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: EC:3.2.1.21 (beta-glucosidase)
3,280 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In addition to the lysosomal glucocerebrosidase, a distinct beta-glucosidase that is also active towards glucosylceramide could be demonstrated in various human tissues and cell types. Subcellular fractionation analysis revealed that the hitherto undescribed glucocerebrosidase is not located in lysosomes but in compartments with a considerably lower density. The non-lysosomal glucocerebrosidase differed in several respects from lysosomal glucocerebrosidase. The non-lysosomal isoenzyme proved to be tightly membrane-bound, whereas lysosomal glucocerebrosidase is weakly membrane-associated. The pH optimum of the non-lysosomal isoenzyme is less acidic than that of lysosomal glucocerebrosidase. Non-lysosomal glucocerebrosidase, in contrast to the lysosomal isoenzyme, was not inhibited by low concentrations of conduritol B-epoxide, was markedly inhibited by taurocholate, was not stimulated in activity by the lysosomal activator protein saposin C, and was not deficient in patients with Gaucher disease. Non-lysosomal glucocerebrosidase proved to be less sensitive to inhibition by castanospermine or deoxynojirimycin but more sensitive to inhibition by D-gluconolactone than the lysosomal glucocerebrosidase. The physiological function of this second, non-lysosomal, glucocerebrosidase is as yet unknown.
...
PMID:Demonstration of the existence of a second, non-lysosomal glucocerebrosidase that is not deficient in Gaucher disease. 845 6

A heteroglycan responsible for the binding of the enzyme beta-1,4-D-glucosidase (EC 3.2.1.21) to fungal cell walls was isolated from cell walls of the filamentous fungus Trichoderma reesei. The heteroglycan, composed of mannose, galactose, glucose, and glucuronic acid, also activated beta-1,4-D-glucosidase, beta-1,4-D-xylosidase and N-acetyl-beta-1,4-D-glucosaminidase activity in vitro. The structural backbone of this heteroglycan was prepared by acid hydrolysis and gel filtration. The molecular structure of the core of the heteroglycan was determined by NMR studies as a linear alpha-1,6-D-mannan. The mannan core obtained by acid degradation stimulated the beta-glucosidase activity by 90%. Several glycosidases from Aspergillus niger were also activated by the T. reesei heteroglycan. The beta-glucosidase of Trichoderma was activated by mannan from Saccharomyces cerevisiae to a comparable extent.
...
PMID:The alpha-D-mannan core of a complex cell-wall heteroglycan of Trichoderma reesei is responsible for beta-glucosidase activation. 858 43

A 33-year-old man was admitted to our hospital because of thrombocytopenia found on a periodic physical examination. Splenomegaly was recognized Peripheral blood showed WBC 4,510/microliters, Hb 12.5 g/dl, and Plt 40,000/microliters. Increased serum levels of acid phosphatase and angiotensin converting enzyme were observed on laboratory tests. Bone marrow aspirate revealed Gaucher cells. Decreased beta-glucosidase activity was demonstrated in blood leukocytes, cultured blood lymphocytes, and cultured bone marrow fubroblasts from the patient. His glucocerebrosidase genotype was T1448C/C1504T (L444P/R463C). Since neurological examination and skeletal X ray results were normal, Gaucher disease type 1 was diagnosed.
...
PMID:[Gaucher disease type 1, incidentally found on a periodic physical examination]. 868 74

A human liver microsomal beta-glucosidase has been purified to apparent homogeneity in sodium dodecyl sulfate-polyacrylamide gel electrophoresis where a single protein band of Mr 100,000 was obtained under reducing conditions. The enzyme was enriched about 73, 000-fold over starting microsomal membranes by polyethylene glycol fractionation, anion exchange chromatographies on DEAE-Trisacryl, and Mono Q followed by affinity chromatography on N-(9-carboxynonyl)-1-deoxynojirimycin-AH-Sepharose 4B. The purified enzyme had a pH optimum between 5.0 and 6.4, was activated by divalent metal ions, and required phospholipids for exhibition of activity. The enzyme catalyzed the hydrolysis of 3beta-D-glucosido-lithocholic and 3beta-D-glucosido-chenodeoxycholic acids with high affinity (Km, 1.7 and 6.2 microM, respectively) and of the beta-D-glucoside (Km, 210 microM) and the beta-D-galactoside of 4-methylumbelliferone. The ratio of relative reaction rates for these substrates was about 6:3:11:1. No activity was detectable toward 6beta-D-glucosido-hyodeoxycholic acid, glucocerebroside, and the following glycosides of 4-methylumbelliferone: alpha-D-glucoside, alpha-L-arabinoside, beta-D-fucoside or beta-D-xyloside. Immunoinhibition and immunoprecipitation studies using antibodies prepared against lysosomal glucocerebrosidase showed no cross-reactivity with microsomal beta-glucosidase suggesting that these two enzymes are antigenically unrelated.
...
PMID:Purification and characterization of a microsomal bile acid beta-glucosidase from human liver. 911 Oct 29

