Purification and characterization of two lipoxygenase isoenzymes from germinating barley

Doderer, A.; Kokkelink, I.; Veen, S. van der; Valk, B.E.; Schram, A. W.; Douma, A.C.

doi:10.1016/0167-4838(92)90429-h

Cited by 233 publications

(139 citation statements)

References 22 publications

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“…The first eluted enzyme formed a ratio 9-HPODE:13-HPODE of 74:26 while the second eluted enzyme provided a ratio 39:61. As described 4,20,21 , LOX1 (first peak) formed 9-hydroperoxide predominantly, whereas LOX2 (second peak) primarily yielded 13-hydroperoxide. These data are in good agreement with results described in other publications.…”

Section: Regioselectivity Of Partial Purified Lox Isoenzymesmentioning

confidence: 60%

“…12). Doderer et al 4 demonstrated the same pH optimum (pH 6.5) for both LOX1 and LOX2, but indicated that LOX1 has a broader optimum pH range than LOX2. Yang et al 21 using also acetate, phosphate and Tris-HCl buffers, demonstrated an optimal activity for LOX1 at pH 6.3 and for LOX2 two maximal activities at pH 6.0 and at pH 8.0.…”

Section: Ph Optimummentioning

confidence: 99%

“…These derivatives were prepared from HPODE as follows: After enzymatic reaction, 4 mg 12-monohydroxystearic acid (internal standard) was added, the solution was extracted with CHCl 3 :MeOH 3:1 19 and hydroperoxides were reduced to hydroxides (HODE) with NaBH 4 5 . HODEs were extracted with diethyl ether, methylated with diazomethane 9 , hydrogenated (PtO 2 /H 2 ) 15 , silylated 9 and analysed by gas chromatography-mass spectrometry GC/MS 19 .…”

Section: Sample Preparation and Determination Of Regioisomer Ratiosmentioning

confidence: 99%

“…Flavour active compounds found in wort or beer, such as hexanal, hexenal, trans-2-nonenal and 2,4-decadienal, originate from these hydroperoxides 17 . While lipoxygenase 1 (LOX1) is already present in barley and catalyses the formation of (S)-9-hydroperoxy-10E,12Z-octadecadienoic acid ((S)-9-HPODE), lipoxygenase 2 (LOX2) is formed during germination and catalyses the formation of (S)-13-hydroperoxy-9Z,11E-octadecadienoic acid ((S)-13-HPODE) when reacting with linoleic acid 4,10 . These facts suggest that these isoenzymes play different roles during barley germination.…”

Section: Introductionmentioning

confidence: 99%

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Regio- and Stereoselectivity of Malt Lipoxygenases LOX1 and LOX2

Almeida

Garbe

Nagel

et al. 2005

Journal of the Institute of Brewing

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The characterisation of lipoxygenases LOX1 and LOX2 and hydroperoxyoctadecadienoic acid (HPODE) degrading enzymes from barley green malt is reported. Hydroxylapatite chromatography (HAC) and isoelectric focussing (IEF) were performed to separate and purify LOX isoenzymes. The regio-and stereoselectivity of LOX1 and LOX2 towards linoleic acid as substrate was characterised. HAC purified isoenzyme LOX1 showed a 9-HPODE:13-HPODE ratio of 75:25 and LOX2 a ratio of 39:61. IEF separated LOX1 and LOX2 transformed linoleic acid to 9-:13-HPODE ratios of 90:10, and 13:87, respectively. 9-HPODE stereoisomers from LOX1 exhibited a S:R ratio of 93:7 and 13-HPODE from LOX2 a S:R ratio of 89:11. However, the minor regioisomers were analysed with S:R = 48:52 (LOX1, 13-HPODE) and 40:60 (LOX2, 9-HPODE). These results indicate a complete LOX isoenzyme separation by IEF. Hydroperoxide-metabolising enzymes, which were investigated in the IEF fractions, did not interfere with the dual position specificities of LOX isoenzymes.

