaluation on CPZ was performed in comparison with cefotaxime (CTX), cefazolin (CEZ) and piperacillin (PIPC) by inoculum size of 10(8) cells/ml. CPZ showed antibacterial activity against Gram-negative bacteria almost similar to CTX and PIPC. (5) CLINICAL RESULTS: CPZ was given 48.3 approximately 360 mg/kg/day (average 146.1 mg/kg/day) by intravenous route to 46 patients with various infection. The overall efficacy rate was 80.4%. The rate of bacteriological effectiveness was 78.9% in 19 cases. (6) Side effects: As side effects, diarrhea, fever, rash, urticaria, leukopenia, eosinophilia, elevation of GOT, GPT, and LDH were observed, but not seriously.

Adolescent↗
PubMed1979

A study of flavin-protein and flavoprotein-ligand interactions. Binding aspects and spectral properties of D-amino acid oxidase and riboflavin binding protein.

To study flavin-protein and flavoprotein-ligand interaction, the absorption, CD and MCD spectra of riboflavin, FAD, roseoflavin, the complexes of riboflavin and roseoflavin with riboflavin binding protein(RBP),D-amino acid oxidase(D-AO) and its complexes with ligands were observed in the spectral region of 310-600 nm and the binding properties of D-AO with di-substituted benzoate derivatives and of RBP with roseoflavin were also measured. The dimer of D-amino acid oxidase has a higher affinity for di-substituted benzoate derivatives than the monomer. The change in the absorption of FAD in D-AO caused by the binding of the first ligand to the dimer, which can bind two ligands, was similar to that caused by the binding of the second ligand. Roseoflavin could bind to RBP in a 1 : 1 ratio and the dissociation constant was 3.8 x 10(-8)M. The protein fluorescence of RBP was quenched by about 86% due to complex formation with roseoflavin. The MCD spectra showed similar patterns for all molecular complexes of riboflavin and FAD, with two negative extrema of ellipticity which probably correspond to the Faraday B-term, but the Faraday A-term could not be observed, suggesting that there was no degeneracy in the excited state of flavins. It is also suggested, based on a comparison of the absorption, CD and MCD spectra, that the vibronic structure of flavin was modified differently by each flavin-protein or flavoprotein-ligand interaction. Comparison of the absorption, CD and MCD spectra(310-600 nm) for roseoflavin and the roseoflavin-RBP complex revealed that there were five spectral components around 320, 340, 400, 500, and 550 nm in roseoflavin.

Carrier Proteins↗