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K Nosaka

Publications and source records attributed to K Nosaka.

At least 109 records · Page 6Linked to original sources
PubMed1990

High affinity of acid phosphatase encoded by PHO3 gene in Saccharomyces cerevisiae for thiamin phosphates.

The enzymatic properties of acid phosphatase (orthophosphoric-monoester phosphohydrolase, EC 3.1.3.2) encoded by PHO3 gene in Saccharomyces cerevisiae, which is repressed by thiamin and has thiamin-binding activity at pH 5.0, were investigated to study physiological functions. The following results led to the conclusion that thiamin-repressible acid phosphatase physiologically catalyzes the hydrolysis of thiamin phosphates in the periplasmic space of S. cerevisiae, thus participating in utilization of the thiamin moiety of the phosphates by yeast cells: (a) thiamin-repressible acid phosphatase showed Km values of 1.6 and 1.7 microM at pH 5.0 for thiamin monophosphate and thiamin pyrophosphate, respectively. These Km values were 2-3 orders of magnitude lower than those (0.61 and 1.7 mM) for p-nitrophenyl phosphate; (b) thiamin exerted remarkable competitive inhibition in the hydrolysis of thiamin monophosphate (Ki 2.2 microM at pH 5.0), whereas the activity for p-nitrophenyl phosphate was slightly affected by thiamin; (c) the inhibitory effect of inorganic phosphate, which does not repress the thiamin-repressible enzyme, on the hydrolysis of thiamin monophosphate was much smaller than that of p-nitrophenyl phosphate. Moreover, the modification of thiamin-repressible acid phosphatase of S. cerevisiae with 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide resulted in the complete loss of thiamin-binding activity and the Km value of the modified enzyme for thiamin monophosphate increased nearly to the value of the native enzyme for p-nitrophenyl phosphate. These results also indicate that the high affinity of the thiamin-repressible acid phosphatase for thiamin phosphates is due to the thiamin-binding properties of this enzyme.

Acid Phosphatase↗
PubMed1990

Hepatoid adenocarcinoma: a distinctive histological subtype of alpha-fetoprotein-producing lung carcinoma.

Seven cases of alpha-fetoprotein (AFP)-producing lung carcinoma were studied histologically to determine whether they fell into any previously described category. The patients were all males from 40 to 73 years of age and their serum AFP levels ranged from 1039 to 320,000 ng/ml. Five cases of hepatoid adenocarcinoma, one case of endodermal sinus tumour, and one case of papillary adenocarcinoma were found. The possible origins of the tumours and their differential diagnosis are discussed. Hepatoid adenocarcinoma is a major histological category among AFP-producing lung carcinoma; other types are less frequent. The occurrence of hepatoid adenocarcinoma in both the stomach and the lung suggests that this neoplasm may also be seen in other organs of endodermal origin. It may be a major histological subtype of AFP-producing endodermal neoplasms of non-germ cell origin.

Adenocarcinoma↗
PubMed1990

Regulation of thiamine biosynthesis in Saccharomyces cerevisiae.

A pho6 mutant of Saccharomyces cerevisiae, lacking a regulatory gene for the synthesis of periplasmic thiamine-repressible acid phosphatase activity, was found to be auxotrophic for thiamine. The activities of four enzymes involved in the synthesis of thiamine monophosphate were hardly detectable in the crude extract from the pho6 mutant. On the other hand, the activities of these enzymes and thiamine-repressible acid phosphatase in a wild-type strain of S. cerevisiae, H42, decreased with the increase in the concentration of thiamine in yeast cells. These results suggest that thiamine synthesis in S. cerevisiae is subject to a positive regulatory gene, PHO6, whereas it is controlled negatively by the intracellular thiamine level.

Acid Phosphatase↗
PubMed1989

Photoaffinity labeling of thiamin-binding component in yeast plasma membrane with [3H]4-azido-2-nitrobenzoylthiamin.

When prepared from Saccharomyces cerevisiae through an acid precipitation at pH 5.0 for a crude particulate fraction obtained by mechanical agitation of yeast protoplasts with glass beads, the plasma membranes have more remarkable binding quantities of [14C]thiamin (Kd, 51 nM; Bmax, 263 pmol per mg of protein) compared with our previously prepared membranes [(1986) Experientia 42, 607-608]. Photoaffinity labeling of these yeast plasma membranes with [3H]4-azido-2-nitrobenzoylthiamin resulted in the covalent modification of a membrane component with an apparent molecular mass of 6-8 kDa. The extent of its labeling was markedly decreased by previous addition of thiamin. This result suggests that the small membrane component (6-8 kDa) takes part in the thiamin binding of thiamin carrier protein(s) in yeast plasma membranes.

