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Y Uda

Publications and source records attributed to Y Uda.

At least 37 records · Page 2Linked to original sources
PubMed1993

Purification and characterization of an alpha-L-fucosidase from Pomacea canaliculata.

An alpha-L-fucosidase (EC 3.2.1.51) was isolated from the hepatopancreas of Pomacea canaliculata. The enzyme was purified 285-fold from the crude enzyme extract by procedures involving first heat treatment, ammonium sulfate fractionation, second heat treatment, and chromatography on DEAE-Sepharose, hydroxylapatite, and L-fucosylamine-CH-Sepharose. When assayed by using p-nitrophenyl glycosides as substrates, the final preparation was free from other glycosidase activities and gave a single protein band which corresponded to alpha-L-fucosidase activity on disc gel electrophoresis. The molecular weight of the enzyme was estimated to be 260,000 by Sephacryl S-300 column chromatography. The enzyme has two optimum pH values, 2.5 and 5.0, and the apparent Km value and the maximum velocity for p-nitrophenyl alpha-L-fucoside at both pH were calculated to be 0.45 mM and 1.46 mumol/min/mg of protein, respectively. The enzyme was shown to hydrolyze the Fuc alpha 1-->2Gal, the Fuc alpha 1-->4GlcNAc, and the Fuc alpha 1-->6GlcNAc linkages, but hardly acts on the Fuc alpha 1-->3GlcNAc linkage in various oligosaccharides.

Ammonium Sulfate↗
PubMed1993

Effects of cyclodextrins on the hydrolysis of ganglioside GM1 by acid beta-galactosidases.

The hydrolysis of ganglioside GM1 by acid beta-galactosidases was greatly enhanced by the inclusion of heptakis(2,6-di-O-methyl)-beta-cyclodextrin or alpha-cyclodextrin in the assay mixture. The other cyclodextrins tested were not effective. The extent of stimulation by these cyclodextrins was relatively smaller than those by taurodeoxycholate and taurochenodeoxycholate. However, it is suggested that stimulation by bile salts may be partly a reflection of the detergent effects of bile salts on GM1 and partly a reflection of the interaction between bile salts and the enzyme itself. On the other hand, the stimulation by the cyclodextrins seems to correlate to the formation of an inclusion complex between GM1 and cyclodextrin without enzyme protein interaction.

Animals↗
PubMed1993

Activation of human lysosomal sialidase.

An acid sialidase [EC 3.2.1.18], partially purified from human placenta by Con A-Sepharose adsorption and p-aminophenyl thio-beta-D-galactoside-CH-Sepharose (PATG-Sepharose) affinity chromatographies, was activated by incubation at 37 degrees C. This activation showed both time and temperature dependencies, with the most effective activation observed at 37 degrees C in the pH range between 4.3 and 5.2. The influence of various protease inhibitors on its activation was investigated. Among the protease inhibitors tested, amastatin, an inhibitor of aminopeptidase A, significantly inhibited activation. The partially purified enzyme preparation contained aminopeptidase activity, which was inhibited by amastatin. Zinc ions inhibited either the activation of sialidase or the aminopeptidase activity in the enzyme preparation. These results suggest the possibility of participation of aminopeptidase function in the activation process of sialidase.

Aminopeptidases↗
PubMed1993

A study on gamma-aminobutyric acid (GABA) and its analogues by using molecular orbital methods: on epileptogenicity of new quinolones.

Using the molecular orbital methods, we examined molecular structure, electron density distribution, electrostatic potential field and receptor structure of gamma-aminobutyric acid (GABA), and its analogues. The following findings were obtained: a comparison of the biological activity and the morphology electrostatic potentials of GABA analogues disclosed that the active site is the amino group, and the biological activity correlates closely with the electrostatic potential structure around the amino group. The active sites were compared between the receptor-binding molecules and the GABA uptake inhibitory molecules, and the results suggested that the receptor structure differed between the two groups of molecules and that the GABA A receptors had two subtypes. On these results, the epileptogenicity of new quinolones was studied using this method. These results suggested that the new quinolones blockaded the GABA receptor-binding system and that the important active site of the new quinolones for GABA receptor-binding was the the piperazyl amino group. These results suggested that the concentration of zwitterion type of the new quinolones was very important clinically.

Animals↗
PubMed1993

A case of protein C deficiency associated with cerebral infarction and obstruction of deep leg and inferior mesenteric veins.

Protein C, a vitamin K-dependent protein, is a blood coagulation inhibitor. Its deficiency causes systemic thrombosis. A 31-year-old woman developed cerebral infarction followed by late psychomotor seizures, and thrombosis in the inferior mesenteric vein and bilateral crural veins. Her parents were first cousins. Her mother died of cerebral thrombosis in her 30's. Her elder brother died of suspected purpura fulminans immediately after birth. Her protein C activity and protein C antigen level decreased markedly and were less than 5% of those of normal controls and 0.3 microgram/ml, respectively. Her father, a paternal aunt and a maternal uncle also showed a low protein C activity and protein C antigen level. This patient seems to have congenital protein C deficiency which produced thrombosis in the leg veins and the mesenteric vein, probably cerebral infarction.

