| | 1 | Author
| Pedro Macias, M., Carmen Pinto, JoseE. Campillo | Requires cookie* | | | Title
| Purification and Partial Characterization of Rat Liver Lipoxygenase  | | | | Abstract
| Lipoxygenase was purified from rat liver cytosolic fraction by a method involving two successive chromatographic steps on Sephacryl S-200 and Phenyl Sepharose CL-4B. The enzyme has a molecular weight of 96 Kdal and it seems to be composed of two identical subunits. Chromatofocusing of the enzyme revealed a single band of activity at pi 6.3. The enzyme activity of the purified fraction showed maximum activity at pH 7.0 with a Km for linoleic acid of 1.4 /<M and is competitively inhibited by the specific lipoxygenase inhibitor nordihydroguaiaretic acid. The purified enzyme shows absorption and fluorescence spectra similar to those of lipoxygenase from other sources. However, the molecular weight of lipoxygenase purified from liver is found to be different from that of the enzyme from polymorphonuclear leukocytes. It is suggested that there are different isoenzymes of lipoxygenases in mammals. | | | |
Reference
| Z. Naturforsch. 42b, 1343—1348 (1987); received March 16 1987 | | | |
Published
| 1987 | | | |
Keywords
| Lipoxygenase, Enzyme Purification, Hydrophobic Chromatography | | | |
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| default:Reihe_B/42/ZNB-1987-42b-1343.pdf | | | | Identifier
| ZNB-1987-42b-1343 | | | | Volume
| 42 | |
| 2 | Author
| Claus Fuchs, Gerhard Spiteller | Requires cookie* | | | Title
| Iron Release from the Active Site of Lipoxygenase | | | | Abstract
| In the course of the lipoxygenase-catalyzed transformation of linoleic acid to 135-hydro-p eroxy-9Z ,ll£'-octad ecad ien oic acid, iron ions are liberated. This iron release has been de termined using a spectrophotom etric assay based on the complexation of ferrous iron by 3-(2-pyridyl)-5,6-bis-(4-phenylsulfonic acid)-l,2,4-triazine disodium salt (ferrozine). Further comparative measurements demonstrated that iron release correlates to deficient oxygen supply. We speculate that release of iron ions is caused by modifications of histidine residues located at the active site of the enzyme. Liberation of iron ions may be responsible for increased generation of lipid peroxidation (L P O) products observed after a myocardial in farction since iron ions induce nonenzymic LPO processes. | | | |
Reference
| Z. Naturforsch. 55c, 643 (2000); received March 23/April 17 2000 | | | |
Published
| 2000 | | | |
Keywords
| Lipoxygenase, Iron Release, Myocardial Infarction | | | |
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| default:Reihe_C/55/ZNC-2000-55c-0643.pdf | | | | Identifier
| ZNC-2000-55c-0643 | | | | Volume
| 55 | |
| 3 | Author
| Elizabeth Blée | Requires cookie* | | | Title
| Effect of the Safener Dichlormid on Maize Peroxygenase and Lipoxygenase | | | | Abstract
| S-Ethyl-N,N-dipropylthiocarbam ate (EPTC) was oxidized into its corresponding sulfoxide by microsomal fractions from etiolated maize seedlings. This reaction is catalyzed by a hydro-peroxide-dependent enzyme, identified as a peroxygenase. The hydroperoxides formed from fatty acids by a lipoxygenase are efficient co-substrates o f the EPTC sulfoxidation. The effects o f the safener dichlormid on the peroxygenase and lipoxygenase activities were studied in vitro and in vivo. In vitro, the safener is not an inhibitor o f these enzymes. Dichlormid seems to act, in vivo, by modulating the amounts o f peroxygenase and lipoxygenase in treated plants. | | | |
Reference
| Z. Naturforsch. 46c, 920 (1991); received March 26 1991 | | | |
Published
| 1991 | | | |
Keywords
| Dichlormid, EPTC Sulfoxidation, Hydroperoxide-Dependent Oxygenase, Lipoxygenase | | | |
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| default:Reihe_C/46/ZNC-1991-46c-0920.pdf | | | | Identifier
| ZNC-1991-46c-0920 | | | | Volume
| 46 | |
| 4 | Author
| KenjiM. Atsui, Hiroyuki Shinta, H. Irom, Itsu Toyota, Tadahiko Kajiwara, AkikazuH. Atanaka | Requires cookie* | | | Title
| Comparison of the Substrate Specificities of Lipoxygenases Purified from Soybean Seed, Wheat Seed, and Cucumber Cotyledons | | | | Abstract
