Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

---

Query: KEGG:D03345 (beta-Galactosidase)
434 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A 28-month-old child was found to have several clinical features of lysosomal storage diseases, including: coarse facies, hepatosplenomegaly, lumbar kyphosis due to hypoplastic beaked L1 and L2 vertebral bodies, vacuolated lymphocytes in blood smears and rare foamy hystiocytes in bone marrow. However, no signs of neurological or ocular abnormalities were detected. A beta-galactosidase deficiency was demonstrated in leukocytes and cultured skin fibroblasts, with a residual activity toward 4-methylumbelliferyl-beta-galactopyranoside ranging between 5 and 15% of the normal mean. Normal activities were found for several other lysosomal acid hydrolases. beta-Galactosidase activities in leukocytes and cultured skin fibroblasts from both parents were within the normal ranges. The patient seems to represent an atypical expression of acid beta-galactosidase deficiency, since his clinical picture does not exaclty correspond to that of either the two classical types of GM1-gangliosidosis or other atypical patients reported in the literature havining beta-galactosidase deficiency.
...
PMID:Atypical expression of beta-galactosidase deficiency in a child with Hurler-like features but without neurological abnormalities. 9 48

1. Human liver acid beta-galactosidase A2 and A3 were isolated by chromatography on concanavalin A-Sepharose 4B, Sepharose 6B, and Sepharose 4B-6-aminohexyl 1-thio-beta-D-galactopyranoside. beta-Galactosidase A2 and A3 were purified to final specific activities of 45.5 and 20.6 mumol/min per mg respectively with 4-methylumbelliferyl beta-D-galactopyranoside as substrate. 2. Form A2 had a mol.wt. of 150000 +/- 15000 (gel filtration) and appeared as a single band of protein (mol.wt 65000 +/- 1000) on electrophoresis in the presence of sodium dodecyl sulphate. 3. Form A3 had a mol.wt. (gel filtration) of 660000 +/- 66000. On electrophoresis in the presence of sodium dodecyl sulphate, form A3 appeared as a major band of protein (72% of total) of mol.wt. 65000 +/- 1000 and minor protein bands of mol.wt. 44000 +/- 1000 and 26,000 +/- 1000 and 22000 +/- 1000. 4. Gel-filtration chromatography of purified beta-galactosidase A3 generated approximately equal amounts of forms A3 and A2. beta-Galactosidase A1 was not detected by gel-filtration chromatography of partially or highly purified preparations of forms A2 and A3. 5. Both forms A2 and A3 had identical isoelectric points of 4.42 +/- 0.02. The data suggest that forms A2 and A3 are dimeric and multimeric forms of beta-galactosidase A1. 6. Amino acid analysis of beta-galactosidase A2 gave a ratio of acidic to basic amino acids of 2.6:1. 7. beta-Galactosidase A2 contained 7.5% carbohydrate by weight and sialic acid, D-galactose, D-glucosamine and D-mannose were present in the molar proportions 1.1:1.0:1.7:2.7.
...
PMID:Characterization of purified human liver acid beta-D-galactosidases A2 and A3. 10 12

The expression of cell cycle events in Caulobacter crescentus CB13 has been shown to be associated with regulation of carbohydrate utilization. Growth on lactose and galactose depends on induction of specific enzymes. Prior growth on glucose results in a delay in enzyme expression and cell cycle arrest at the nonmotile, predivisional stage. Dibutyryl cyclic adenosine 3',5'-monophosphate (AMP) was shown to stimulate expression of the inducible enzymes and, thus, the initiation of the cell cycle. beta-Galactosidase-constitutive mutants did not exhibit a cell cycle arrest upon transfer of cultures from glucose to lactose. Furthermore, carbon source starvation results in accumulation of the cells at the predivisional stage. The cell cycle arrest therefore results from nutritional deprivation and is analogous to the general control system exhibited by yeast (Hartwell, Bacteriol. Rev. 38:164-198, 1974; Wolfner et al., J. Mol. Biol. 96:273-290, 1975), which coordinates cell cycle initiation with metabolic state. Transfer of C. crescentus CB13 from glucose to mannose did not result in a cell cycle arrest, and it was demonstrated that this carbon source is metabolized by constitutive enzymes. Growth on mannose, however, is stimulated by exogenous dibutyryl cyclic AMP without a concomitant increase in the specific activity of the mannose catabolic enzymes. The effect of cyclic AMP on growth on sugars metabolized by inducible enzymes, as well as on sugars metabolized by constitutive enzymes, may represent a regulatory system common to both types of sugar utilization, since they share features that differ from glucose utilization, namely, temperature-sensitive growth and low intracellular concentrations of cyclic guanosine 3',5'-monophosphate.
...
PMID:Effect of carbon source and the role of cyclic adenosine 3',5'-monophosphate on the Caulobacter cell cycle. 19 60