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Section: Regioselectivity Of Partial Purified Lox Isoenzymesmentioning

confidence: 60%

Section: Ph Optimummentioning

confidence: 99%

Section: Sample Preparation and Determination Of Regioisomer Ratiosmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Regio- and Stereoselectivity of Malt Lipoxygenases LOX1 and LOX2

Almeida

Garbe

Nagel

et al. 2005

Journal of the Institute of Brewing

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“…0-4°C temperature was maintained for performing all the activities. Lipoxygenase (EC 1.13.11.12) activity was determined following the method of Doderer et al (1992) by monitoring the increase in absorbance at 234 nm using linoleic acid as a substrate. Superoxide dismutase (EC 1.15.1.1) activity was measured based on xanthine-xanthine oxidase system following the method of El-Shabrawi et al (2010).…”

Section: Enzyme Extraction and Assaysmentioning

confidence: 99%

Relative tolerance of different species of Brassica to cadmium toxicity: Coordinated role of antioxidant defense and glyoxalase systems

Mahmud¹,

Hasanuzzaman²,

Rahman³

et al. 2017

Plant Omics

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The present study was carried out to examine the metal accumulation and tolerance abilities of three Brassica species (B. napus, B. campestris, and B. juncea) seedlings exposed to two levels of cadmium (Cd) stress (0.25 and 0.5 mM CdCl 2 for three days). Of the Brassica species studied, B. juncea accumulated the highest amount of Cd in a dose-dependent manner, and in every case, the Cd content was higher in the roots than the shoots. Cadmium stress reduced seedlings biomass, leaf relative water content (RWC), and chlorophyll (chl) content, whereas proline (Pro), MDA, and H 2 O 2 content and lipoxygenase (LOX) activity increased in all species. Under Cd stress, ascorbate (AsA) content reduction was lower and glutathione (GSH) content increase was higher in B. juncea compared with other species. Monodehydroascorbate reductase (MDHAR), glutathione reductase (GR), and superoxide dismutase (SOD) activities increased significantly in B. juncea under Cd stress compared with the other species. Catalase (CAT) activity did not decrease in B. juncea due to Cd stress, compared with the other species. Dehydroascorbate reductase (DHAR) activity decreased with both levels of Cd stress in all species except for B. juncea under 0.25 mM CdCl 2 stress. Glyoxalase system components performed better in B. juncea than the other species under Cd stress. Methylglyoxal (MG) increased substantially under both levels of Cd stress, but MG content was lower in B. juncea compared with the others. Considering the antioxidant defense and glyoxalase systems performance B. juncea is relatively tolerant species to Cd toxicity though it accumulated highest Cd.

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Use of ChemiluminescenceHPLC for Measurement of Positional Isomers of Hydroperoxy Fatty Acids in Malting and the Protein Rest Stage of Mashing

Walker¹,

Hughes²,

Simpson³

1996

J. Sci. Food Agric.

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Fatty acid hydroperoxides (9‐ and 13‐hydroperoxides of linoleic acid and linolenic acid) were extracted from barley, malt and wort, and quantified by chemiluminescence HPLC. Although not detected in dried barley (<0·5 μmol kg−1 (dry wt)), the concentrations of hydroperoxides increased during germination (up to 156 μmol kg−1 (dry wt) in the case of 9‐hydroperoxylinoleic acid). Lipoxygenase (LOX) activity increased more than two‐fold during germination. LOX activity and hydroperoxide concentrations were reduced considerably on kilning of malt. During mashing on a laboratory scale, malts with higher total LOX activities produced higher concentrations of hydroperoxides. The concentrations of 9‐hydroperoxides were double those of the 13‐hydroperoxides during malting and up to 10‐fold greater during mashing, indicating a greater activity of LOX‐1 in both processes.

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Purification and characterization of two lipoxygenase isoenzymes from germinating barley

Cited by 233 publications

References 22 publications

Regio- and Stereoselectivity of Malt Lipoxygenases LOX1 and LOX2

Regio- and Stereoselectivity of Malt Lipoxygenases LOX1 and LOX2

Relative tolerance of different species of Brassica to cadmium toxicity: Coordinated role of antioxidant defense and glyoxalase systems

Use of ChemiluminescenceHPLC for Measurement of Positional Isomers of Hydroperoxy Fatty Acids in Malting and the Protein Rest Stage of Mashing

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