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Maxey C M Chung - One of the best experts on this subject based on the ideXlab platform.

  • purification and properties of the l Amino Acid Oxidase from malayan pit viper calloselasma rhodostoma venom
    Archives of Biochemistry and Biophysics, 1994
    Co-Authors: Gnanajothy Ponnudurai, Maxey C M Chung
    Abstract:

    Abstract The L-Amino Acid Oxidase of Malayan pit viper ( Calloselasma rhodostoma ) venom was purified to electrophoretic homogeneity. The molecular weight of the enzyme was 132,000 as determined by Sephadex G-200 gel filtration chromatography and 66,000 as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. It is a glycoprotein, has an isoelectric point of 4.4, and contains 2 mol of flavin mononucleotide per mole of enzyme. The N-terminal Amino Acid sequence of the enzyme was A-D-D-R-N-P-L-A-E-E-F-Q-E-N-N-Y-E-E-F-L. Kinetic studies suggest the presence of a alkyl side-chain binding site in the enzyme and that the binding site comprises at least four hydrophobic subsites. The characteristics of the binding site differ slightly from those of cobra venom L-Amino Acid Oxidases.

  • purification and properties of the l Amino Acid Oxidase from malayan pit viper calloselasma rhodostoma venom
    Archives of Biochemistry and Biophysics, 1994
    Co-Authors: Gnanajothy Ponnudurai, Maxey C M Chung
    Abstract:

    Abstract The L-Amino Acid Oxidase of Malayan pit viper ( Calloselasma rhodostoma ) venom was purified to electrophoretic homogeneity. The molecular weight of the enzyme was 132,000 as determined by Sephadex G-200 gel filtration chromatography and 66,000 as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. It is a glycoprotein, has an isoelectric point of 4.4, and contains 2 mol of flavin mononucleotide per mole of enzyme. The N-terminal Amino Acid sequence of the enzyme was A-D-D-R-N-P-L-A-E-E-F-Q-E-N-N-Y-E-E-F-L. Kinetic studies suggest the presence of a alkyl side-chain binding site in the enzyme and that the binding site comprises at least four hydrophobic subsites. The characteristics of the binding site differ slightly from those of cobra venom L-Amino Acid Oxidases.

Gnanajothy Ponnudurai - One of the best experts on this subject based on the ideXlab platform.

  • purification and properties of the l Amino Acid Oxidase from malayan pit viper calloselasma rhodostoma venom
    Archives of Biochemistry and Biophysics, 1994
    Co-Authors: Gnanajothy Ponnudurai, Maxey C M Chung
    Abstract:

    Abstract The L-Amino Acid Oxidase of Malayan pit viper ( Calloselasma rhodostoma ) venom was purified to electrophoretic homogeneity. The molecular weight of the enzyme was 132,000 as determined by Sephadex G-200 gel filtration chromatography and 66,000 as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. It is a glycoprotein, has an isoelectric point of 4.4, and contains 2 mol of flavin mononucleotide per mole of enzyme. The N-terminal Amino Acid sequence of the enzyme was A-D-D-R-N-P-L-A-E-E-F-Q-E-N-N-Y-E-E-F-L. Kinetic studies suggest the presence of a alkyl side-chain binding site in the enzyme and that the binding site comprises at least four hydrophobic subsites. The characteristics of the binding site differ slightly from those of cobra venom L-Amino Acid Oxidases.

  • purification and properties of the l Amino Acid Oxidase from malayan pit viper calloselasma rhodostoma venom
    Archives of Biochemistry and Biophysics, 1994
    Co-Authors: Gnanajothy Ponnudurai, Maxey C M Chung
    Abstract:

    Abstract The L-Amino Acid Oxidase of Malayan pit viper ( Calloselasma rhodostoma ) venom was purified to electrophoretic homogeneity. The molecular weight of the enzyme was 132,000 as determined by Sephadex G-200 gel filtration chromatography and 66,000 as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. It is a glycoprotein, has an isoelectric point of 4.4, and contains 2 mol of flavin mononucleotide per mole of enzyme. The N-terminal Amino Acid sequence of the enzyme was A-D-D-R-N-P-L-A-E-E-F-Q-E-N-N-Y-E-E-F-L. Kinetic studies suggest the presence of a alkyl side-chain binding site in the enzyme and that the binding site comprises at least four hydrophobic subsites. The characteristics of the binding site differ slightly from those of cobra venom L-Amino Acid Oxidases.

