Search PubMed⌕ Search

Biomedical subjects

K Matsuda

Publications and source records attributed to K Matsuda.

At least 703 records · Page 39Linked to original sources
PubMed1984

Inhibition of leukocyte chemotaxis by Glu-Glu-Glu-Glu-Tyr-Pro-Met-Glu and Leu-Ile-Glu-Asp-Asn-Glu-Tyr-Thr-Ala-Arg-Gln-Gly.

Chemotaxis of rabbit peritoneal leucocytes stimulated by fMet-Leu-Phe, a synthetic chemoattractant, was inhibited by Glu-Glu-Glu-Glu-Tyr-Pro-Met-Glu (MT peptide) and Leu-Ile-Glu-Asp-Asn-Glu-Tyr-Thr-Ala-Arg-Glu-Gly (Src peptide). Both peptides did not inhibit the binding of [3H] formyl-NLe-Leu-Phe, a chemoattractant, to neutrophils, suggesting that the peptides inhibit the events distal to the chemotactic receptors. These peptides blocked the release of arachidonic acid from phospholipids in neutrophils stimulated with chemoattractants, whereas they had no effect on phospholipase A2 activity itself. The peptides markedly reduced the phosphorylation of lipomodulin, a phospholipase inhibitory protein, in either intact cells or isolated plasma membranes. Lipomodulin immunoprecipitated by monoclonal anti-lipomodulin antibody had phosphorylserine and phosphoryltyrosine as analyzed upon electrophoresis. The MT peptide which does not contain threonine or serine was phosphorylated by isolated plasma membranes. These results, taken together, suggest that a tyrosine phosphorylating kinase is involved in biochemical events of chemotactic receptors, and that lipomodulin is a substrate for this kinase.

Animals↗
PubMed1984

Separate transfer of mouse protection and delayed-type hypersensitivity with Salmonella typhimurium transfer factor.

Delayed-type hypersensitivity (DTH) induced with Salmonella typhimurium transfer factor (TF) contributed to an increase in mean survival days of mice challenged with homologous organisms and afforded only a low level of host protection as determined by survival rate, compared with that obtained by active immunization. TF of other enteric bacteria could transfer DTH which is cross-reactive to salmonella antigen but did not afford host protection. Although TF of Listeria monocytogenes did not transfer the cross-reactive DTH, it could confer the significant increase in mean survival days against the lethal challenge with S. typhimurium. Listerial ribosomal vaccine conferred the high level of mouse protection without inducing DTH to salmonella antigen. The resistance generated upon active immunization with listerial ribosomal vaccine could be enhanced by the injection of S. typhimurium TF to the same level as that obtained after immunization with homologous ribosomal vaccine. Among salmonella TF, there could be no cross-reactive immunity between S. typhimurium and S. choleraesuis, although the cross-reactive DTH was observed. The DTH transfer ability of TF was sensitive to Pronase which could not affect the ability to transfer host immunity, but RNase could abolish the ability to transfer host immunity without impairing DTH transfer activity. These results suggest that in mouse typhoid infection, DTH is not associated with host protection as determined by survival rate.

Animals↗
PubMed1984

Phosphorylation at a tyrosine residue of lipomodulin in mitogen-stimulated murine thymocytes.

When murine thymocytes were stimulated by mitogens such as concanavalin A, the Ca2+ ionophore A23187, or 4 beta-phorbol 12-myristate 13-acetate, there was a marked increase of 32P incorporation into immunoprecipitable lipomodulin, a phospholipase inhibitory protein. These compounds enhanced 45Ca2+ influx into thymocytes, which, in turn, increased protein phosphorylation, probably by Ca2+- and phospholipid-dependent protein kinase (protein kinase C). Cyclic 8-bromo-AMP, an inhibitor of lymphocyte mitogenesis, blocked the mitogen-stimulated phosphorylation of lipomodulin, although it stimulated the protein phosphorylation via cyclic AMP-dependent kinase (protein kinase A). On electrophoresis, the hydrolysates of 32P-labeled lipomodulin showed a single radioactive spot, which comigrated with authentic phosphotyrosine. The partially purified middle-sized tumor antigen was able to phosphorylate lipomodulin after being phosphorylated by protein kinase C but not by the catalytic subunit of protein kinase A. Our findings suggest that the activity of a tyrosine-specific kinase, which phosphorylates lipomodulin in vivo as well as in vitro, is stimulated by protein kinase C and inhibited by protein kinase A.

