Interaction of human thiol-specific antioxidant protein 1 with erythrocyte plasma membrane
Interaction of human thiol-specific antioxidant protein 1 with erythrocyte plasma membrane
复制标题
DOI：
10.1021/bi000034j
复制
发表时间：
2000-06-13
期刊：
影响因子：
2.9
通讯作者：
Kim, IH
中科院分区：
文献类型：
--
作者：
Cha, MK;Yun, CH;Kim, IH
在从人红细胞中纯化的过程中，人硫醇特异性抗氧化蛋白1（hTSA 1）（TSA/烷基氢过氧化物还原酶亚基C（AhpC）家族的一个人类成员）被片段化至分子量20 323.9300。与完整形式相反，片段化形式不与C-末端肽（Gln-185-Gln-197）抗体结合。基于片段化形式的分子量，计算切割位点在瓦尔-186和Asp-187之间。hTSA 1的C-末端区域似乎是不必要的抗氧化反应。除了hTSA 1，两种同工酶（hORF 06和hTSA 2）中检测到的可溶性部分，而只有hTSA 1中检测到的膜部分。膜结合研究表明，完整形式与红细胞质膜结合，但片段不结合，这表明膜结合需要缺失的C-末端军团（Asp 187-Gln-197）。使用磷脂囊泡的模型膜研究显示hTSA 1与磷脂的强缔合。人TSA 1。如K-m和V-max所示，对脂肪酸氢过氧化物的还原表现出高的催化活性（亚油酸氢过氧化物为89.9 μ M，分别为28.64 μ mol（-1）min（-1）mg（-1））。在本文中，我们首次报道了hTSA 1的C-末端区域参与膜结合，作为支持红细胞中存在膜结合形式的证据。我们的观察的基础上，我们认为，hTSA 1可以作为一个非常有效的抗氧化剂，以消除氧化应激不仅在基质中作为一个自由的形式，但也在膜表面的红细胞（RB C）作为膜相关的形式。
During the purification from human erythrocytes, human thiol-specific antioxidant protein 1 (hTSA1), one human member of the TSA/alkyl hydroperoxide reductase subunit C (AhpC) family, was fragmented to a molecular mass of 20 323.9300. The fragmented form, in contrast to the intact form, did not bind to the C-terminal peptide (Gln-185-Gln-197) antibody. On the basis of the molecular mass of the fragmented form, the cleavage site was calculated to be between Val-186 and Asp-187. The C-terminal region of hTSA1 appeared to be unnecessary for the antioxidant reaction. In addition to hTSA1, two isoenzymes (hORF06 and hTSA2) were detected in the soluble fraction, whereas only hTSA1 was detected in the membrane fraction. A membrane binding study shows that the intact form binds to erythrocyte plasma membrane but the fragment does not, which suggests that the deleted C-terminal legion (Asp187-Gln-197) is required for the membrane binding. A model membrane study using phospholipid vesicle showed a strong association of hTSA1 with the phospholipid. Human TSA1. exhibited high catalytic activity for the reduction of the fatty acid hydroperoxide as indicated by K-m and V-max (89.9 mu M for linoleic acid hydroperoxide, 28.64 mu mol(-1) min(-1) mg(-1), respectively). In this paper, we are making the first report of the involvement of the C-terminal region of hTSA1 in membrane binding as evidence supporting the existence of the membrane-associated forms in the erythrocyte. On the basis of our observations, we suggest that hTSA1 can act as a very effective antioxidant to remove oxidative stresses not only in matrix as a free form but also in the membrane surface of red blood cells (RB C) as a membrane-associated form.