| Lipoxygenases were highly purified from soybean seed, wheat seed and cucumber cotyle dons. Substrate specificities o f these lipoxygenases were studied by using an entire series o f (co6Z ,co9Z)-C 13~C24-dienoic acids as synthetic substrate analogues. Soybean lipoxygenase-1 and cucumber lipoxygenase showed broad specificities for these substrates while wheat lipoxygenase showed narrow specificities. Position o f dioxygenation to each substrate was an alyzed by high performance liquid chromatography. W ith soybean lipoxygenase-1 elongation o f the distance between the terminal carboxyl group and the site o f hydrogen removal in a substrate decreased the positional specificity o f dioxygenation, while, with cucumber lipoxy genase, shortening the distance decreased the specificity. It was suggested that cucumber lipoxygenase and soybean lipoxygenase-1 recognized the terminal carboxyl group o f a sub strate to arrange it only in one orientation at the reaction center. In case o f wheat lipoxygen ase, recognition o f the carboxyl group was thought to have crucial and essential role to secure the activity. | | | |
Reference
| Z. Naturforsch. 47c, 85—8 (1992); received M ay 8/A ugust 27 1991 | | | |
Published
| 1992 | | | |
Keywords
| Lipoxygenase, Cucumber Cotyledons, Soybean Seed, W heat Seed, Substrate Specificity | | | |
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| default:Reihe_C/47/ZNC-1992-47c-0085.pdf | | | | Identifier
| ZNC-1992-47c-0085 | | | | Volume
| 47 | |
| 5 | Author
| A. Kikazu, H. Atanaka, Tadahiko Kajiwara, KenjiM. Atsui, AkiraK. Itam Ura | Requires cookie* | | | Title
| Expression of Lipoxygenase and Hydroperoxide Lyase Activities in Tomato Fruits | | | | Abstract
| The distribution (or locarization) o f lipoxygenase (LOX) and hydroperoxide lyase (HPO lyase) activities in ripening and ripe tomato fruits was investigated. The highest LOX activity existed between skin and outer flesh o f tom ato fruits. HPO lyase showed no tissue specificity. LOX specifically formed linoleic acid 9-£',Z-hydroperoxide (9-.E,Z-HPO) from linoleic acid (LA), whereas HPO lyase specifically cleaved 13-Z.^-H PO . A lthough a low level (0.36 ± 0.069 nm ol/g fr. wt.) o f hexanal was detected in the intact tom ato fruit, HPOs were not detected. When a tom ato fruit was injured by cutting it into 8 fragments and incubated at 25 °C, hexanal increased to 1.642 nmol/g fr.wt. by 30 min. By hom ogenizing at pH 6.3, hex-anal increased to 21.1 nm ol/g fr.wt. during a 30 min incubation. U V irradiation o f tom ato fruits also increased the formation o f hexanal. From these results, LOX and HPO lyase are considered to exist as latent forms and to begin the expression o f the activity upon injury. | | | |
Reference
| Z. Naturforsch. 47c, 369—3 (1992); received M ay 27 1991/March 4 1992 | | | |
Published
| 1992 | | | |
Keywords
| H istological Localization, Hydroperoxide Lyase, Injury, Lipoxygenase, T om ato Fruit | | | |
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| default:Reihe_C/47/ZNC-1992-47c-0369.pdf | | | | Identifier
| ZNC-1992-47c-0369 | | | | Volume
| 47 | |
| 6 | Author
| Z. Naturforsch | Requires cookie* | | | Title
| Lipoxygenase Forms Located at the Plant Plasma Membrane | | | | Abstract
| In cucumber cotyledons (Cucumis sativus L.) containing several soluble and particulate forms of lipoxygenase (LOX), the location of LOX forms in microsomes has been studied. We concentrated on the question whether the plasma membrane contains one or more forms of LOX. As methodology, we applied both the two-phase partition with polyethylene glycol/ dextran and density gradient flotation of plasma membrane-enriched membrane fractions. Both methods show that a high percentage of the microsomal LOX can be attributed to the plasma membrane. Emphasis was put on the findings that the LOX located at the plasma membrane consisted of a species behaving as an integral membrane protein and another form characterized as a peripheral membrane protein by solubilization with carbonate. With long distance SDS-PAGE and immunodecoration using anti-lipid body LOX antiserum, it is possible to distinguish between microsomal LOX forms by small but significant differences in size. Treatment of seedlings with methyl jasmonate led to an enhanced level of LOX at the plasma membrane. | | | |
Reference
| Z. Naturforsch. 50c, 29 (1995); received August 29/September 301994 | | | |
Published
| 1995 | | | |
Keywords
| Cucumis (Germination), Integral Membrane Protein, Isoenzyme (Lipoxygenase), Lipoxygenase, Methyl Jasmonate, Plasma Membrane | | | |
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| default:Reihe_C/50/ZNC-1995-50c-0029.pdf | | | | Identifier
| ZNC-1995-50c-0029 | | | | Volume
| 50 | |
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