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)

The polypeptide ligand angiogenin, a potent inducer of angiogenesis, localizes in the nucleus/nucleolus subsequent to endocytosis by relevant cell types. This study examines the kinetic properties of the nucleolar targeting signal (NTS) of angiogenin (IMRRRGL(35)) at the single cell level. We show that the NTS is sufficient to target green fluorescent protein (GFP), but not beta-galactosidase, to the nucleolus of rat hepatoma cells. Mutation of Arg(33) to Ala within the NTS abolishes targeting activity. Nuclear/nucleolar import conferred by the NTS of angiogenin is reduced by cytosolic factors as well as ATP and is independent of importins and Ran. The NTS also confers the ability to bind to nuclear/nucleolar components which is inhibited by ATP hydrolysis; nonhydrolysable GTP analogs prevent nuclear accumulation in the absence of an intact nuclear envelope through an apparent cytoplasmic retention mechanism. Since the lectin wheat germ agglutinin does not inhibit transport, we postulate a mechanism for angiogenin nuclear/nucleolar import involving passive diffusion of angiogenin through the nuclear pore and NTS-mediated nuclear/nucleolar retention, and with cytoplasmic retention modulating the process. This pathway is clearly distinct from that of conventional signal-mediated nuclear protein import.
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PMID:Novel properties of the nucleolar targeting signal of human angiogenin. 1137 89

We have demonstrated previously by Western blotting that in naturally sensitized humans, the serum or salivary antibody response to Streptococcus mutans was directed predominantly to a protein antigen with a size of approximately 60-kDa. To identify this immunodominant antigen, specific serum antibodies were eluted from immunoblots and five positive clones with inserts ranging in length from 3 to 8 kb from identical chromosomal loci were obtained by screening a genomic expression library of Streptococcus mutans GS-5. Amino acid sequencing established the identity of this immunodominant antigen, a 60-kDa immunodominant glycoprotein (IDG-60), to be a cell wall-associated general stress protein GSP-781, which was originally predicted to have a molecular mass of approximately 45 kDa based on the derived nucleotide sequence. Discrepancy in the molecular mass was also observed in recombinant his-tagged IDG-60 (rIDG-60) expressed from Escherichia coli. Glycosylation, consisting of sialic acid, mannose galactose, and N-acetylgalactosamine, was detected by lectin binding to IDG-60 in cell wall extracts from S. mutans and rIDG-60 expressed in vivo or translated in vitro. Despite the presence of multiple Asn or Ser or Thr glycosylation sites, IDG-60 was resistant to the effect of N-glycosidase F and multiple O-glycosidase molecules but not to beta-galactosidase. Insertional inactivation of the gene encoding IDG-60, sagA, resulted in a retarded growth rate, destabilization of the cell wall, and pleiomorphic cell shape with multifold ingrowth of cell wall. In addition, distinct from the parental GS-5 strain, the isogenic mutant GS-51 was unable to survive the challenge of low pH and high osmotic pressure or high temperature. Expression of the wild-type gene in trans within GS-51 from plasmid pDL277 complemented the growth defect and restored normal cell shape. These results suggested that IDG-60 is essential for maintaining the integrity of the cell wall and the uniformity of cell shape, both of which are indispensable for bacteria survival under stress conditions.
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PMID:A 60-kilodalton immunodominant glycoprotein is essential for cell wall integrity and the maintenance of cell shape in Streptococcus mutans. 1159 74

The activities of alpha-glucosidase, beta-glucosidase, and beta-galactosidase were studied during the isolation and purification of lectins from Azospirillum brasilense Sp7 and Azospirillum lipoferum 59b cells. These enzymatic activities were revealed in crude extracts of surface proteins, protein fraction precipitated with ammonium sulfate or ethanol-acetone mixture, and protein fraction obtained by gel filtration on Sephadex G-75. The distribution of the enzymes between different protein fractions varied among the azospirilla studied. The cofunction of the A. brasilense Sp7 lectin and beta-galactosidase on the cell surface is assumed. A strong interaction between the A. lipoferum 59b lectin and glucosidases was revealed. The lectin from A. lipoferum 59b may possess saccharolytic activity.
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PMID:[Relationship between lectin, alpha-, beta-glucosidase, and beta-galactosidase activities of Azospirillum]. 1176 84

