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)

Complex carbohydrates on the surfaces of eukaryotic cells are thought to participate in a wide variety of cell-cell interactions. A model system has therefore been developed to study these processes. In the present experiments, the ability of chicken hepatocytes to recognize and adhere to sugars covalently linked to polyacrylamide gels was investigated. The gels were snythesized by two methods. Type I gels were prepared from a co-polymer of an active ester of acrylic acid (N-succinimidyl acrylate), acrylamide, and bisacrylamide. The "activated" polyacrylamide gel was then treated with the desired ligand containing an amino group, such as 6-aminohexyl O- or S-glycoside. Type II gels were formed by treating similar ligands with acryloyl chloride, followed by co-polymerization of the resulting N-substituted acrylamide with acrylamide and N,N'-methylenebisacrylamide. These polyacrylamide derivatives offer many advantages for studies with intact cells. They are not toxic to any cell type studied, can be cast in any desired shape, are transparent and stable over a wide range of pH values, and contain no cationic and low to negligible levels of anionic charge (charged groups can be introduced if desired), and the polyacrylamide matrix is stable to common biological agents such as bacteria and enzymes. In addition, type I gels can be synthesized using a broad range of molecules containing amino groups, such as glycopeptides, proteins, etc. The hepatocytes were prepared by collagenase perfusion of intact chicken livers. The rate and extent of adhesion of the cells to the derivatized gels was determined by measuring lactate dehydrogenase in these cells. This enzyme was also used to assay viability and cell "leakiness." At 37 degrees C, 70 to 100% of the cells adhered within 60 min to gels derivatized with N-acetylglucosamine, i.e. gels derivatized with 6-aminohexyl 2-acetamido-2-deoxy-beta-D-glucopyranoside (or the corresponding thioglycoside). By contrast, less than 5% of the cells adhered to polyacrylamide or to gels derivatized with 6-aminohexanol or the 6-aminohexyl glycosides of beta-D-glucose, beta-D-galactose, alpha-D-mannose, beta-D-maltose, beta-D-melibiose, beta-D-cellobiose, and (alpha or beta)-D-lactose. Kinetic studies with the chicken hepatocytes and N-acetylglucosamine gels showed that cell-gel binding was dependent upon Ca2+ and was decreased at low temperatures. Binding was inhibited by N-acetylglucosamine or by glycosides of this sugar, the most effective inhibitor being orosomucoid (alpha1-acid glycoprotein) pretreated with sialidase and beta-galactosidase. The cell surface receptor(s) involved in this interaction is not known, but may be related or identical to the chicken liver binding protein described by Lunney and Ashwell (Lunney, J., and Ashwell, G. (1976) Proc. Natl. Acad. Sci. U. S. A. 73, 341--343). The present results suggest that this model system should prove useful in delineating cell surface interactions with carbohydrates.
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PMID:Adhesion of chicken hepatocytes to polyacrylamide gels derivatized with N-acetylglucosamine. 70 Dec 94

The origin and properties of cytosolic neuraminidase (acylneuraminyl hydrolase, EC 3.2.1.18) from pig brain were studied. 1. The brain extracts containing the cytosol derived from neuronal bodies and glial cells carry 0.69 munits neuraminidase/g fresh tissue. The behaviour of neuraminidase during extraction closely paralleled that of authentic cytosolic enzyme, lactate dehydrogenase; whereas, it differed from that of the lysosomal enzymes, beta-hexosaminidase and beta-galactosidase, also found in the extracts. 2. Nerve endings from either crude or purified preparations, when treated by hypoosmotic shock, released neuraminidase activity up to a maximum of 1.25 munits/g fresh tissue. The behaviour of releasable neuraminidase was always identical to that of lactate dehydrogenase and very similar to that of ATPase and acetylcholinesterase. Typical lysosomal enzymes, however, such as beta-galactosidase and beta-hexosaminidase, behaved differently under the same conditions. This neuraminidase activity is thought to be derived from the cytosol of nerve endings. 3. The specific activity of neuraminidase in nerve-ending cytosol is 15--20 times that in neuronal body and glial cell cytosol. Some properties (pH, Km value, V/t relationship) of the cytosolic enzymes of different origin are similar; others (stability on standing at 4 degrees C; resistance to freezing and thawing) are different. Hypoionic solutions caused both cytosolic neuraminidases to slowly precipitate and to assume a stable insoluble form which was still active.
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PMID:Studies on brain cytosol neuraminidase. II. Extractability, solubility and intraneuronal distribution of the enzyme in pig brain. 71 57

