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

1. alpha-d-Mannosidase from rat epididymis was purified 300-fold. beta-N-Acetyl-glucosaminidase and beta-galactosidase were removed from the preparation by treatment with pyridine. Zn(2+) was added during the purification to stabilize the alpha-mannosidase. 2. Mammalian alpha-mannosidase is most stable at pH6. At lower pH values it undergoes reversible spontaneous inactivation. The enzyme is also subject to irreversible inactivation, which is delayed by the addition of albumin. 3. Reversible inactivation of alpha-mannosidase is accelerated by EDTA and reversed or prevented by Zn(2+). Other cations, such as Co(2+), Cd(2+) and Cu(2+), accelerate inactivation and the action of a toxic cation can be prevented by Zn(2+) or by EDTA in suitable concentration. 4. The enzyme is stabilized by substrate and neither Zn(2+), EDTA nor a toxic cation has more than a small effect in the assay of an untreated preparation. The addition of Zn(2+) is necessary, however, for a constant rate of hydrolysis during prolonged incubation of the enzyme with substrate. In an EDTA-treated preparation, Zn(2+) reactivates the enzyme during the assay. 5. Evidence is presented that alpha-mannosidase is a dissociable Zn(2+)-protein complex, in which Zn(2+) is essential for enzyme activity.
...
PMID:Purification and properties of alpha-D-mannosidase from rat epididymis. 498 Mar 9

1. The previous study (Conchie, Gelman & Levvy, 1967b) of the specificity of beta-glucosidase, beta-galactosidase and beta-d-fucosidase in barley, limpet, almond emulsin and rat epididymis was extended to alpha-l-arabinosidase. 2. The inhibitory action of l-arabinono-(1-->5)-lactone was tested against all four types of enzyme, and alpha-l-arabinosidase was examined for inhibition by glucono-, galactono- and d-fucono-lactone. 3. In emulsin, the enzyme that hydrolyses beta-glucosides, beta-galactosides and beta-d-fucosides also hydrolyses alpha-l-arabinosides. Rat epididymis resembles emulsin except that, as already noted, it lacks beta-glucosidase activity. 4. In the limpet, alpha-l-arabinosidase activity is associated with the enzyme that hydrolyses beta-glucosides and beta-d-fucosides, and not with the separate beta-galactosidase. 5. The effects of the different lactones on the barley preparation suggest that alpha-l-arabinosidase activity is associated with the beta-galactosidase rather than with the enzyme that hydrolyses beta-glucosides and beta-d-fucosides. Fractionation and heat-inactivation experiments indicate that there is also a separate alpha-l-arabinosidase in the preparation.
...
PMID:Inhibition of glycosidases by aldonolactones of corresponding configuration. The specificity of alpha-L-arabinosidase. 572 53

1. In barley, beta-glucosidase and beta-galactosidase are separate enzymes. The former also displays beta-d-fucosidase activity. 2. In the limpet, Patella vulgata, beta-glucosidase activity is associated with the beta-d-fucosidase, previously shown to be a separate entity from the beta-galactosidase also present. 3. Almond emulsin presents all three activities as a single enzyme. Each is equally inhibited by glucono-, galactono- and d-fucono-lactone. 4. In rat epididymis, there is no significant beta-glucosidase activity, nor is there appreciable inhibition of the beta-galactosidase and beta-d-fucosidase activities of the preparation by gluconolactone.
...
PMID:Inhibition of glycosidases by aldonolactones of corresponding configuration. The C-4- and C-6-specificity of beta-glucosidase and beta-galactosidase. 606 63

The activity levels of beta-N-acetylglucosaminidase, beta-N-acetylgalactosaminidase, beta-galactosidase and beta-glucosidase were fluorometrically assessed in spermatozoa, principal cells, basal cells and fibroblasts isolated from the rat epididymis by centrifugal elutriation. Among the various cell types, corpus principal cells had the highest activities for beta-N-acetylglucosaminidase, beta-N-acetylgalactosaminidase and beta-galactosidase. These enzymes characteristically react with membrane structural carbohydrates. Corpus/caput principal cell activity ratios of these glycosidases remained constant when determinations were done at an alternate pH and substrate concentration, suggesting that similar enzyme forms were present in both regions. Based on cell number and cell volume, sperm glycosidase activities generally increased from the caput to the corpus region of the epididymis, while decreasing from corpus to cauda. However, when data were expressed on the basis of cell protein, sperm glycosidase activities increased from caput to cauda. Since the total protein of sperm decreases dramatically from caput to cauda, the increase in glycosidase activity based on total protein suggests that relative to other sperm proteins, glycosidases may be selectively retained or taken up during epididymal transit. High levels of glycosidase activity associated with the corpus epididymidis may contribute to modification of sperm glycoproteins and observed increases in fertility of sperm as they emerge from this region.
...
PMID:Glycosidase activities in principal cells, basal cells, fibroblasts and spermatozoa isolated from the rat epididymis. 643 54