A plasmid shuttle vector (pSP10) was designed and constructed to simplify screening of cloned DNA and to facilitate expression of the protein products. The plasmid contained the following features: (i) a selection gene, chloramphenicol acetyltransferase; (ii) an indicator gene encoding beta-galactosidase for visual identification of colonies containing DNA inserts; (iii) a cloning region immediately upstream from the indicator gene; (iv) origins of replication recognized by both Escherichia coli and Bacillus subtilis; and (v) a synthetic DNA expression control sequence, including -35 and -10 regions, ribosomal binding site, and transcriptional and translational start sites. The promoter region is a synthetic consensus sequence derived from published B. subtilis promoters. The plasmid has been shown to replicate actively in E. coli and B. subtilis and to confer chloramphenicol resistance to both hosts. DNA inserted at the cloning region inactivates the indicator gene, resulting in white colonies on 5'-bromo-4-chloro-3-indolyl-beta-D-galactopyranoside plates. beta-Galactosidase has been expressed from pSP10 in both E. coli and B. subtilis. A comparison was made of the expression levels of beta-galactosidase from the same plasmid which had been modified to contain: (i) the synthetic control region, (ii) no promoter region, (iii) the synthetic control region cloned in the opposite orientation, or (iv) the tac promoter.
...
PMID:Protein expression from an Escherichia coli/Bacillus subtilis multifunctional shuttle plasmid with synthetic promoter sequences. 139 13

The beta-galactosidases of several mutagenized strains of Escherichia coli K12 which grew on lactobionate were found to be heat labile. Sequence analysis of the lacZ gene (ligated into Bluescript) of one of these strains (E. coli REH4) showed that the only change in the amino acid sequence was a substitution of an Asp for Gly-794. This change caused a dramatic increase of the activity when lactose was the substrate. The kcat of the purified enzyme from E. coli REH4 (G794D-beta-galactosidase) with lactose as the substrate was five to six times as large as the kcat of the normal enzyme with lactose. Purified G794D-beta-galactosidase was, however, less stable to heat and also to chymotrypsin (which cleaves next to Trp-585) than was normal beta-galactosidase. G794D-beta-Galactosidase bound substrates and substrate analog inhibitors less well than did normal beta-galactosidase while planar transition state analog inhibitors were more strongly bound. The ability to bind 2-amino-D-galactose (a positively charged transition state analog inhibitor) was either unaltered or was decreased somewhat. The data showed that the alteration in structure caused an increase in the value of k2 (the rate constant for the step in which the glycosidic bond is cleaved) with each substrate tested (the increase was at least 25-fold when lactose was the substrate) while k3 was decreased about 4-fold (k3 is the rate constant for the common hydrolysis step with each substrate). Since k2 is rate determining when lactose is the substrate of the normal enzyme, the increase in k2 resulted in a large increase in rate despite the fact that the value of k3 decreased. Large rate increases were not found with the other two substrates because the k2 values were not increased by large factors and because the decrease in the value of k3 negated the effects of the increased k2 values. The destabilization of the substrate binding coupled with a stabilization of the binding of a planar transition state is a possible cause of the significant increase in the value of k2 and of the enhanced activity with lactose.
...
PMID:A highly reactive beta-galactosidase (Escherichia coli) resulting from a substitution of an aspartic acid for Gly-794. 190 May 12

A simple, rapid competitive ultramicroElisa assay has been developed for the measurement of total thyroxine (T4) using only 10 microliters of serum. Our novel UME is based on fluorescence measurements of the hydrolytic product of 4-methyl-umbelliferyl-beta-D-galactopyranoside. T4-beta-Galactosidase conjugates and monoclonal antibodies were immobilized on polyvinyl plates, with sodium salicylate used as a blocking agent for thyroxine binding protein. The analytical steps were carried out using a semiautomated batch-assay system entitled "SUMA" (system for ultramicroanalysis). The T4 assay was completed in 2 h, with a measuring range of 24-386 nmol/L. The intra-assay coefficient of variation (CV) was 4.6-6.9% and the inter-assay C.V. 9.0-12.4% depending on the T4 concentrations. Percentage recovery ranged from 99.2-111%. Regression analysis showed a good correlation with an established radioimmunoassay (n = 121, r = 0.946, P less than 0.01).
...
PMID:An enzyme immunoassay for determining total thyroxine in human serum using an ultramicroanalytical system. 190 3

beta-Galactosidase from psychotrophic Bacillus subtilis KL88 was specific to the beta-D-glycosidic linkage normally present in lactose. The enzyme was completely inhibited by transition metal ions (Cu2+, Fe3+, Fe2+, Zn2+) and partially inhibited by high concentrations of glucose and galactose as well as Ca2+. It was activated by most of the alkaline earth metal ions (NA+, K+, Li+). Oligosaccharides were formed at the different levels of lactose concentrations reaching more than 20% for high lactose concentration (20%). Three types of oligosaccharides were formed in significant concentrations detected by HPLC analysis.
...
PMID:Specificity, inhibitory studies, and oligosaccharide formation by beta-galactosidase from psychrotrophic Bacillus subtilis KL88. 191 56

