文章基本信息

标题：Purified human serum PON1 does not protect LDL against oxidation in the in vitro assays initiated with copper or AAPH
本地全文：下载
作者：John F. Teiber ; Dragomir I. Draganov ; Bert N. La Du 等
期刊名称：JLR Papers In Press
印刷版ISSN：0022-2275
电子版ISSN：1539-7262
出版年度：2004
卷号：45
期号：12
页码：2260-2268
DOI：10.1194/jlr.M400213-JLR200
语种：English
出版社：American Society for Biochemistry and Molecular Biology
摘要：Purified serum paraoxonase (PON1) had been shown to attenuate the oxidation of LDL in vitro. We critically reevaluated the antioxidant properties of serum PON1 in the in vitro assays initiated with copper or the free radical generator 2,2′-azobis-2-amidinopropane hydrochloride (AAPH). The antioxidant activity of different purified PON1 preparations did not correlate with their arylesterase (AE), lactonase, or phospholipase A₂ activities or with the amounts of detergent or protein. Dialysis of three of these preparations resulted in a 30–40% loss of their AE activities but in a complete loss of their antioxidant activities. We also followed the distribution of the antioxidant activity during human serum PON1 purification by two purification methods. The antioxidant activity of the anion-exchange chromatography fractions did not copurify with PON1 using either method and could largely be accounted for by the “antioxidant” activity of the detergent present. In conclusion, using the copper or AAPH in vitro assays, no PON1-mediated antioxidant activity was detected, suggesting that the removal of PON1 from its natural environment may impair its antioxidative activity and that this assay with highly purified PON1 may be an inappropriate method with which to study the antioxidative properties of the enzyme.