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Biomedical subjects

E Ito

Publications and source records attributed to E Ito.

At least 271 records · Page 15Linked to original sources

Structure and functions of linkage unit intermediates in the biosynthesis of ribitol teichoic acids in Staphylococcus aureus H and Bacillus subtilis W23.

The stepwise formation and characterization of linkage unit intermediates and their functions in ribitol teichoic acid biosynthesis were studied with membranes obtained from Staphylococcus aureus H and Bacillus subtilis W23. The formation of labeled polymer from CDP-[14C]ribitol and CDP-glycerol in each membrane system was markedly stimulated by the addition of N-acetylmannosaminyl(beta 1----4)N-acetylglucosamine (ManNAc-GlcNAc) linked to pyrophosphorylyisoprenol. Whereas incubation of S. aureus membranes with CDP-glycerol and ManNAc-[14C]GlcNAc-PP-prenol led to synthesis of (glycerol phosphate) 1-3-ManNAc-[14C]GlcNAc-PP-prenol, incubation of B. subtilis membranes with the same substrates yielded (glycerol phosphate)1-2-ManNAc-[14C]GlcNAc-PP-prenol. In S. aureus membranes, (glycerol phosphate)2-ManNAc-[14C]GlcNAc-PP-prenol as well as (glycerol phosphate)3-ManNAc-[14C]GlcNAc-PP-prenol served as an acceptor for ribitol phosphate units, but (glycerol phosphate)-ManNAc-[14C]GlcNAc-PP-prenol did not. In B. subtilis W23 membranes, (glycerol phosphate)-ManNAc-[14C]GlcNAc-PP-prenol served as a better acceptor for ribitol phosphate units than (glycerol phosphate)2-ManNAc-[14C]GlcNAc-PP-prenol. In this membrane system (ribitol phosphate)-(glycerol phosphate)-ManNAc-[14C]GlcNAc-PP-prenol was formed from ManNAc-[14C]GlcNAc-PP-prenol, CDP-glycerol and CDP-ribitol. The results indicate that (glycerol phosphate)1-3-ManNAc-GlcNAc-PP-prenol and (glycerol phosphate)1-2-ManNac-GlcNAc-PP-prenol are involved in the pathway for the synthesis of wall ribitol teichoic acids in S. aureus H and B. subtilis W23 respectively.

Bacillus subtilis↗

Biosynthesis of the wall neutral polysaccharide in Bacillus cereus AHU 1356.

The pathway for the biosynthesis of a cell wall polysaccharide, composed of glucosamine, mannosamine, galactosamine and glucose in a molar ratio of 4:1:1:1, was studied with a membrane system from Bacillus cereus AHU 1356. In this system a glycolipid characterized as GalNAc(alpha 1----4)ManNAc(beta 1----4)GlcNAc-PP-undecaprenol was formed from GlcNAc-PP-undecaprenol by sequential transfer of N-acetylmannosamine and N-acetylgalactosamine residues from UDP-ManNAc and UDP-GalNAc respectively. An additional N-acetylglucosamine residue and a glucose residue were individually transferred from their UDP derivatives to the trisaccharide-linked lipid with the formation of tetrasaccharide-linked lipids, which seem to serve as intermediates in the polysaccharide synthesis. Incubation of membranes with the trisaccharide-linked lipid even in the absence of sugar-linked nucleotides led to the formation of polysaccharide. These results, together with the data on Smith degradation of the synthesized polysaccharide, indicate that the repeating trisaccharide units of the main chain of the polysaccharide arise from the GalNAc-ManNAc-GlcNAc moiety of the glycolipid intermediates and that the sugar residues in the lateral branches of the polymer are at least partly introduced through oligosaccharide-linked lipid intermediates. In addition, the structure of native polysaccharide was re-examined, and the presence of the disaccharide sequence ManNAc(beta 1----4)GlcNAc in the polysaccharide chain was confirmed.

