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K Horiike

Publications and source records attributed to K Horiike.

At least 37 records · Page 2Linked to original sources
PubMed1994

Identification and characterization of a new plasmid carrying genes for degradation of 2,4-dichlorophenoxyacetate from Pseudomonas cepacia CSV90.

Pseudomonas cepacia CSV90 is able to utilize 2,4-dichlorophenoxyacetate (2,4-D) and 2-methyl-4-chlorophenoxyacetate as sole sources of carbon and energy. Mutants of the strain CSV90 which had lost this ability appeared spontaneously on a nonselective medium. The wild-type strain harbored a 90-kb plasmid, pMAB1, whereas 2,4-D-negative mutants either lost the plasmid or had a 70-kb plasmid, pMAB2. The plasmid pMAB2 was found to have undergone a deletion of a 20-kb fragment of pMAB1. The plasmid-free mutants regained the ability to degrade 2,4-D after introduction of purified pMAB1 by electroporation. Cloning in Escherichia coli of a 10-kb BamHI fragment from pMAB1, the region absent in pMAB2, resulted in the expression of the gene tfdC encoding 3,5-dichlorocatechol 1,2-dioxygenase. After subcloning, the tfdC gene was located in a 1.6-kb HindIII fragment. The nucleotide sequence of the tfdC gene and the restriction map of its contiguous region are identical to those of the well-characterized 2,4-D-degradative plasmid pJP4 of Alcaligenes eutrophus, whereas the overall restriction maps of the two plasmids are different. The N-terminal 44-amino-acid sequence of the enzyme purified from the strain CSV90 confirmed the reading frame in the DNA sequence for tfdC and indicated that the initiation codon GUG is read as methionine instead of valine.

2,4-Dichlorophenoxyacetic Acid↗
PubMed1993

Purification of 3,5-dichlorocatechol 1,2-dioxygenase, a nonheme iron dioxygenase and a key enzyme in the biodegradation of a herbicide, 2,4-dichlorophenoxyacetic acid (2,4-D), from Pseudomonas cepacia CSV90.

An enzyme which cleaves the benzene ring of 3,5-dichlorocatechol has been purified to homogeneity from Pseudomonas cepacia CSV90, grown with 2,4-dichlorophenoxyacetic acid (2,4-D) as the sole carbon source. The enzyme was a nonheme ferric dioxygenase and catalyzed the intradiol cleavage of all the examined catechol derivatives, 3,5-dichlorocatechol having the highest specificity constant of 7.3 microM-1s-1 in an air-saturated buffer. No extradiol-cleaving activity was observed. Thus, the enzyme was designated as 3,5-dichlorocatechol 1,2-dioxygenase. The molecular weight of the native enzyme was ascertained to be 56,000 by light scattering method, while the M(r) value of the enzyme denatured with 6 M guanidine-HCl or sodium dodecyl sulfate was 29,000 or 31,600, respectively, suggesting that the enzyme was a homodimer. The iron content was estimated to be 0.89 mol per mole of enzyme. The enzyme was deep red and exhibited a broad absorption spectrum with a maximum at around 425 nm, which was bleached by sodium dithionite, and shifted to 515 nm upon anaerobic 3,5-dichlorocatechol binding. The catalytic constant and the Km values for 3,5-dichlorocatechol and oxygen were 34.7 s-1 and 4.4 and 652 microM, respectively, at pH 8 and 25 degrees C. Some heavy metal ions, chelating agents and sulfhydryl reagents inhibited the activity. The NH2-terminal sequence was determined up to 44 amino acid residues and compared with those of the other catechol dioxygenases previously reported.

2,4-Dichlorophenoxyacetic Acid↗
PubMed1993

Triphasic vascular effects of thiol compounds and their oxidized forms on dog coronary arteries.

