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Biomedical subjects

T Kawata

Publications and source records attributed to T Kawata.

At least 253 records · Page 14Linked to original sources
PubMed1984

Classification of Vibrio bacteriophages.

85 Vibrio phages, 84 of them tailed and 1 filamentous, were surveyed. The tailed phages belonged to six basic morphotypes and to the Myoviridae, Siphoviridae, or Podoviridae families. 63 phages were classified into 18 species. The filamentous phage is a member of the Inovirus genus of the Inoviridae family. Vibrio phages are very heterogenous and include some morphologically interesting viruses. Several Vibrio phages closely resemble phages of other gram-negative bacteria, possibly indicating phylogenetic relationships between their hosts.

Bacteriophages↗
PubMed1983

Isolation and characterization of the outer membrane from Vibrio parahaemolyticus.

The outer membrane of Vibrio parahaemolyticus strain 3283-61 (serotype O2:K3) was isolated from blebs released upon spheroplast formation, in the presence of lysozyme and EDTA, by isopycnic sucrose density gradient centrifugation. SDS-PAGE of the outer membrane fraction prepared from cells grown in nutrient broth containing 3% (w/v) NaCl revealed five major proteins, designated a to e, with apparent approximate molecular weights: a, 44 000; b, 36 000; c, 33 500; d, 26 500; e, 22 000. An increase in NaCl concentration in the growth medium resulted in an increase of proteins b and c, whereas a decrease to 0.5% (w/v) induced two additional major proteins with respective molecular weights of about 35 000 and 32 000. Proteins a and b appeared to be loosely associated with the peptidoglycan layer since they were largely retained after extraction with 2% (w/v) SDS at 50 degrees C for 30 min. Proteins c and/or e may play a role in phage VP1-receptors since phage-resistant mutants derived from strain 3283-61 had significantly diminished amounts of both proteins. The major outer membrane proteins varied in number and molecular weight in strains of V. parahaemolyticus belonging to different K-serotypes.

Bacterial Outer Membrane Proteins↗
PubMed1983

Isolation and partial properties of a porin-like protein from Vibrio parahaemolyticus cell envelope.

The cell envelope of Vibrio parahaemolyticus pilot strain K-11 contains a major protein with an apparent molecular weight of 35,000 which was not solubilized with 2% sodium dodecyl sulfate (SDS) at 50 C for 30 min and was resistant to trypsin. The protein was extracted from the SDS-insoluble envelope with SDS containing 0.4 M NaCl and purified by acetone precipitation and gel filtration. The purified protein was completely dissociated into a monomer with a molecular weight of 35,000 in SDS at 60 C. The amino acid composition of the protein was nearly the same as that of porins from Escherichia coli and Salmonella typhimurium. Thus the protein seems to be porin-like.

Amino Acids↗
PubMed1983

Purification and characterization of a wall protein antigen from Clostridium botulinum type A.

A wall surface protein, designated antigen S, was extracted from Clostridium botulinum type A strain 190L with 0.1% Brij 58-2 M LiCl and purified sequentially by acetone pecipitation, ion-exchange chromatography, hydroxyapatite chromatography, chromatofocusing, and gel filtration. Crossed immunoelectrophoresis of the purified antigen S preparation against homologous multispecific antiserum to whole cells revealed only a single precipitin line. Antigen S had an apparent molecular weight of about 195,000, as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The antigen was composed predominantly of acidic amino acid residues, and the isoelectric point was estimated to be at pH 4.75. Tryptic digestion of antigen S destroyed antigenic activity and produced one major polypeptide fragment with a molecular weight of about 44,000. Indirect immunoferritin labeling showed that antigen S was located on the outer layer of the cell wall.

Amino Acids↗
PubMed1982

Purification and characterization of spirosomes in Lactobacillus brevis.

Spirosomes, very find spiral particles, were isolated from a protoplastlysate of Lactobacillus brevis ATCC 8287 by differential centrifugation and purified further by potassium tartrate density gradient centrifugation. The purified spirosome preparation showed a maximum peak around 275 nm on the ultraviolet absorption spectrum and it consisted of about 94.5% protein. The buoyant density in CsCl of the spirosomes was 1.320 g/cm3. The spirosomes were composed mainly of a single protein (spirosin with an apparent molecular weight of about 95,000 as determined by sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis. The protein of the spirosomes was found to be composed predominantly of neutral amino acids accompanied by approximately equal amounts of acidic and basic amino acids. The spirosomes showed one antigenic determinant in the immunodiffusion test. The spirosomes were readily degraded by the action or proteolytic enzymes and lost their antigenicity, but they were not affected by treatment with either deoxyribonuclease or ribonuclease. The spiral structure of the spirosome was also found to be disintegrated by treatment with 1 M guanidine hydrochloride, 4 M urea or 0.1% SDS, but not by the action of deoxycholate, nonionic detergents or mercaptoethanol, as observed in the electron microscope.