Affinity Labels↗

Biosynthesis of the wall acidic polysaccharide in Bacillus cereus AHU 1356.

Biosynthetic studies on an acidic polysaccharide, comprising galactose, rhamnose, N-acetylglucosamine and sn-glycerol 1-phosphate, were carried out with a membrane system obtained from Bacillus cereus AHU 1356. Incubation of the membranes with UDP-[14C]Gal, TDP-[14C]Rha and UDP-[14C]GlcNAc resulted in the formation of four or more labeled-sugar-linked lipids and a labeled polysaccharide. Data on structural analysis of the sugar moieties released from the glycolipids, together with results of enzymatic conversion of [14C]galactose-linked lipid and [14C]Rha-Gal-linked lipid to higher-oligosaccharide-linked lipids and polysaccharide, led to the conclusion that the acidic polysaccharide is probably synthesized through the following pathway: (sequence in text) The glycerophosphate residues seem to be derived from phosphatidylglycerol.

Anti-Bacterial Agents↗

Structural studies on the minor teichoic acid of Bacillus coagulans AHU 1631.

The minor teichoic acid linked to glycopeptide was isolated from lysozyme digests of Bacillus coagulans AHU 1631 cell walls, and the structure of the teichoic acid moiety and its junction with the peptidoglycan were studied. Hydrolysis of the teichoic-acid--glycopeptide complex with hydrogen fluoride gave a nonreducing oligosaccharide composed of glucose, galactose and glycerol in a molar ratio of 3:1:1 which was presumed to be dephosphorylated repeating units of the polymer chain. From the results of structural analysis involving NaIO4 oxidation, methylation and acetolysis, the above fragment was characterized as glucosyl(beta 1----3)glucosyl(beta 1----6)galactosyl(beta 1----6)glucosyl(alpha 1----1/3)glycerol. In addition, the Smith degradation of the complex yielded a phosphorus-containing fragment identified as glycerol-P-6-glucosyl(beta 1----1/3)glycerol. These results led to the most likely structure for the repeating units of the teichoic acid, -6[glucosyl(beta 1----3)]glucosyl(beta 1----6)galactosyl(beta 1----6)glucosyl(alpha 1----1/3)glycerol-P-. The minor teichoic acid, just like the major teichoic acid bound to the linkage unit, was released by heating the cell walls at pH 2.5. The mild alkaline hydrolysis of the minor teichoic acid after reduction with NaB3H4 gave labeled saccharides characterized as glucosyl(beta 1----6)galactitol and glucosyl(beta 1----3)glucosyl(beta 1----6)galactitol, together with a large amount of the unlabeled repeating units of the teichoic acid chain. Thus, the minor teichoic acid chain is believed to be directly linked to peptidoglycan at the galactose residue of the terminal repeating unit without a special linkage sugar unit.

Acetone↗

Histopathological studies on experimental marine toxin poisoning. I. Ultrastructural changes in the small intestine and liver of suckling mice induced by dinophysistoxin-1 and pectenotoxin-1.

Sequential ultrastructural changes were studied in mouse digestive organs after i.p. injections of dinophysistoxin-1 and pectenotoxin-1, causative agents of diarrhetic shellfish poisoning. Dinophysistoxin-1, a diarrheagenic substance, produced severe mucosal injuries in the small intestine within 1 hr after the administration of the toxin. The injuries were divided into 3 consecutive stages: extravasation of villi vessels, degeneration of absorptive epithelium and desquamation of the degenerated epithelium from the lamina propria. In contrast to dinophysistoxin-1, pectenotoxin-1, a non-diarrheagenic toxin from diarrhetic shellfish poisoning causative mussels, resulted in no abnormalities in the small intestine, but did cause characteristic liver injuries. Within 1 hr after the injection of pectenotoxin-1 numerous non-fatty vacuoles appeared in the hepatocytes around the periportal regions of the hepatic lobules. Electron microscopic observations with colloidal iron demonstrated that these vacuoles originated from invaginated plasma membranes of the hepatocytes.