The vascular effects of 2-mercaptoethanol, cysteamine, L-cysteine, glutathione (GSH), cystamine and oxidized GSH (GSSG) on the isometric tension of isolated dog coronary arterial strips were examined, and these effects were compared with the triphasic response induced by dithiothreitol (DTT); a rapid and weak contraction (phase A), an intervening slow relaxation (phase B) and a slowly-developing strong contraction (phase C) which we previously reported. The responses of the arteries induced by 2-mercaptoethanol, cysteamine and L-cysteine consisted of phases A, B and C. The order of contractile potency (ED50 of phase C) was DTT approximately L-cysteine > 2-mercaptoethanol approximately cysteamine, while the order of relaxant potency (ED50 of phase B) was DTT > cysteamine approximately 2-mercaptoethanol. GSSG and cystamine mainly produced relaxation, which corresponded to phase B. The phase C contraction was specific to the reduced forms of thiols, except for GSH, which produced only relaxation. The participation of endothelial cells was not essential for the contracting or relaxing effects of the thiol compounds. The phase C contraction was depressed by W-7, a calmodulin antagonist, while phase A was not. Therefore calmodulin-dependent protein kinases may participate in phase C, not in phase A.

Animals↗
PubMed1991

Immunochemical relationship of D-amino acid oxidases in various tissues and animals.

1. By means of an enzyme immunoassay, the contents of D-amino acid oxidase (DAO) were determined in kidney, liver, cerebellum and lung of hog, but the oxidase was not detectable in heart or cerebrum. 2. The oxidases in kidney, liver and cerebellum of hog were indistinguishable as regards immunoreactivity toward anti-hog kidney DAO antibody, specific activity and molecular weight. 3. The oxidases in rat and dog kidneys immunochemically cross-reacted with anti-hog DAO antibody. 4. The overall structure of the hog oxidase was more similar to that of the dog enzyme than that of the rat, while the structure around the catalytic site of the hog oxidase was more similar to that of the rat oxidase than that of the dog enzyme. 5. On immunoblot analysis, two forms of the oxidase were detected in extracts of hog, rat and dog kidneys.

Animals↗
PubMed1991

Urate oxidase activity and copper content in the liver of macular mutant mouse, a model animal for human congenital copper deficiency, Menkes' kinky hair disease.

The macular mouse is an X-linked recessive inherited mutant and is considered to be a model for human congenital copper deficiency, Menkes' kinky hair disease. The activity of urate oxidase, which has been believed to be a copper enzyme, and copper content in the liver of the mutant mouse were determined. The oxidase activity was maintained at normal level even though there was very low level of copper present in the liver through days 7 to 14. Copper administration increased the copper content in the liver to the normal level, but did not affect the oxidase activity.

Animals↗
PubMed1990

Three isozymes of catechol 1,2-dioxygenase (pyrocatechase), alpha alpha, alpha beta, and beta beta, from Pseudomonas arvilla C-1.

Three isozymes of catechol 1,2-dioxygenase (pyrocatechase) from Pseudomonas arvilla C-1 were separated using DEAE-Toyopearl chromatography. The specific activities of each isozyme were similar to one another. The molecular weights of isozymes 1, 2, and 3 were estimated to be approximately 67,000, 64,000, and 59,000, respectively, from gel filtration. On sodium dodecyl sulfate-polyacrylamide gel electrophoresis, isozymes 1 and 3 gave a single protein band, corresponding to Mr = 32,000 and 30,000, respectively, and isozyme 2 gave two bands corresponding to Mr = 32,000 and 30,000. These results indicated that isozymes 1 and 3 were homodimers, while isozyme 2 was a heterodimer. The NH2-terminal sequences up to 20 residues of these three isozymes confirmed that isozymes 1, 2, and 3 consisted of beta beta, alpha beta, and alpha alpha, respectively, based on our previous data (Nakai, C., Kagamiyama, H., Saeki, Y., and Nozaki, M. (1979) Arch. Biochem. Biophys. 195, 12-22). Properties of these isozymes such as absorption spectrum, iron content, substrate specificity, and kinetic constants were similar to one another. Subunit exchange between the different isozymes and dissociation of the isozymes into subunits was not observed under nondenaturing conditions. Available evidence indicates that these isozymes exist naturally in the bacterium and were not due to artifacts caused by purification.