Adult↗
PubMed1993

Characterization of lignoceroyl-CoA ligase activity in chicken liver microsomes.

Lignoceroyl-coenzyme A (CoA) ligase activity was detected in microsomal fractions from chicken liver in the presence of alpha-cyclodextrin as a solubilizing agent of lignoceric acid. Heptakis(2,6-di-O-methyl)-beta-cyclodextrin (dimethyl-beta-cyclodextrin) and hexakis(2,6-di-O-methyl)-alpha-cyclodextrin (dimethyl-alpha-cyclodextrin), among the cyclodextrins tested, were more effective than alpha-cyclodextrin as solubilizing agents. We have characterized lignoceroyl-CoA ligase activity in comparison with palmitoyl-CoA ligase activity. Lignoceroyl-CoA and palmitoyl-CoA ligase activities showed a similar dependency on CoA concentration. However, lignoceroyl-CoA ligase activity exhibited responses to the Mg2+ ion, adenosine triphosphate (ATP), ATP analogues (adenosine monophosphate (AMP) and adenosine diphosphate (ADP)), and heat treatment, which were distinctly different from the responses of palmitoyl-CoA ligase activity. These results are consistent with the idea that lignoceroyl-CoA and palmitoyl-CoA are synthesized by two different enzymes.

Adenosine Triphosphate↗
PubMed1991

Human placental sialidase complex: characterization of the 60 kDa protein that cross-reacts with anti-saposin antibodies.

Sialidase isolated from human placenta is associated with several proteins including acid beta-galactosidase, carboxypeptidase, N-acetyl-alpha-galactosaminidase, and others. These proteins are thought to form an aggregated complex during isolation of sialidase. One of the proteins of 60 kDa was recently identified by Potier et al. (Biochem. Biophys. Res. Comm. 173, 449-456, 1990) as a sialidase protein: this protein also cross-reacted with anti-prosaposin antibodies. We have isolated this protein and from the following evidence identified it as a heavy chain component of immunoglobulin G and not sialidase or a derivative of prosaposin. On gel filtration HPLC, sialidase activity and the 60 kDa protein were clearly separated from one another. The 60 kDa protein cross-reacted not only with antibodies raised against human saposins A, C, and D, but also with second antibody (goat anti-rabbit immunoglobulin G antibody) alone. This 60 kDa protein strongly cross-reacted with anti-human immunoglobulin G antibodies. The sequence of the initial 15 amino acids from the N-terminus of the 60 kDa protein was identical to the sequence of an immunoglobulin G heavy chain protein Tie (gamma 1).

Amino Acid Sequence↗
PubMed1990

Molecular cloning of two species of cDNAs for human alpha-N-acetylgalactosaminidase and expression in mammalian cells.

Two species of cDNAs for human alpha-N-acetylgalactosaminidase were isolated from a human fibroblast cDNA library. The two species differ each other by a 70 bp insertion in the coding region. Transient expression study in COS cells demonstrated that only the cDNA without the 70 bp insertion expressed alpha-N-acetylgalactosaminidase activity. Analysis of mRNA species utilizing polymerase chain reaction revealed that the majority of the mRNA does not contain the 70 bp insertion, and the mRNA containing the 70 bp insertion is present only in a minor amount in human brain.

Acetylglucosaminidase↗
PubMed1989

Molecular cloning of a full-length cDNA for human alpha-N-acetylgalactosaminidase (alpha-galactosidase B).

In the process of molecular cloning of cDNA for proteins associated with a purified human placental sialidase fraction, we discovered one of the proteins with apparent molecular weight of 46 kDa is in reality alpha-N-acetylgalactosaminidase. The full length cDNA, pcD-HS1204, codes for 358 amino acids with the first 17 residues representing a putative signal peptide. The predicted amino acid sequence shows striking homology with human alpha-galactosidase A and yeast alpha-galactosidase. The substrate specificities as well as the behavior of the 46 kDa protein on hydroxylapatite chromatography confirmed that the 46 kDa protein is in reality alpha-N-acetylgalactosaminidase.

Amino Acid Sequence↗
PubMed1988

Human placental sialidase: further purification and characterization.

