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K Sogawa

Publications and source records attributed to K Sogawa.

135 records · Page 8Linked to original sources
PubMed1981

Comparison of some characteristics of membrane-bound neutral proteinase activity in the microsomal fractions of rat kidney and small intestine.

Some characteristics of the membrane-bound neutral proteinase activity in the microsomal fractions of rat kidney and small intestine were compared, using heat-denatured casein as a substrate. The proteinases of both kidney and small intestine showed maximal activity between pH 8.0 and 8.5, and were strongly inhibited by EDTA, o-phenanthroline, p-chloromercuriphenyl sulfonate, dithiothreitol, and chymostatin. Phosphoramidon and other reagents tested, including deoxycholate and bestatin, which strongly inhibited the contaminating aminopeptidase activity, were without marked effect on the neutral proteinase activity. Among urea-denatured proteins tested as substrates, casein, histone, and hemoglobin were hydrolyzed rapidly by both proteinase preparations. Fibrinogen was a good substrate for the kidney enzyme whereas it was not hydrolyzed well by the small intestine proteinase. On the other hand, serum albumin was hydrolyzed well by the small intestine proteinase, but not by the kidney proteinase. These results indicate that the neutral proteinase activity of the microsomal membrane fractions is largely due to metalloproteinases, which are quite similar, but not identical, in the kidney and small intestine.

Animals↗
PubMed1981

[Comparative study on cytotoxicity of main components of three luting cements in vitro (author's transl)].

In order to elucidate cytotoxicity of main components of glass ionomer, polycarboxylate and zinc phosphate cements, cell culture method was utilized. Criteria of cellular responses were made on the basis of cell growth and changes in cell morphology. The results obtained were as follows: 1. SiO2, AlF3, Al2O3, Ca3(PO4)2 and NaAlF6 of powder components in glass ionomer cement did not yield any unfavourable effects on either cell growth nor morphology. On the other hand, AlPO4 yielded moderate cytotoxic reaction and CaF2 marked reaction. 2. ZnO and MgO of powder components in polycarboxylate and zinc phosphate cements yielded marked cytotoxic reaction. Moreover, CaO of zinc phosphate cement brought very marked cytotoxic reaction. On the other hand, SiO2 and Bi2O3 did not yield any unfavourable effects on either cell growth nor morphology. 3. All the liquids of three cements brought cytotoxic reaction ranging from marked to very marked levels. The present results seemed to reveal that mild cytotoxic reaction of glass ionomer cement, which had been reported, was due to inclusion of less cytotoxic components compared to polycarboxylate or zinc phosphate cements. It was also discussed the relationship between biocompatibility of the cements and dissolution of the components. It is considered that the present results could shed a light on biocompatibility of dental cements.

Animals↗
PubMed1979

A neutral proteinase of monkey liver microsomes. Solubilization, partial purification, and properties.

Conditions for the solubilization of membrane-bound neutral proteinase associated with monkey liver microsomes were investigated. Among the reagents tested, deoxycholate, cholate, and some nonionic detergents, including Triton X-100, with hydrophilic-lipophilic balance values of around 13, were effective. The solubilization profile indicated that the enzyme is bound to the microsomal membranes by strong hydrophobic interaction. The enzyme was partially purified from monkey liver microsomal fraction, previously washed with 1 M KCl and 0.05% sodium dodecyl sulfate, by Triton X-100 extraction, followed by chromatography on columns of hydroxylapatite and Sepharose CL-6B. The apparent molecular weight of the enzyme was estimated to be about 88,000 from the elution position on Sepharose CL-6B column chromatography in the presence of 0.5% sodium cholate. It was optimally active at pH 8.0 with heat-denatured casein as a substrate. It was strongly inhibited by diisopropyl phosphorofluoridate and phenylmethanesulfonyl fluoride, indicating that the enzyme is a serine proteinase. EDTA, EGTA, and chymostatin also inhibited the enzyme strongly. Among urea-denatured protein substrates tested, calf thymus histone was hydrolyzed most rapidly, followed by casein, hemoglobin, and bovine serum albumin, whereas practically no hydrolysis occurred with denatured ovalbumin, fibrinogen, and gamma-globulin as substrates.

