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K Shimura

Publications and source records attributed to K Shimura.

At least 55 records · Page 3Linked to original sources
PubMed1990

Detection of the schizont stage in experimentally infected cattle with Japanese Theileria sergenti.

Calves infected with a sporozoite suspension of the Ikeda strain of Theileria sergenti were examined in attempts to detect the schizont stage. A suspension equivalent to the contents of 70-200 ticks was inoculated subcutaneously into 10 splenectomized calves. Schizonts and micromerozoites were found in the prescapular lymph nodes of 5 calves about 8 days after the sporozoite inoculation. Schizonts detected at the time of nuclear division had large and diffuse nuclei, and many of the schizonts were very large and extracellular in lymph node smears. The schizonts were also detected by the direct fluorescent antibody staining.

Animals↗
PubMed1989

Primary structure of the silk fibroin light chain determined by cDNA sequencing and peptide analysis.

A cDNA clone, pFL18, carrying a putative full-length fibroin light chain (L-chain) sequence was isolated and its nucleotide sequence was determined. This revealed the presence of an open reading frame corresponding to a polypeptide with 262 amino acid residues. The sequence was concluded to be that of the L-chain with its signal peptide because corresponding amino acid sequences for the seven tryptic and the four chymotryptic peptides from the purified L-chain were all included and an N-terminal region having typical properties of a signal peptide was present. The N terminus of the mature form of L-chain was identified as N-acetyl serine by analyzing the acyl-dansylhydrazide derived from the N-acyl-amino acid which had been released from the N-terminal blocked chymotryptic peptide by the acylamino acid-releasing enzyme. It was suggested that a signal peptide had cleaved between Pro18 and Ser19, yielding a mature L-chain polypeptide consisting of 244 amino acid residues. The molecular weight of the L-chain was calculated to be 25,800 including the N-acetyl group. The L-chain contained three Cys residues, two of which were suggested to form an intramolecular disulfide linkage, leaving the third one at the most C-terminal position and in a relatively hydrophilic region as the most probable site of disulfide linkage with the fibroin heavy chain.

Amidohydrolases↗
PubMed1989

Preparation of adsorbents for affinity chromatography using TSKgel Tresyl-Toyopearl 650M.

The optimum conditions for the coupling of proteins were investigated using TSKgel Tresyl-Toyopearl 650M. They were dependent on the proteins coupled. For example, when soybean trypsin inhibitor was coupled at pH 8 the coupling was completed within 1 h and the subsequent adsorption capacity for trypsin was maximal. Longer coupling times decreased the adsorption capacity due to multi-point attachment. The adsorbents obtained were successfully used for affinity chromatography in a short time.

Adsorption↗
PubMed1989

Influence of a soluble anionic polymer on the electrophoresis of proteins.

The influence of a soluble anionic polymer on electrophoresis of proteins was studied in relation to the nonspecific ionic effect of an affinophore on application to affinophoresis. Zone electrophoresis of proteins was carried out in agarose gel in the presence of succinyl-poly-L-lysine (degree of polymerization, 120) by using three electrophoresis buffers differing in ionic strength (0.06, 0.12 and 0.18) and pH (7.0 and 7.9). Proteins migrated as distinct single bands even in the presence of the polymer. The mobility of cationic proteins towards the cathode was first decreased and then increased towards the anode as the polymer concentration increased, while that of anionic proteins was not affected. The dependence of the apparent mobility changes of the proteins on the concentration of the polymer was treated quantitatively in the same way as affinity electrophoresis. The extent of the ionic interaction between a cationic protein and the polymer could be estimated as an apparent dissociation constant. It greatly depended on the ionic strength of the electrophoresis buffer. Except for the extremely cationic proteins such as lysozyme, the ionic interaction with up to 0.1 mM of the polymer could be practically suppressed by the use of 0.1 M sodium phosphate buffer (pH 7.0).

Anions↗
PubMed1989

Affinophoresis of red blood cells: surface antigen-specific acceleration of electrophoresis.