Amino Acid Sequence↗
PubMed1989

A simple and sensitive determination for plasmalogen lysophosphatidylethanolamine in rabbit platelets.

Plasmalogen lysophosphatidylethanolamine (LPE) in rabbit platelets was quantitatively determined as glycero-3-phosphorylethanolamine (GPE) after treatment with 5% trichloroacetic acid at 20 degrees C for two hours. GPE was measured directly using a high performance liquid chromatography with monitoring the fluorescence of o-phthaldialdehyde/2-mercaptoethanol adducts. The assay was sensitive to 50 pmol of plasmalogen LPE and was linear over a 200-fold concentration range. While, 1-acyl LPE and phosphatidylethanolamine from bovine brain (containing about 50% plasmalogen) were hardly cleaved to GPE under the same conditions. These procedures were specific for plasmalogen LPE, and simpler and more sensitive in comparison with conventional analytical methods, e.g., two-dimensional thin layer chromatography with subsequent phosphorus assay. Employing the present method, plasmalogen LPE was found to increase rapidly and to decrease subsequently when rabbit platelets were stimulated by thrombin.

Animals↗
PubMed1989

Dithiothreitol-induced triphasic response of dog coronary arteries.

Exposure of dog coronary arterial strips to dithiothreitol resulted in a triphasic response which was characterized by an initial rapid, weak contraction (phase A), an intervening slow relaxation (phase B) and finally, a slowly developing intense contraction (phase C). No responses were observed when either oxidized dithiothreitol or threitol were used. No contractions were observed if the extracellular Ca2+ was omitted. Ca2+ channel blockers (nicardipine and diltiazem), a protein kinase inhibitor (1-(5-isoquinolinesulfonyl)-2-methylpiperazine, H-7), and a myosin light chain kinase inhibitor (1-(5-chloronaphthalene-1-sulfonyl)-1H-hexahydro-1,4-diazepine, ML-9), all suppressed the dithiothreitol-induced responses. The calmodulin antagonists, N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide (W-7) and N-(6-aminohexyl)-1-naphthalenesulfonamide (W-5), however, augmented phase A, and W-7 and chlorpromazine depressed phase C. Prolonged exposure of the arteries to dithiothreitol was essential to elicit phase C. The implications of these data are discussed with respect to the possible mechanisms of dithiothreitol-induced vascular responses.

Animals↗
PubMed1989

Kinetic studies on the inhibition mechanism of diamine oxidase from porcine kidney by aminoguanidine.

The mechanism of inhibition of diamine oxidase [DAO, histaminase, amine: oxygen oxidoreductase (deaminating) (copper-containing), EC 1.4.3.6] by aminoguanidine was studied kinetically. The DAO reaction was carried out with putrescine as a substrate in the presence of o-aminobenzaldehyde and followed by the continuous increase in A430. An enzymatic reaction product, 4-aminobutyraldehyde, was spontaneously cyclized to delta 1-pyrroline, which coupled with o-aminobenzaldehyde to give rise to a yellow quinazolinium chromophore [Holmstedt et al. (1961) Biochim. Biophys. Acta 48, 182-186]. First, to measure the initial velocities as accurately as possible, the kinetic relationship between the oxidase reaction rate and the color development rate was formulated. The reaction proceeded linearly in the absence of aminoguanidine, but slowed down time-dependently in its presence. When the color development velocities in the presence of the inhibitor were plotted against time, the plot was nonlinear and there seemed to be at least two phases of the inhibition. Nonlinear least-squares analysis of the data dA430/dt showed that the simplest model that fitted best was a model composed of two species of enzyme-inhibitor complexes: E + I k+1 in equilibrium k-1 EI k+2 in equilibrium k-2 E'I where E is the enzyme, I is aminoguanidine (an inhibitor), and the ks are the rate constants.(ABSTRACT TRUNCATED AT 250 WORDS)

Aldehydes↗
PubMed1988

Interaction of protein with a self-associating ligand. Deviation from a hyperbolic binding curve and the appearance of apparent co-operativity in the Scatchard plot.