1. A mixed membrane fraction prepared from pig platelets was subfractionated, using the "B 14" zonal rotor, into two distinct subpopulations of membrane vesicles, each associated with a different phosphodiesterase activity. 2. The lighter subfraction (MI) was enriched 7-8 fold with bis-(p-nitrophenyl) phosphate phosphodiesterase activity and the denser subfraction (MII) showed a similar degree of enrichment of 5'dTMP-p-nitrophenyl ester phosphodiesterase activity. 3. Assays for other enzyme activities revealed slight enrichement (approx. 2 fold) of acid phosphatase, 3'-dTMP-p-nitrophenyl ester phosphodiesterase and beta-glucuronidase activities in MI, and beta-galactosidase in MII. Cyclic AMP phosphodiesterase, lactate dehydrogenase and N-acetyl-beta-glucosaminidase showed negligible activity in both MI and MII, and succinate dehydrogenase activity could not be detected in either subfraction. 4. Chemical analyses of the membrane subfractions demonstrated that MI contained approx. twice as much cholesterol, phospholipid, sialic acid and hexosamine per unit weight of protein than MII. These results are consistent with our previously reported observations from surface-labelling experiments, which indicated that MI was derived principally from the platelet surface-exposed membranes and that MII was probably intracellular in origin. 5. Analysis of the membrane polypeptides by sodium dodecyl sulphate-polyacrylamide gel electrophoresis revealed the presence of 12-15 components, in each subfraction, in the mol. wt. range 12000-200000, including a prominent band of approx. mol. wt. 46000, which has beeen identified to be actin. Qualitative as well as possible quantitative differences were apparent in that MII contained three components in addition to those present in MI. 6. Analysis of the periodate-Schiff staining components by sodium dodecyl sulphate-polyacrylamide gel electrophoresis demonstrated the presence of 4 major glycoproteins in both subfractions with apparent mol. wt. ranging from approx. 95000 to 150000; in addition two minor components were also present. Further, a very fast-migrating band, which did not stain with Coomassie blue, was observed in both MI and MII and probably represents lipid material.
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PMID:Enzymatic and chemical analyses of pig platelet membrane subfractions isolated by zonal centrifugation. 127 16

Various biochemical parameters of renal tubular function were examined for a period of up to 12 weeks in rats rendered diabetic by an i.v. injection of streptozotocin. Except for a statistically significant decrease in the urinary excretion of gamma-glutamyl-transpeptidase to 64% of control values, the urinary excretion of beta-N-acetyl-D-glucosaminidase, beta-galactosidase, alanine aminopeptidase, and lactate dehydrogenase significantly increases in diabetic rats to between 154% and 712% of control values. This increased enzymuria is not correlated to the marked polyuria induced by diabetes (r between 0.14 and 0.35, not significant). Enzymuria is also accompanied by a 10-fold increase in the urinary excretion of the low molecular weight protein beta 2-microglobulin while the excretion of albumin is not significantly modified, indicating impairment of tubular reabsorption in diabetic animals. Clearance studies reveal that the clearance of both beta 2-microglobulin and infused egg-white lysozyme are also increased. Finally the histopathologic examination of paraffin sections of the kidney show hydropic degenerescence and pycnosis of the tubular cells. It is concluded that early-stage diabetes results in tubular impairment and that the streptozotocin-rat model appears well suited to the study of these early signs of renal dysfunction.
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PMID:Enzymuria and tubular proteinuria in diabetic rats: a 12-week follow-up study. 134 85

