A simple and efficient method for hemoglobin removal from mammalian tissue cytosol by zinc sulfate and its application to the study of lipoxygenase

Hover, Carl G; Kulkarni, Arun P.

doi:10.1054/plef.1999.0126

Cited by 8 publications

(7 citation statements)

References 34 publications

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“…High-performance liquid chromatography (HPLC) analyses of arachidonate metabolites suggested the predominance of 15-LO in human lung [36]. Some data on the properties of LOs from human term placenta and intrauterine conceptual tissues [37,38] and other tissues are also available. Among plants, the most studied LO is from soybean (SLO).…”

Section: Dioxygenase Activitymentioning

confidence: 99%

“…Hemoglobin, a common contaminant in preparations of mammalian tissue LOs, poses a serious problem, since it exhibits both pseudo-dioxygenase and pseudo-peroxidase activities. A recently developed method using ZnSO 4 [38] was found to alleviate this problem without significantly affecting either the dioxygenase or co-oxidase activities of human term placental LO (HTPLO). The K m values for dioxygenation noted with different LOs range between 6 and 28 mM for arachidonate and between 3.5 and 26 mM for oxygen [43].…”

Section: Dioxygenase Activitymentioning

confidence: 99%

“…Human term placentas from non-smoker donors exhibit a marked deficiency in P450, MFMO, and PGS activities. However, LO is plentiful in human placenta [37,38]. It assumes a unique role in the activation of chemical teratogens and developmental toxicants [1].…”

Section: Importance Of Lo-mediated Xenobiotic Metabolismmentioning

confidence: 99%

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Lipoxygenase - a versatile biocatalyst for biotransformation of endobiotics and xenobiotics

Kulkarni¹

2001

CMLS, Cell. Mol. Life Sci.

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Lipoxygenase, a member of the arachidonate cascade enzymes, dioxygenates polyenoic fatty acids to finally yield products with profound and distinct biological activity. This review summarizes the available evidence for another role played by lipoxygenases in the metabolism of endobiotics and xenobiotics. Although other mechanisms exist, a direct hydrogen abstraction by the enzyme and the peroxyl radical-dependent chemical oxidation appear to be central to the co-oxidase activity of lipoxygenases. Besides polyunsaturated fatty acids, H2O2, fatty acid hydroperoxides, and synthetic organic hydroperoxides support the lipoxygenase-catalyzed xenobiotic oxidation. The major reactions documented thus far include oxidation, epoxidation, hydroxylation, sulfoxidation, desulfuration, dearylation, and N-dealkylation. It is noteworthy that lipoxygenases are also capable of glutathione conjugation of certain xenobiotics. The enzyme system appears to be inducible following exposure to chemicals. Lipoxygenases are inhibited by a large number of chemicals, some of which also serve as co-substrates. Available data suggest that lipoxygenases contribute to in vivo metabolism of xenobiotics in mammals.

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Section: Dioxygenase Activitymentioning

confidence: 99%

Section: Dioxygenase Activitymentioning

confidence: 99%

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Lipoxygenase - a versatile biocatalyst for biotransformation of endobiotics and xenobiotics

Kulkarni¹

2001

CMLS, Cell. Mol. Life Sci.

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“…Hemoglobin, a common contaminant in the preparations of tissue LOs, poses a major problem since it possesses pseudo-dioxygenase and pseudo-peroxidase activities. A recently developed method using ZnSO 4 [108] essentially eliminates this problem without significantly affecting the dioxygenase and co-oxidase activities of human term placental LO (HTPLO).…”

Section: Occurrence Of Lomentioning

confidence: 99%

Role of Biotransformation in Conceptal Toxicity of Drugs and Other Chemicals

Kulkarni

2001

CPD

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Many developmental toxicants and teratogens require prior metabolism to reactive species or free radicals to exert toxicity. Thus the knowledge of conceptal biotransformation is absolutely critical in understanding toxicity of these chemicals. Due to extremely low content of cytochrome P450 in the embryo and other conceptal tissues, the research focus in recent years has steadily shifted toward enzymes capable of peroxidative oxidation of xenobiotics. At least three enzymes viz. lipoxygenase, peroxidase and prostaglandin synthase, each capable of peroxidative xenobiotic metabolism, occur in conceptal tissues of man and laboratory animals in biologically significant amounts. This review mainly summarizes the available information on the enzymatic bioactivation of teratogens and developmental toxicants belonging to diverse classes such as drugs, pesticides, environmental contaminants, industrial and other chemicals. Additionally, some discussion is devoted toward issues such as drug-drug interactions. The emerging new information on the peroxidative glutathione conjugate formation from xenobiotics is also presented. A critical need for gathering more information on this subject using different enzyme preparations from human conceptal tissues is stressed to avoid tragedies in the future.

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“…33 It is also possible that HbLDL-associated heme catalyzes a rapid decomposition of peroxides by interaction with various particles via a pseudo-lipoxygenase reaction. 34,35 This reaction was previously described for membrane-associated LOOH, wherein decomposition of heme and of peroxides was rapid if a suitable catalyst was present. 36 Although the absolute levels of lipid peroxidation products contained in HbLDL are low, they are sufficient to promote oxidation.…”

Section: Discussionmentioning

confidence: 99%

Heme and lipid peroxides in hemoglobin-modified low-density lipoprotein mediate cell survival and adaptation to oxidative stress

Asatryan

Ziouzenkova

Duncan

et al. 2003

Blood

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Low-density lipoprotein (LDL) oxidation mediated by a variety of catalysts in atherosclerotic lesions plays a crucial role in the genesis and evolution of atherosclerotic plaques. In this study we focused on oxidative properties of hemoglobin (Hb)-modified LDL because Hb is present in atherosclerotic lesions. Under low oxygen tensions Hb was previously found to modify apolipoprotein B100 with covalent binding of Hb fragments and formation of electronegative LDL particles (LDL ؊ ). Here we show that HbLDL is highly susceptible to oxidation, but is not cytotoxic to vascular cells, as was found for LDL ؊ isolated from human plasma. HbLDL and LDL ؊ have similar levels of oxidized lipid products and low uptake rates; however, the virtual absence of HbLDL-induced toxicity depends on a marked adaptive oxidative stress response. This was evidenced by a time-and dose-dependent induction of heme oxygenase (HO-1)

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A simple and efficient method for hemoglobin removal from mammalian tissue cytosol by zinc sulfate and its application to the study of lipoxygenase

Cited by 8 publications

References 34 publications

Lipoxygenase - a versatile biocatalyst for biotransformation of endobiotics and xenobiotics

Lipoxygenase - a versatile biocatalyst for biotransformation of endobiotics and xenobiotics

Role of Biotransformation in Conceptal Toxicity of Drugs and Other Chemicals

Heme and lipid peroxides in hemoglobin-modified low-density lipoprotein mediate cell survival and adaptation to oxidative stress

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