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K Tadano

Publications and source records attributed to K Tadano.

46 records · Page 3Linked to original sources
PubMed1981

A trisialosyl ganglioside GT3 of hog kidney. Structure and biosynthesis in vitro.

A trisialosyl ganglioside was isolated from hog kidney cortex and purified with a yield of 6.8 nmol/g tissue or 13 mol % of total gangliosides. The homogeneous ganglioside was subjected to graded neuraminidase treatment, mild acid hydrolysis, periodate oxidation-borohydride reduction, permethylation analysis and chromium trioxide oxidation. The results suggested that the structure of this ganglioside is NeuAc alpha 2-8NeuAc alpha 2-8NeuAc alpha 2-3Gal beta 1-4Glc beta 1-1Cer (GT3). On the addition of exogenous disialosyl ganglioside GD3 and radioactive CMP-NeuAc, a GT3 synthesis activity was demonstrated in a crude membrane fraction of hog kidney. The activity was greatest in the presence of detergents and had a pH optimum of 6.4. Apparent Km values for CMP-NeuAc and GD3 were about 0. 6 and 0.1 mM, respectively. The reaction produce was assigned as GT3 by chromatographic separation, carbohydrate analysis and periodate oxidation followed by borohydride reduction.

Animals↗
PubMed1980

Chemical modification of fortimicin A.

Chlorination of antibiotic fortimicin A with triphenylphosphine and carbon tetrachloride has been attempted, and 2-chloro-, 2,5-dichloro-, and 2-chloro-4-ene derivatives have been obtained. Successive dehalogenation of the chlorinated fortimicins A with tributylstannane gave the corresponding deoxyfortimicins A. Among five deoxyfortimicins A, 2-deoxyfortimicin A exhibits improved antimicrobial activity, compared to the parent fortimicin A.

Aminoglycosides↗
PubMed1979

Enzymatic sulfation of galactosyl- and lactosylceramides in cell lines derived from renal tubules.

1. The renal cell lines, JTC-12 and MDCK, not only synthesize galactosylceramide 3-sulfate and lactosylceramide 3'-sulfate in vivo, but also contain enzymes that catalyze the transfer of sulfate to galactosylceramide and lactosylceramide in vitro. 2. Concentration of cations necessary for maximum sulfotransferase activity occurred at 40 mM Ca2+ with galactosylceramide and 15 mM Ca2+ with lactosylceramide as the substrate. Na+ was also found to stimulate the sulfation of galactosylceramide, but was slightly inhibitory for the sulfation of lactosylceramide. 3. The products of the in vitro assay mixture were characterized as galactosylceramide 3-sulfate and lactosylceramide 3'-sulfate by a variety of TLC separations. 4. The apparent Km of JTC-12 cells for galactosylceramide was 17 microM, while that for lactosylceramide was 82 microM. The Km values of MDCK cells were comparable to those of JTC-12 cells. Competition studies suggested that galactosylceramide and lactosylceramide were sulfated by a single enzyme in both cell lines.

Adenosine Triphosphate↗
PubMed1978

Hormone-specific responses and biosynthesis of sulfolipids in cell lines derived from mammalian kidney.

The established cell lines isolated from mammalian kidney were characterized by its receptor activities against hormones and the ability to synthesize sulfolipids localized in the renal tubule. The level of 3':5'-cyclic AMP in JTC-12.P3 (monkey kidney) cells increased in 2 min as much as 2.5-5-fold on activation with 1.0 unit/ml of bovine parathyroid hormone or 1.9 units/ml of synthetic parathyroid hormone (1-34) resulting in intracellular cyclic AMP concentration of more than 40 pmol/mg protein. Prostaglandin E1 (14 micronM) and isopropylnorepinephrine (10 micronM) were also found to increase the concentration of cyclic AMP by more than 30- and 9-fold, respectively. Addition in medium of calcitonin, arginine vasopressin, adrenocorticotropic hormone and glucagon caused no significant changes of cyclic AMP level in the cell. In contrast, MDCK, a cell line isolated from canine kidney, reacted to arginine vasopressin, isopropylnorepinephrine and prostaglandin E1 and only slightly to parathyroid hormone. MDBK cell line derived from bovine kidney or fibroblast cell lines from rat lung and guinea pig kidney did not react to any of the hormones specific to kidney, i.e. arginine vasopressin, calcitonin or parathyroid hormone in the presence of theophylline. However, in the presence of 2 mM isobutylmethylxanthine, small but significant elevation of cellular cyclic AMP levels in response to calcitonin, arginine vasopressin, isopropylnorepinephrine and prostaglandin E1 was observed. The cell lines JTC-12, MDCK and MDBK, when incubated with H235SO4, incorporated the isotope into sulfolipids assigned as sulfatides and ceramide dihexoside sulfate or in MDCK also into cholesterol sulfate. The results suggested that JTC-12, MDCK and MDBK cell lines are epithelial origin and also JTC-12 and MDCK originated most probably from renal tubular cells of cortex and medulla, respectively.

Calcitonin↗