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T Fukasawa

Publications and source records attributed to T Fukasawa.

90 records · Page 5Linked to original sources
PubMed1980

The enzymes of the galactose cluster in Saccharomyces cerevisiae. II. Purification and characterization of uridine diphosphoglucose 4-epimerase.

Uridine diphosphoglucose 4-epimerase (EC 5.1.3.2) of Saccharomyces cerevisiae was purified to homogeneity with a yield of 30%. The purification procedure involved ammonium sulfate precipitation, streptomycin treatment, chromatography on diethylaminoethyl cellulose and hydroxylapatite, and Bio-Gel A-0.5m gel filtration. With the purified enzyme preparation, Km and Vmax values for uridine diphosphogalactose were determined and found to be 0.22 mM and 1.26 mmol/h/mg of protein, respectively. The value of Vmax corresponds to a turnover rate of 3890 molecules of uridine diphosphogalactose converted to uridine diphosphoglucose/min/enzyme molecule. The pH optimum of the enzyme was found to be between 6.8 and 8.0. Amino acid analysis was carried out on the final preparation. Based on the result, the partial specific volume was calculated to be 0.74 ml/g. The NH2-terminal residue of the enzyme was studied by two different methods and found to be threonine. The molecular weight and subunit composition were determined by the combination of the sucrose density gradient centrifugation and gel filtration under nondissociating conditions, and by polyacrylamide gel electrophoresis under dissociating conditions. The results indicated that the enzyme has a molecular weight of 183,000, consisting of two identical subunits. Each molecule of the native enzyme contained 1 molecule of NAD+.

Amino Acids↗
PubMed1978

Regional replication of the bacterial chromosome induced by derepression of prophage lambda. IV. Escape synthesis of gal operon in phage 82.

Derepression of prophage lambda in E. coli strain K12 results in constitutive synthesis of the enzymes directed by the nearby bacterial operon, gal (escape synthesis). Phage 82 fails to cause escape synthesis despite that it lysogenizes the strain K12 at the site identical to that of lambda on the host chromosome. The reason for the observed difference between 82 and lambda is studied in the light of the recent finding that escape synthesis in lambda-lysogen is closely associated to phage-promoted replication of bacterial chromosome contiguous to the prophage including gal operon (escape replication). Excision-defective mutants from 82, 82int or 82xis, do initiate escape synthesis, suggest that the prophage 82 is normally excised too quickly after induction to allow sufficient escape replication. In support of this, much more DNA hybridizable to bacterial DNA contained in lambdagal accumulates after induction if 82int than after induction of 82. Studies with various hybrid phages between 82 and lambda have suggested: 1. The occurrence of gal escape synthesis depends on the nature of the region between b2 and N in the lambda map. 2. Regions of the 82 genome on both sides of the attachment site contribute independently to prevent gal escape synthesis. Implications of these results are discussed with regard to the factors involved in the prophage excision.

Chromosomes, Bacterial↗
PubMed1978

Regional replication of the bacterial chromosome induced by derepression of prophage lambda. III. Role of the replication in escape synthesis of gal operon.

Recent evidence suggests that the escape synthesis of gal operon following derepression of the prophage lambda in Escherichia coli K12 involves transcription originating at the lambda promoter (PL) to extend through gal under the conditions in which lambda DNA replication is prevented. Whether the observed expression of gal is due to transcription initiating at PL or at the bacterial promoter for gal (Pgal) was examined in the case of lambda DNA replication being normal. The experiments are based on that two types of transcription are distinguished from each other by the following properties: 1. Pgal-promoted transcription is inhibited by chloramphenicol, while PL-promoted transcription is not. 2. PL-promoted transcription suppresses the polar effect caused by nonsense mutation in a bacterial gene, while Pgal-promoted transcription does not do so. -he results have suggested that gal escape synthesis in lambda-induced lysogen results from transcription which initiates not only at PL but also at Pgal. The Pgal-promoted transcription may be a consequence, direct or indirect, of the concomitant replication of gal DNA.

Chloramphenicol↗
PubMed1977

Clinical significance of specific IgE antibody against streptokinase-streptodornase in renal diseases of childhood.

The immediate skin reaction (IR) with streptokinase-streptodornase (SK-SD) was found with a high incidence in children with renal disease and was confirmed to be mediated by a specific IgE antibody against SK-SD by means of the radioallergosorbent test (RAST). This test revealed high radiocounts in children with renal disease who showed the IR and there was a close correlation between the RAST counts and the intensity of the IR. Furthermore, the RAST counts in the severe nephrotic syndrome belonging to corticosteroid dependent and resistant group were far higher than those in the corticosteroid sensitive group. From these results, a determination of the RAST counts against SK-SD seemed to help evaluate the severity of some nephrotic syndromes and the specific IgE antibody may be involved in the pathogenesis of the disease.

