caa a22 4500 37888400X CHVBK 20180305123438.0 cr unu---uuuuu 161128e20040901xx s 000 0 eng 10.1515/BC.2004.106 doi (NATIONALLICENCE)gruyter-10.1515/BC.2004.106 Oxidative modification of low-density lipoprotein: lipid peroxidation by myeloperoxidase in the presence of nitrite [Elektronische Daten] [Tilo Kraemer, Inthanongsack Prakosay, Rahul A. Date, Helmut Sies, Tankred Schewe] Oxidative modification of low-density lipoprotein (LDL) is a pivotal process in early atherogenesis and can be brought about by myeloperoxidase (MPO), which is capable of reacting with nitrite, a NO metabolite. We studied MPO-mediated formation of conjugated dienes in isolated human LDL in dependence on the concentrations of nitrite and chloride. This reaction was strongly stimulated by low concentrations (5-50 µM) of nitrite which corresponds to the reported concentration in the arterial vessel wall. Under these conditions no protein tyrosine nitration occurred; this reaction required much higher nitrite concentrations (100 µM—1 mM). Chloride neither supported lipid peroxidation alone nor was its presence mandatory for the effect of nitrite. We propose a prominent role of lipid peroxidation for the proatherogenic action of the MPO/nitrite system, whereas peroxynitrite may be competent for protein tyrosine nitration of LDL. Monomeric and oligomeric flavan-3-ols present in cocoa products effectively counteracted, at micromolar concentrations, the MPO/nitrite-mediated lipid peroxidation of LDL. Flavan-3-ols also suppressed protein tyrosine nitration induced by MPO/nitrite or peroxynitrite as well as Cu2+-mediated lipid peroxidation of LDL. This multi-site protection by (-)-epicatechin or other flavan-3-ols against proatherogenic modification of LDL may contribute to the purported beneficial effects of dietary flavan-3-ols for the cardiovascular system. © Walter de Gruyter Biochemistry nationallicence Molecular biology nationallicence Cellular biology nationallicence antioxidant nationallicence atherosclerosis nationallicence cocoa nationallicence epicatechin nationallicence flavonoids nationallicence LDL oxidation nationallicence procyanidins nationallicence Kraemer Tilo Institut für Biochemie und Molekularbiologie I, Heinrich-Heine-Universität Düsseldorf, P.O. Box 10 10 07, D-40001 Düsseldorf, Germany aut Prakosay Inthanongsack Institut für Biochemie und Molekularbiologie I, Heinrich-Heine-Universität Düsseldorf, P.O. Box 10 10 07, D-40001 Düsseldorf, Germany aut Date Rahul A. Institut für Biochemie und Molekularbiologie I, Heinrich-Heine-Universität Düsseldorf, P.O. Box 10 10 07, D-40001 Düsseldorf, Germany aut Sies Helmut Institut für Biochemie und Molekularbiologie I, Heinrich-Heine-Universität Düsseldorf, P.O. Box 10 10 07, D-40001 Düsseldorf, Germany aut Schewe Tankred Institut für Biochemie und Molekularbiologie I, Heinrich-Heine-Universität Düsseldorf, P.O. Box 10 10 07, D-40001 Düsseldorf, Germany aut Biological Chemistry Walter de Gruyter 385/9(2004-09-01), 809-818 1431-6730 385:9<809 2004 385 bchm https://doi.org/10.1515/BC.2004.106 text/html Onlinezugriff via DOI 1 research article jats NATIONALLICENCE 856 40 https://doi.org/10.1515/BC.2004.106 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Kraemer Tilo Institut für Biochemie und Molekularbiologie I, Heinrich-Heine-Universität Düsseldorf, P.O. Box 10 10 07, D-40001 Düsseldorf, Germany aut NATIONALLICENCE 700 1- Prakosay Inthanongsack Institut für Biochemie und Molekularbiologie I, Heinrich-Heine-Universität Düsseldorf, P.O. Box 10 10 07, D-40001 Düsseldorf, Germany aut NATIONALLICENCE 700 1- Date Rahul A. Institut für Biochemie und Molekularbiologie I, Heinrich-Heine-Universität Düsseldorf, P.O. Box 10 10 07, D-40001 Düsseldorf, Germany aut NATIONALLICENCE 700 1- Sies Helmut Institut für Biochemie und Molekularbiologie I, Heinrich-Heine-Universität Düsseldorf, P.O. Box 10 10 07, D-40001 Düsseldorf, Germany aut NATIONALLICENCE 700 1- Schewe Tankred Institut für Biochemie und Molekularbiologie I, Heinrich-Heine-Universität Düsseldorf, P.O. Box 10 10 07, D-40001 Düsseldorf, Germany aut NATIONALLICENCE 773 0- Biological Chemistry Walter de Gruyter 385/9(2004-09-01), 809-818 1431-6730 385:9<809 2004 385 bchm CC0 http://creativecommons.org/publicdomain/zero/1.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-gruyter