Animals↗

Chondrosarcoma arising in the nasal septum: a case report.

A rare case of chondrosarcoma arising in the nasal septum, which appeared in an eighty-year-old female, was reported. The tumor extended bilaterally in the nasal cavity and to the skull base. Radiation therapy was performed for the patient, considering of her age. Histological findings including electron micrograph were shown, and pertinent literatures were reviewed to discuss clinicopathological features of the tumor.

Aged↗

Studies on glucosyltransferase and endogenous glucosyl acceptor in Bacillus cereus AHU 1030 membranes.

A glucosyltransferase, extracted from the membranes of Bacillus cereus AHU 1030 with Tris-HCl buffer containing 0.1% Triton X-100 at pH 9.5, was separated from an endogenous glucosyl acceptor by chromatography on DEAE-Sepharose CL-6B subsequent to chromatography on Sepharose 6B. Structural analysis data showed that the glucosyl acceptor was a glycerol phosphate polymer linked to beta-gentiobiosyl diglyceride. The enzyme catalyzed the transfer of glucosyl residues from UDP-glucose to C-2 of the glycerol residues of repeating units of the acceptor. On the other hand, a lipoteichoic acid which contained 0.3 D-alanine residue per phosphorus was isolated from the cells by phenol treatment at pH 4.6. Except for the presence of D-alanine, this lipoteichoic acid had the same structure as the glucosyl acceptor. The rate of glucosylation observed with the D-alanine-containing lipoteichoic acid as the substrate was less than 40% of that observed with the D-alanine-free lipoteichoic acid, indicating that the ester-linked D-alanine in the lipoteichoic acid interferes with the action of the glucosyltransferase. The enzyme also catalyzed glucosylation of poly(glycerol phosphate) which was synthesized in the reaction of a separate enzyme fraction with CDP-glycerol. Thus, it is likely that the glucosyltransferase functions in the synthesis of cell wall teichoic acid.

Bacillus cereus↗

Structural studies on N-acetylmannosaminuronic acid-containing and glucuronic acid-containing teichuronic acids in the cell wall of Bacillus megaterium AHU 1375.

Structural studies were carried out on two kinds of teichuronic acid-glycopeptide complexes (designated as TU-GP-I and TU-GP-II) isolated from lysozyme digest of N-acetylated cell walls of Bacillus megaterium AHU 1375 by ion-exchange chromatography and gel chromatography. TU-GP-I, accounting for about 25% of the cell walls, contained N-acetylmannosaminuronic acid, N-acetylglucosamine, glucose, galactose, glycerol, and phosphorus in an approximate molar ratio of 1:1:2:1:0.5:0.5, together with small amounts of glycopeptide components. TU-GP-II, accounting for about 9% of the cell walls, contained glucuronic acid, glucose, and fucose in a molar ratio of about 2:1.5:1, together with small amounts of glycopeptide components. The results of analyses involving Smith degradation, chromium oxidation, methylation, acetolysis, and H-NMR measurement led to the conclusion that the polysaccharide chain of TU-GP-I comprised repeating units,----6) Glc(alpha 1----3)-ManNAcUA(beta 1----4)[Gal(alpha 1----3)][Glc(beta 1----6)]GlcNAc(beta 1----. About half of the repeating units were substituted by glycerophosphoryl residues at C-6 of the beta-glucosyl residues linked to the N-acetylglucosamine residues. By means of a similar procedure, the polysaccharide chain of TU-GP-II was shown to comprise repeating units,----4)GlcUA(alpha 1----3)GlcUA(alpha 1----3)Glc(alpha 1----3)Fuc(alpha 1----, of which about half were substituted by alpha-glucosyl residues at C-3 of the 4-substituted glucuronosyl residues.