A flow cytometric assay is described for the determination of glucocerebrosidase (GC) activity using fluorescein di-beta-glucopyranoside (FDGlu). Fluorescent product is formed upon intracellular hydrolysis of FDGlu and is measured in the FL1 channel of a flow cytometer. We show that the assay is specific for lysosomal beta-glucosidase or glucocerebrosidase (1) by concentration-dependent inhibition of GC activity by conditurol-beta-epoxide (CBE), a specific irreversible inhibitor; (2) by the absence of activity in fibroblasts isolated from patients with Gaucher disease; (3) correction of the biochemical Gaucher phenotype in these cells is detectable following gene transfer and can be inhibited by CBE; (4) murine fibroblasts transfected with the human GC cDNA and expressing 1.5- to 2.5-fold higher levels of human GC in in vitro assays can be distinguished from nontransfected cells in mixing experiments; and (5) preincubation of GC expressing cells with the lysosomotropic compound chloroquine leads to a loss of the GC-mediated increase in fluorescence supporting lysosomal localization of the FDGlu hydrolyzing enzyme. This flow cytometric GC assay will be useful for monitoring GC activity at the single cell level and can be used for monitoring the efficacy of Gaucher patient treatments such as enzyme supplementation and gene therapy. Finally, our findings suggest that other lysosomal enzymes can be measured in this way using alternate fluorescein derivatives.
...
PMID:A flow cytometric assay for lysosomal glucocerebrosidase. 917 87

A patient with what is now known as Gaucher's disease was first described by P.C.E. Gaucher in 1882. Fifty years later, Aghion reported that patients with this condition accumulated a sphingoglycolipid called glucocerebroside. Considerably more time was required for the demonstration by Brady and co-workers in 1964 that Gaucher's disease was due to reduced activity of a beta-glucosidase called glucocerebrosidase. This information provided the basis for the development of reliable diagnostic tests, detection of most of the carriers of this disorder and the prenatal diagnosis of this condition. Evidence was presented in 1990 and 1991 indicating the highly beneficial effects of enzyme replacement therapy in patients with Gaucher's disease. Gene therapy for Gaucher's disease was initiated in 1995. While little indication of success was obtained in this inaugural attempt, it is expected that improvements in this technology will provide a permanent cure for patients with this disorder.
...
PMID:Gaucher's disease: past, present and future. 949 55

Abdominal ultrasonographic findings of Gaucher's disease had been reported, but a specific pattern has not been described. We report here a patient with an abdominal sonographic pattern which was concluded to be strongly suggestive of Gaucher's disease: solid focal splenic lesions with different patterns (hypoechoic, hiperechoic and mixed nodules associated with hypoechoic irregular areas) and bright liver and spleen echo pattern with posterior beam attenuation. Gaucher's disease was subsequently confirmed by determination of leukocyte beta-glucosidase activity and mutations of glucocerebrosidase gene.
...
PMID:[Gaucher's disease suspected by abdominal echography findings]. 963 79

The current study reports active glycosidases in the lens of ICR/f rats, which generate a hereditary cataract approximately 90 d after birth, and the variation in enzyme activity with cataract progression. Seven active glycosidases, beta-D-galactosidase, alpha-D-glucosidase, beta-D-glucosidase, beta-D-glucuronidase, beta-D-galactosaminidase, beta-D-glucosaminidase and alpha-D-mannosidase, were detected in ICR/f rat lenses. Of these, beta-D-glucuronidase and beta-D-galactosidase showed a tendency to increase in activity with the cataract progression. Furthermore, beta-D-glucosidase and alpha-D-mannosidase showed a transitory increase in activity at the time of cataract formation. This result suggests that several glycosidases in the lens may be involved in the hereditary cataract formation. The optimal pH and temperature of the seven active glycosidases in rat lenses were also measured in this study.
...
PMID:Variation in glycosidase activity in soluble fractions in ICR/f rat lenses with the progression of cataract formation. 1007 42

Diagnostic difficulties of Gaucher disease, a disorder resulted from a deficient activity of glucocerebrosidase is reported. Gaucher disease was described in the 16 year old male, 5 years after manifestation of the very first symptoms (fracture and osteomyelitis). At the age of 14, the cirrhosis due to viral hepatitis accompanied with splenomegaly was diagnosed. This findings was not associated with the earlier osseous disorders. Histopathologic examination of the removed spleen facilitate the diagnosis. The second case refers to 20 year old female. Clinical symptoms and additional test pointed to malignant neoplasm of thyroid, the reproductive organs or cancer of indistinguishable primary focus with metastases in the liver. Trepanobiopsy of bone marrow had made an accurate diagnosis possible, while determination of beta-glucosidase activity in peripheral white blood cells, chitotriosidase activity, and molecular investigations of gene specific to beta-glucocerebrosidase proved it.
...
PMID:[Diagnostic difficulties in Gaucher disease: report of two cases]. 1033 43

Gaucher disease (GD) is the most frequent lysosomal storage disease, caused by mutations in the acid beta-glucosidase gene (GBA). The c.1226A > G (N370S) mutation is associated with non-neuronopathic disease (type 1). However, we have observed some discrepancy between genotype and phenotype in Spanish Gaucher disease patients homozygous for the c.1226A > G mutation. A deletion of 55 bp in the exon 9 GBA gene, corresponding to the deleted portion of the beta-glucosidase pseudogene, has been previously reported as a cause of erroneous assignment of 1226G/1226G homozygous patients when the genotype has been performed by PCR assay. We had originally identified 25 (out of 124) unrelated Gaucher disease patients as being putative homozygotes for the c.1226A > G mutation. By means of a new PCR-based assay, we were able to distinguish between the true homozygous patients and the carriers of the 55-bp deletion in exon 9 of the GBA gene. The 55-bp deletion was detected in 10 out of 25 samples (40%) [7 with the 55-bp deletion, 1 RecTL, 1 RecNciI (both including the deletion) and one rearrangement]. Such a high prevalence in this sample suggests that this allele can be more common than expected among GD patients.
...
PMID:High prevalence of the 55-bp deletion (c.1263del55) in exon 9 of the glucocerebrosidase gene causing misdiagnosis (for homozygous N370S (c.1226A > G) mutation) in Spanish Gaucher disease patients. 1248 1


<< Previous 1 2 3 4 5 6 Next >>

---