Acid Phosphatase↗
PubMed1989

A possible role for acid phosphatase with thiamin-binding activity encoded by PHO3 in yeast.

Periplasmic soluble thiamin-binding protein in Saccharomyces cerevisiae (Iwashima, A. et al. (1979) Biochim. Biophys. Acta 577, 217-220) was demonstrated to be encoded by PHO3 gene that codes for thiamin repressible acid phosphatase (Schweingruber, M.E. et al. (1986) J. Biol. Chem. 261, 15877-15882) by genetic analysis. The pho3 mutant cells of S. cerevisiae in contrast to the parent cells have markedly reduced activity of the uptake of [14C]thiamin phosphates, suggesting that thiamin repressible acid phosphatase plays a role in the hydrolysis of thiamin phosphates in the periplasmic space prior to the uptake of their thiamin moieties by S. cerevisiae.

Acid Phosphatase↗
PubMed1989

A successful delivery of an extremely immature infant in Rh incompatibility after plasma exchange.

When Rh incompatible pregnancies occur, intrauterine fetal transfusion (IUT) and plasma exchange (PE) have made it possible to prolong the prenatal duration and to dramatically decrease the neonatal mortality. We administered a total of 10 PEs (from 20 weeks to 27 weeks of gestation) and one IUT (at 27 weeks and 1 day) for an Rh-isoimmunized gravida who already had a high maternal serum Rh antibody titer at the 14th gestational week, and delivered by Caesarian section (CS) an extremely immature infant of only 873 grams at 27 weeks and 4 days of gestation. The infant was hydropic with hyperbilirubinemia, therefore exchange transfusions were administered immediately after birth. The infant's weight reached the lowest point of 669 grams on the 13th day after birth, but began to increase thereafter. The baby weighted 3,052 grams on the 144th day and left the hospital without any complications.

Blood Transfusion, Intrauterine↗
PubMed1989

Identity of soluble thiamine-binding protein with thiamine repressible acid phosphatase in Saccharomyces cerevisiae.

Two secretory glycoproteins of S. cerevisiae, a soluble thiamine-binding protein and a thiamine-repressible acid phosphatase, were shown to be repressed to a similar extent by excess thiamine in the growth medium. Thiamine-repressible acid phosphatase was co-purified throughout the purification of the soluble thiamine-binding protein. Purified and deglycosylated soluble thiamine-binding proteins exhibited both thiamine-binding and acid phosphatase activities on non-denaturing polyacrylamide gel electrophoresis. Heat treatment of the purified soluble thiamine-binding protein caused a decrease in both activities with a similar inactivation profile. Two thiamine-repressible acid phosphatase-defective mutants isolated were found to be also defective in soluble thiamine-binding activity. The uptake of [14C]thiamine phosphate esters, such as thiamine monophosphate and thiamine pyrophsphate, was remarkably impaired in the mutant cells, whereas the uptake of [14C]thiamine by the mutant was almost the same with that by the parent strain. From these results, it was concluded that the soluble thiamine-binding protein is identical to the thiamine-repressible acid phosphatase in S. cerevisiae, which is involved in the hydrolysis of exogenous thiamine phosphate esters in the periplasmic space prior to the uptake of their thiamine moiety by yeast cells.

Acid Phosphatase↗
PubMed1988

Identity of soluble thiamin-binding protein with thiamin-repressible acid phosphatase in Saccharomyces cerevisiae.

Two secretory glycoproteins of Saccharomyces cerevisiae, a soluble thiamin-binding protein and a thiamin-repressible acid phosphatase, were shown to be repressed to a similar extent by excess thiamin in the growth medium. Thiamin-repressible acid phosphatase was co-purified throughout the purification of the soluble thiamin-binding protein. Purified and deglycosylated soluble thiamin-binding proteins exhibited both thiamin-binding and acid phosphatase activity on non-denaturing polyacrylamide gel electrophoresis. Heat treatment of the purified soluble thiamin-binding protein caused a decrease in both activities with a similar inactivation profile. Furthermore, two thiamin-repressible acid phosphatase-defective mutants isolated had no and decreased soluble thiamin-binding activity, respectively. From the results, it was concluded that the soluble thiamin-binding protein is identical to the thiamin-repressible acid phosphatase in S. cerevisiae.

Acid Phosphatase↗
PubMed1988

Inactivation of the thiamine transport system in Saccharomyces cerevisiae with O-bromoacetylthiamine.

