[The deficiency of UDP-GlcNAc: lysosomal enzyme alpha-N-acetylglucosaminylphosphotransferase and the related diseases].
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Humans↗
Biomedical subjects
S Gasa
Publications and source records attributed to S Gasa.
Apoenzyme of aspartate aminotransferase isoenzymes in maternal plasma during labor and following delivery.
In eight normal mothers the effects of pyridoxal 5'-phosphate (PLP) addition on the plasma activities of aspartate aminotransferase isoenzymes (AST-s and AST-m) during labor and following delivery were investigated. The AST-s activities with and without reactivation by PLP appeared to increase immediately after delivery and they were even higher on the 4th day postpartum. On the other hand, there were significant elevations in both the AST-m activities immediately and at 2 h after delivery, but not on the 4th day postpartum. Of AST isoenzymes measured in the nonstress test, only the relative activation rate of AST-m by PLP added was significantly higher than the control value. The present study may come to the following conclusions: 1) The relative activation rate of plasma AST-m activity by PLP may be a reliable index of vitamin B6 nutritional status during pregnancy. 2) The increases in AST-m activity with and without PLP added during labor suggest a minimal damage of mitochondria in skeletal, cardiac and uterine muscle cells. 3) The AST-s isoenzyme determinations with and without PLP may be especially useful as sensitive indication of erythrocyte and/or liver damage after delivery.
Adult↗
Studies of the biosynthesis of the cation-dependent mannose 6-phosphate receptor in murine cell lines.
We have studied the biosynthesis of the cation-dependent mannose 6-phosphate receptor in murine BW5147 lymphoma cells and MOPC 315 plasmacytoma cells. The cells were labeled with [35S]methionine or [2-3H]mannose and the receptor immunoprecipitated with an anti-receptor antiserum. The receptor was first detected as a glycoprotein with an apparent molecular mass of 40 kDa. This intermediate was rapidly processed to a mature form which was stable during 22 h of chase. In these cells, the mature receptor has an apparent molecular mass of 43 kDa. The 3-kDa increase occurs as a result of processing of Asn-linked high-mannose oligosaccharides to complex-type units.
Animals↗
Estimation and characterization of glycosylated carbonic anhydrase I in erythrocytes from patients with diabetes mellitus.
Glycosylated form of carbonic anhydrase isozyme I was found in human erythrocytes. The percent of glycosylated enzyme of the total erythrocyte carbonic anhydrase I of patients with diabetes mellitus was significantly higher than that from normal controls. Characterization of the glycosylated carbonic anhydrase I was studied using an enzyme purified from diabetic patients. The glycosylated enzyme showed a slightly acidic isoelectric point in comparison with that of a nonglycosylated enzyme. The specific activity of the glycosylated enzyme was approximately 40% of that of the normal enzyme, and the immunological activity decreased to 52% of that of the normal enzyme. Estimation of carbohydrates which may form a ketoamine linkage with the enzyme was studied using [3H]-labelled glycosylated enzyme synthesized by incubation of the enzyme with [3H]-D-glucose in vitro, and it was found that one mol of glucose binds to one mol of enzyme. Exposure of red cells to a higher concentration of glucose in diabetics brought about glycosylation of carbonic anhydrase, which is associated with its low activity enzymatically and immunologically.
Adult↗
Phosphorylation of human lysosomal arylsulfatase B by cAMP-dependent protein kinase. Different sites of phosphorylation between normal and cancer tissues.
We previously demonstrated that an acidic variant (B1) of lysosomal arylsulfatase B from transplanted human lung cancer is phosphorylated on its protein and carbohydrate moieties (Gasa, S., and Makita, A. (1983) J. Biol. Chem. 258, 5034-5039). The present study identifies that a cAMP-dependent protein kinase is responsible for phosphorylation of arylsulfatase B. The protein kinase activity toward the sulfatase was considerably higher in the transplanted lung cancer than in normal lung in the presence of cAMP. B enzyme purified from normal human liver was found to contain 0.6 mol/mol B enzyme, and protein kinase treatment added further 1.3 mol of Pi to give a single phosphopeptide (X). On the other hand, B1 enzyme purified from the transplanted human lung cancer which had been labeled in vivo with 32Pi revealed at least two phosphopeptides (X and Y). Assuming that the sulfatase from normal liver and lung cancer possesses the same number of available phosphorylation sites, phosphorylation of site X which was available only by deliberate phosphorylation of the native, ordinary B enzyme appears to be cancer-associated. Increasing phosphorylation of the sulfatase resulted in a maximum 50% elevation in arylsulfatase activity, followed by a decrease of the activity upon overphosphorylation, using an artificial substrate.
