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

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Query: EC:3.2.1.23 (beta-galactosidase)
14,648 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Acid beta-D-galactosidases (EC 3.2.1.23) from human urine samples have been characterized using GM1-ganglioside, asialofetuin, and 4-MU-beta-D galactopyranoside. Sepharose 6-B column chromatography of crude urine supernatant fluids resolved three forms of acid beta-D-galactosidase activity with apparent molecular weights of 500 X 10(3)--700 X 10(3) (I), 90 X 10(3)--120 X 10(3) (II), and 20 X 10(3)--27 X 10(3) (III), which hydrolyzed 4-MU-beta-D-galactopyranoside, GM1-ganglioside and asialofetuin. The crude urine supernatant fluids and the separated forms of acid beta-D-galactosidase exhibited similar apparent KM values for the respective substrates. Starch gel electrophoresis of urine samples at pH 7.0 revealed a slow anodally migrating form of acid beta-D-galactosidase which electrophoretically corresponded to form I and a faster anodally migrating form corresponding to form II. Form III migrated as a composite of forms I and II suggesting that aggregation to the larger molecular weight activity forms occurred during starch gel electrophoresis. This report represents the first characterization of urinary acid beta-D-galactosidase with respect to naturally occurring glycolipid and glycoprotein substrates. In addition, data is presented to indicate that the enzyme may be composed of an enzymatically active form with an apparent molecular weight of 20 X 10(3)--27 X10(3), which is also capable of hydrolyzing the glycolipid and glycoprotein substrates.
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PMID:Characterization of the acid beta-D-galactosidases from human urine. 2 27

The distributions of acid alpha1-glycoprotein, alpha1-fetoprotein, beta-galactosidase and gastrin in gastric carcinoma and gastric ulcer as well as in the neighbourhood of these lesions were studied by means of immunohistochemical methods on imprint preparation. We could not find significant differences between gastric carcinoma and the nonneoplastic lesions, except for the acid alpha1-glycoprotein. The results of this first study indicate that the immunochemical and immunohistological assay of acid alpha1-glycoprotein might be of practical value in diagnosing malignant changes of gastric mucosa.
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PMID:[Immunohistochemical studies on non neoplastic and neoplastic gastric mucosa. Determination of embryonic and specific antigens (author's transl)]. 5 51

A case of adult type mucolipidosis with beta-galactosidase and sialidase deficiency is described. This patient, a woman aged 20, had mental retardation, macular cherry-red spots, corneal clouding, gargoyle-like face, cerebellar ataxia, myoclonus and convulsions beginning at the age of 14. Bony deformities, vacuoles in the peripheral lymphocyte and foamy cells in the bone marrow were also noted. Biopsy study of the sural nerve and vermiform appendix disclosed many vacuoles in almost every kind of cells, although the accumulated substance in these vacuoles could not be characterized histochemically or ultrastructurally. Deficient leukocyte beta-galactosidase and sialidase were confirmed. There was increased urinary sialoglycopeptide and increased siliac acid and hexosamine in the glycoprotein of lymphocytes. Leukocytes sialidase activites of the parents were 30 to 50% of the control values. These results suggest a genetic defect of sialidase.
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PMID:Adult type mucolipidosis with beta-galactosidase and sialidase deficiency. Histological and biochemical studies. 9 67

Fruiting body formation in the bacterium Myxococcus xanthus consists of a temporal sequence of cellular aggregation and sporulation. During the period of cellular aggregation, a major new development-specific protein that has lectin-like activity is synthesized. This protein, called myxobacterial hemagglutinin (MBHA), was able to agglutinate sheep or guinea pig erythrocytes but not horse, ox, chicken, or human erythrocytes. MBHA was undetectable in extracts of vegetative cells, cells starved in liquid buffer, or in glycerol-induced cells. However, cells starved on a fruiting medium produced large amounts of MBHA (about 5% of protein synthesis), starting at about 6-8 hr of development. The protein accumulated in the soluble fraction of cells, reaching a peak of 1-2% of total protein at about the time when aggregation was completed. At later times the amount of MBHA present in the soluble fraction declined although synthesis continued. The hemagglutinating activity of MBHA could not be inhibited with simple sugars or aminosugars but could be inhibited with fetuin, a fetal calf serum glycoprotein. The O-glycosidically linked trisaccharide glycopeptide of fetuin was shown to be inhibitory by itself. The penultimate galactose of this glycopeptide was directly implicated in the inhibitory activity, because the inhibition by asialofetuin was reduced to 1/60th by periodate oxidation and to 1/15th after beta-galactosidase treatment. MBHA is an abundant biochemical marker of development in M. xanthus. The fact that it is a lectin suggests that it may play a role in cell-cell recognition or agglutination.
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PMID:Myxobacterial hemagglutinin: a development-specific lectin of Myxococcus xanthus. 9 78