Aminopeptidases↗
PubMed1979

[Solubility of metallic mercury into the solutions containing various amino acids (author's transl)].

The solubility of metallic mercury in water containing various amino acids were investigated with flameless atomic absorption spectrometry. The following results were obtained; 1. Metallic mercury dissolved into aqueous solutions of various amino acids. It was found that solubility was dependent on kind and concentration of the amino acids. The amino acid with SH radicals, i.e., L-cysteine HCl, in particular, remarkably accelerated solubility. 2. The pH value gave large effects on solubility of metallic mercury. The least solubility was observed at neutral range. Solubility was, however, increased above or below the neutral range. 3. The solubility was greater in Hanks' balanced salt solution than in distilled water. The present results confirmed that solubility of metallic mercury in various solutions was largely dependent on the presence of amino acids, in particular, those which contained SH radicals, change of pH and presence of various salts.

Amino Acids↗
PubMed1978

Use of fluorescamine-labeled casein as a substrate for assay of proteinases.

Conditions have been investigated for the use of fluorescamine-labeled casein as a substrate for fluorometric assay of proteinases. Fluorescamine-labeled casein can be prepared simply by mixing solutions of casein and fluorescamine at pH 8.0 and used without removal of the excess reagent or its hydrolysis product. The fluorescence of the labeled casein and its enzymatic digest is moderately stable in the range of pH 7.0 to 10.0. Activities can be determined by measuring the fluorescence of the hydrolysis products soluble in 0.1 M trichloro acetic acid solution at pH 4.0 after adjusting the pH of the acid-soluble fraction to 7.7. This method is suited for assay of proteinases active at neutral to slightly alkaline pH values, and is capable of quantitating about 0.05 microgram of trypsin or 0.5 microgram of alpha-chymotrypsin or papain. The assay can be done in the presence of large amounts of contaminating amino acid, protein and/or exopeptidases which may interfere with the ordinary assay of proteinases.

Caseins↗
PubMed1977

The structure and function of acid proteases. VII. Distribution and some properties of acid proteases in monkey tissues.

1. The distribution of acid protease activity in various tissues of Japanese monkey (Macaca fuscata fuscata) was investigated with hemoglobin as a substrate at pH 3.0. The activity per protein weight in crude extracts was highest in spleen and lung, and decreased in the order: spleen, lung greater than kidney, testis greater than brain greater than liver, placenta greater than thyroid gland, muscle. The activity in crude muscle extract was about one-tenth those of spleen and lung. The activity per wet tissue weight was in roughly the same order except for a lower activity per wet weight of brain. 2. Upon chromatography of each crude extract on a Sephadex G-100 column, one major activity peak was eluted at a position corresponding to a molecular weight of about 41,000. This enzyme activity is attributed to cathepsin D [EC 3.4.23.5]. In addition, a minor activity peak was eluted in the case of spleen, lung and kidney at the break-through position, corresponding to a molecular weight of more than 100,000. This activity peak is presumably due to cathepsin E. These acid protease activities were, in most cases, strongly inhibited by pepstatin, an acid protease-specific peptide inhibitor. 3. The distribution of acid protease activity was investigated in the brain of crab-eating monkey (Macaca fascicularis). The activity was fairly evenly distributed among several regions of the brain, and its distribution was similar to those of other acid hydrolases, especially N-acetyl-beta-D-glucosaminidase [EC 3.2.1.30] and acid phosphatase [EC 3.1.3.2], which are marker enzymes of lysosomes.

Acetylglucosaminidase↗
PubMed1976

A novel neutral protease(s) from monkey liver.

A novel neutral protease(s), which is presumably membrane-bound, was found in monkey liver using heat-denatured casein as a substrate and was separated from other major catheptic proteases by successive procedures of gel filtration on Ultrogel AcA 22, solubilization by deoxycholate and gel filtration on Sepharose 6B. The enzyme(s) showed maximal activity at pH 8.0, and was strongly inhibited by DFP and PMSF. Many other reagents tested, including TPCK, TLCK, pCMB, iodoacetic acid, and EDTA, were without marked effect on the activity. Activation of the enzyme(s) by NaCl was not observed.

Animals↗