Animals↗
Characterization of neutral glycosphingolipids from porcine erythrocyte membranes.
1. Six neutral GSL fractions were purified from porcine erythrocyte membranes. 2. They were identified to be LacCer (14% of total neutral GSLs), 2-hydroxy acid-rich and -poor Gb3Cer (3 and 7%, respectively) and Gb4Cer (71%) by means of NMR spectrometry. 3. Monohexosylceramides (5%) were composed of GlcCer and GalCer with near amount. 4. All these GSL classes contained a high concentration (more than 20% of total acids in each class) of 2-hydroxy fatty acids. 5. GalCer and GlcCer contained considerable amounts of C16- and C18-acids, and of C18-phytosphingosine, whereas C24-acids and C18-sphingosine were predominant in the other GSLs. 6. A minor GSL fraction (less than 1% of total neutral GSLs) which migrated more slowly than Gb5Cer on a thin layer plate and composed of several GSL components contained L-fucose.
Animals↗
Characterization of neutral glycosphingolipids from fetal human brain: evidence for stage-specific expression of the globo, ganglio, and neolacto series in the central nervous system.
Neutral glycosphingolipids were isolated from normal human fetal brains, at 22 to 23 weeks gestation. They were identified as monohexosylceramides, lactosylceramide, and glycolipids belonging to the globo (globotriaosylceramide) and ganglio (gangliotriaosylceramide) series. In addition, considerable amounts of neolactotetraosylceramide and III3-alpha-fucosyl-neolactotetraosylceramide were detected. Although neutral glycolipids of the globo, ganglio, and neolacto series have been demonstrated in the brains of cases with some sphingolipidoses, they are not present in appreciable amounts in differentiated normal brain. Therefore, the present and previous observations would imply that the metabolism of these glycolipid series actively occurs in the normal brain at an early stage of differentiation and continues thereafter in the brain in the case of some sphingolipidoses. The diseased brain is most probably accompanied by a disturbance of differentiation.
Antibodies, Monoclonal↗
Biochemical heterogeneity in I-cell disease. Sucrose-loading test classifies two distinct subtypes.
Since we observed the normalization of intracellular hydrolases in some cell lines of I-cell disease (ICD) by 88 mmol/l sucrose, we have hypothesized that the degree of responses of the hydrolases might be due to biochemical heterogeneity among ICD. In this study the changes of intracellular lysosomal enzymes as well as Golgi enzymes including N-acetylglucosaminyl phosphotransferase (GlcNAcPTase) and extracellular hexosaminidase (HEX) were investigated using normal and ICD fibroblasts. Sucrose loading induced the activities of intracellular HEX and GlcNAcPTase simultaneously only in responding-type ICD cells, and not in nonresponding-type ICD cells, indicating that two biochemical heterogeneous groups exist in ICD.
Cells, Cultured↗
[Phosphorylation of lysosomal hydrolases in human cancer and its significance].