A method employing the technique of affinophoresis to increase the electrophoretic mobility of specific cells according to their surface antigens was developed. Red blood cells were treated consecutively with the maximum subagglutinating dose of an anti-red blood cell serum, a biotinylated second antibody, avidin and finally with a negatively charged biotin-affinophore which was prepared by coupling biotin to polylysine (average degree of polymerization, 270 or 1150), followed by complete succinylation. The electrophoretic mobility of cells was analyzed with an automatic cell electrophoresis analyzer. The use of a homologous anti-serum increased the electrophoretic mobility of rabbit, human and rat blood cells by 2.9, 1.7 and 1.6 times, respectively. A larger affinophore containing fewer biotin moieties was more effective. In the case of a mixture of red blood cells from two species, cells from only one species could be accelerated by using homologous antiserum, e.g., affinophoresis of a mixture of human and rat red blood cells by using either homologous antiserum gave two separate peaks on the histogram, whereas a single peak would be obtained in usual electrophoresis because there is little difference in the original migration velocities of the two cell types.

Agglutination↗
PubMed1989

A gamma methionine-310 to threonine substitution and consequent N-glycosylation at gamma asparagine-308 identified in a congenital dysfibrinogenemia associated with posttraumatic bleeding, fibrinogen Asahi.

In an abnormal fibrinogen with severely impaired polymerization of fibrin monomers, we identified a methionine-to-threonine substitution at position 310 of the gamma chain. Furthermore, asparagine at position 308 was found to be N-glycosylated due to a newly formed consensus sequence, asparagine(308)-glycine(309)-threonine(310). The two structural defects in the mutant gamma chain may well perturb the conformation required for fibrin monomer polymerization that is specifically assigned to the D domain of fibrinogen. This alteration also seems to affect the intermolecular gamma chain cross-linking of fibrin and fibrinogen, although the amine acceptor gamma glutamine-398 was found to function normally. These functional abnormalities may well be related to posttraumatic hemorrhage as observed in a 33-yr-old man with moderate hemorrhagic diathesis related to injuries since his early adolescence. The structure of the extra carbohydrate moiety attached to asparagine-308 was found to be identical with those derived from the normal B beta and gamma chains as evidenced by HPLC.

Adult↗
PubMed1989

Enhancing effect of antitumor polysaccharide from Astragalus or Radix hedysarum on C3 cleavage production of macrophages in mice.

Effects of Astragalus polysaccharide (APS) and Radix hedysari polysaccharide (RHPS) on the third component of complement (C3) cleavage production of macrophages in ICR mouse were investigated by the immunofluorescent method. By two hours after intraperitoneal injection of 500 mg/kg of APS or RHPS, there was an obvious increase in the deposition of C3 on peritoneal macrophages. When APS or RHPS was injected 5 times (1 time/day), the proportion of C3 positive macrophages was more than that of 1-time injection. At the same time, the number of peritoneal macrophages also increased. Since C3 cleavage product occurred with the activation of C3, the results suggest that the immuno-potentiating action of APS and RHPS may be related to the activity of mouse complement C3.

Animals↗
PubMed1989

In vitro and in vivo interferon production in NOD mice.

The production of interferon-alpha/beta (INF-alpha/beta) and interferon gamma (IFN-gamma) in NOD and ICR mice was studied in vitro and in vivo. The in vitro IFN-alpha/beta production in the spleen cells of NOD mice, which were stimulated with either Newcastle disease virus (NDV), Sendai virus, poly(I:C) or lipopolysaccharide (LPS), was very similar to the IFN-alpha/beta production in the spleen cells of ICR mice. Contrastingly, the in vitro IFN-gamma production in the spleen cells of NOD mice, which were stimulated with either concanavalin A (Con A), phytohemagglutinin (PHA) or pokeweed mitogen (PWM), was greater than the IFN-gamma production in spleen cells of ICR mice. The in vivo IFN-alpha/beta production in NOD mice induced by NDV was also very similar to that in ICR mice, whereas the in vivo IFN-gamma production in the BCG-sensitized NOD mice, which was induced by purified protein derivative (PPD), was greater than that in the ICR mice. These results may indicate that NOD mice have abnormalities on the IFN-gamma production.

Animals↗
PubMed1988

Further evidence for the presence of a thiazoline ring in the isoleucylcysteine dipeptide intermediate in bacitracin biosynthesis.