Adenoid cystic carcinoma (ACC) is characterized by persistent, relentless growth and a high rate of eventual metastasis. In contrast, polymorphous low-grade adenocarcinoma (PLGA) has a much lower risk of recurrence and rarely metastasizes. The histologic patterns of these two neoplasms can be similar. Expression of c-kit, a transmembrane receptor tyrosine kinase, has recently been reported to be expressed in ACC but not PLGA. Expression of galectin-3, a nonintegrin beta-galactosidase-binding lectin, has been reported to be significant in PLGA and decreased in ACC.Formalin-fixed paraffin-embedded tissue from 9 ACC and 14 PLGA were immunostained for c-kit and galectin-3. Cases were scored as 1+ (5-25% positive), 2+ (26-50% positive), or 3+ (>50% positive). C-kit was expressed by 100% of ACC (3+: 7 cases; 2+: 1 case; 1+: 1 case) and by 57% of PLGA (2+: 2 cases; 1+: 6 cases). In all but one ACC, c-kit expression was confined to the inner cell layer. C-kit expression was also noted in the intercalated duct epithelium of the salivary glands and the acinar cells of the lacrimal gland. Galectin-3 was expressed in 8 of 9 cases of ACC and 14 of 14 cases of PLGA. The results of this, the first study to compare c-kit and galectin-3 expression in ACC and PLGA, suggest that c-kit expression characterizes ACC, but not PLGA. Galectin-3 immunohistochemistry does not have a role in the differentiation of ACC and PLGA. C-kit immunostaining may be a valuable adjunctive tool for this differential diagnosis, particularly in the setting of a limited biopsy. Our finding of different patterns of c-kit expression in tubular and solid variants of ACC supports the concept of solid variant ACC as a high-grade tumor, with progression toward an entirely "inner cell" phenotype.
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PMID:C-kit expression distinguishes salivary gland adenoid cystic carcinoma from polymorphous low-grade adenocarcinoma. 1211 4

Thiolactosyl lipids designed for carbohydrate-protein binding studies have been synthesised. One representative was selected for binding studies with a plant lectin RCA120, the agglutinin from Ricinus communis. The interactions were measured quantitatively in real time using a BIAcore surface plasmon resonance instrument. Removal of much of the galactose from the thiolactosyl lipid in situ with beta-galactosidase showed that the lectin binding was highly specific. A dissociation constant KD = 8.77 x 10(-8) M was measured for 1-[2-[2-(2-[beta-D-galactopyranosyl-(1-->4)-1-thio-beta-D -glucopyranosyl]ethoxy)ethoxy]ethoxy]octadecane 30 which is four orders of magnitude greater than that determined for binding to lactose in solution. A concentration of lactose of > 80 mM was required to block the lectin binding to thiolactosyl lipid in a neomembrane.
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PMID:Carbohydrate-protein interactions at interfaces: synthesis of thiolactosyl glycolipids and design of a working model for surface plasmon resonance. 1292 30

Galactosialidosis is a lysosomal storage disease associated with a combined deficiency of beta-galactosidase and neuraminidase, caused by a defect of another lysosomal protein, the protective protein. Three subtypes are recognized: the early infantile form, the late infantile form and the juvenile/adult form. We saw a patient with galactosialidosis of the juvenile/adult form, a 51-year-old Japanese man with angiokeratomas on both elbows and knees, myoclonus, ataxia, mental retardation and macular cherry-red spots. An electron-microscopic study of a skin biopsy showed membrane-limited vacuoles in the cytoplasm of the endothelial cells, pericytes and fibroblasts. Assays of enzymatic activity in cultured fibroblasts showed a marked decrease in both beta-galactosidase and neuraminidase (sialidase). The substance contained in the cytoplasmic vacuoles appears to be glycoproteins with sialic acid, which is a terminal glycosyl residue, because the cytoplasm of the endothelial cells of the vessels and pericytes are stained by the Limax flavus agglutinin, a lectin that binds specifically with sialic acid. This technology may be useful for easy investigation of the distribution of the accumulation of such substances in the central nervous system.
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PMID:A case of galactosialidosis. 1293 52

The normal aged brain undergoes pro-inflammatory changes. We investigated the effect of injecting a potential inflammatory stimulus, an adenoviral vector, on the response of microglia and astroglia in the aged brain. Groups of young (4 months) and old (31 months) male C57BL/Icrfat mice received a unilateral injection into the striatum of adenoviral vector encoding the LacZ gene. After 48 h, the mice were killed and the brains analysed for numbers of activated microglia and macrophages using the biotinylated lectin Griffonia simplicifolia as a marker; astroglia were identified by immunohistochemistry for glial fibrillary acidic protein (GFAP). The cell counts were analysed using two-way analysis of variance (anova). Transgene expression was assessed by beta-galactosidase histochemistry. The numbers of activated microglia in the striatum increased in response to the adenovirus in both young [contralateral 19.5 (3.7), ipsilateral 36 (3.0)] and old [contralateral 23.1 (9.6), ipsilateral 40.8 (6.9)] mice (two-way anova; P < 0.0001), but there was no significant difference between the two age groups. There was a significant age-related increase in the number of GFAP-positive astroglia in the uninjected, contralateral striatum [4 months, 2.5 (1.4); 31 months, 29.7 (9.3)] (two-way anova; P < 0.0001). However, there was no difference in response to the adenovirus in both young [contralateral 2.5 (1.4), ipsilateral 3.2 (1.2)] and old [contralateral 29.7 (9.3), ipsilateral 28.9 (8.2)] mice. We conclude that even though it has been argued that the aged brain is in a pro-inflammatory state, under the experimental conditions used in this study, there was no difference in the nature of the immune response between young and old mice of this strain to an adenoviral load.
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PMID:The glial cell response to a viral vector in the aged brain. 1472 Jan 74