We have synthesized and characterized O-bromoacetylthiamine (BrAcThiamine), a new reagent for inactivating the thiamine transport system in Saccharomyces cerevisiae. A Lineweaver-Burk plot of data from the transport kinetic measurements showed that BrAcThiamine was a competitive inhibitor of thiamine transport in S. cerevisiae with a Ki value of 0.60 microM. Incubating BrAcThiamine with yeast cells at 40 degrees C in 0.05 M potassium phosphate buffer, pH 5.0, caused concentration- and time-dependently a remarkable loss of thiamine transport activity. The inactivating reaction of yeast thiamine transport by BrAcThiamine proceeded most effectively at pH 5.0, coinciding with the optimal pH of the transport activity. Thiamine and thiamine analogs (pyrithiamine and O-acetylthiamine) protected yeast thiamine transport activity against the inactivation by BrAcThiamine. In addition, it was found that a membrane fraction prepared from yeast cells treated with BrAcThiamine had a thiamine-binding activity only 20% of that from control cells without inactivating the binding activity of the soluble fraction. These results suggest that BrAcThiamine inactivates the uptake activity by irreversible binding to the binding site of carrier protein(s) in the thiamine transport system.

Biological Transport↗
PubMed1988

Contribution of hepatic reticuloendothelial system to glomerular IgA deposition in rat liver injury.

Liver damage was induced in rats by a single dose of dimethylnitrosamine or D-galactosamine. In the dimethylnitrosamine model, marked glomerular IgA deposition occurred between Days 4 and 28, with its peak at Day 14. Serum IgA levels were significantly increased at Days 2 and 4, then gradually decreased, and normalized at Day 14. In the D-galactosamine model, however, no such deposition was observed, though serum IgA levels similarly increased on Days 2 and 4. IgA content in high molecular weight fraction from serum increased at Day 3 in both models. This increment remained at Day 7 only in the dimethylnitrosamine model, in which carbon clearance from the circulation was significantly decreased at Day 3. These data suggest that dysfunction of the hepatic reticuloendothelial system is a factor contributing to glomerular IgA deposition occurring in liver injury.

Alanine Transaminase↗
PubMed1987

[Bone disorder in long-term survival after gastrectomy with reference to bone mineral content].

To investigate post-gastrectomy metabolic bone disorder, the radial bone mineral content (BMC) was measured with 125I-photon absorptiometry in 131 long-term survivors, the postoperative periods ranged 3 to 30 years. Sixty-eight patients (52 per cent) showed abnormally low BMC levels compared with healthy controls. The 43 patients with total gastrectomy manifested a higher incidence of decreased BMC levels than did the other 88 patients with partial gastrectomy. In females, patients subjected to the Billroth II procedure manifested low BMC values. The extent of the decline in BMC was much higher in females than in males, and higher in totally gastrectomized patients than in partial gastrectomy group. At more than 10 years postoperatively many patients manifested markedly low BMC levels; in totally gastrectomized patients this finding was made at less than 5 years postoperatively. A significant correlation was found between the extent of the decreased BMC levels and the postoperative periods. Of the patients with decreased BMC values, 30 per cent of them gave histories of osseous symptom after gastrectomy, however, 70 per cent of patients were asymptomatic. Based on the results, in long-term survival treated by total or partial gastrectomy, many patients present an osteopenic status, however, the number of those with clinically manifested bone disease such as osteomalacia may be low.

Age Factors↗
PubMed1987

The tarsal tunnel syndrome. Report of two cases of unusual cause.

Since Keck described the tarsal tunnel syndrome (TTS) in 1962, it has been one of the most frequently diagnosed of the entrapment neuropathies. TTS is usually of unknown origin. This is a report of two unusual cases: TTS caused by neurilemmoma in a 33-year-old woman, and TTS caused by subperiosteal ganglion in a 14-year-old girl. The symptoms were relieved, in both instances, with surgical excision.

Adolescent↗
PubMed1986

Effect of tunicamycin on thiamine transport in Saccharomyces cerevisiae.

The activity of thiamine transport in Saccharomyces cerevisiae was decreased by the treatment with tunicamycin without affecting the growth of yeast cells. Although the total activity of a soluble thiamine-binding protein in yeast periplasm, which is known to be a glycoprotein, was decreased by tunicamycin treatment, the activity of thiamine uptake by yeast protoplasts was inhibited as much as by whole cells. Furthermore, tunicamycin decreased the activity of the membrane-bound thiamine-binding protein in a dose dependent way and in parallel with the thiamine transport activity. These findings suggested that the membrane-bound thiamine-binding protein is a glycoprotein which plays a functional role in thiamine transport in S. cerevisiae.