Peter Macheroux - One of the best experts on this subject based on the ideXlab platform.

  • Structure and characterization of the glycan moiety of L-Amino-Acid Oxidase from the Malayan pit viper Calloselasma rhodostoma
    2013
    Co-Authors: Armin Geyer, Teresa B Fitzpatrick, Peter D Pawelek, Karina Kitzing, Alice Vrielink, Ro Ghisla, Peter Macheroux
    Abstract:

    deaminating, EC 1.4.3.2) is found in the venom of many poisonous snakes (crotalids, elapids and viperids). This FAD-dependent glycoprotein has been studied from several snake species (e.g. Crotalus adamanteus, Crotalus atrox and Calloselasma rhodostoma) in detail with regard to the biochemical and enzymatic properties. The nature of glycosylation, however, as well as the chemical structure(s) of the attached oligosaccharide(s) are unknown. In view of the putative involvement of the glycan moiety in the biological effects of ophidian l-Amino-Acid Oxidase, notably the apoptotic activity of the enzyme, structural knowledge is needed to evaluate its exact function. In this study we report on the glycosylation of l-Amino-Acid Oxidase from the venom of the Malayan pit viper (Calloselasma rhodostoma). Its glycosylation is remarkably homogenous with the major oligosaccharide accounting for approximately 90 % of the total sugar content. Based on detailed analysis of the isolated oligosaccharide by 2D NMR spectroscopies and MALDI-TOF mass spectrometry the glycan is identified as a bis-sialylated, biantennary, core-fucosylated dodecasaccharide. The biological significance of this finding is discussed in light of the biological activities of the enzyme

  • induction of apoptosis in yeast by l Amino Acid Oxidase from the malayan pit viper calloselasma rhodostoma
    Yeast, 2008
    Co-Authors: Sandro Ghisla, Sudharsana Rao Ande, Heike Fussi, Heide Knauer, Michael Murkovic, Kai Uwe Fröhlich, Peter Macheroux
    Abstract:

    Here we report for the first time that L-Amino Acid Oxidase (LAAO), a major component of snake venom, induces apoptosis in yeast. The causative agent for induction of apoptosis has been shown to be hydrogen peroxide, produced by the enzymatic activity of LAAO. However, the addition of catalase, a specific hydrogen peroxide scavenger, does not prevent cell demise completely. Intriguingly, depletion of leucine from the medium by LAAO and the interaction of LAAO with yeast cells are shown to be the major factors responsible for cell demise in the presence of catalase. Copyright © 2008 John Wiley & Sons, Ltd.

  • structure and characterization of the glycan moiety of l Amino Acid Oxidase from the malayan pit viper calloselasma rhodostoma
    FEBS Journal, 2001
    Co-Authors: Armin Geyer, Sandro Ghisla, Teresa B Fitzpatrick, Peter D Pawelek, Karina Kitzing, Alice Vrielink, Peter Macheroux
    Abstract:

    Ophidian L-Amino-Acid Oxidase (L-Amino-Acid oxygen:oxidoreductase, deaminating, EC 1.4.3.2) is found in the venom of many poisonous snakes (crotalids, elapids and viperids). This FAD-dependent glycoprotein has been studied from several snake species (e.g. Crotalus adamanteus, Crotalus atrox and Calloselasma rhodostoma) in detail with regard to the biochemical and enzymatic properties. The nature of glycosylation, however, as well as the chemical structure(s) of the attached oligosaccharide(s) are unknown. In view of the putative involvement of the glycan moiety in the biological effects of ophidian L-Amino-Acid Oxidase, notably the apoptotic activity of the enzyme, structural knowledge is needed to evaluate its exact function. In this study we report on the glycosylation of L-Amino-Acid Oxidase from the venom of the Malayan pit viper (Calloselasma rhodostoma). Its glycosylation is remarkably homogeneous with the major oligosaccharide accounting for approximately 90% of the total sugar content. Based on detailed analysis of the isolated oligosaccharide by 2D NMR spectroscopies and MALDI-TOF mass spectrometry the glycan is identified as a bis-sialylated, biantennary, core-fucosylated dodecasaccharide. The biological significance of this finding is discussed in light of the biological activities of the enzyme.

