Biomedical subjects
T Ueda
Publications and source records attributed to T Ueda.
Isolation and characterization of 101-beta-lysozyme that possesses the beta-aspartyl sequence at aspartic acid-101.
In the reaction of the intramolecular cross-linking between Lys-13 (epsilon-NH3+) and Leu-129 (alpha-COO-) in lysozyme using imidazole and 1-ethyl-3-[3-(dimethylamino)propyl]carbodiimide hydrochloride [Yamada, H., Kuroki, R., Hirata, M., & Imoto, T. (1983) Biochemistry 22, 4551-4556], it was found that two-thirds of the protein (both the recovered and cross-linked lysozymes) showed a lower affinity than the rest against chitin-coated Celite, an affinity adsorbent for lysozyme. The protein with the reduced affinity was separated on chitin-coated Celite affinity chromatography and found to be slightly different from native lysozyme in the elution position of the tryptic peptide of Ile-98-Arg-112 on reversed-phase high-performance liquid chromatography. In contrast with native lysozyme, the limited hydrolysis of this abnormal tryptic peptide of Ile-98-Arg-112 in 6 N HCl at 110 degrees C gave a considerable amount of beta-aspartylglycine. Therefore, it was concluded that two-thirds of the protein obtained from this reaction possessed the beta-aspartylglycyl sequence at Asp-101-Gly-102. As a result, we obtained four lysozymes from this reaction, the derivative with the beta-aspartyl sequence at Asp-101 (101-beta-lysozyme), the cross-linked derivative between Lys-13 and Leu-129 (CL-lysozyme), the CL-lysozyme derivative with the beta-aspartyl sequence at Asp-101 (101-beta-CL-lysozyme), and native lysozyme. In the ethyl esterification of Asp-52 in lysozyme with triethyloxonium fluoroborate [Parsons, S. M., Jao, L., Dahlquist, F. W., Borders, C. L., Jr., Groff, T., Racs, J., & Raftery, M. A. (1969) Biochemistry 8, 700-712; Parsons, S. M., & Raftery, M. A. (1969) Biochemistry 8, 4199-4205], the same bond rearrangement was detected in the same ratio.(ABSTRACT TRUNCATED AT 250 WORDS)
[Serial magnetic resonance imaging (MRI) on experimental brain edema in rats].
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Ozonolysis of supercoiled pBR322 DNA resulting in strand scission to open circular DNA.
Treatment of supercoiled pBR322 DNA with ozone resulted in the conversion of closed circular DNA to open circular DNA. Restriction analysis of the resulting open circular DNA showed that ozonolysis in the absence of salt caused single strand cleavage at specific sites.
An intramolecular cross-linkage of lysozyme. Formation of cross-links between lysine-1 and histidine-15 with bis(bromoacetamide) derivatives by a two-stage reaction procedure and properties of the resulting derivatives.
Hen egg white lysozyme was treated at pH 5.5 with four bifunctional reagents, bis(bromoacetamide) derivatives [BrCH2CONH(CH2)nNHCOCH2Br, 1-n, n = 0, 2, 4, and 6], to alkylate His-15 monofunctionally. The excess bifunctional reagent was then removed, and the pH was raised to 9.0 to allow the other end of the reagent molecule to react. The shortest reagent (1-0) gave no intramolecularly cross-linked lysozyme derivative but only histidine-15-modified lysozyme monomer and intermolecularly cross-linked lysozyme dimer. However, the reagents with longer arms (1-2, 1-4, and 1-6) gave lysozyme derivatives cross-linked intramolecularly between the nitrogen at epsilon 2 of His-15 and the epsilon-amino group of Lys-1 without formation of any other intramolecularly cross-linked lysozyme derivative. These results are consistent with our previous proposal that lysozyme has a small hydrophobic pocket that binds small molecules in the direction from His-15 to Lys-1 [Yamada, H., Uozumi, F., Ishikawa, A., & Imoto, T. (1984) J. Biochem. (Tokyo) 95, 503-510]. The thermal stabilities of three cross-linked lysozymes thus obtained were investigated in 0.1 M acetate buffer containing 3 M guanidine hydrochloride at pH 5.5. All derivatives were stabilized but to different degrees. The derivative cross-linked with 1-4 was most stabilized (2.3 kcal/mol), but the derivatives cross-linked with the reagents both shorter (1-2) and longer (1-6) than 1-4 were less stabilized (both 1.6 kcal/mol).(ABSTRACT TRUNCATED AT 250 WORDS)
[Chemotherapy of carcinomatous peritonitis and carcinomatous pleuritis by using activated charcoal particle adsorbing mitomycin C (MMC-CH)--studies on the clinical trials].
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[Interstitial irradiation by after-loading technic with 192Ir seed-assemblies for deep-seated malignant tumors. 2. Clinical application in lung and esophageal cancers after incomplete resections].
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Studies of cefotaxime serum concentrations during surgery under general anaesthesia and its passage to the wound fluid after surgery for breast cancer.