Two forms of beta-galactosidase from newborn rat epidermis could be separated by DEAE-cellulose chromatography. Both enzymes showed similar enzymic properties. They had a pH optimum around 3.5--4.5 and the optimal temperature of these enzymes was approximately 60 degrees C. They were not affected by divalent cations, ethylenediaminetetraacetic acid(EDTA) and 2-mercaptoethanol(2-ME), while rho-chloromercuribenzoic acid (PCMB) was a strong inhibitor for each enzyme. These enzymes showed the same Km value (1.25 x 10(-4) M) towards 4-methylumbelliferyl-beta-D-galactoside. However they had different isoelectric points at pH 6.3 and 9.0, respectively. Six different forms of beta-galactosidase activity were found by using isoelectric focusing. When the crude extract was incubated with neuraminidase before electrofocusing, the acidic forms of the enzyme were largely lost and converted to more basic forms without loss of the total activity. This finding suggests the glycoprotein nature of newborn rat epidermal beta-galactosidase.
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PMID:Heterogeneity and some properties of beta-galactosidase from newborn rat epidermis. 11 67

Bovine testicular beta-galactosidase (beta-D-galactoside galactohydrolase, EC 3.2.1.23) is rapidly and selectively assimilated by human skin fibroblasts. The assimilation of the enzyme is strongly inhibited by mannose 6-phosphate and by a glycoprotein fraction isolated from bovine testes (glycoprotein inhibitors). These results suggest that beta-galactosidase and the glycoprotein inhibitors have a common recognition marker that contains mannose 6-phosphate. The presence of mannose phosphate in the glycoprotein inhibitors was demonstrated by acid hydrolysis of the glycoproteins to liberate mannose phosphate followed by reduction with NaB(3)H(4) to give [(3)H]mannitol phosphate. The (3)H-labeled compound was identified by paper electrophoresis and by the release of [(3)H]mannitol on treatment with phosphatase. The [(3)H]mannitol phosphate was oxidized with periodate and the resulting phosphorylated fragment, on reduction with NaB(3)H(4), yielded [(3)H]ethylene glycol phosphate, indicating substitution of phosphate on carbon 6 of mannitol. Mannose 6-phosphate was also found in a major carbohydrate-containing fraction of peptides produced from the glycoprotein inhibitors by tryspin digestion. It was estimated that about 2% of the mannose residues were present as mannose 6-phosphate. Phosphorylated oligosaccharides were also identified in hydrolysates of the glycoprotein inhibitors. One, a disaccharide, was identified as alpha-(mannosyl-6-phosphate)-(1 --> 2)-mannose. These observations suggest that the recognition marker of beta-galactosidase contains alpha1,2-linked mannose 6-phosphate; terminal alpha1,2-linked mannose residues are known to occur in the high-mannose type oligosaccharides present on beta-galactosidase.
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PMID:Identification of mannose 6-phosphate in glycoproteins that inhibit the assimilation of beta-galactosidase by fibroblasts. 11 30

