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 objective of this research was to gain a better understanding of the degree to which recovery of activity of model proteins after freeze-drying can be maximized by manipulation of freeze-dry process conditions in the absence of protective solutes. Catalase, beta-galactosidase and lactate dehydrogenase (LDH) were used as model proteins. All of the three proteins exhibited a concentration-dependent loss of activity after freezing, with significantly higher recovery at higher concentration. The freezing method and the type of buffer were also important, with sodium phosphate buffer and freezing by immersion of vials in liquid nitrogen associated with the lowest recovery of activity. Differential scanning calorimetry was predictive of the onset of collapse during freeze-drying only for beta-galactosidase. For the other proteins, either no Tg' transition was observed, or the apparent glass transition did not correlate with the microscopically-observed collapse temperature. The time course of activity loss for beta-galactosidase and LDH was compared during freeze-drying under conditions which produced collapse of the dried matrix and conditions which produced retention of microstructure in the dried solid. Recovery of activity decreased continuously during primary drying, with no sharp drop in recovery of activity associated with the onset of collapse. The most important drying process variable affecting recovery of activity was residual moisture level, with a dramatic drop in activity recovery associated with residual moisture levels less than about 10%.
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PMID:Effect of process conditions on recovery of protein activity after freezing and freeze-drying. 965 29

Chloragocytes were isolated from the earthworm species Lumbricus terrestris. After mechanical dissociation and sedimentation through Percoll, a highly purified fraction of viable chloragocytes was obtained. The isolated chloragocytes accumulated the vital dye neutral red and reduced the tetrazolium dye MTT, thereby indicating cellular integrity. Time of flight flow cytometric analyses revealed a main population of large and highly granulated cells in the 30-33 microm size range. Hydrolase measurements showed that beta-D-N-acetyl-glucosaminidase and acid phosphatase exhibited the highest activities (146.6 and 24.9 mU/mg of protein, respectively), possibly indicating a major role for these 2 hydrolases in the physiological function of chloragocytes. In contrast, other acid hydrolases such as beta-D-galactosidase and beta-D-glucuronidase had specific activities of respectively 26 and 182 times lower than the glucosaminidase. The specific activity of the membrane-bound alkaline phosphatase was comparable to that of its acid counterpart (18.9 vs. 24.9 mU/mg of protein, respectively) and this level of activity may show an important trans-membrane activity in chloragocytes. The cytoplasmic and mitochondrial enzyme isocitrate dehydrogenase had a level of activity comparable to that of the exclusively cytoplasmic enzyme lactate dehydrogenase (6.6 vs. 8.1 mIU/mg of protein, respectively). When L. terrestris chloragocyte homogenates were separated on Percoll, results showed that hydrolases and dehydrogenases were mainly associated with the lighter materials that remained above the Percoll layer. Nonetheless, the detection of significant proportions (15-25%) of the total recovered activity of acid phosphatase and beta-galactosidase in the enriched chloragosome fraction supports the notion that some chloragosomes may be 'lysosome-like' organelles.
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PMID:Isolation, purification and partial characterization of chloragocytes from the earthworm species Lumbricus terrestris. 974 18

The mechanisms by which heparin protects the liver during induced episodes of liver ischemia-reperfusion are poorly understood. Previous work in a swine model demonstrated that serum levels of glycohydrolases and lipid peroxide peaked within 3 h after 45 minutes of hepatic ischemia followed by reperfusion. Serum levels of lactate dehydrogenase and aspartate aminotransferase peaked 20-24 h later. The aim of this study was to evaluate the effect of heparin on these two-phases of enzyme release, using a pig model of hepatic ischemia-reperfusion injury. Twenty male swine were divided into control (n = 8) and heparin (n = 12) groups. In the heparin group, heparin was administered prior to and concurrent with ischemia-reperfusion. Following 45 min of hepatic ischemia, the levels of beta-galactosidase, beta-glucosidase, acid phosphatase, purine nucleoside phosphorylase, lipid peroxides, lactate dehydrogenase, and aspartate aminotransferase in serum were monitored for up to 166 h and compared to pre-ischemic and control levels. With heparin infusion, the peak levels of beta-galactosidase, beta-glucosidase, and the lipid peroxide were reduced to 50-60% of the control levels. Acid phosphatase and purine nucleoside phosphorylase activities in serum were reduced to 25% and 60%, respectively. The peak concentrations of lactate dehydrogenase and aspartate aminotransferase were reduced to about 25% of the control level. In addition, the serum enzymes of control pigs did not return to pre-ischemic levels until 2 weeks after hepatic ischemia, while they normalized in less than 1 week in the heparin-treated animals. Systemic heparinization had different protective effects on the first and secondary phases of liver injury. These differences may reflect heparin protection of different types of liver cells. The protection of the parenchymal cells may be the combined result of reduced sinusoidal cell injury and the anticoagulant properties of heparin.
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PMID:Differential effects of heparin on the early and late phases of hepatic ischemia and reperfusion injury in the pig. 1044 94