We are reporting on a comparison of serum concentrations of cefotaxime during and after surgery and on its passage to the wound fluid after surgery. Five patients undergoing mastectomy and dissection of the axillary lymph nodes for breast cancer were studied. Serum concentrations were compared after 2 g of cefotaxime dissolved in 20 ml of saline had been administered by i.v. bolus injection intraoperatively during general anaesthesia and six to eight days postoperatively in a conscious state. After intraoperative administration under general anaesthesia, cefotaxime serum concentrations were 157.3 mg/l at 15 min, 87.5 mg/l at 30 min, 43.08 mg/l at 1 h, 15.54 mg/l at 2 h and 9.56 mg/l at 3 h. In a conscious state, cefotaxime serum concentrations were 122.0 mg/l at 15 min, 84.35 mg/l at 30 min, 47.63 mg/l at 1 h, 18.2 mg/l at 2 h and 9.63 mg/l at 3 h, comparable to the time course under general anaesthesia. The half-life of cefotaxime was 0.86 h under general anaesthesia and 0.92 h in a conscious state. Urinary recovery of cefotaxime (0 to 3 h) under anaesthesia and in a conscious state was 53.8% and 56.3%, respectively (as reported previously for a nonsurgical state). Samples of wound fluid were taken at the completion of surgery from the drain inserted subcutaneously into the wound or by means of a tracheal aspirator kit attached to a portable aspirator. Cefotaxime concentrations were determined postoperatively on days six to eight, when the wound fluid became no longer serous.(ABSTRACT TRUNCATED AT 250 WORDS)
Asplenia syndrome complicated by purulent pericarditis.
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Oscillations in cell shape and size during locomotion and in contractile activities of Physarum polycephalum, Dictyostelium discoideum, Amoeba proteus and macrophages.
Changes in cell shape and size were measured during locomotion, together with the motive force of the protoplasmic streaming, in various amoeboid cells in different stages of their life cycle, and under various environmental conditions. The variations in these measurements with time were examined by Fourier spectral analysis. Notwithstanding a change in cell type in the life cycle of P. polycephalum, myxamoebae and tiny plasmodia showed a similar time pattern of locomotion, exhibiting oscillations having a mixture of several periods. A regular oscillation with protoplasmic streaming appeared in the plasmodium only above a critical cell size. D. discoideum amoebae oscillated with two periods of a few minutes in preaggregation stage, but with a period of 10 min in aggregation stage, the latter being induced by cAMP. Macrophages and A. proteus also oscillated with periods of a few minutes. Periods of all these oscillations were prolonged severalfold by respiratory inhibition with NaCN, but were unaffected by glycolytic inhibition with 2-deoxyglucose. Cell fragments of A. proteus containing fewer granules oscillated more slowly and with a larger amplitude than those containing more granules. Among the granules, the nucleus was excluded as a possible modifier of the oscillation. The oscillation in Physarum plasmodium was reversibly suppressed by combining respiratory and ATPase inhibitions in mitochondria with NaCN and oligomycin, intracellular ATP concentration being kept at an appropriate level. The present results show that amoeboid motility, as well as cell shape, is oscillatory and that mitochondria are involved in time keeping.
Antitumor effect of 6-phenyl-7(6H)-isoselenazolo[4,3-d]pyrimidone on the growth of Ehrlich ascites tumor.
Two selenium compounds have a strong antitumor effect on Ehrlich ascites tumor; 6-phenyl-7(6H)-isoselenazolo[4,3-d]pyrimidone (ISP) especially, markedly inhibited the growth of tumor inoculated i.p. in mice, inducing almost complete regression of tumors at doses of 100 micrograms/mouse per day X 10 with no sign of toxicity. The antitumor activity of 4,5-dihydro-4-methyl-6-oxo-5-phenyl-6H-pyrazolo [4,5-c]isoselenazole(PIS) was weaker than that of ISP. The total lipid and phospholipid contents in the tumor cells treated with ISP were significantly decreased. In addition, the fatty acid pattern of cholesterol esters, phosphatidyl choline and phosphatidyl ethanolamine from the ISP-treated Ehrlich ascites tumor cells differed markedly from that of the corresponding lipids from the control tumor cells.
Large scale isolation and some properties of AGY-specific serine tRNA from bovine heart mitochondria.
A method was developed for large scale isolation of AGY-specific serine tRNA (tRNASerAGY) from bovine heart mitochondria. By this method, 5 A260 units of tRNASerAGY were recovered from 6.3 kg of bovine hearts. The nucleotide sequence was identical to that reported previously. tRNASerAGY showed abnormal melting profiles, as was predicted from its unique primary sequence. Its secondary and/or tertiary structure was analyzed by nuclease digestion method. It was suggested that three extra base pairs could occur in the anticodon stem region, with one adenosine residue protruding. The T loop was quite sensitive to nuclease S1, suggesting that the T loop doesn't interact with other regions. This finding is consistent with the model proposed by Sundaralingam (1980). tRNASerAGY was aminoacylated in vitro with only mitochondrial enzyme but not with the enzymes from E. coli and yeast. The aminoacylation rate of tRNASerAGY with mitochondrial enzyme was much faster than that of cytosolic tRNASerUCN, perhaps reflecting differences due to the presence and absence of the D arm of the tRNAs.
