• Microbiology and Biotechnology Letters
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• v.20 no.1
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• pp.40-45
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• 1992

Acidic nucleotidase from Asfiergilius nlger has been partially purified by Sepharose CL-6B gel filtration and DEAE-Sephacel ion exchange chromatography. The optimum pH and temperature for the enzyme reaction with 5'-AMP or 3'-AMP as a substrate were 4.5 and 55%, respectively. However, the optimum temperature became 70% when p-nitrophenyl phosphate was used as a substrate. The enzyme was stable at acidic pH. The enzyme activity was not affected by addition of various nucleotides, nucleosides and inorganic phosphates. Ferric, aluminium, vanadate and molybdate ions inhibited the enzyme activity dramatically. In kinetic studies, $K_m$), values for 3'-AMP, 5'-AMP and p-nitrophenyl phosphate were 1.39 mM, 1.5 mM and 5.77 mM, respectively. The substrate efficiency ($V_{max}/K_m$) shows 3'-AMP is the prefered substrate for the enzyme among tested substrates.

• Korean Journal of Pharmacognosy
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• v.20 no.3
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• pp.154-161
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• 1989

Effects of panaxydol, panaxynol and panaxytriol isolated from Panax ginseng C.A. Meyer on some enzyme activities were determined. Activities of ATPase, membrane-bound enzyme from Sarcoma 180 and rat liver were slightly inhibited by panaxydol. Activities of 5'-nucleotidase, membrane-bound enzyme and succinate cytochrome c reductase in mitochonidria from sarcoma 180 and rat livers were significantly inhibited in a dose-dependent manner by panaxynol. The inhibitory effects of panaxydol and panaxynol on succinate cytochrome c reductase activities were more potent than those on 5'-nucleotidase activities and panaxynol was found to be a very potent inhibitor of succinate cytochrome c reductase. Activities of glucose-6-phosphatase in endoplasmic reticulum from Sarcoma 180 and rat livers were not affected by all three polyacetylenes. These results suggested that the inhibitory effects of panaxydol and panaxynol on enzyme activities might contribute to their biological activities.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.3
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• pp.959-963
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• 2015

Purpose: To find parameters that can increase alpha-fetoprotein (AFP) sensitivity and so help in accurate diagnosis and rapid management of hepatocullular carcinoma (HCC), as AFP has limited utility of distinguishing HCC from benign hepatic disorders for its high false-positive and false negative rates. Materials and Methods: Serum levels of AFP, 5'-nucleotidase enzyme activity (5-NU) and leucine aminopeptidase enzyme (LAP) activity were measured in 40 individuals. Results: LAP and 5'NU were elevated in HCC at p<0.001. Pearson correlation coefficients showed that changes in AFP exhibited positive correlation with both 5'-NU and LAP at (p<0.001). The complementary use of LAP only with AFP resulted in an increase in sensitivity of AFP from 75% to 90% in detecting HCC. The complementary use of both LAP and 5-NU with AFP resulted in an increased sensitivity of AFP in detecting HCC from 75% to 95%. Conclusions: LAP and 5-FU can be determined in HCC patients in combination with AFP to improve its sensitivity and decrease false negative results.

• Journal of Applied Biological Chemistry
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• v.42 no.4
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• pp.169-174
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• 1999

Arabidopsis AHL gene contains 4 exons encoding a putative protein highly homologous to the yeast salt-sensitive enzyme HAL2, a 3'(2'),5'-bisphosphate nucleotidase involving in reductive sulfate assimilation. AHL cDNA complemented yeast met22 (hal2) mutant. AHL fusion protein expressed in E. coli exhibited $Mg^{2+}$-dependent, 3'-phosphoadenosine 5'-phosphate (PAP)-specific phosphatase activity. $Li^+,\;Na^+,\;K^+$ and $Ca^{2+}$ ions inhibit the enzyme activity by competing with $Mg^{2+}$ for the active site of the enzyme. The enzyme activity was also sensitive to ${\mu}M$ concentrations of toxic heavy metal ions such as $Cd^{2+},\;Cu^{2+}$ and $Zn^{2+}$, but was not recovered by addition of more $Mg^{2+}$ ions, suggesting that these ions inactivate the enzyme with a mechanism other than competition with $Mg^{2+}$ ions. Inhibition of the AHL enzyme activity may result in accumulation of PAP, which is highly toxic to the cell. Thus, the AHL enzyme could be one of the intial targets of heavy metal toxicity in plants.