Bacillus megaterium↗

The structure of the O-specific chain of lipopolysaccharide from Pseudomonas aeruginosa IID 1008 (ATCC 27584).

Structural studies were carried out on the O-polysaccharide fraction obtained from the lipopolysaccharide of Pseudomonas aeruginosa IID 1008 (ATCC 27584). The O-polysaccharide comprises L-rhamnose, N-acetyl-D-quinovosamine, N-acetyl-D-galactosaminuronic acid, and N-formyl-D-galactosaminuronic acid. The characterization of oligosaccharide fragments resulting from acid hydrolysis, Smith degradation and alkaline degradation of the O-polysaccharide, together with 1H-NMR and 13C-NMR spectroscopic data of the polysaccharide, led to the following structure for the repeating units: ----3)Rha(alpha 1----4)GalNAcA(alpha 1----4 GalNFoA(alpha 1----3)QuiNAc(alpha 1----. Almost all of the carboxyl groups of the N-acetylgalactosaminuronic acid residues and about half of the same groups of the N-formylgalactosaminuronic acid residues were in an amide form.

Antigens, Bacterial↗

Comparative studies of lipoteichoic acids from several Bacillus strains.

Structural studies were carried out on lipoteichoic acids obtained from defatted cells of 10 Bacillus strains by phenol-water partition followed by chromatography on DEAE-Sephacel and Octyl-Sepharose columns. A group of the tested bacteria (group A), Bacillus subtilis, Bacillus licheniformis, and Bacillus pumilus, was shown to have a diacyl form of lipoteichoic acids which contained D-alanine, D-glucose, D-glucosamine, fatty acids, and glycerol in molar ratios to phosphorus of 0.35 to 0.69, 0.07 to 0.15 to 0.43, 0.06 to 0.11, and 0.95 to 1.18, respectively, whereas the other group (group B), Bacillus coagulans and Bacillus megaterium, had diacyl lipoteichoic acids which contained D-galactose, fatty acids, and glycerol in molar ratios to phosphorus of 0.05 to 0.42, 0.06 to 0.12, and 0.96 to 1.07, respectively. After treatment with 47% hydrogen fluoride, the lipoteichoic acids obtained from group A strains commonly gave a hydrophobic fragment, gentiobiosyl-beta (1----1 or 3)diacylglycerol, in addition to dephosphorylated repeating units, glycerol, 2-D-alanylglycerol, N-acetyl-D-glucosaminyl-alpha (1----2)glycerol, and D-alanyl-N-acetyl-D-glucosaminyl-alpha (1----2)glycerol, whereas the lipoteichoic acids from group B strains yielded diacylglycerol in addition to glycerol and D-galactosyl-alpha (1----2)glycerol. The results together with data from Smith degradations indicate that in the lipoteichoic acids of group A strains the polymer chains, made up of partially alanylated glycerol phosphate and glycosylglycerol phosphate units, are joined to the acylglycerol anchors through gentiobiose. However, in the lipoteichoic acids of group B strains, the partially galactosylated poly(glycerolphosphate) chains are believed to be directly linked to the acylglycerol anchors.

Alanine↗

Biosynthetic studies on N-acetylmannosaminuronic acid containing teichuronic acid in Bacillus megaterium.

The particulate enzymes obtained from four strains of Bacillus megaterium AHU 1240, AHU 1373, AHU 1375, and T catalyzed the synthesis of a polysaccharide and glycolipids from UDP-N-acetylmannosaminuronic acid, UDP-N-acetylglucosamine, and UDP-glucose. Chemical studies involving Smith degradation, acid hydrolysis, and N-acetylation revealed that the polysaccharide product has a backbone made up of trisaccharide repeating units comprising glucose, N-acetylmannosaminuronic acid, and N-acetylglucosamine and that the main oligosaccharide moieties of the glycolipids were identical with N-acetylmannosaminuronosyl-N-acetylglucosamine and glucosyl-N-acetylmannosaminuronosyl-N-acetylglucosamine. Incubation of the disaccharide-linked lipid with each particulate enzyme in the presence of UDP-glucose produced the trisaccharide-linked lipid and a polysaccharide. It is therefore suggested that in this polysaccharide-synthesizing system the repeating unit is formed on a carrier lipid from appropriate nucleotide derivatives first and the polymerization of the units then occurs to synthesize the backbone while the growing chain remains in pyrophosphate linkage to the carrier lipid presumed to be undecaprenol.

