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Biomedical subjects

S Udaka

Publications and source records attributed to S Udaka.

At least 109 records · Page 6Linked to original sources
PubMed1984

Molecular cloning of a major cell wall protein gene from protein-producing Bacillus brevis 47 and its expression in Escherichia coli and Bacillus subtilis.

Bacillus brevis 47 contains two major cell wall proteins. Each protein forms a hexagonal array in the cell wall. A 4.8-kilobase HindIII fragment of B. brevis 47 DNA cloned into Escherichia coli with pBR322 as a vector directed the synthesis of polypeptides cross-reactive with antibody to the middle wall protein. A 700-base-pair BamHI-HpaI fragment was shown to be the essential region for the synthesis of immunoreactive polypeptides. Furthermore, this fragment appeared to contain the promoter activity. The 3.5-kilobase BamHI fragment covering the essential region as well as its downstream sequence was subcloned into the corresponding restriction site of pUB110 by using Bacillus subtilis as the cloning host. Both E. coli and B. subtilis carrying the cloned DNA synthesized several immunoreactive polypeptides which were mainly found in the cytoplasm. B. subtilis secreted polypeptides cross-reactive with antibody to the middle wall protein. These extracellular polypeptides were degraded upon prolonged culture.

Bacillus↗
PubMed1984

The fermentation, isolation and characterization of macromolecular peptide antibiotics: AN-7A, -7B and -7D.

A group of new macromolecular peptide antibiotics, named AN-7, was isolated from the culture broth of Streptomyces griseoincarnatus AJ9424. AN-7 was fractionated into three different components, A, B and D. From 18 liters of culture broth (78 units/ml), 10 mg of AN-7A with a specific activity of 2,053 units/mg, 9 mg of AN-7B (1,167 units/mg) and 11 mg of AN-7D (6,225 units/mg) were obtained. All of these samples gave single bands on polyacrylamide gel electrophoresis. They are acidic polypeptides with molecular weights ranging from 12,400 to 13,000. Their UV absorption spectra showed maxima peaks at 280 nm and shoulders at 290 nm. Each AN-7 component has a nonprotein chromophoric component. AN-7A, -7B and -7D have no antibacterial activity against the Gram-negative bacteria tested but strongly inhibit the growth of Gram-positive bacteria and Escherichia coli MP2, a macromolecule permeable mutant strain. The AN-7 components are mutagenic. These antibiotics inhibit the in vitro growth of L1210 cells (ED50 0.13 approximately 0.18 micrograms/ml). AN-7A, -7B and -7D also inhibit the growth of L1210 cells in mice.

Amino Acids↗
PubMed1984

The fermentation, isolation and characterization of a macromolecular peptide antibiotic: AN-1.

A new macromolecular peptide antibiotic, named AN-1, was isolated from the culture broth of Streptomyces albus AJ9003. From 18 liters of culture broth (110 units/ml activity) a 300 mg sample of AN-1 was obtained with a specific activity of 1,160 units/mg was obtained. AN-1 is a basic polypeptide with a molecular weight of 12,000, isoelectric point of pH 8.3, and gives a single band on SDS polyacrylamide gel electrophoresis. It is soluble in water but insoluble in ethanol, butanol and acetone. It was stable at pH 6 approximately 9 but very unstable at pH 2. The UV absorption spectrum shows a maximum at 280 nm. AN-1 had no antibacterial activity against the Gram-positive and Gram-negative bacteria tested, but shows strong inhibitory activity toward Escherichia coli MP2, a macromolecule permeable mutant. In addition to being highly mutagenic, AN-1 inhibits the in vitro cell growth of L1210 (ED50 0.41 micrograms/ml). However, AN-1 had no antitumor activity against mouse leukemia L1210 or Lewis lung carcinoma in mouse.

Animals↗
PubMed1983

Uncoupled release of protein and lipid in a protein-secreting bacterium, Bacillus brevis 47.

Bacillus brevis 47 was found to release approx. 10% of the total cellular lipids into the medium, and the protein secretion process in B. brevis 47 was studied to determine whether any relationship exists with lipid synthesis or alteration in the lipid composition. B. brevis 47 contained the usual phospholipids such as phosphatidylethanolamine, phosphatidylglycerol and cardiolipin as well as diglycerides as major neutral lipids. The extracellular lipid consisted of the same constituents as the cellular lipid but with a significantly altered composition. Divalent cations such as Ca2+, which specifically inhibit protein secretion, had no effect on the lipid release. A nonprotein-secreting mutant released lipid to the same extent as wild-type cells. Based on these results, we conclude that protein secretion occurs independently of lipid release.