Continuous superporous agarose beds constitute a new support material for chromatography, biocatalysis and electrophoresis. The bed consists of a single piece of agarose gel, homogeneously transected by flow-carrying pores, which easily can be varied in the range of 10-100 microm. In this work, large diameter beds (60 mm) were prepared and used in specially designed radial flow columns. The basic chromatographic properties of the beds were investigated by size-exclusion chromatography experiments. In an affinity chromatography application one bed was derivatized with Cibacron Blue 3GA and used for the purification of lactate dehydrogenase from a crude bovine heart extract. In a biotransformation application one bed was provided with immobilized beta-galactosidase and used in the production of lactose-free milk.
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PMID:Continuous superporous agarose beds in radial flow columns. 1151 18

Evidence has accumulated for a role of toxic oxygen radicals in the pathogenesis of ischemia-reperfusion injury in the kidney. The aim of this study was to evaluate the hypothesis that reducing postischemic renal injury is possible by delivery of the gene for the antioxidant enzyme superoxide dismutase (SOD). Female Sprague-Dawley rats received intravenous injections of recombinant adenovirus (1 x 10(9) pfu) containing the transgenes for Escherichia coli beta-galactosidase (Ad-LacZ, as control) or human Cu/Zn-SOD (Ad-SOD). Three days later, renal ischemia was produced by cross-clamping the left renal vessels for 60 min. The right kidney was removed before reperfusion and processed for the transgene. Renal SOD protein and activity in rats given Ad-SOD was 2.5-fold higher than from the animals receiving Ad-LACZ: Urinary lactate dehydrogenase concentrations were elevated by ischemia-reperfusion in the Ad-LacZ group (1403 +/- 112 U/L), yet values were 50% lower in Ad-SOD-treated rats. Free radical production was elevated by ischemia-reperfusion but was significantly lower in SOD-treated animals. Importantly, on postischemic day 1, glomerular filtration rates were reduced to 0.21 ml/min per 100 g in the Ad-LacZ group, whereas values remained significantly higher (0.39) in the Ad-SOD group. Two weeks after ischemia-reperfusion, inflammation, interstitial fibrosis, tubular atrophy and tissue levels of tumor necrosis factor alpha and interleukin-1 were significantly higher in the Ad-LacZ-treated than in Ad-SOD-treated rats. In conclusion, these results indicate that SOD expression can be increased by delivery of the sod gene to the kidney by intravenous injection and that sod gene transduction minimized ischemia-reperfusion-induced acute renal failure.
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PMID:Cu/Zn-superoxide dismutase gene attenuates ischemia-reperfusion injury in the rat kidney. 1172 38

Urea, at concentrations routinely observed in the renal inner medulla during antidiuresis in many mammals, is a potent protein destabilizing agent that reduces the activity of many enzymes. The molecular chaperone heat shock protein 72 (HSP72) is expressed at about 5 ng/ micro g protein in the renal papilla and is thus 40 times more abundant than in the isosmotic cortex and may counteract the deleterious effects of high urea concentrations in the inner medulla. To test this hypothesis, we examined the effect of recombinant HSP72 on lactate dehydrogenase activity in the presence of 0.8 M urea in a cell-free system. The urea-induced increase in K(m) was reduced by 85% in the presence of 1 microM HSP72 but only by 6% by 100 mM betaine, a "counteracting" trimethylamine osmolyte. Conversely, the decrease in V(max) with 0.8 M urea was not affected by HSP72 but was attenuated by 42% in the presence of betaine. The protective effect of HSP72 was confirmed by the attenuation of the urea-induced decrease in the activity of another model enzyme, beta-galactosidase, by lysate of HSP72-overexpressing MDCK cells. Hence, in addition to the trimethylamine osmolytes, HSP72 may participate in counteracting urea-mediated effects on protein function in the renal papilla.
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PMID:Heat shock protein 72, a chaperone abundant in renal papilla, counteracts urea-mediated inhibition of enzymes. 1239 89

The purpose of the present research was to compare the enzyme activity of alkaline phosphatase (ALP), lactate dehydrogenase (LDH), alpha-amylase, alpha-manosidase, beta-N-acetyloglucosaminidase, beta-glucuronidase, and beta-galactosidase in the cervical mucus of cows during spontaneous and induced estrus. Friesian cows (n = 106) were assigned to 4 groups: 1) no treatment; 2) progesterone releasing intervaginal device (PRID) for 12 days plus pregnant mare serum gonadotrophin (PMSG) at the removal of the PRID; 3) PGF2alpha 2 doses 11 days apart; and 4) PRID for 7 days plus PGF2alpha 1 dose, 24 hours before removal of the PRID. Fourteen cows were excluded from the trial because of an inadequate quantity of cervical mucus collected or a lost PRID. The cows from the 3 induced estrus groups were artificially inseminated (AI) twice, while those with spontaneous estrus received only a single AI. Cervical mucus samples were collected from all cows 5 to 30 min before the first AI. The results are summarized as follows: 1) ALP and alpha-amylase activity for spontaneous estrus were similar to those for induced estrus; 2) LDH activity levels during spontaneous estrus were significantly lower (P < 0.001) than that in the P4 and P4+PGF2alpha induced estrus groups; and 3) glycosidases' activity was significantly lower (P < 0.001) in the spontaneous estrus group than that in the induced estrous groups. In conclusion, the activity of most enzymes in the cervical mucus of cows, in the present study, was significantly different between the spontaneous and the induced estrus groups.
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PMID:Enzyme activity in bovine cervical mucus during spontaneous and induced estrus. 1288 24