Acetylglucosamine↗

[Correlation of LH and prolactin pulses in normoprolactinemic women with ovulatory disturbances and variation of LH and FSH pulses and secreting capacity by administration of bromocriptine in the same cases].

The difference between prolactin (PRL) basal levels on separate days in the 6 normoprolactinemic women--one case with an anovular cycle and 5 cases with 1 degree amenorrhea--among 14 normoprolactinemic women with ovulatory disturbances, showed significantly variation over 13 ng/ml within the normal range of the PRL basal level. PRL pulse frequencies of the same cases from 0900 h. to 1400 h. increased slightly compared with follicular phase. At the same time, the PRL pulse amplitudes were significantly higher than in the follicular phase but significantly lower than the PRL pulse amplitudes in hyperprolactinemic women. The net increase in PRL to TRH in the 6 cases was over 100 ng/ml. When the PRL net increase to TRH was over 100 ng/ml in normoprolactinemic women with ovulatory disturbances, the case is regarded as latent hyperprolactinemia. And 1 or 2 may be latent hyperprolactinemic syndrome. The LH/FSH basal level and delta LH/delta FSH to LH-RH before administration of bromocriptine increased in these cases compared with the follicular phase. During the administration of bromocriptine, the ratios decreased and approached the ratio in the follicular phase. The effect of clomid was improved by increased E2 in these cases.

Amenorrhea↗

Structural studies on the linkage unit between poly(N-acetylglucosamine 1-phosphate) and peptidoglycan in cell walls of Bacillus pumilus AHU 1650.

Structural studies were carried out on the polymer chains and their linkage regions in two kinds of teichoic acids, poly(N-acetylglucosamine 1-phosphate) [poly(GlcNAc-1-P)] and glycerol teichoic acid, bound to peptidoglycan in the cell walls of Bacillus pumilus AHU 1650. The poly(GlcNAc-1-P)-glycan complex isolated from lysozyme digests of the cell walls contained mannosamine and glycerol as minor components. On the basis of proton NMR spectroscopic data and isolation of N-acetylglucosamine 4-phosphate from acid hydrolysates, the poly(GlcNAc-1-P) was shown to be a polymer in which N-acetylglucosamine 1-phosphate units are joined at C-4 of the glucosamine residues. Mild alkaline hydrolysis of the poly(GlcNAc-1-P)-glycan complex gave a mannosamine-linked glycan fragment and the acidic polymer fraction that contained glycerol residues. Mild acid treatment of the mannosamine-linked glycan fragment gave the linkage disaccharide, ManNAc(beta 1----4)GlcNAc, whereas the acidic polymer fraction was degraded by this treatment into N-acetylglucosamine 4-phosphate and a glycerol-containing fragment characterized as P-(Gro-P)7 (Gro = glycerol). On the other hand, direct mild acid hydrolysis of the complex gave a fragment characterized as P-(Gro-P)7-ManNAc(beta 1----4)GlcNAc. These results lead to a conclusion that in the cell walls the poly(GlcNAc-1-P) chain is attached to peptidoglycan through a linkage unit, (Gro-P)7-ManNAc(beta 1----4)GlcNAc. By means of similar procedures, it was shown that the other cell wall polymer, glycerol teichoic acid, is also attached to peptidoglycan through the same disaccharide, ManNAc(beta 1----4)GlcNAc.

Acetylglucosamine↗