Isolation, characterization, and comparison of a ubiquitous pigment-protein complex consisting of a reaction center and light-harvesting bacteriochlorophyll proteins present in purple photosynthetic bacteria.
Protein complexes (photochemical reaction complex; PR complex) bound to both light-harvesting bacteriochlorophyll-1 (LH-Bchl-1) and reaction center Bchl (RC-Bchl) were purified from Rhodospirillum rubrum (wild and carotenoid-less), Rhodopseudomonas sphaeroides (wild), and Chromatium vinosum (wild). Another protein complex (LH-2 complex) bound to LH-Bchl-2 was also purified from Rps. sphaeroides. The bacteria were grown in the presence of a [14C]amino acid mixture. The purification procedure included molecular-sieve chromatography in the presence of cholate-deoxycholate, and non-equilibrated isoelectric electrophoresis with 3-[(3-cholamidopropyl)dimethylamino]-1-propanesulfonate. The purified complexes were separated into their constituent proteins by sodium dodecylsulfate-polyacrylamide gel electrophoresis. The molar ratios of the proteins were determined by comparing their radioactivities divided by their molecular weights after consideration of the molecular masses of the complexes. The PR complexes all contained per mol: 1 mol each of RC H-, M-, and L-subunits, 10-13 (probably 12) mol each of two other proteins with molecular weights of 11-12K and 8-11K, 28-32 mol Bchl, 13-15 mol carotenoids (except in the carotenoid-less mutant), 2.6-3.9 mol ubiquinone (or menaquinone in Chr. vinosum), and 53-79 mol phosphate without phospholipid. The LH-2 complex contained per mol: 1 mol 52K protein, about 13 (probably 12) mol each of 9K and 8K proteins, 30 mol Bchl, 10 mol carotenoids, and 38 mol phosphate without phospholipid. The PR complexes and LH-2 complex showed similar X-ray diffraction patterns, implying that they had similar, highly organized molecular structures.
Characterization of glutamate uptake into synaptic vesicles.
Recent evidence indicates that L-glutamate is taken up into synaptic vesicles in an ATP-dependent manner, supporting the notion that synaptic vesicles may be involved in glutamate synaptic transmission. In this study, we further characterized the ATP-dependent vesicular uptake of glutamate. Evidence is provided that a Mg-ATPase, not Ca-ATPase, is responsible for the ATP hydrolysis coupled to the glutamate uptake. The ATP-dependent glutamate uptake was inhibited by agents known to dissipate the electrochemical proton gradient across the membrane of chromaffin granules. Hence, it is suggested that the vesicular uptake of glutamate is driven by electrochemical proton gradients generated by the Mg-ATPase. Of particular interest is the finding that the ATP-dependent glutamate uptake is markedly stimulated by chloride over a physiologically relevant, millimolar concentration range, suggesting an important role of intranerve terminal chloride in the accumulation of glutamate in synaptic vesicles. The vesicular glutamate translocator is highly specific for L-glutamate, and failed to interact with aspartate, its related agents, and most of the glutamate analogs tested. It is proposed that this vesicular translocator plays a crucial role in determining the fate of glutamate as a neurotransmitter.
Sodium-calcium exchange across the synaptic plasma membrane.
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Optimum conditions for ursodeoxycholic acid production from lithocholic acid by Fusarium equiseti M41.
Ursodeoxycholic acid dissolves cholesterol gallstones in humans. In the present study optimum conditions for ursodeoxycholic acid production by Fusarium equiseti M41 were studied. Resting mycelia of F. equiseti M41 showed maximum conversion at 28 degrees C, pH 8.0, and dissolved oxygen tension of higher than 60% saturation. Monovalent cations, such as Na+, K+, and Rb+, stimulated the conversion rate more than twofold. In the presence of 0.5 M KCl, the initial uptake rate and equilibrium concentration of lithocholic acid (substrate) were enhanced by 5.7- and 1.7-fold, respectively. We confirmed that enzyme activity catalyzing 7 beta-hydroxylation of lithocholic acid was induced by substrate lithocholic acid. The activity in the mycelium was controlled by dissolved oxygen tension during cultivation: with a dissolved oxygen tension of 15% and over, the activity peak appeared at 25 h of cultivation, whereas the peak was delayed to 34 and 50 h with 5 and 0% dissolved oxygen tension, respectively. After reaching the maximum, the 7 beta-hydroxylation activity in the mycelium declined rapidly at pH 7.0, but the decline was retarded by increasing the pH to 8.0. Several combinations of operations, such as pH shift (from pH 7 to 8), addition of 0.5 M KCl, and dissolved oxygen control, were applied to the production of ursodeoxycholic acid in a jar fermentor, and a much larger amount of ursodeoxycholic acid (1.2 g/liter) was produced within 96 h of cultivation.
Modification of adenine residues of mouse 5S ribosomal ribonucleic acid with monoperphthalic acid: the secondary structure of 5S ribosomal ribonucleic acid (nucleosides and nucleotides. LVI).
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[Studies on cardiac ingredients of plants: biological activities and structural variation of xanthines].
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