Isoleucylcysteine dipeptide, a first intermediate peptide in bacitracin biosynthesis, was liberated from the enzyme protein and oxidized with manganese dioxide in dimethylsulfoxide. The resulting oxidation product was identified by thin-layer chromatography as 2-(2-methyl-l-oxobutyl)-thiazole-4-carboxylic acid which has been isolated from the hydrolysate of bacitracin F. This result shows that the intermediate dipeptide contains a thiazoline ring, and that the thiazoline ring is synthesized at the dipeptide stage in the process of peptide chain elongation in bacitracin biosynthesis. Improbability of non-enzymatic dehydrative cyclization of the dipeptide is discussed.

Bacitracin↗
PubMed1988

Immobilized anhydrochymotrypsin as a biospecific affinity adsorbent for the peptides produced by chymotryptic hydrolysis.

Anhydrochymotrypsin immobilized on Sepharose specifically adsorbed various peptides containing L-tryptophan, L-tyrosine, or L-phenylalanine residues at their carboxy-termini. These peptides correspond to the specific products of chymotryptic cleavage of polypeptides. A mixture of the chymotryptic peptides once adsorbed on the column could be effectively separated by eluting them with a pH gradient. This adsorbent, on the other hand, showed no substantial affinity toward the substrate-type peptides that contain the aromatic amino acid(s) within the peptide chain, or toward the C-terminal leucine peptides. By taking advantage of this unique property of anhydrochymotrypsin-Sepharose in combination with reversed-phase high-performance liquid chromatography, we have succeeded in separating the C-terminal peptides from chymotryptic digests of reduced and S-carboxymethylated bovine insulin and from tryptic digests from reduced and S-carboxymethylated Streptomyces subtilisin inhibitor.

Adsorption↗
PubMed1987

Affinophoresis of pea lectin and fava bean lectin with an anionic affinophore, bearing rho-aminophenyl-alpha-D-mannoside as an affinity ligand.

Affinophoresis is an electrophoretic separation technique for biological polymers with the aid of an affinophore, which is a macromolecular polyelectrolyte bearing affinity ligands. The affinophore migrates rapidly in an electric field, and consequently the electrophoretic mobility of molecules having an affinity for the ligand is specifically changed. An anionic affinophore-bearing mannosyl residue was synthesized for the affinophoresis of lectins. rho-Aminophenyl-alpha-D-mannopyranoside and aminomethanesulphonic acid were coupled to about one-tenth and one-fifth, respectively, of the carboxyl groups of succinyl-poly-L-lysine with an average degree of polymerization of 120 by the use of a water-soluble carbodiimide. Extracts of seeds of pea (Pisum sativum) or fava bean (Vicia fava) were subjected to two-dimensional agarose gel electrophoresis, in which the first dimension was ordinary agarose gel electrophoresis and the second dimension was affinophoresis with the affinophore. The separated proteins were stained with Coomassie Blue R250. The lectins in both seed extracts were separated from a diagonal line formed by other proteins in the extracts. About 10 ng of the separated pea lectin was detected on a nitrocellulose blot by immunostaining with a horseradish peroxidase-conjugated second antibody.

Aniline Compounds↗
PubMed1987

Affinophoresis in two-dimensional agarose gel electrophoresis: specific separation of biomolecules by a moving affinity ligand.

Affinophoresis is an electrophoretic separation technique for biomolecules which uses an affinophore. An affinophore is a macromolecular polyelectrolyte bearing affinity ligands. It migrates rapidly in an electric field, and consequently the electrophoretic mobility of molecules having affinity for the ligand is specifically changed. This technique has now been incorporated in two-dimensional agarose gel electrophoresis in a procedure which utilizes normal electrophoresis in the first dimension and affinophoresis in the second dimension. Proteins which do not have affinity for the ligand migrate to locations along a diagonal line passing through the origin, whereas proteins which have affinity are carried away from the line by the affinophore. Accordingly, molecules having affinity for the ligand can be readily assigned. Trypsins contained in Pronase and pancreatin were separated by this procedure using an affinophore bearing a competitive inhibitor for trypsin, benzamidine, on a polyanionic molecule (a polyacrylic acid derivative).

Affinity Labels↗