Moxness M S, Brunauer L S, Huestis W H
Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota 55905, USA.
Biochemistry. 1996 Jun 4;35(22):7181-7. doi: 10.1021/bi952167o.
Hydrogen peroxide oxidation of human erythrocytes induces a transfer of phospholipid from the membrane into the cytosol [Brunauer, L.S., Moxness, M.S., & Huestis, W.H. (1994) Biochemistry 33, 4527-4532]. The current study examines the mechanism of lipid reorganization in oxidized cells. Exogenous phosphatidylserine was introduced into the inner monolayer of erythrocytes, and its distribution was monitored by microscopy and radioisotopic labeling. Pretreatment of cells with carbon monoxide prevented both hemoglobin oxidation and the transfer of phosphatidyserine into the cytosolic compartment. The roles of the various hemoglobin oxidation products in lipid extraction were investigated using selective oxidants. Nitrite treatment of intact cells produced almost complete conversion to methemoglobin, but no detectable lipid extraction. Treatments designed to produce the green hemoglobin derivatives, sulfhemoglobin and choleglobin, resulted in cytosolic extraction of phosphatidylserine. Ion exchange and size exclusion chromatography of oxidized cytosolic components revealed a lipid-hemoglobin complex. The interaction between lipid and hemoglobin oxidation products was verified in a model system. Purified hemoglobin, enriched in sulfhemoglobin and choleglobin by treatment with H2O2, H2S, or ascorbate, extracted phospholipid from small unilamellar phospholipid vesicles. Electron paramagnetic resonance studies demonstrated that hemoglobin oxidation products also adsorb fatty acids from solution. This newly described activity of hemoglobin may play a role in the clearance of oxidatively damaged and senescent cells from circulation.
过氧化氢对人红细胞的氧化作用会诱导磷脂从细胞膜转移至细胞质溶胶中[布鲁瑙尔，L.S.，莫克斯尼斯，M.S.，& 休斯蒂斯，W.H.（1994年）《生物化学》33卷，4527 - 4532页]。本研究考察了氧化细胞中脂质重组的机制。将外源性磷脂酰丝氨酸引入红细胞的内层单分子层，并通过显微镜和放射性同位素标记监测其分布。用一氧化碳预处理细胞可防止血红蛋白氧化以及磷脂酰丝氨酸向细胞质溶胶区室的转移。使用选择性氧化剂研究了各种血红蛋白氧化产物在脂质提取中的作用。用亚硝酸盐处理完整细胞几乎可使其完全转化为高铁血红蛋白，但未检测到脂质提取。旨在产生绿色血红蛋白衍生物（硫血红蛋白和胆绿蛋白）的处理导致磷脂酰丝氨酸从细胞质中被提取出来。对氧化的细胞质成分进行离子交换和尺寸排阻色谱分析，发现了一种脂质 - 血红蛋白复合物。在一个模型系统中验证了脂质与血红蛋白氧化产物之间的相互作用。经过氧化氢、硫化氢或抗坏血酸处理而富含硫血红蛋白和胆绿蛋白的纯化血红蛋白，从小单层磷脂囊泡中提取磷脂。电子顺磁共振研究表明，血红蛋白氧化产物也能从溶液中吸附脂肪酸。这种新描述的血红蛋白活性可能在从循环中清除氧化损伤和衰老细胞方面发挥作用。