The total protein glycosylation profile and specific activity of lysosomal enzymes were investigated in rat submandibular glands isolated from very young (1-month), young (1.5-months) and adult rats (3-months) rats. The specific activity of lysosomal hydrolases (i.e. acid phosphatase, arylsulfatases A and B, beta-N-acetyl-D-glucosaminidase, beta-galactosidase and beta-glucuronidase) decreased in parallel to increasing age of the animals. Furthermore, the thermal stability of acid phosphatase and beta-N-acetyl-D-glucosaminidase was influenced by the age of rats. Age-related changes in protein profile regarding the intensity of particular bands as well as the appearance of certain proteins limited to special age groups were also demonstrated as revealed by Coomassie and lectin staining. Moreover, the marked age-related increase in structures Man (alpha1-2, alpha1-3, alpha1-6) Man, Fuc (alpha1-6) GlcNAc as well as Gal (beta1-3) GlcNAc was observed, whereas staining with terminal NeuAc and GlcNAc showed an inverse correlation. The reaction with (beta1-6) branched N-glycans and Gal (beta1-3) Gal structures was limited to 1-month-old rats. No significant changes in a specific reaction with NeuAc (alpha2-3) Gal were observed. We speculate that the observed differences with respect to protein and glycosylation profiles between 1-month-old rats and older ones could be caused by a modification of the diet composition as well as by the functional and morphological maturation of the rat submandibular gland.
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PMID:Rat submandibular gland during the maturation process: changes in enzyme activities, protein and lectin-binding profiles. 1520 40

1. Recent studies have revealed an association between coronary risk factors and both the number and function of bone marrow-derived endothelial progenitor cells (EPC). We investigated the effect of oxidized low-density lipoprotein (ox-LDL) on the senescence of EPC, leading to cellular dysfunction. 2. Endothelial progenitor cells were isolated from human peripheral blood and characterized. The exposure of cultured EPC to ox-LDL (10 microg/mL) significantly accelerated the rate of senescence compared with control during 20 days in culture as determined by acidic beta-galactosidase staining. Oxidized LDL-induced EPC senescence was significantly inhibited by pretreatment with either lectin-like ox-LDL receptor-1 (LOX-1) antibody (Ab) or atorvastatin (P < 0.01). 3. Because cellular senescence is critically influenced by telomerase, which elongates telomeres, we measured telomerase activity using a polymerase chain reaction-ELISA-based assay. Oxidized LDL significantly diminished telomerase activity to approximately 50%, an effect that was significantly abolished by pretreatment with either LOX-1 Ab or atorvastatin (P < 0.01). 4. We examined whether ox-LDL-induced EPC senescence translates into EPC dysfunction. An MTS assay disclosed an inhibitory effect of ox-LDL on EPC proliferation. In a Matrigel assay, EPC treated with ox-LDL were less likely to participate in network formation compared with controls. 5. In conclusions, ox-LDL accelerates the onset of EPC senescence, which may be related to telomerase inactivation. Oxidized LDL-induced EPC senescence leads to the impairment of proliferative capacity and network formation.
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PMID:Oxidized low-density lipoprotein induces endothelial progenitor cell senescence, leading to cellular dysfunction. 1523 25

Expression of galectin-3, a member of the beta-galactosidase binding lectin family, is reported to correlate with cell adhesion. The present immunohistochemical study was performed to clarify the impact of galectin-3 expression on patients with esophageal squamous cell carcinoma. Galectin-3 expression was examined immunohistochemically in 154 patients with esophageal squamous carcinoma, who had undergone surgery without preoperative supplemental therapy at the Department of Surgery II in the Hospital of the Faculty of Medicine, Oita University, between 1990 and 2000. The cases with > or =30% nuclear-stained cancer cells were considered high nuclear expression cases. In contrast, the cases with > or =45% cytoplasm-stained cancer cells were considered high cytoplasm expression cases. Twenty-three of 154 ESCC cases were regarded as high nuclear expression (14.9%) and 72 of 154 cases were regarded as high cytoplasm-expression (46.5%). High expression of galectin-3 in the nuclei inversely correlated with vascular invasion (p=0.030) and histological differentiation (p=0.0064). In contrast, cytoplasmic expression of galectin-3 revealed no significant impact on clinicopathological factors. Neither nuclear nor cytoplasmic expression of galectin-3 was a prognostic indicator in ESCC. Elevated expression of galectin-3 in the nuclei but not the cytoplasm may be an important biological parameter related to histological differentiation and vascular invasion in patients with ESCC.
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PMID:Impact of nuclear galectin-3 expression on histological differentiation and vascular invasion in patients with esophageal squamous cell carcinoma. 1564 4


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