The serum concentrations of FSH, LH, prolactin, testosterone, and estradiol and the enzymatic activities of hyaluronidase, glucosidases (alpha-glucosidase, beta-glucosidase, alpha-mannosidase, N-acetyl-beta-D-glucosaminidase, beta-glucuronidase, and beta-galactosidase), lactate dehydrogenase and its isoenzymes (LDH1, LDH2, LDH3, LDH-X, LDH4), and total proteins were measured in the semen of 69 subjects (8 normozoospermic controls, 7 secretory, and 54 excretory azoospermic subjects). FSH levels rose with the deterioration in spermatogenesis and served to differentiate the secretory from the excretory azoospermias. The only source of hyaluronidase and LDH-X in the ejaculate is the spermatozoa. alpha-Glucosidase activity essentially originates in the epididymis. The seminal determination of alpha-glucosidase and, to a lesser extent, alpha-mannosidase and N-acetyl-beta-D-glucosaminidase helps rapidly, sensitivity, reliably, and noninvasively to differentiate secretory azoospermias (with higher enzymatic activity) from the excretory type (less enzymatic activity) and may be of use in identifying with a certain degree of reliability the site of obstruction in the male genital tract.
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PMID:Enzyme and hormonal markers in the differential diagnosis of human azoospermia. 153 Mar 67

Mediators released from injured human skin that initiate the inflammatory response have not been adequately identified. Organ culture of full-thickness skin explants enables us to do so, because injury to the skin can be made in vitro, eliminating the rapid leakage of serum and infiltration of leukocytes that occur in vivo. In our studies, the military vesicant sulfur mustard (SM) (10 microliters of a 0.01 to 1.0% dilution) was topically applied to injure the epidermis of the explant. Then, the explants were cultured in small Petri dishes, usually for 18 h at 36 degrees C, and the organ-culture fluids were assayed for various inflammatory mediators. We found that the culture fluids from SM-exposed and control explants contained similar amounts of angiotensin-converting enzyme, trypsin-like and chymotrypsin-like proteases, acid phosphatase, beta-glucuronidase, beta-galactosidase, lysozyme, deoxyribonuclease, ribonuclease, interleukin 1, and lactic dehydrogenase. However, the culture fluids from SM-exposed explants contained increased amounts of histamine and plasminogen-activating activity, and often prostaglandin E2, when compared to culture fluids from control explants. After 3 to 4 d in culture, full-thickness human skin explants, when exposed to 0.2% SM (but not when exposed to 1.0% SM), sometimes showed separation of the epidermis and increased collagenase activity (i.e., hydroxyproline release). Thus, histamine (from local mast cells), and prostaglandin E2 and plasminogen-activating activity (probably from both mast cells and epidermal cells) are apparently involved in early mediation of the inflammatory response.
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PMID:Mediators, initiating the inflammatory response, released in organ culture by full-thickness human skin explants exposed to the irritant, sulfur mustard. 171 Jun 39