A multivariate model is proposed relating short-term biomarker measurements in Daphnia magna to chronic effects (21-d exposure) occurring at the population level (time to death, mean brood size, mean total young per female, intrinsic rate of natural increase, net reproductive rate, and growth). The results of the short-term exposure (48 h-96 h) to eight model toxicants (cadmium, chromium, mercury, tributyl tin, linear alkylsulfonic acid, sodium pentachlorophenolate, lindane, and 2,4-dichlorophenoxyacetic acid) on the following biomarkers were used for the multivariate model: digestive enzymes (amylase, cellulase, beta-galactosidase, trypsin, and esterase), enzymes of the intermediary metabolism (glycogen phosphorylase, glucose-6-phosphate dehydrogenase, pyruvate kinase, lactate dehydrogenase, and isocitrate dehydrogenase), cellular energy allocation (CEA) (protein, carbohydrate, and lipid content and electron transport activity), and DNA damage and antioxidative stress activity. Using partial least squares to latent structures (PLS), a two-component model was obtained with R2 of 0.68 and a Q2 value of 0.60 based on the combined analysis of a limited number of the 48- and 96-h biomarker responses. For the individual population-level responses, the R2 values varied from 0.66 to 0.77 and the Q2 values from 0.52 to 0.69. Energy-related biomarkers (cellular energy allocation, lipid contents, anaerobic metabolic activity--pyruvate kinase, and lactate dehydrogenase), combined with parameters related to oxidative stress (catalase) and DNA damage measured after 48 and 96 h of exposure, were able to predict long-term effects at higher levels of biological organization.
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PMID:A multivariate biomarker-based model predicting population-level responses of Daphnia magna. 1295 51

Transcription of the mouse testis-specific lactate dehydrogenase c (mldhc) gene is limited to cells of the germinal epithelium. Cloning and analysis of the mldhc promoter revealed that a 100-bp core promoter was able to regulate testis-specific transcription in vitro and in transgenic mice. Surprisingly, expression of the reporter in transgenic testes was limited to pachytene spermatocytes, whereas native LDH-C(4) was detected in pachytene and all later germ cells. To locate additional regulatory sequence that could recapitulate the native LDH-C(4) distribution pattern, we investigated the contribution of 5' and 3' flanking sequences to the regulation of LDH-C(4) expression. We found that transcription factor YY1 binds to the mldhc promoter, that the mldhc 3' untranslated sequence does not permit a postmeiotic expression of a beta-galactosidase reporter in transgenic mice, and that native mldhc mRNA is predominately meiotic, with only a low level of postmeiotic distribution. Our results suggest that the high level of LDH-C(4) in postmeiotic cells results from mRNA and protein stability.
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PMID:A transgenic analysis of mouse lactate dehydrogenase C promoter activity in the testis. 1458 10

A waste incinerator fly ash was separated into different grain-size fractions by sieving and sedimentation in butanol. The element content of each fraction was determined by atomic absorption and emission spectrometry. The fly-ash fractions, an eluted fine fly-ash fraction and an eluted airborne dust were analysed microscopically for particle size and numbers, together with standard quartz DQ 12 and three element-analysed airborne dusts. Rabbit alveolar macrophages, isolated by lung lavage, were incubated for 24 h with the particulates, the two eluates and a mixed element compound solution corresponding to the element concentrations of one airborne dust. At the end of incubation, the activities of lactate dehydrogenase, N-acetyl-beta-glucosaminidase, beta-galactosidase and acid phosphatase were determined in medium and cell lysates. Cytotoxicity was expressed as ratio of extracellular to total LDH (lactate dehydrogenase) activity. Release of N-acetyl-beta-glucosaminidase and beta-galactosidase was correlated positively with LDH release, whereas the total activity of acid phosphatase decreased with increasing LDH release. Cytotoxicity of the dusts was correlated with particle numbers, and As, Sb and Pb contents. The contribution of As to particle toxicity is discussed. Eluates of dusts did not affect rabbit alveolar macrophage viability.
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PMID:Cytotoxicity to alveolar macrophages of airborne particles and waste incinerator fly-ash fractions. 1509 35


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