Animals↗
PubMed1984

Structure of the cell wall proteogalactomannan from Neurospora crassa. I. Purification of the proteoheteroglycan and characterization of alkali-labile oligosaccharides.

Proteoheteroglycan (PHG) was prepared from Neurospora crassa cells by extraction with hot water followed by cetyltrimethylammoniumbromide fractionation. The polymer was purified by DEAE-cellulose chromatography followed by gel filtrations. The PHG was fractionated into five subfractions containing carbohydrate (65-88%), protein (19-36%), and a trace amount of phosphate (0.3-1.9%). The sugar compositions of the fractions were similar to each other (D-mannose, 47-60%, D-galactose, 35-50%, D-glucose, 2-5%) while the fractions showed significant heterogeneity in molecular size. Mild alkali treatment of the PHG in the presence of sodium borohydride yielded three kinds of reduced oligosaccharides. Structural studies using a methylation-GC-MS method, and proton and carbon NMR indicated that the tetrasaccharide fragment is beta-D-Galf(1-5)-beta-D-Galf(1-2)-alpha-D-Manp(1-2)man nitol, the trisaccharide is beta-D-Galf(1-2)-alpha-D-Manp(1-2)mannitol, and the disaccharide is alpha-D-Manp(1-2)mannitol.

Carbohydrates↗
PubMed1984

Structure of the cell wall proteogalactomannan from Neurospora crassa. II. Structural analysis of the polysaccharide part.

The native proteoheteroglycan (PHG) from mycelia of Neurospora crassa contain two kinds of carbohydrate chains differing structure. The oligosaccharides containing mannose and galactofuranose are attached by O-glycosidic linkages to serine or threonine residues in the protein (J. Biochem. 96, 1005-1011, 1984). The second kind of carbohydrate chain is a polysaccharide containing mannose and galactofuranose as the main sugar components. The results of structural studies with methylation and NMR analyses on the native PHG and some of its specifically degraded products obtained on partial acid hydrolysis and acetolysis indicate that the polysaccharide moiety of the PHG has an (alpha 1-6) linked mannan backbone with mainly (alpha 1-2) linked side chains, each of which consists of 2 to 5 mannose units, and most of the mannosyl side chains bear beta-galactofuranosyl residues linked to the 2 positions of the mannosyl nonreducing terminals. The galactofuranose residues are linked with each other by (beta 1-5) bonds.

Amino Acids↗
PubMed1984

Purification and characterization of a cellulase from Dolabella auricularia.

A highly purified cellulase [EC 3.2.1.4] preparation (B beta) was obtained from a crude extract of gastric teeth of Dolabella auricularia by successive chromatographies on Sephadex G-100, DEAE-Toyopearl and CM-Toyopearl. The purified cellulase showed a single protein band on disc electrophoresis, and its isoelectric point was at pH 8.6. It contained relatively large amounts of basic amino acids and its molecular weight was estimated to be approximately 44,000 by sodium dodecyl sulfate (SDS) electrophoresis. The highest activity of this enzyme was attained at pH 6.3, but the enzyme was rather labile to heat. The activity of this enzyme was strongly inhibited by Hg2+, Mn2+, Zn2+, and Cu2+, whereas Ca2+ and Mg2+ showed no significant effect on the activity. The purified cellulase hydrolyzed sodium carboxymethyl cellulose (CMC) and phosphoric acid-swollen cellulose (swollen cellulose), as well as cellooligosaccharides and their reduction products, in an endowise fashion. It produced higher cellooligosaccharides effectively from swollen cellulose. Cellooligosaccharides with degrees of polymerization of 4-6 (G4-G6) were also hydrolyzed by the purified cellulase, but the modes of hydrolysis of these oligosaccharides were different from each other. The enzyme did not effectively attack cellooligosaccharides lower than G4. It produced G4 and G2 from G6, and G4 and glucose from G5. When these oligosaccharides were modified by reduction with sodium borotritide, the second linkage from the reducing end became, in each case, significantly susceptible to the enzyme and was preferentially cleaved.