Yeong Shik Kim - One of the best experts on this subject based on the ideXlab platform.

  • Characterization and cytotoxicity of l-Amino Acid Oxidase from the venom of king cobra (Ophiophagus hannah)
    The international journal of biochemistry & cell biology, 1997
    Co-Authors: Mi Young Ahn, Byung Mu Lee, Yeong Shik Kim
    Abstract:

    The aim of this project was to determine the cytotoxic components from the venom of king cobra, Ophiophagus hannah. Venom was purified by a combination of gel-filtration, ion-exchange and reversed-phase chromatographic steps. The biochemical properties of the cytotoxic component were consistent with those of l-Amino Acid Oxidase. The molecular weight of the enzyme was estimated to be 150 000 by gel filtration and 70 000 under the denaturing conditions of SDS-PAGE, indicating a dimer. It has an isoelectric point of 4.5 and is a glycoprotein. The N-terminal sequence of l-Amino Acid Oxidase from the king cobra venom was determined to be SVINLEESFQEPEYE. The cytotoxicity of l-Amino Acid Oxidase was observed in stomach cancer, murine melanoma, fibrosarcoma, colorectal cancer and Chinese hamster ovary cell lines. Cytotoxicity resulted in the loss of ability in attachment and inhibition of cell proliferation. The cytotoxic protein decreased the level of cell proliferation by 74% according to [3H]thymidine uptake assay. The mechanism of enzyme action may be related to the inhibition of thymidine incorporation and an interaction with DNA.

M.s. Kanthimathi - One of the best experts on this subject based on the ideXlab platform.

  • Antiproliferative Activity of King Cobra (Ophiophagus hannah) Venom l-Amino Acid Oxidase
    Basic & clinical pharmacology & toxicology, 2013
    Co-Authors: Mui Li Lee, Ivy Chung, M.s. Kanthimathi
    Abstract:

    King cobra (Ophiophagus hannah) venom l-Amino Acid Oxidase (LAAO), a heat-stable enzyme, is an extremely potent antiproliferative agent against cancer cells when compared with LAAO isolated from other snake venoms. King cobra venom LAAO was shown to exhibit very strong antiproliferative activities against MCF-7 (human breast adenocarcinoma) and A549 (human lung adenocarcinoma) cells, with an IC50 value of 0.04 ± 0.00 and 0.05 ± 0.00 μg/mL, respectively, after 72-hr treatment. In comparison, its cytotoxicity was about 3–4 times lower when tested against human non-tumourigenic breast (184B5) and lung (NL 20) cells, suggesting selective antitumour activity. Furthermore, its potency in MCF-7 and A549 cell lines was greater than the effects of doxorubicin, a clinically established cancer chemotherapeutic agent, which showed an IC50 value of 0.18 ± 0.03 and 0.63 ± 0.21 μg/mL, respectively, against the two cell lines. The selective cytotoxic action of the LAAO was confirmed by phycoerythrin (PE) annexin V/7-Amino-actinomycin (AAD) apoptotic assay, in which a significant increase in apoptotic cells was observed in LAAO-treated tumour cells than in their non-tumourigenic counterparts. The ability of LAAO to induce apoptosis in tumour cells was further demonstrated using caspase-3/7 and DNA fragmentation assays. We also determined that this enzyme may target oxidative stress in its killing of tumour cells, as its cytotoxicity was significantly reduced in the presence of catalase (a H2O2 scavenger). In view of its heat stability and selective and potent cytotoxic action on cancer cells, king cobra venom LAAO can be potentially developed for treating solid tumours.