Characterization of the hydroperoxide-reducing activity of human plasma.
Characterization of the hydroperoxide-reducing activity of human plasma.
复制标题
人血浆氢过氧化物还原活性的表征。
DOI：
10.1016/0003-9861(87)90075-0
复制
发表时间：
1987
影响因子：
3.9
通讯作者：
Marnett,LJ
中科院分区：
文献类型：
--
作者：
Maddipati,KR;Gasparski,C;Marnett,LJ
使用一种新型过氧化物酶测定法在人血浆中鉴别出一种过氧化物酶。在本试验中，通过HPLC定量底物5-苯基-4-戊烯基氢过氧化物（PPHP）及其还原产物5-苯基-4-戊烯醇（PPA）。底物特异性研究表明，过氧化物酶需要谷胱甘肽作为还原底物。没有减少使用经典的血红素过氧化物酶还原底物，苯酚和氢醌检测。过氧化物酶活性不是由于谷胱甘肽转移酶。未能饱和的过氧化物酶活性与还原型谷胱甘肽和抑制Cd+2表明，它可能是硒依赖。根据动力学和免疫学实验，该酶似乎不同于红细胞谷胱甘肽过氧化物酶。在0.5mm还原型谷胱甘肽时，PPHP对红细胞过氧化物酶的表观Km值为25 μ m，对血浆过氧化物酶的表观Km值为54 μ m。对牛红细胞谷胱甘肽过氧化物酶制备的抗过氧化物酶部分抑制人红细胞过氧化物酶，但不抑制人血浆过氧化物酶。
A peroxidase was identified in human plasma using a novel peroxidase assay. In this assay both the substrate 5-phenyl-4-pentenyl hydroperoxide (PPHP) and its reduction product, 5-phenyl-4-pentenyl alcohol (PPA) are quantitated by HPLC. Substrate specificity studies indicated that the peroxidase requires glutathione as reducing substrate. No reduction was detected using the classical heme peroxidase reducing substrates, phenol and hydroquinone. Peroxidase activity was not due to glutathione transferases. Failure to saturate the peroxidase activity with reduced glutathione and inhibition by Cd+2indicated that it is probably selenium dependent. The enzyme appears to be different from erythrocyte glutathione peroxidase based on kinetic and immunological experiments. The apparentKmvalues for PPHP are 25 μmfor erythrocyte peroxidase and 54 μmfor plasma peroxidase at 0.5 mmreduced glutathione. Anti-peroxidase prepared against bovine erythrocyte glutathione peroxidase partially inhibited human erythrocyte peroxidase but did not inhibit human plasma peroxidase.