Amino Acids↗
PubMed1984

Immunogenic dialyzable factor derived from a ribosomal fraction of Salmonella typhimurium III. Analysis of resistance induced by dialyzable factors.

Dialyzable factors (DF) were prepared from ribosomal fractions of several organisms including rough mutants of Salmonella typhimurium LT2, salmonella species of different serogroups, other enteric bacteria and gram-positive organisms, and tested for their immunogenicity against S. typhimurium infection in mice. All of them conferred local resistance on mice challenged intramuscularly with S. typhimurium LT2 in the early stage of immunization before the establishment of delayed-type hypersensitivity (DTH) to salmonella antigens. Although DFs of enteric bacteria including rough mutants of S. typhimurium induced DTH to salmonella antigens, only DF of a two-heptose mutant of S. typhimurium LT2 afforded significant mouse protection but others only prolonged the mean time to death. DF of Listeria monocytogenes induced the cross-reacting immunity which afforded the low level of mouse protection as well as an increase in mean time to death without inducing DTH. Passive transfer of anti-O antibody did not enhance the mouse protection provided by each DF. Resistance conferred by DF of S. typhimurium LT2 consisted of two phases: (i) nonspecific macrophage activation resulting in reduction of organisms at the infected site, which became active in the early stage of immunization and (ii) salmonella-specific immunity capable of preventing systemic infection, which became active in the late stage of immunization.

Animals↗
PubMed1984

Ammonium ions suppress the amino acid metabolism involved in the biosynthesis of protylonolide in a mutant of Streptomyces fradiae.

Protylonolide is a lactonic precursor of tylosin aglycone, produced by a mutant of Streptomyces fradiae. It originates from n-butyrate, propionate and acetate units. Studies were carried out using a protylonolide-producing mutant on the correlation between protylonolide biosynthesis, regulation by NH4+ and amino acid metabolism. Protylonolide production decreased in a defined medium containing high levels of NH4+, but was restored by adding lower fatty acids expected to serve as precursors of protylonolide biosynthesis. Resting cell studies demonstrated that 14C-labeled valine, threonine, leucine, isoleucine and alanine, but not lysine, were efficiently incorporated into protylonolide, indicating that these amino acids are metabolized to lower fatty acids. The incorporation of amino acids into protylonolide was reduced when the mutant strain was previously grown under high NH4+ conditions. We suggest that NH4+ suppresses the relevant amino acid metabolism, thereby reducing protylonolide formation.

Amino Acids↗
PubMed1984

Elevation of erythroid colony-stimulating activity in the serum of mice with graft-versus-host disease.

Serum obtained from (C3H X C57BL) F1 hybrid mice injected with parental (C57BL) lymph node cells after 600 rad irradiation contained a high level of an erythropoietic factor, which enhanced erythroid colony formation by fetal C57BL liver cells in methylcellulose cultures. The serum level of this erythroid colony-stimulating activity increased as the dose of lymph node cells injected increased and as suppression of endogenous spleen colonies (indicative of GVH severity) became more marked. Erythropoietin was also elevated in the sera of these mice. When these animals were transfused with washed packed red cells to induce plethora after sublethal irradiation and injection of lymph node cells, the erythropoietin level decreased, but erythroid colony-stimulating activity remained elevated. On the other hand, in anemic mice treated with phenylhydrazine, this erythropoietic factor was not detected, although the serum level of erythropoietin was elevated. These results suggest that a graft-versus-host (GVH) reaction may induce the production of an erythropoietic factor other than erythropoietin and that anemia itself may not be a stimulus for its in vivo production.

Anemia↗