The enzyme beta-galactosidase (EC 3.2.1.23) from Aspergillus niger was purified and resolved into three multiple forms, using molecular sieving, ion-exchange, an hydrophobic chromatography. The isolated enzyme forms accounted for 83%, 8%, and 9% of the total beta-galactosidase activity, respectively. They were glycoproteins with estimated molecular weights of 124,000, 150,000 and 173,000, isoelectric points of about 4.6, and pH optima between 2.5 and 4.0. Amino acid and carbohydrate analyses showed that multiplicity was mainly due to dissimilar carbohydrate contents (about 12.5%, 20.5% and 29% neutral carbohydrates, respectively). The multiple form pattern might depend on the culture conditions. The beta-galactosidase forms were heat-stable up to about 60 degrees C. The Km values for lactose ranged from 85 mM to 125 mM, whereas those for the synthetic substrate o-nitrophenyl-beta-D-galactopyranoside were equal to about 2.4 mM. The V values obtained at 30 degrees C for lactose and o-nitrophenyl-beta-D-galactopyranoside were 104 units/mg enzyme protein and 121 units/mg enzyme protein, respectively (weighted averages for the three enzyme forms). The slight reactional dissimilarities between the three enzyme forms are unlikely to be physiologically relevant. The biological significance of A. niger beta-galactosidase multiplicity might be related to the observed differences in carbohydrate content, as suggested by recent reports on other microbial glycoprotein enzymes.
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PMID:beta-Galactosidase from Aspergillus niger. Separation and characterization of three multiple forms. 11 48

Deposition of PAS2-positive materials and thickening of the basement membrane in vascular lesions are characteristic findings in diabetes mellitus, suggesting altered metabolism of glycoprotein. Changes in the activities of the glycosidases, beta-N-acetylglucosaminidase [EC 3.2.1.30], beta-glucuronidase [EC 3.2.1.31], beta-galactosidase [EC 3.2.1.23], and beta-glucosidase [EC 3.2.1.21] were measured in various organs and the serum of diabetic rats. The activities of the first three enzymes listed above were found to be much reduced in the kidney but increased in the serum. The decreased activities of beta-glycosidases in the kidney may be one of the factors responsible for the pathogenesis of microangiopathy.
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PMID:Beta-glycosidases and diabetic microangiopathy. I. Decreases of beta-glycosidase activities in diabetic rat kidney. 13 96

Coupling of ribonucleoprotein particles from L cells infected with vesicular stomatitis virus to a pre-incubated ribosomal system obtained from uninfected HeLa cells allowed synthesis of two proteins. G1 (molecular weight 63,000) and G2 (molecular weight 67,000), and all other proteins of vesicular stomatitis virus except the spike protein G (molecular weight 69,000). Analyses of the tryptic peptides showed that G1, G2, and G had identical peptide sequences. The synthesis of G2 required the presence of membranes; only G1 was synthesized in the absence of any membranes. G2 but not G1 was shown to be a glycoprotein by affinity chromatography on a concanavalin A-Sepharose column. Removal of sialic acid residues from G by neuraminidase resulted in a product having an identical mobility to G2. Digestion of G2 or G with a mixture of neuraminidase (EC 3.2.1.18), beta-galactosidase (EC 3.2.1.23), and beta-N-acetylglucosaminidase (EC 3.2.1.30), however, produced a protein of molecular weight 65,000. These data suggest that G2 is the desialated G and is formed by glycosylation of G1, which is the unglycosylated polypeptide backbone of G.
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PMID:Synthesis and glycosylation in vitro of glycoprotein of vesicular stomatitis virus. 19 4

A protein, present in bovine seminal plasma, initiates forward motility in immature, immotile caput spermatozoa that have been incubated with a cyclic AMP phosphodiesterase inhibitor. An improved motility assay was developed to study this process and the protein involved. This forward motility protein exhibits multiple forms when fractionated on the basis of charge or molecular weight. Molecular sieving in urea or sodium dodecyl sulfate and dithiothreitol results in a single peak of activity which will re-form the larger aggregates in the absence of these agents. The molecular weight of this monomeric motility protein, as estimated from molecular sieving under these dissociating conditions, is 37,500. The forward motility protein can be partially purified by heat treatment, gell chromatography in urea, and affinity chromatography on concanavalin A/agarose. Enzymatic treatments further suggest a glycoprotein nature, i.e. treatment with beta-galactosidase, neuraminidase, alpha-mannosidase, or galactose oxidase reduces its activity by 50%; treatment with trypsin completely abolishes forward motility protein activity. On the basis of concurrent studies on the activity, properties, and distribution of forward motility protein in bovine body fluids, it is suggested that this protein is involved in the development of the capacity for motility as sperm traverse the epididymis.
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PMID:Bovine sperm forward motility protein. Partial purification and characterization. 21 Nov 30


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