Effect of temperature and phase transition on oxidation resistance of low density lipoprotein.
The study of the effect of temperature on the kinetics of low density lipoprotein (LDL) oxidation was carried out by measuring the conjugated diene (CD) versus time curves at a fixed LDL concentration (0.1 microM) and at different Cu2+ concentrations (0.5-10 microM) in a wide temperature range, from...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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Elsevier
1996-01-01
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| Series: | Journal of Lipid Research |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S0022227520391963 |
| _version_ | 1818647247919775744 |
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| author | P Ramos S P Gieseg B Schuster H Esterbauer |
| author_facet | P Ramos S P Gieseg B Schuster H Esterbauer |
| author_sort | P Ramos |
| collection | DOAJ |
| description | The study of the effect of temperature on the kinetics of low density lipoprotein (LDL) oxidation was carried out by measuring the conjugated diene (CD) versus time curves at a fixed LDL concentration (0.1 microM) and at different Cu2+ concentrations (0.5-10 microM) in a wide temperature range, from 10 degrees C to 45 degrees C. The core melting point of the LDL determined with differential scanning calorimetry was 31.1 degrees C. We have demonstrated that temperature exerts a clear effect in the Cu(2+)-mediated LDL oxidation, with a strong decrease in lag time and a notable increase in the rate of propagation. This temperature dependence of lag time and rate of propagation fully obeys the Arrhenius law, suggesting that the core melting point of the LDL has no or only a minor effect on these oxidation indices. The Arrhenius plots of the binding of Cu2+ to LDL, measured by K, gave two breaks suggesting that this value is affected by the core transition of the LDL as well as by structural changes at around 15 degrees C. The mean activation energy during rate of initiation was 13.5 kcal/mol and tended to decrease with increasing Cu2+ concentration. The activation energy in the propagation phase was 10.6 kcal/mol and was independent of Cu2+ concentration. In this work we have also shown that the CD method can be conducted with high reproducibility and that a sucrose-supplemented plasma frozen at -80 degrees C can be used as a source of LDL with an unvarying vitamin E content and reproducible oxidation properties. |
| first_indexed | 2024-12-17T00:59:30Z |
| format | Article |
| id | doaj.art-c8baad592917427386ccbff9b76e5893 |
| institution | Directory Open Access Journal |
| issn | 0022-2275 |
| language | English |
| last_indexed | 2024-12-17T00:59:30Z |
| publishDate | 1996-01-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Journal of Lipid Research |
| spelling | doaj.art-c8baad592917427386ccbff9b76e58932022-12-21T22:09:31ZengElsevierJournal of Lipid Research0022-22751996-01-01361021132128Effect of temperature and phase transition on oxidation resistance of low density lipoprotein.P Ramos0S P Gieseg1B Schuster2H Esterbauer3Institute of Biochemistry, University of Graz, Austria.Institute of Biochemistry, University of Graz, Austria.Institute of Biochemistry, University of Graz, Austria.Institute of Biochemistry, University of Graz, Austria.The study of the effect of temperature on the kinetics of low density lipoprotein (LDL) oxidation was carried out by measuring the conjugated diene (CD) versus time curves at a fixed LDL concentration (0.1 microM) and at different Cu2+ concentrations (0.5-10 microM) in a wide temperature range, from 10 degrees C to 45 degrees C. The core melting point of the LDL determined with differential scanning calorimetry was 31.1 degrees C. We have demonstrated that temperature exerts a clear effect in the Cu(2+)-mediated LDL oxidation, with a strong decrease in lag time and a notable increase in the rate of propagation. This temperature dependence of lag time and rate of propagation fully obeys the Arrhenius law, suggesting that the core melting point of the LDL has no or only a minor effect on these oxidation indices. The Arrhenius plots of the binding of Cu2+ to LDL, measured by K, gave two breaks suggesting that this value is affected by the core transition of the LDL as well as by structural changes at around 15 degrees C. The mean activation energy during rate of initiation was 13.5 kcal/mol and tended to decrease with increasing Cu2+ concentration. The activation energy in the propagation phase was 10.6 kcal/mol and was independent of Cu2+ concentration. In this work we have also shown that the CD method can be conducted with high reproducibility and that a sucrose-supplemented plasma frozen at -80 degrees C can be used as a source of LDL with an unvarying vitamin E content and reproducible oxidation properties.http://www.sciencedirect.com/science/article/pii/S0022227520391963 |
| spellingShingle | P Ramos S P Gieseg B Schuster H Esterbauer Effect of temperature and phase transition on oxidation resistance of low density lipoprotein. Journal of Lipid Research |
| title | Effect of temperature and phase transition on oxidation resistance of low density lipoprotein. |
| title_full | Effect of temperature and phase transition on oxidation resistance of low density lipoprotein. |
| title_fullStr | Effect of temperature and phase transition on oxidation resistance of low density lipoprotein. |
| title_full_unstemmed | Effect of temperature and phase transition on oxidation resistance of low density lipoprotein. |
| title_short | Effect of temperature and phase transition on oxidation resistance of low density lipoprotein. |
| title_sort | effect of temperature and phase transition on oxidation resistance of low density lipoprotein |
| url | http://www.sciencedirect.com/science/article/pii/S0022227520391963 |
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