Acid Phosphatase↗
PubMed1986

Thiamine-binding activity of Saccharomyces cerevisiae plasma membrane.

The specific binding activity to [14C]thiamine was found to be located in hte plasma membrane of Saccharomyces cerevisiae. The activity was inhibited by several thiamine analogs and it was hardly detectable in the plasma membrane from a thiamine transport mutant of Saccharomyces cerevisiae. Some properties of the thiamine-binding activity of yeast plasma membrane are discussed in connection with those of the thiamine transport system.

Biological Transport↗
PubMed1986

Bone disorder following partial and total gastrectomy with reference to bone mineral content.

To study post-gastrectomy metabolic bone disorders, we measured the radial bone mineral content (BMC), serum levels of calcium, inorganic phosphorus, alkaline phosphatase, and 25-hydroxyvitamin D(25-OH-D) in 59 patients with partial- and 39 patients with total gastrectomy. Total gastrectomy patients manifested a higher incidence of decreased BMC levels than did partial gastrectomy patients (56 per cent vs. 25 per cent). Patients subjected to the Billroth II procedure, especially females, manifested abnormally low BMC values. The decline in BMC was age-related; it was pronounced in females. At 10 years postoperatively, many of the partial gastrectomy patients manifested markedly low BMC levels; in totally gastrectomized patients this finding was made at less than 5 years postoperatively. Approximately 30 per cent of our patients showed abnormalities in serum minerals, alkaline phosphatase or 25-OH-D.

Alkaline Phosphatase↗
PubMed1986

Some properties of a Saccharomyces cerevisiae mutant resistant to 2-amino-4-methyl-5-beta-hydroxyethylthiazole.

A mutant of Saccharomyces cerevisiae highly resistant to 2-amino-4-methyl-5-beta-hydroxyethylthiazole (2-aminohydroxyethylthiazole), an antimetabolite of 4-methyl-5-beta-hydroxyethylthiazole (hydroxyethylthiazole), has been isolated. Its resistance to 2-aminohydroxyethylthiazole was about 10(4) times that of the sensitive parent strain. The amount of thiamin synthesized in the cells of the resistant strain grown in minimal medium was less than half of that of the sensitive strain. The ability to synthesize thiamin from 2-methyl-4-amino-5-hydroxymethylpyrimidine (hydroxymethylpyrimidine) and hydroxyethylthiazole in the resistant strain was low compared with that of the sensitive strain. These results were found to be due to a deficiency of hydroxyethylthiazole kinase in the resistant strain: in sonic extracts of cells the enzyme activity was only 0.67% of that of the sensitive strain. Although the cells of the sensitive strain could accumulate exogenous hydroxyethylthiazole in the form of hydroxyethylthiazole monophosphate, no significant uptake of hydroxyethylthiazole by the cells of the resistant strain was observed. The possibilities that 2-aminohydroxyethylthiazole monophosphate may be the actual inhibitor of the growth of Saccharomyces cerevisiae, and that hydroxyethylthiazole may not be involved in the pathway of de novo synthesis of thiamin via hydroxyethylthiazole monophosphate, are discussed.

Drug Resistance, Microbial↗
PubMed1984

Inactivation of rice bran thiamine-binding protein by N,N'-dicyclohexylcarbodiimide.

The addition of a carboxyl-modifying reagent N,N'-dicyclohexylcarbodiimide (DCCD) to thiamine-binding protein isolated from rice bran resulted in a remarkable loss of its binding activity with [14C]thiamine. Thiamine and chloroethylthiamine substantially protected the protein against inactivation by DCCD, whereas thiamine phosphates did not. Another carboxyl reagent N-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline (EEDQ) also inactivated rice bran thiamine-binding protein. Inactivation of the thiamine-binding protein was accompanied by covalent binding of DCCD to the protein as shown by the use of [14C]DCCD. The binding of [14C]DCCD to the thiamine-binding protein was specific, and significantly inhibited by the addition of thiamine. The loss of thiamine-binding activity was proportional to the specific binding of [14C]DCCD. For complete inactivation of the thiamine-binding activity, the binding of 2.46 mol of [14C]DCCD per mol of thiamine-binding protein was required. Furthermore, limited proteolysis of the binding protein by trypsin yielded two polypeptides with molecular weights of 35,000 (large polypeptide) and 12,500 (small polypeptide) which were separated by SDS-polyacrylamide gel electrophoresis. The binding sites of [14C]DCCD were found to be located on the large polypeptide. These results suggest that a specific carboxyl residue in the large polypeptide releasable from rice bran thiamine-binding protein by trypsin digestion when modified by DCCD is involved in the binding of thiamine.

Binding Sites↗