Many lysosomal hydrolases in cases of human cancer were found to be accompanied by acidic variant forms together with the major hydrolase components. Such variants were found to be phosphorylated not only at their carbohydrate moiety which contributes largely to their acidic property, but also at the protein moiety. We identified a cAMP-dependent protein kinase which is responsible for phosphorylation of arylsulfatase B. The protein kinase activity toward the sulfatase was considerably higher in transplanted lung cancer than in normal lung in the presence of cAMP. The B enzyme purified from normal human liver was found to contain 0.6mol of Pi/mol of B enzyme, and protein kinase treatment added a further 1.3mol Pi to give a single phosphopeptide (X) containing phosphothreonine. On the other hand, the B1 enzyme purified from transplanted human lung cancer which had been labeled in vivo with [32P] Pi revealed at least two phosphopeptides (X and Y). Assuming that the sulfatase from liver and lung cancer possesses the same number of available phosphorylation sites, phosphorylation of site X (Thr) which is available only by deliberate phosphorylation of the native, ordinary B enzyme, appears to be cancer-associated. Increased phosphorylation of the sulfatase resulted in a maximum 50% elevation in arylsulfatase activity, followed by a decrease in the activity upon overphosphorylation, using an artificial substrate.
Adenocarcinoma↗
Protein phosphorylation of lysosomal arylsulfatase B in normal and leukemic leukocytes.
An acidic variant form of arylsulfatase B from normal leukocytes and chronic myelogenous leukemia (CML) leukocytes was found to be phosphorylated at its serine and threonine residues through in vivo phosphorylation with 32Pi. However, the predominant phosphorylation site was serine in normal cells, in contrast to threonine in CML cells. A cyclic AMP-dependent protein kinase was responsible for phosphorylation of the sulfatase of CML cells.
Chondro-4-Sulfatase↗
Complete structural analysis of globoseries glycolipids by two-dimensional nuclear magnetic resonance.
Combined two-dimensional proton nuclear magnetic resonance allowed the determination of complete oligosaccharide structures of glycolipids belonging to the globo series, without any other analytical methods. Although a chemical modification by peracetylation was required for the above purpose, the derivatization permitted facile assignment of the pyranose ring proton resonances of the oligosaccharide moiety. Two-dimensional chemical-shift-correlated spectroscopy of the acetylated glycolipid enabled us to elucidate the glycosidic positions from the chemical shifts of the protons at the substituted sites. The monosaccharide species were also identified from the characteristic splitting patterns of the methine protons on individual pyranose rings. The sequence of the monosaccharides was inferred from the interresidue connectivity across glycosidic linkages shown by two-dimensional nuclear Overhauser effect spectroscopy, which also gave intraresidue interaction on the pyranose rings. The linkage sites of long oligosaccharide chains having more than five monosaccharides, such as globopentaosylceramide, were analyzed by two-dimensional J-relayed coherence transfer, which yielded 1,3 interactions along with 1,2 interactions.
Acetylation↗
A new type of blood group B active glycosphingolipid in rat bone marrow cells. Occurrence of the glycolipid in rat immunocytes and ascites hepatoma.
A major glycosphingolipid in rat bone marrow cells was purified, and its structure was studied. The glycolipid was found to exhibit blood group B activity by the hemagglutination inhibition test. The structure was determined to be (formula; see text) by studies of nuclear magnetic resonance, sequential hydrolysis by exoglycosidases, linkage analysis of methylated sugars by gas chromatography-mass spectrometry, and immunological tests. The blood group B active glycolipid was detected not only in the bone marrow cells but also in spleen, thymus, and rat ascites hepatoma AH 7974F cells. Besides the glycolipid, gangliotriaosylceramide, gangliotetraosylceramide, and fucogangliotetraosylceramide were commonly detected in these cells. The similarity between the glycolipid species on the cell surfaces of the immunocytes and the tumor cells is discussed with the respect to an escape mechanism of the tumor cells from the immunosurveillance system.
ABO Blood-Group System↗
Purification and properties of galactosylceramide sulfatase activator from human liver.
Activator protein for galactosylceramide sulfatase (GSase) was purified from human liver. The activator has an approximate molecular weight of 22,000, is glycoprotein in nature, and is most probably a trimer consisting of an 8,000 dalton monomer. Monospecific rabbit antiserum raised against the activator strongly inhibited the activity of the activator. In the presence of a 10-fold or more excess of galactosylceramide sulfate (GS) on a molar basis, GS binding to the GSase activator occurred, and was saturated at an equimolar ratio. Binding studies on the GSase activator were conducted using affinity chromatography on derivatives of GS as ligands, and gel filtration of mixtures containing glycolipids and the activator. A "GS-acid" derivative, which was prepared by oxidative cleavage of sphingosine moiety in GS, and a sulfonamide derivative of GS as ligands still retained affinity for the GSase activator, while a hydrophobic ligands, an aminohexyl group did not bind completely the activator. A ligand of "galactosylceramide-acid" had weak affinity for GSase activator. These results suggest that the sulfate group and one of the two hydrocarbon chains in GS are not essential for the binding of the activator. The affinity of galactosylceramide for the GSase activator was confirmed by the detection of the lipid-protein complex on gel filtration. The activator weakly stimulated porcine GM1-beta-galactosidase activity.