One hundred and one young-adult female Sprague-Dawley rats were acclimatized to metabolic cages for 2 days. After that time 24-hour urine was collected at a constant cooling temperature of 0-4 degrees C. After gel filtration the enzyme activities were determined, and the resulting values were used to calculate 24-hour excretions. The following reference ranges (2.5 and 97.5 percentiles) were determined (in mU/24 h): lactate dehydrogenase 43-181; phosphohexoseisomerase 45-1445; glutathione-S-transferase 1-299; alkaline phosphatase 27-1239; leucine arylamidase 72-377; gamma-glutamyltransferase 1334-9188; arylsulphatase A 59-309; beta-galactosidase 76-305; beta-glucuronidase 20-2756; beta-N-acetyl-D-glucosaminidase 66-491; glutamate dehydrogenase 7-711. There was a significant (though not very high) correlation with diuresis for the lysosomal enzymes beta-N-acetyl-D-glucosaminidase, arylsulphatase A and beta-galactosidase, and for glutamate dehydrogenase, lactate dehydrogenase, phosphohexoseisomerase and alkaline phosphatase. The relation to creatinine excretion was markedly close for the lysosomal enzymes beta-N-acetyl-D-glucosaminidase, arylsulphatase A and beta-galactosidase (r = 0.71-0.83), as well as for alkaline phosphatase, leucine arylamidase and gamma-glutamyltransferase. There was a relatively high correlation between the excretion of beta-N-acetyl-D-glucosaminidase, arylsulphatase A and beta-galactosidase among themselves (r = 0.63-0.81) as well as between leucine arylamidase and gamma-glutamyltransferase (r = 0.75).
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PMID:Excretion of urinary enzymes in female Sprague-Dawley rats in relation to cellular compartment, creatinine excretion and diuresis. 179 3

During liver transplantation in the pig, the plasma activities of beta-galactosidase, beta-glucuronidase and beta-glucosidase were elevated as early as 15 min after establishing the hepatic circulation. The enzyme activities peaked at 3 h and returned to the initial level within 2-3 days. However, such substantial alterations were not observed in other enzymes, alpha-mannosidase and alpha-glucosidase. Similar reactions to those of the first three enzymes were found in aspartate aminotransferase and lactate dehydrogenase but with later peaks and slower eliminations. In light of the current study, the serial estimation of acid hydrolases may be useful to discover the extent of tissue injury and also to evaluate the effectiveness of various organ-preservation methods.
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PMID:Plasma lysosomal enzymes after liver transplantation in the pig. 181 48

The effect of cyclosporine on hepatic ischemia was investigated. Hepatic ischemia was produced for 90 min in mongrel dogs. Experimental dogs were divided into three groups as follows: group A (control group), group B (CsA pretreatment group), group C (CsA posttreatment group). CsA was administered at a dose of 10 mg/kg body weight/day for 3 days in the pre- or postoperative period. Survival rates were 61.5% in group A, 84.6% in group B, and 30.8% in group C. Enzymatic activity such as aspartate aminotransferase and lactate dehydrogenase was highest in group C, lowest in group B, and intermediate in group A. Opposite results were obtained for serum albumin concentrations. The mechanisms of the effect was investigated using a 60-min hepatic ischemia model. Serum levels of beta-glucosidase and beta-galactosidase in group B were lower than those in group A and group C. Electronmicroscopic specimens taken at 16 h after 60-min hepatic ischemia demonstrated that the extent of ischemic injury was mildest in group B. The present study demonstrated a beneficial effect on hepatic ischemia of CsA administered for 3 days prior to the ischemia. One of the mechanisms for this beneficial effect could be the stabilization of lysosomal membranes. These results suggest that CsA should be administered to a donor before organ harvesting for liver transplantation because of this beneficial effect.
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PMID:Beneficial effect of cyclosporine pretreatment in canine liver ischemia. Enzymatic and electronmicroscopic studies. 190 40

Cathepsin D, acid phosphatase, beta-galactosidase, N-acetyl hexosaminidase, leucine aminopeptidase (LAP), lactate dehydrogenase, glucose-6-phosphate dehydrogenase (g-6-PDH), and peroxidase activities were measured in the buccal mucosa of rats kept for 60 days on high-sucrose (68% of sucrose) caries-inducing diet. The findings evidence that this diet observed for 30 days results in a significant elevation of beta-galactosidase and LAP activities and in reduction of peroxidase level. After 60-day diet the examined parameters virtually did not differ from the reference characteristics (a control group kept on 68% starch diet), except elevated g-6-PDH and lowered peroxidase activities. Enzymic activity changes are adaptive and evidence changes in the metabolic processes in the buccal mucosa, that may eventuate in the development of periodontal diseases.
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PMID:[The effect of a high-saccharose diet on the enzymatic activity of the oral mucosa in rats]. 192 95


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