Adrenal Cortex Hormones↗
PubMed1976

The pathogenesis of experimental membranous glomerulonephritis induced with homologous nephritogenic tubular antigen.

The renal tubular epithelial antigen (Tub-Ag) of rats was solublized by Pronase and purified by gel filtration and acrylamide gel electrophoresis. Purified Tub-Ag was a glycoprotein with S20,W value of 8.4. Utilizing radiolabeled Tug-Ag, a sensitive radioimmunoassay for Tub-Ag and homologous antibody (anti-Tub-Ag) was developed. Tub-Ag activity associated with a protein of the same molecular size was demonstrated in the serum, as well as in Pronase extracts of all the organs tested, including kidney, liver, lung, spleen, intestine, stomach, and heart. The physiochemical properties of the Tub-Ag of rats and its distribution were essentially the same as the Tub-Ag of humans, which had been found in immune deposits in the kidney of some patients with idiopathic membranous glomerulonephritis. Rats were immunized with the purified Tub-Ag emulsified in Freund's complete adjuvant and followed for Tub-Ag and anti-Tub-Ag in the serum, as well as for proteinuria and immunohistological changes in the kidney. Serum Tub-Ag dropped sharply after 20 days, when anti-Tub-Ag appeared in the circulation. Persistent, massive proteinuria appeared still later, more than 30 days after injection, when anti-Tub-Ag disappeared and Tub-Ag reappeared in the serum of some of those rats. In others, anti-Tub-Ag in the serum persisted throughout the observation period of 90 days. The pathology of the kidney of the rats with proteinuria was that of a typical membranous glomerulonephritis; thickening of glomerular capillary walls with granular deposits of gamma-globulin and Tub-Ag was observed. On the basis of these results, Tub-Ag in the serum, probably released from cellular membranes of various organs as a physiological metabolite, is considered to maintain the pathological process in the kidney by providing the antigen continuously to form immune complexes.

Animals↗
PubMed1976

Regional replication of the bacterial chromosome induced by derepression of prophage lambda. II. Direction and origin.

We have demonstrated previously by DNA-DNA hybridization that induction of lambda phage with wild type O and P genes results in an increase of bacterial DNA in the chromosomal region adjacent to the left of the prophage; is a segment between gal and attlambda (gal DNA) (Imae and Fukasawa, 1970). Evidence is presented in this report that such an increase of bacterial DNA is also seen in the region to the right of the prophage; a segment between bio and attlambda (bio DNA). We postulate therefore that the bidirectional replication of lambda DNA extends beyond the prophage and copies the neighboring host DNA until the prophage is excised. The model is verified by making use of excision-defective lambda phages. The synthesis of gal DNA (or bio DNA) slows down to a halt within 40 min after the induction in the normal lysogens. The results are attributed to the prophage excision: (1) In lysogens for lambdaint, synthesis of the bacterial DNA continues for longer times. (2) The synthesis of the bacterial DNA slows down to a halt in lysogens for lambdaxis or lambdab2 as in the control. However lambda DNA synthesis also slows down in parallel so that the amount of the bacterial DNA relative to that of lambda DNA synthesized by a given time stays constant from 20 min to 80 min. During that time the relative amount of the bacterial DNA rapidly decreases in the normal lysogen.

Chromosome Mapping↗
PubMed1975

Laboratory model of membranous glomerulonephritis in rats induced by pronase-digested homologous renal tubular epithelial antigen.

The laboratory counterpart of tubular antigen-mediated membranous glomerulonephritis in humans was produced in rats by a single injection of homologous nephritogenic tubular antigen with adjuvant. The rat developed membranous glomerulonephritis with typical clinicopathologic features of human nephritis mediated by the tubular antigen, i.e., massive proteinuria and diffuse thickening of glomerular basement membranes due to deposition of tubular antigen-antibody complexes which were demonstrated by immunofluorescent technique. The nephritogenic tubular antigen was solubilized by pronase digestion, further purified by gel filtration, and demonstrated to have the same physicochemical properties as the human tubular antigen which was found in the deposits together with beta1C- and immunoglobulins in the glomeruli of patients with membranous glomerulonephritis.

Animals↗
PubMedDate not supplied

Hyperviscosity syndrome in a patient with systemic lupus erythematosus.

The occurrence of hyperviscosity syndrome in a 22-year-old woman with systemic lupus erythematosus was reported. Ultracentrifuge study of her serum revealed the presence of intermediate complexes with sedimentation coefficients of 10.9S to 14.2S. The complexes were shown to consist of immunoglobulin G and immunoglobulin A and considered to be mainly responsible for the increased serum viscosity. This unusual protein abnormality responded remarkably well to the treatment with prednisolone.

Adult↗