Phenylhydrazine (Phz) is a powerful hemolytic agent which has several effects on both normal and G6PD deficient red blood cells (RBCs). We have studied the mechanism of removal of Phz-damaged human RBCs by murine macrophages. Phagocytosis of Phz-treated RBCs was found to be 50 RBCs/100 mac as compared to 2 RBCs/100 mac of the controls. EGTA and sodium azide inhibited the phagocytosis, indicating a requirement for both calcium ions and energy. Incubation of macrophages with sugars such as D-galactose or D-mannose reduced phagocytosis of Phz-treated RBCs by up to 60%, indicating the involvement of a macrophage lectin-like receptor in the recognition of Phz-treated RBCs. The presence of serum in the phagocytosis assay did not affect either phagocytosis of Phz-treated RBCs or inhibition by sugars. beta-Galactosidase, but not neuraminidase, treatment of RBCs caused a significant inhibition in phagocytosis of Phz-treated RBCs. These results suggest that galactosyl residues are exposed on RBC membrane during oxidation, probably not as a result of desialization. We conclude that Phz-treated RBCs are detected as damaged cells mainly due to sugar changes on their membrane, which are directly recognized by lectin-like receptors on the macrophages.
...
PMID:A lectin-like receptor on murine macrophage is involved in the recognition and phagocytosis of human red cells oxidized by phenylhydrazine. 210 24

To ascertain whether mannose 6-phosphate-containing peptides that bind to the insulin-like growth factor II (IGF II)/mannose 6-phosphate receptor activate phospholipase C, we determined the effect of proliferin, transforming growth factor-beta 1 (TGF-beta 1) precursor, and beta-galactosidase on production of inositol trisphosphate (Ins-P3) in basolateral membranes isolated from the renal proximal tubule of dogs. Both proliferin and TGF-beta 1 precursor stimulated Ins-P3 production in a concentration-dependent manner. Maximal production was stimulated by approximately 10(-13) M of each peptide. beta-Galactosidase had no effect on Ins-P3 generation. Neither proliferin nor TGF-beta 1 precursor potentiated IGF II-stimulated Ins-P3 production. Mannose 6-phosphate itself had no effect on Ins-P3 generation. However, mannose 6-phosphate potentiated production stimulated by 10(-11) M proliferin or 10(-11) M TGF-beta 1 precursor while inhibiting production stimulated by 10(-14) M of either peptide. Addition of anti-mannose 6-phosphate receptor antibodies to basolateral membranes abolished proliferin and TGF-beta 1 precursor-stimulated Ins-P3 generation. We conclude that, in addition to IGF II, mannose 6-phosphate-containing ligands for the IGF II/mannose 6-phosphate receptor activate basolateral membrane phospholipase C. Such activation could reflect a common mechanism for signal transduction by these peptides mediated via the IGF II/mannose 6-phosphate receptor.
...
PMID:Mannose 6-phosphate-containing peptides activate phospholipase C in proximal tubular basolateral membranes from canine kidney. 216 41

beta-Galactosidase from an autolytic strain of Streptococcus salivarius subsp. thermophilus was purified 109-fold to near homogeneity. The yield of purified enzyme was 41% and the specific activity was 592 o-nitrophenyl beta-D-galactopyranoside U/mg at 37 degrees C. Two isozymes were present, but only one subunit was detected, having a mol. wt of 116,000. Enzyme stability was 37-83 times greater in milk than in buffer in the range 60-65 degrees C. At 60 degrees C the half-life in milk was 146 min. Denaturation in buffer was first-order, but in milk the overall reaction order with respect to enzyme concentration was approximately 0.5. The activation energy for denaturation was 453 kJ/mol in milk and 372 kJ/mol in buffer. In milk the activation energy for lactose hydrolysis was 35.1 kJ/mol.
...
PMID:Purification and thermostability of beta-galactosidase (lactase) from an autolytic strain of Streptococcus salivarius subsp. thermophilus. 249 13


1 2 3 4 5 6 7 Next >>

---