We derived a general formula to analyze a binding system in which a ligand self-associates, in terms of experimentally determinable quantities, i.e. r, the average number of bound ligands per protein molecule, and Lft, the total free ligand concentration, which are expressed as a ligand monomer unit. The limiting behaviors of the Scatchard plot (r/Lft vs r plot), that is, the intercepts on the r-axis and the r/Lft-axis, and the limiting slopes, are generally given. Three models that may be encountered are considered in detail. Numerical examples are also presented to illustrate how the self-association of a ligand affects the binding curves. The ligand self-association alone can cause deviation of the profile of the binding curve (r vs Lft plot) from a hyperbola, resulting in a nonlinear Scatchard plot. Therefore, analysis of the binding data without consideration of ligand self-association may lead to erroneous conclusions as to the numbers and classes of binding sites, co-operativity among the sites and binding parameter values.

Allosteric Regulation↗
PubMed1988

A simple purification method for a glucosyltransferase complex from Streptococcus mutans OMZ 176 with a high yield.

1. Glucosyltransferase was purified from Streptococcus mutans OMZ 176 by ammonium sulfate fractionation and gel filtration. 2. The overall purification was about 15,000-fold with a yield of 53%. 3. The purified enzyme appeared to be a multienzyme complex consisting of three different components with molecular weights of 158,000, 153,000 and 149,000, respectively.

Ammonium Sulfate↗
PubMed1988

Immediate hypersensitivity skin reactions to human dander in atopic dermatitis. Partial purification and characterization of human dander allergens.

Using high-speed gel filtration chromatography, an aqueous extract of human dander was divided into four fractions (fractions I to IV). Scratch tests with the crude human dander extract and each fraction were performed in 147 patients with atopic dermatitis and 100 control subjects. The crude extract provoked positive reactions in 61.9% (91/147) of patients with atopic dermatitis and 6% (6/100) of control subjects. The most potent allergenic component was present in fraction II, which induced positive reactions in 61.2% (90/147) of patients with atopic dermatitis. Sodium dodecyl sulfate polyacrylamide gel electrophoresis analysis demonstrated that fraction II contained two proteins with molecular weights of 10,000 and 13,000, respectively.

Adolescent↗
PubMed1987

Localization of D-amino acid oxidase in Bergmann glial cells and astrocytes of rat cerebellum.

The localization of D-amino acid oxidase in rat cerebellum was systematically studied in serial fixed sections at the levels of both light and electron microscopy using a coupled peroxidation method based on the intensifying effect of nickel ions. Deposits were only seen in astrocytes and Bergmann glial cells, and not in neuronal components, endothelial cells or ependymal cells. In the molecular layer, heavy deposits were present in the profiles of Bergmann glial processes around the complexes of synapses where the parallel fiber varicosities form synapses with the thorns emerging from the spiny branchlets of Purkinje cell dendrites. In the Purkinje cell layer, the oxidase-containing processes of Bergmann glial cells enveloped basket cell axons, their terminals, the terminals of the recurrent collaterals of Purkinje cell axons and Purkinje cell bodies. In the granular layer, the cerebellar glomeruli were enveloped by the heavily stained processes of astrocytes. Based on this characteristic localization of the oxidase, we discussed the physiological role of the oxidase in connection with the function of glial cells.

Animals↗
PubMed1985

Self-association mode of a flavoenzyme D-amino acid oxidase from hog kidney. I. Analysis of apparent weight-average molecular weight data for the apoenzyme in terms of models.

