Human serum, cysteine and histidine inhibit the oxidation of low density lipoprotein less at acidic pH

FEBS Letters

Leake, David S¹  Patterson, Rebecca A¹ 

[1]School of Animal and Microbial Sciences, The University of Reading, Whiteknights, P.O. Box 228, Reading, Berks. RG6 6AJ, UK

关键词: Acidic pH;    Antioxidant;    Atherosclerosis;    Copper;    Low density lipoprotein;    Oxidized low density lipoprotein;   

DOI  :  10.1016/S0014-5793(98)01002-3

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Low concentrations of serum or interstitial fluid have been shown to inhibit the oxidation of low density lipoprotein (LDL) catalysed by copper or iron, and may therefore protect against the development of atherosclerosis. As atherosclerotic lesions may have an acidic extracellular pH, we have investigated the effect of pH on the inhibition of LDL oxidation by serum and certain components of serum. Human serum (0.5%, v/v), lipoprotein-deficient human serum at an equivalent concentration and the amino acids l-cysteine (25 μM) and l-histidine (25 μM), but not l-alanine (25 μM), inhibited effectively the oxidation of LDL by copper at pH 7.4, as measured by the formation of conjugated dienes. The antioxidant protection was reduced considerably at pH 6.5, and was decreased further at pH 6.0. These observations may help to explain why LDL becomes oxidised locally in atherosclerotic lesions in the presence of the strong antioxidant protection offered by extracellular fluid.

【 授权许可】

Unknown