Bacillus↗
PubMed1983

Major proteins released by a protein-producing bacterium, Bacillus brevis 47, are derived from cell wall protein.

B. brevis 47 secretes a vast amount of protein consisting mainly of two kinds with approximate molecular weights of 130,000 and 150,000. The two major extracellular proteins were indistinguishable from those of cell wall protein by SDS-polyacrylamide gel electrophoresis. Based on the results of analysis of amino acid composition, limited proteolysis followed by electrophoresis, and the cross-reactivity of antisera, we conclude that the 130K and 150K extracellular proteins are derived from the respective cell wall proteins. Furthermore, the NH2-terminal amino acid analysis suggests that the two major extracellular proteins are released from the cell wall without any modification of the NH2-terminal portion.

Amino Acids↗
PubMed1983

Genetic transformation of Bacillus brevis 47, a protein-secreting bacterium, by plasmid DNA.

A method has been developed for introducing plasmid DNA into Bacillus brevis 47, a protein-secreting bacterium. Treatment of B. brevis 47 cells with 50 mM Tris-hydrochloride buffer of alkaline pH was effective for inducing DNA uptake competence. In the presence of polyethylene glycol, the Tris-treated cells incorporated plasmid DNA with a frequency of 10(-4) (transformants per viable cell) when 1 microgram of plasmid DNA was added to 10(9) Tris-treated cells. The pH of Tris-hydrochloride buffer as well as the concentration and molecular weight of the polyethylene glycol affected the transformation frequency. The growth phase of B. brevis 47 cells strongly influenced the frequency. Two plasmids, pHW1 and pUB110, have been introduced into B. brevis 47 by this method. The mechanism of induction of competence for DNA uptake in connection with removal of the outer two protein layers of the cell wall by treatment of B. brevis 47 cells with Tris-hydrochloride buffer is discussed.

Bacillus↗
PubMed1983

The fermentation, isolation and characterization of a macromolecular peptide antibiotic: AN-3.

A new macromolecular peptide antibiotic, named AN-3, was isolated from the culture broth of Streptomyces albulus. From 19 liters of culture broth containing AN-3 with 90 units/ml activity, a 400 mg sample with a specific activity of 109 units/mg was obtained. Purified AN-3 gave a single band on polyacrylamide gel electrophoresis. AN-3 was a basic polypeptide with a molecular weight of 12,000 approximately 12,500 and an isoelectric point of pH 7.6. It showed a peak of absorption at 280 nm and seemed to have no nonprotein chromophoric component. It was soluble in water but insoluble in ethanol, butanol and acetone, and was stable at pH 4 approximately 9 but unstable at pH2. AN-3 had no antibacterial activity against Gram-positive and Gram-negative bacteria so far as tested. But, it showed a strong inhibitory effect on a macromolecule permeable mutant of Escherichia coli. It was not mutagenic. It appeared to inhibit synthesis of DNA and RNA without affecting DNA itself. It also inhibited the in vitro cell growth of L1210 and its ED50 was 5 micrograms/ml. AN-3 had antitumor activity against Lewis lung carcinoma in mouse in vivo.

Animals↗
PubMed1983

New streptothricin-group antibiotics, AN-201 I and II. Screening, fermentation, isolation, structure and biological activity.

Two streptothricin-group antibiotics, AN-201 I and II, were newly discovered and isolated from the culture broth of Streptomyces nojiriensis C-13. These antibiotics were purified by IRC-50 (H+) and CM-Sephadex C-50 chromatography, and paper electrophoresis. Structural analysis of AN-201 I and II showed that they were N beta-acetylated derivatives of streptothricin E and D, respectively. They had antibacterial activities against several strains of Escherichia coli, Bacillus subtilis, Micrococcus luteus and Staphylococcus aureus, and showed a strong selective cytotoxic effect on 3T3 cells transformed with SV-40 as compared with their normal cells in a test system in vitro as well as in vivo.

Animals↗
PubMed1982

Hexagonal surface array in a protein-secreting bacterium, Bacillus brevis 47.