Antigen-Antibody Complex↗
Expression of arylsulfatase B variant from leukocytes in chronic myelogenous leukemia related to chemotherapy.
Lysosomal arylsulfatase B of human leukocytes consisted of two forms; a basic form (B) and a variant form (B1) which is phosphorylated at the carbohydrate chains of the B form (Uehara, Y., Gasa, S., Makita, A., Sakurada, K., and Miyazaki, T. (1983) Cancer Res. 43, 5618-5622). The amounts of the variant form relative to the basic form were considerably increased in leukocytes of chronic myelogenous leukemia (CML). The present communication demonstrates that, upon chemotherapy of the patients with CML, degree of phosphorylation as well as the relative amounts of the phosphorylated variant form of CML leukocytes are markedly decreased concomitantly with an increase of the basic, less phosphorylated form. This effect of chemotherapy on the variant form preceded to clinical improvement of the CML patients, suggesting that the relative amount of the phosphorylated enzyme will be a potential prognostic indicator for the therapeutic effect of CML.
Adult↗
Glycosphingolipids of equine erythrocytes membranes: complete characterization of a fucoganglioside.
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Animals↗
Arylsulfatase a from normal human lung and lung tumors showed different patterns of microheterogeneity.
Arylsulfatase A was purified from human lung to apparent homogeneity as determined by electrophoresis in the presence of sodium dodecyl sulfate. The enzyme from normal lung as well as that from lung adenocarcinoma showed considerable microheterogeneity when examined by isoelectric focussing, with an isoelectric point (pI) ranging from 5.1 to 4.6. The tumor enzyme was more heterogeneous and contained more acidic components than the normal lung enzyme. The cause of the charge heterogeneity was examined by treatment with exogenous hydrolases. Upon treatment with sialidase, phosphatase or endo-beta-N-acetylglucosaminidase H (endoglycosidase H), the acidic enzyme forms shifted to an alkaline region on isoelectric focussing gels. Combined treatment of the arylsulfatase A with endoglycosidase H and sialidase resulted in complete loss of the most acidic components to give the less acidic components with pI 5.1, 5.0, and 4.9. These results strongly suggest that the charge heterogeneity of arylsulfatase A is due not only to sialylation but also to phosphorylation at the carbohydrate moiety of the enzyme, and the extent of substitution by acidic groups is markedly increased in the tumor enzyme.
Acetylglucosaminidase↗
Arylsulfatase A activities in urine and tissues taken from bladder cancer patients.
Urinary arylsulfatase A activity expressed as units/mg of urinary creatinine was significantly increased in bladder cancer patients, but not in patients with other genitourinary tract disorders, such as cystitis, urethritis and prostatic cancer, nor in patients with non-urological malignant diseases. The urinary enzyme activity was positively correlated with the stage of the bladder cancer, while post surgical follow-up revealed a marked decrease of the activity. Arylsulfatase A activity was also shown to be higher in malignant than in normal bladder tissue, demonstrating the activity to be a function of the grade of the tumor. Furthermore, the isoelectric point (pI 5.2-5.3) of the tissue enzyme in the bladder tumor coincided with that of the urine enzyme from the same cancer patients; the pI of the enzyme in urine from normal subjects was 4.7. These results suggest that most of the urinary arylsulfatase A in bladder cancer originates from tumor tissue.
Cerebroside-Sulfatase↗
[Structural analysis of glycosphingolipids by nuclear magnetic resonance spectroscopy].
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Animals↗