The self-association of D-amino acid oxidase apoenzyme in 0.1 M sodium pyrophosphate, pH 8.3, at 25 degrees C was studied by low-angle laser light scattering. The concentration (c) dependence of the apparent weight-average molecular weight (Mwapp) was determined over a wide concentration range of 0.04 to 6.1 mg/ml. The extrapolated Mwapp value, to zero enzyme concentration, corresponded to the Mr value of the monomer. The self-association mode of the apoenzyme was systematically explored with nonlinear least-squares analysis of the Mwapp versus c data. The simplest model that fitted the data well was a model of isodesmic indefinite self-association of the monomer with the isodesmic association constant of 0.467 +/- 0.034 liter/g. The monomer-dimer model proposed previously, but only in a low enzyme concentration range of less than 0.9 mg/ml at 5-20 degrees C (Henn, S. W., and Ackers, G. K. (1969) Biochemistry 8, 3829-3838), did not fit the Mwapp versus c data either in the limited low concentration range or in the whole concentration range examined at 25 degrees C. To test the validity of the chosen model, the observed sedimentation boundary profiles were compared with the idealized boundary profiles calculated for the better-fit models. The profile calculated with the model of the isodesmic indefinite self-association mechanism was qualitatively consistent with the observed ones. The utility of the nonlinear least-squares procedure for analyzing self-associating systems was demonstrated.

Animals↗
PubMed1985

Self-association mode of a flavoenzyme D-amino acid oxidase from hog kidney. II. Stoichiometry of holoenzyme association and energetics of subunit association.

The self-association pattern of D-amino acid oxidase holoenzyme in 0.1 M sodium pyrophosphate, pH 8.3, at 25 degrees C was examined by the low-angle laser light-scattering method. As to the results of nonlinear least-squares analysis of the apparent weight-average molecular weight (Mwapp) versus protein concentration (c) data, the following three models fitted equally well the data over the concentration range of 0.03-11.4 mg/ml: 1) the model of isodesmic indefinite self-association of the monomer where the dimerization constant differs from the isodesmic association constant, 2) the model which involves the dimerization of the monomer and isodesmic indefinite self-association of the dimer, and 3) the model which involves the trimerization of the monomer and isodesmic indefinite self-association of the trimer. In a more limited concentration range (0.3-11.4 mg/ml), a model of isodesmic indefinite self-association of the stable dimer where the dimer does not dissociate into the monomers cannot be excluded from the above three models. Measurements with the concentration range lowered to 0.03 mg/ml enabled us to exclude unequivocally the model involving such a stable dimer and to extrapolate the Mwapp data to the Mr of the monomer at infinite dilution as in the case of the apoenzyme. The observed sedimentation boundary profiles were qualitatively consistent with the idealized boundary profiles calculated with the model which involves the dimerization of the monomer and isodesmic indefinite self-association of the dimer, so this model is the most probable of the models examined. These results provide the first evidence that the association mode of the holoenzyme is different from that of the apoenzyme, i.e. isodesmic indefinite self-association of the monomer (Tojo, H., Horiike, K., Shiga, K., Nishina, Y., Watari, H., and Yamano, T. (1985) J. Biol. Chem. 260, 12607-12614). The overall linkage scheme, between binding of coenzyme FAD and subunit association, was considered, and the overall free energy change in each process in the scheme was calculated. The total stabilization energies of the intersubunit interaction in the holoenzyme relative to the apoenzyme were found to be -2.2 kcal/mol at the dimerization step and -0.5 kcal/mol at the step of the addition of the dimer to any 2i-mer (i = 1,2, ...).

Animals↗
PubMed1985

Kinetic properties of rat kidney D-amino acid oxidase associated with peroxisomes.

In contrast to hog kidney D-amino acid oxidase, the v vs s plots of D-amino acid oxidase in homogenized rat kidney did not have the form of a rectangular hyperbola, and showed an apparent negative cooperativity. After subcellular fractionation of rat kidney, both of the oxidases in the supernatant fraction and the peroxisomal fraction showed Michaelis-Menten type kinetics. The Km values for D-alanine and D-proline of the peroxisomal fraction were significantly lower than those of the supernatant fraction. The partially purified enzyme from the peroxisomal fraction showed the same kinetic properties as the supernatant fraction. These facts suggest that the two types of rat kidney D-amino acid oxidase were originally identical and that some interaction between the enzyme and peroxisomes is physiologically important for the function of the enzyme.

Alanine↗