Bacillus brevis 47, a protein-secreting bacterium, contained two major proteins with approximate molecular weights of 150 000 and 130 000 in the cell wall. The cell surface was covered with a hexagonally arranged array of six structural units about 4 nm in diameter with a lattice constant of 14.5 nm. The regular array structure as well as the chemical composition of cell envelopes remained the same regardless of the growth conditions. A mutant, strain 47-57, which was isolated as a phage resistant colony, contained only the 150 000 protein as a major cell wall protein. Although the mutant had hexagonally arranged arrays with the same lattice constant as that of wild-type cells, the distribution of mass in the unit cell differed considerably from that of the wild-type cells. The number of structural units in the unit cell of the mutant was reduced from six to three. Taking these results together with filtered images of the wild-type and mutant envelopes, two possible models for the surface array of B. brevis 47 are discussed.

Bacillus↗
PubMed1982

Characterization of polyadenylated RNA in a protein-producing bacterium, Bacillus brevis 47.

Up to about 50% of the total radioactivity in pulse-labeled RNA in Bacillus brevis 47-5, a high-protein-producing bacterium, was found in the polyadenylated fraction [termed poly(A)-RNA] isolated by adsorption to oligodeoxythymidylic acid-cellulose. Labeled RNA was bound to the cellulose regardless of whether the radioactive precursor was [3H]adenosine or [3H]uridine, showing that the adsorbed material was poly(A)-RNA rather than free poly(A). Poly(A) tracts, isolated after digestion of pulse-labeled RNA with pancreatic and T1 RNases, were homogeneous, with a length of about 95 nucleotides. Susceptibility of the isolated poly(A) tracts to degradation by snake venom phosphodiesterase and polynucleotide phosphorylase indicated that the poly(A) sequences were located directly at the 3'-terminal of the RNA molecules. Comparison of the poly(A)-RNA content in high-protein-producing and nonprotein-producing cells of B. brevis 47 showed much higher levels in the former. Electrophoretic analysis in both denaturing and denaturing polyacrylamide gels of the poly(A)-RNAs showed a heterogeneous population of molecules ranging in size from 23S to 4S. Comparison of the molecular-weight distribution patterns revealed that a significantly greater amount of high-molecular-weight poly(A)-RNA (comigrating with 23S RNA) was present under conditions in which extracellular protein production was high. The possibility that a substantial fraction of the poly(A)-RNA might be involved in the synthesis of extracellular proteins in B. brevis 47 is discussed.

Bacillus↗
PubMed1982

Reassembly in vitro of hexagonal surface arrays in a protein-producing bacterium, Bacillus brevis 47.

Bacillus brevis 47 had two protein layers (the outer and middle walls) and a peptidoglycan layer (the inner wall) and contained two major proteins with approximate molecular weights of 130,000 and 150,000 in the cell wall. Both the total and Triton-insoluble envelopes revealed a hexagonal lattice array with a lattice constant of 14.5 nm. The proteins of 130,000 and 150,000 molecular weight isolated from the Triton-insoluble envelopes were serologically different from each other and assembled in vitro on the peptidoglycan layer. A mixture of 130,000- and 150,000-molecular-weight proteins led to the formation of a five-layered cell wall structure, two layers on each side of the peptidoglycan layer, which resembled closely the Triton-insoluble envelopes. A three-layered cell wall structure, one layer on each side of the peptidoglycan layer, was reconstituted when only the 150,000-molecular-weight protein was used. Both five- and three-layered cell walls reconstituted in vitro also contained hexagonally arranged arrays with the same lattice constant as that of the total and Triton-insoluble envelopes. A mutant, strain 47-57, which was isolated as a phage-resistant colony, had a two-layered cell wall consisting of the middle and inner wall layers and contained only 150,000-molecular-weight protein as the major cell wall protein. The cell envelopes of the mutant revealed the hexagonal arrays with the same lattice constant as that of the wild-type cell envelopes. We conclude that the outer and middle wall layers consist of proteins with approximate molecular weights of 130,000 and 150,000, respectively. Furthermore, the 150,000-molecular-weight protein formed the hexagonal arrays in the middle wall layer.

Bacillus↗
PubMed1982

A new test system for screening macromolecular antitumor antibiotics and its application to culture fluids of actinomycetes.

In searching for macromolecular antitumor antibiotics, a new screening method was developed that consisted of 1) a macromolecular antibiotic detecting system employing macro-molecule permeable mutants of Escherichia coli, 2) a system to detect DNA-affecting antibiotics using DNA repair mutants, and 3) a mutagenicity detecting system, employing a valine resistance test. This new test system was applied to about 2,900 kinds of culture fluids of Actinomycetes and consequently 15 samples were found which contained macromolecular antibiotics with DNA affecting properties.