An acid sialidase [EC 3.2.1.18] has been purified from human placenta by means of successive procedures including extraction, Con A-Sepharose adsorption, ammonium sulfate precipitation, activation, p-aminophenyl thio-beta-D-galactoside-CH-Sepharose (PATG-Sepharose) affinity chromatography and high-performance liquid chromatography on a Shim pack Diol 300 column. The purified enzyme liberated sialic acid residues from sialooligosaccharides, sialoglycoproteins, and gangliosides. In particular, gangliosides GM3, GD1a, and GD1b were hydrolyzed much faster than alpha (2-3) and alpha (2-6)sialyllactoses, and sialoglycoproteins by the enzyme. On sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the purified enzyme gave five protein bands with molecular weight of 78,000 (78K), 64,000 (64K), 46,000 (46K), 30,000 (30K), and 20,000 (20K). Rabbit antisera were raised against 78K and 46K proteins, and the two antibodies were specifically reactive with the respective component on immunoblot analysis. Both anti-78K protein and anti-46K protein antisera could precipitate sialidase activity. It is likely that the 78K protein and 46K protein are sub-components which are essential for sialidase activity.

Female↗
PubMed1988

GM1 ganglioside beta-galactosidases from bovine liver.

Two GM1 ganglioside beta-galactosidases, multimeric form (enzyme I) and monomeric form (enzyme IV), have been purified from bovine liver by the procedures comprising Sephadex G-100 gel filtration, affinity chromatographies on Concanavalin A (Con A)-Sepharose and p-aminophenyl thio-beta-galactoside-CH-Sepharose (PATG-Sepharose) and Sephadex G-200 gel filtration. The multimeric form of the enzyme was purified 13,000-fold and monomeric form was 68,700-fold. On sodium dodecyl sulfate poly acrylamide gel electrophoresis, the monomeric form of the enzyme gave a single protein band with a molecular weight of 65,000, while the multimeric form gave two minor protein bands with molecular weights of 32,000 and 20,000 in addition to the major band at 65,000. Both enzymes liberated the terminal galactose from GM1 ganglioside and lactosylceramide. Enzyme I showed a broad pH optimum between pH 4.3 and 5.0, while enzyme IV was most active at pH 4.75. The pI values of beta-galactosidases I and IV were 4.6 and 5.8, respectively. Both enzymes were quite stable upon preincubation at 45 degrees C under acidic condition (pH 4.5), but rapidly lost their activities under neutral condition (pH 7.0). The apparent Km values for GM1 ganglioside of beta-galactosidases I and IV were calculated to be 2.0 x 10(-4) M and 3.3 x 10(-4) M, respectively.

Animals↗
PubMed1987

Purification and properties of beta-D-glucosidase (linamarase) from the butter bean, Phaseolus lunatus.

A beta-D-glucosidase (linamarase) was purified 11,700-fold from the butter bean, Phaseolus lunatus L., by means of successive procedures including extraction, ammonium sulfate fractionation, acetone treatment, and chromatographies on CM-Sephadex, DEAE-Sephadex, and Sephadex G-200. The final preparation gave a single protein band on both disc polyacrylamide gel electrophoresis and SDS-polyacrylamide gel electrophoresis. In spite of its electrophoretic purity, the final enzyme preparation showed four glycosidase activities; beta-D-glucosidase, beta-D-galactosidase, beta-D-fucosidase, and beta-D-xylosidase. The molecular weight of the enzyme was determined to be 124,000 +/- 9,000 by Sephadex G-200 gel filtration, and 59,000 +/- 2,400 by SDS-disc gel electrophoresis. The enzyme showed a pH optimum in the range of 5.1 to 6.0 with p-nitrophenyl beta-D-glucoside, 4-methylumbelliferyl beta-D-glucoside, and linamarin. Among natural substrates containing a beta-glucosyl terminal, linamarin, prunasin, and salicin were hydrolyzed by the enzyme from butter beans, but amygdalin, cellobiose, gentiobiose, and laminarin were hardly hydrolyzed.

Amino Acids↗
PubMed1987

Human placental sialidase: partial purification and characterization.

A sialidase [EC 3.2.1.18] has been partially purified from human placenta by means of procedures comprising Con A-Sepharose adsorption, ammonium sulfate precipitation, sucrose density gradient centrifugation, and high-pressure liquid chromatography on a Shim pack Diol 300 column. On high-pressure liquid chromatography, most of the beta-galactosidase that comigrated with the sialidase on sucrose density gradient centrifugation was removed. The sialidase was purified 3,600-fold from the preparation obtained by Con A-Sepharose adsorption. The enzyme liberated the sialic acid residues from (alpha 2-3) and (alpha 2-6) sialyllactose, colomic acid, fetuin, and transferrin, but not from bovine submaxillary mucin. The enzyme also hydrolyzed gangliosides GM3, GD1a, and GD1b in the presence of sodium cholate as a detergent, but GM1 and GM2 were less susceptible to the enzyme. The optimum pHs for 4-methylumbelliferyl-N-acetylneuraminate, sialyllactose, fetuin, and GM3 lay between 4.0 and 5.0.

Chromatography, Affinity↗