• Korean Journal of Food Science and Technology
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• v.21 no.1
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• pp.1-8
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• 1989

Ten cultivars of malting barley grown at four locations were malted and assayed for six enzymes involved in the degradation of nucleic acids. Among these enzymes were deoxyrinonuclease, ribonuclease, phosphodiesterase, 3'- and 5'- nucleotidases and phosphomonesterase. Activities of all enzymes in five-day malts were significantly affected by variety and location of growth. The average levels of ribonuclease, deoxyribonuclease, 3'-nucleotidase and 5'-nucleotidase of 80 five-day malts were 11.2, 5.7, 5.6 and 1.2 units per gram of malt, respectively. Six-rowed barley malts contained higher levels of deoxyribonuclease, phosphodiesterase and 3'-nucleotidase than those of two-rowed barley malts, while two-rowed barley malts contained significantly higher ribonuclease levels than those of six-rowed barley malts.

• Proceedings of the PSK Conference
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• 2000.10a
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• pp.186.2-187
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• 2000

• The Journal of the Korean bone and joint tumor society
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• v.7 no.2
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• pp.41-50
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• 2001

Purpose : To investigate biochemical markers for osteosarcoma, activities of deoxyribocuclease(DNase), ribonuclease(RNase), 5'-nucleotidase, alkaline phosphatase and amylase were determined in the osteosarcoma tissue and serum of patients with osteosarcoma. Also studied were DNase, RNase in osteosarcoma tissue, isolating the enzymes from the sarcoma tissue and investigating the sarcoma specific enzymes. Materials and Methods : The experimental tissue and serum were obtained from twelve patients with osteosarcoma. The control group were obtained from the normal healthy tissue of the same patients. The tissue were centrifugalized to obtain extracts. The extracts were analized for the estimation of nucleic acid, protein contents and enzyme activities. And then each enzymes were isolated and analized by DEAE-cellulose chromatography and estimated for activities. Result : Activities of acid DNase, RNase, 5'-nucleotidase and alkaline phosphatase were significantly increased in osteosarcoma tissue. Neutral RNase in osteosarcoma tissue was shown to bo highly active, exhibiting secretory form of RNase inhibitor associated with the RNase was also increased. In the serum of patients with osteosarcoma, RNase activity was significantly increased. DEAE-cellulose column chromatographical analysis revealed that acid DNase was isolated as a single enzyme and neutral RNase as five isozymes in osteosarcoma tissue. Conclusion : The results indicated that combination of these enzymes could be used as markers for osteosarcoma. The results indicated that acid DNase and neutral RNase might play a role in genesis of sarcoma and suppression of sarcoma.

• Journal of the Korean Society of Food Science and Nutrition
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• v.14 no.2
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• pp.137-144
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• 1985

In order to evaluate the effect of water soluble extract of lichens (Physcia, Parmelia and Clandonia species) on liver damage, activities transaminase(GPT) and 5'-nucleotidase in serum and liver were measured in rats fed lichens extract. DNA and RNA were measured in liver and spleen, as well as various organ weights and blood components. Control group was fed water to compare with the lichen group. Three sets of experiments were conducted: the first set was done with normal rats, the second one with rats with liver damage induced by $CCl_4$ injection was divided into three subgroups. i.e. no treatment group, pre-treatment group and post-treatment group, and the third one was with rats with acute and chronic liver damage. In normal rats, lichens extract feeding reduced serum GOT and GPT activities. In liver damaged rats, both pre-and post-treatment had suppressing effect against increase of serum enzymes. In rats with acute and chronic liver damage, lichens fed group had lower activities of serum GOT, GPT and 5'-nucleotidase but higher activities of liver enzymes than control group. This effect was more pronounced in rats with acute liver damage. Liver weight increased considerably with lichens intake. Hemoglobin and hematocrit levels were also higher in lichens fed group. Nucleic acid contents in spleen but not in liver were increased in lichens fed group. The latter increase was more significant with chronic liver damage. It is suggested from the present study that water soluble lichens extract play protective and therapeutic roles in organs against infection and atrophic disease.