Amino Acids↗
PubMed1982

Morphological varieties and host ranges of Vibrio parahaemolyticus bacteriophages isolated from seawater.

Eighteen bacteriophages lytic for Vibrio parahaemolyticus were isolated from seawater, and their ultrastructure was examined by electron microscopy. Based on the phage morphology, they were classified in four groups. Group I phages consisted of a hexagonal head and a tail with a contractile sheath. All the phages of the other three groups had a relatively long, noncontractile tail, but there were differences in the head structure among these phages. The phages of groups II and III had a hexagonal head and an elongated polyhedral head, respectively. Group IV phages exhibited a unique hexagonal head with knoblike projections. There appeared to be no correlation between the O and K serotypes of V. parahaemolyticus strains and the host ranges of the phages. The phages had varying sensitivities to heat and organic solvents.

Bacteriophages↗
PubMed1982

Isolation, properties, and reassembly of outer sheath carrying a polygonal array from an oral treponeme.

The outer sheath carrying a polygonal array was isolated from an oral treponeme, Treponema sp. strain E-21, by disruption of cells by means of repeated freeze-thawing and by removal of flagella under acidic conditions followed by linear sucrose density gradient centrifugation. Electron microscopy revealed that the outer sheath was isolated as a triple-layered vesicle having a polygonal array, free of flagella and wall membrane complex. Using optical diffraction, negatively stained preparations of the outer sheath fragments showed that the polygonal array appeared to be composed of a hexagonal pattern with a predominant spacing of about 16.3 nm. The isolated outer sheath contained 49.7% protein, 30.8% total lipid, and 11.0% carbohydrate. Phospholipid comprised about 95% of the total lipid. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed that the outer sheath was composed primarily of one major protein with an apparent molecular weight of about 62,000. The material from the isolated outer sheath solubilized with 1% sodium deoxycholate was reassembled into vesicles having a roughly polygonal array upon removal of the detergent by dialysis against 10 mM Tris-hydrochloride buffer with or without Mg2+.

Bacterial Proteins↗
PubMed1982

Potentiation of insulin secretory response of rats by BCG injection.

Effects of BCG cells on blood insulin, glucose, glycerol and free fatty acid (FFA), and liver glycogen were examined in rats in vivo. Freund's complete adjuvant (FCA) was used as a solution containing BCG cells. Insulin secretion and lactate production by isoproterenol were enhanced by FCA injection. Hyperglycemia induced by epinephrine was somewhat attenuated by treating rats with FCA. The increment of plasma FFA by isoproterenol was smaller in FAC-injected rats than that in control rats. The amount of glycogen in liver was increased by FCA treatment Anti-insulin antiserum (AIS) did not modify the lactate producing action of isoproterenol. FFA release stimulated by isoproterenol was enhanced by AIS. Liver glycogen content in FCA-injected rats was decreased by AIS injection. These results suggest that some component(s) of BCG cells may enhance insulin release stimulated by secretagogues, and insulin thus released attenuates some metabolic effects of the agonist.

Animals↗
PubMed1981

Characterization of two inducible bacteriophages, alpha 1 and alpha 2, isolated from Clostridium botulinum type A 190L and their deoxyribonucleic acids.

Two inducible bacteriophages, alpha 1 and alpha 2, isolated from Clostridium botulinum type A strain 190L and their deoxyribonucleic acids (DNAs) were purified and characterized. Phage alpha 1, which is unable to form plaques on any strain of C. botulinum, was produced in large quantities after treatment with mitomycin C (MC), whereas phage alpha 2, which was induced in much lower quantities than phage alpha 1, propagated in cultures of type A strain Hall. The phage DNAs were exclusively synthesized after induction with MC. Alpha 1 and alpha 2 DNAs had sedimentation coefficients of 34.0 and 30.6 S, corresponding to molecular weights of 31.9 x 10(6) and 23.5 x 10(6), respectively. The buoyant density in CsC1 was 1.682 g/cm3 for alpha 1 DNA and 1.680 g/cm3 for alpha 2 DNA. Based on thermal denaturation characteristics, the genomes of both phages were shown to be double-stranded DNAs. Agarose gel electrophoretic profiles of the phage DNAs digested with restriction endonuclease EcoRI revealed nine fragments for alpha 1 DNA and six fragments for alpha 2 DNA. The molecular weights of the phage DNAs as determined by restriction enzyme analysis were 30.55 x 10(6) for alpha 1 DNA and 25.83 x 10(6) for alpha 2 DNA. Nontoxigenic mutants obtained from strain 190L could, like the toxigenic parent strain, produce the two phages after treatment with MC. Lysogenic conversion to toxigenicity by phage alpha 2 was not observed with the nontoxigenic mutants. It seems likely that there is no relationship between either phage genome and the toxigenicity of C. botulinum type A.

Bacteriophages↗