This study demonstrates that beta-glucuronidase from rat preputial glands binds with high affinity to spermatozoa from the cauda epididymis. The binding was calcium-independent and was inhibited by mannose-6-phosphate, but not by other phosphorylated or non-phosphorylated sugars. Binding was also inhibited by alpha-mannosidase from Dictyostelium discoideum, an enzyme known to have mannose-6-phosphate as the ligand. From solubilized sperm membranes, a protein of > 200 kDa and one of 45 kDa, were absorbed to a column of D. discoideum enzyme and to a phosphomannan column respectively, and eluted with mannose-6-phosphate. According to histochemical observations at the light and the electron microscopic level, gold particles coated with the enzyme became bound to the external surface of the plasmalemma in the acrosomal region of caudal spermatozoa. Similar labelling was observed using gold particles coated with antibodies against the rat 300 kDa phosphomannosyl receptor. The existence of phosphomannosyl receptors on the sperm plasma membrane, and our previous demonstration of the presence of affinity sites for epididymal beta-galactosidase on these gametes which is inhibited by phosphofructosyl derivatives, suggest strongly that maturing spermatozoa could be a target for glycosidases secreted into the lumen of the cauda epididymis, which then become bound to these cells via different ligand-receptor systems.
...
PMID:Phosphomannosyl receptors on the surface of spermatozoa from the cauda epididymis of the rat. 755 73

The epithelium of caput and cauda epididymidis of the rat was studied with transmission electron microscopy (TEM) and freeze-fracture techniques. In thin sections of both zones, the tissue consisted mainly of tall columnar cells (principal cells) with long sterocilia. Clusters of small membrane-bound vesicles were located in the lumen between or immediately over the stereocilia. Freeze-fracture replicas also displayed groups of smooth-surface vesicles in the same location. Membrane-bound vesicles isolated from the lumen of the rat epididymis were studied by TEM. In thin sections, some of them contained an electron dense material and others looked empty. In addition, the hydrolases: beta-galactosidase, N-acetyl-glycosaminidase, alpha-mannosidase, aryl-sulfatase and beta-glucuronidase were detectable in pellets of vesicles treated with Triton X-100. The results presented here indicate the presence of membrane-bound vesicles observed by two different methodologies in the rat epididymal fluid and demonstrate five glycosidases in their content.
...
PMID:Morphological and enzymatic study of membrane-bound vesicles from the lumen of the rat epididymis. 775 84

A neutral beta-D-galactosidase has been partially purified from rat epididymis and characterized. The enzyme having molecular mass of approximately 50 kilodaltons has been purified 400-fold by using calcium phosphate gel adsorption, DEAE-cellulose chromatography, Sephadex G-100 gel filtration, and concanavalin A--agarose affinity chromatography. Although the neutral enzyme binds to the concanavalin A affinity column, the activity could be eluted with alpha-methyl mannoside only if the buffer contained salt (NaCl) at a concentration as high as 0.3 M. The enzyme was of cytosolic origin, since 90% of the total enzymic activity of the tissue homogenate was recovered in the soluble fraction of these cells. The neutral beta-galactosidase was not dependent on metal ions for its activity and it had a pH optimum of 7.0. Zn2+, p-chloromercuribenzoate, Hg2+, and Pb2+ served as potent inhibitors of the enzyme. There was a marked increase (approximately fourfold) in the specific activity of the neutral beta-galactosidase during sexual maturity of epididymis in vivo.
...
PMID:Purification and characterization of rat epididymal neutral beta-galactosidase and its changes during in vivo development. 832 73

Activity of glycosidases in the epididymis was influenced by several factors originating in the testis. Activities of all the three glycosidases studied viz., beta-glucosidase, beta-galactosidase and alpha-mannosidase were found to be significantly lower in the epididymis of orchidectomized animals than in sham operated rats. However, an enhanced activity of epididymal beta-galactosidase and alpha-mannosidase was noticed in prolactin treated orchidectomized rats compared to orchidectomized rats given vehicle alone. On the other hand, activity of these two enzymes in bromocriptine treated orchidectomized rats was even lower than that found in orchidectomized rats given vehicle. Neither prolactin nor bromocriptine treatment had any significant influence on the epididymal beta-glucosidase. The results suggest a selective but definite action of prolactin on epididymal glycosidases.
...
PMID:Modulation in activity of some epididymal glycosidases by prolactin. 835 47

This study reports on the binding of beta-galactosidase obtained from different organs of the rat urogenital tract to membranes of these organs. Homologous and cross binding saturation assays indicated that: (1) high-affinity sites that recognize fructose-6-phosphate derivates (FPR) are present in spermatozoa from the rete testis, epididymal membranes and testes, although the latter may reflect binding to testicular spermatozoa; (2) the membranes of the other organs studied do not have FPR; (3) the FPR of the epididymis does not recognize enzymes purified from other organs of the reproductive tract. These results suggest that the FPR-binding system belongs to a peculiar transport route that permits maturing spermatozoa to acquire hydrolytic enzymes secreted by the epididymal epithelium. In the epididymis and seminal vesicles more than 50% of the enzymatic activity of beta-galactosidase was recovered in cytosol, suggesting that the enzyme is located mainly in the secretory fluid of these organs.
...
PMID:Organ-specific binding system for beta-galactosidase in the male reproductive tract. 856 94

The purpose of the present study is to purify, kinetically characterize and measure the amount of soluble acid beta-D-galactosidase (EC 3.2.1.23) in different anatomical regions (caput, corpus, and cauda) of the adult rat epididymis. Based upon SDS-PAGE analysis, the subunit molecular mass of the caput and cauda enzyme is approximately 85,000 daltons while the corpus enzyme is approximately 50,000 daltons. The apparent Km and Vmax values are 67, 24, and 59 microM and 5.0, 1.88 and 6.3 microM/min./-mg protein for the enzyme purified from the caput, corpus, and cauda regions of the epididymis, respectively. However, no regional differences in the amount of soluble enzyme protein are observed. These data demonstrates regional differences in the activity of epididymal acid beta-D-galactosidase and suggest that the observed regional differences in enzyme activity may be due to posttranslational modifications.
...
PMID:Purification, characterization, and expression of rat epididymal beta-D-galactosidase. 924 2


<< Previous 1 2 3 4 Next >>

---