• Journal of Microbiology and Biotechnology
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• v.21 no.5
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• pp.483-493
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• 2011

An acid phosphatase (HppA) activated by $NH_4Cl$ was purified 192- and 34-fold from the periplasmic and membrane fractions of Helicobacter pylori, respectively. SDS-polyacrylamide gel electrophoresis revealed that HppA from the latter appears to be several kilodaltons larger in molecular mass than from the former by about 24 kDa. Under acidic conditions (pH${\leq}$4.5), the enzyme activity was entirely dependent on the presence of certain mono- and/or divalent metal cations (e.g., $K^+$,$ NH_4{^+}$, and/or $Ni^{2+}$). In particular, $Ni^{2+}$ appeared to lower the enzyme's $K_m$ for the substrates, without changing $V_{max}$. The purified enzyme showed differential specificity against nucleotide substrates with pH; for example, the enzyme hydrolyzed adenosine nucleotides more rapidly at pH 5.5 than at pH 6.0, and vice versa for CTP or TTP. Analyses of the enzyme's N-terminal sequence and of an $HppA^-$ H. pylori mutant revealed that the purified enzyme is identical to rHppA, a cloned H. pylori class C acid phosphatase, and shown to be the sole bacterial 5'-nucleotidase uniquely activated by $NH_4Cl$. In contrast to wild type, $HppA^-$ H. pylori cells grew more slowly. Strikingly, they imported $Mg^{2+}$ at a markedly lowered rate, but assimilated urea rapidly, with a subsequent increase in extracellular pH. Moreover, mutant cells were much more sensitive to extracellular potassium ions, as well as to metronidazole, omeprazole, or thiophenol, with considerably lowered MIC values, than wild-type cells. From these data, we suggest that the role of the acid phosphatase HppA in H. pylori may extend beyond 5'-nucleotidase function to include cation-flux as well as pH regulation on the cell envelope.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.12 no.1
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• pp.27-40
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• 1990

In recent years, tissue antigens and enzymes that will serve as phenotypic markers for malignant cells are becoming increasingly important as diagnostic aids. This study was undertaken to investigate the specific activities of these enzymes in DMBA-induced rat submaxillary gland carcinogenesis. One hundred and twenty Sprague-Dawley rats about 100 gms of body weight were used. In experimental group, DMBA pellet (5mg) was implanted into right submaxillary gland and sham operation was performed into left gland to serve as control. The animals were sacrificed every three weeks up to 15 weeks. Submaxillary glands were excised on both sides and enzyme assays for ${\gamma}-glutamyl$ transpeptidase (GGT), 5'-Nucleotidase, Ornithine decarboxylase(ODC) and Acetyl-Co A carboxylase were carried out biochemically. The obtained results were as follows ; 1. In control group, there was no significant weight change of submaxillary gland, while experimental group, weight was increased remarkably about 7-fold at 15th week since DMBA implantation. 2. In control group, there was no change in specific activities of enzymes during the experimental period. 3. GGT activity was rapidly increased reaching a peak of 1.766${\pm}$0.082units/mg of DNA, 8-fold greater than that of onset. 4. 5'-Nucleotidase activity was increased reaching a peak of $362.1{\pm}53.2{\mu}moles/mg$ of DNA at 9th week. 5. ODC activity was rapidly increased, reaching a peak of 26.2${\pm}$4.8nmoles/mg of DNA at 9th week and quickly returned to that of control at 15th week. 6. Acetyl-Co A carboxylase activity was rapidly increased earlier than other enzymes, reaching a peak of 0.178${\pm}$0.013units/mg of DNA at 6th week and quickly declined to the control level at 15th week.