Actinomycetales↗
PubMed1982

Screening and some properties of new macromolecular peptide antibiotics.

In searching for macromolecular antitumor antibiotics of microbial origin, 2,875 kinds of Actinomycetes culture fluids were applied to a newly developed test system which consisted of antimicrobial assay using a macromolecule permeable mutant, DNA damage assay and mutagenicity test. As a result, 78 macromolecular antibiotics were found. Among them, 15 antibiotics precipitable with ammonium sulfate were macromolecular peptide antibiotics (protein antibiotics), of which molecular weight ranged from 10,000 to 14,000. Macromolecular peptide antibiotics AN-1, -5 and -15, termed type I antibiotics, showed stronger growth inhibitory effect on the uvrA and recA mutants, as compared to the effect on their parent, MP2. They also had mutagenic activity. AN-7, -9, -16, -18, -20, -22, -23, -25, and -26, termed type II, exhibited an increased inhibitory activity to a recA mutant but did not to an uvrA mutant. They all showed mutagenicity. AN-3, -11 and -13, type III antibiotics, gave similar influence on the DNA repair mutants, and on their parent, MP2. They had no mutagenic activity. Except for AN-11 and -13 of type III antibiotics, all antibiotics were inhibitory to the cell growth of a cancer cell, L1210.

Actinomycetales↗
PubMed1981

Morphological alterations of cell wall concomitant with protein release in a protein-producing bacterium, Bacillus brevis 47.

Bacillus brevis 47 secreted vast amounts of protein into the medium and had a characteristic three-layered cell wall. The three layers are designated, from the outermost to the innermost layer, as the outer wall (4.2 nm), the middle wall(8.5 nm), and the inner wall (2.1-3.7 nm). The inner wall might be a peptidoglycan layer. The fine cell wall structure was morphologically altered to various extents, depending on the growth period. At the early stationary phase of growth, cells began to shed the outer two layers of a limited area of the surface. This shedding was complete after further cell growth. The morphological alterations in the cell wall occurred concomitantly with a prominent increase in protein excretion. When protein secretion was severely inhibited by growing cells with Mg2+, morphological alterations in the cell wall were not observed, even at the late stationary phase of growth. This was also the case with a nonprotein-producing mutant, strain 47-5-25. When cells were incubated in buffers, the outer two layers of the cell wall were specifically removed, leaving cells surrounded only by the inner wall layer. The layers removed by incubation were recovered by high-speed centrifugation. This fraction consisted of two layers resembling the outer and middle wall layers. Protein secreted by B. brevis 47-5 consisted mainly of two proteins with approximate molecular weights of 150,000 and 130,000. Proteins released by incubating cells in buffers and proteins in the outer- and middle-wall-enriched fraction were also composed mainly of two proteins with the same molecular weights as those secreted into the medium. Therefore, we conclude that B. brevis 47 secretes proteins derived from the outer two layers of cell wall and these components are synthesized even after the shedding of the outer two layers.

Bacillus↗
PubMed1980

Formation of mutagens by sorbic acid-nitrite reaction: effects of reaction conditions on biological activities.

Conditions of the reaction between sorbic acid and sodium nitrite generating mutagenic principles were examined. In the rec-assay and the Ames reversion assay, the maximal mutagenic activity was obtained in a pH range of 3.5-4.2. Mutagenic and growth-inhibitor activities of five C-nitro and C-nitroso compounds were studied. The product Y, 2-methyl-1,4-dinitropyrrole, was the strongest mutagen among them.

Drug Interactions↗
PubMed1980

Preferential utilization of phenol rather than glucose by Trichosporon cutaneum possessing a partially constitutive catechol 1,2-oxygenase.

A phenol-utilizing yeast, Trichosporon cutaneum POB 14, which has a partially constitutive activity of catechol 1,2-oxygenase, utilized phenol in preference to glucose in a medium containing both phenol (200 mg/liter) and glucose (0.15%) as carbon sources. The glucose consumption was not observed until the concentration of phenol decreased to around 10 mg/liter. This phenomenon was confirmed by [U-14C]glucose uptake experiments. The intracellular activities of hexokinase (EC 2.7.1.1) and catechol 1,2-oxygenase (EC 1.13.1.1) changed inversely when phenol was added during growth in the glucose medium.

Biological Transport, Active↗