Haest C W, Plasa G, Kamp D, Deuticke B
Biochim Biophys Acta. 1978 May 4;509(1):21-32. doi: 10.1016/0005-2736(78)90004-4.
After treatment of intact human erythrocytes with SH-oxidizing agents (e.g. tetrathionate and diamide) phospholipase A2 cleaves approx. 30% of the phosphatidylserine and 50% of the phosphatidylethanolamine without causing hemolysis (Haest, C.W.M. and Deuticke, B (1976) Biochim. Biophys. Acta 436, 353--365). These phospholipids are scarcely hydrolysed in fresh erythrocytes and are assumed to be located in the inner lipid layer of the membrane (Verkleij, A.J., Zwaal, R.F.A., Roelofsen, B., Comfurius, P., Kastelijn, D. and van Deenen, L.L.M. (1973) Biochim. Biophys Acta 323, 178--193). The enhancement of the phospholipid cleavage is now shown to be accompanied by a 50% decrease of the membrane SH-groups and a cross-linking of spectrin, located at the inner surface of the membrane, to oligomers of less than 10(6) dalton. Blocking approx. 10% of the membrane SH groups with N-ethylmaleimide suppresses both the polymerization of spectrin and the enhancement of the phospholipid cleavage. N-Ethylmaleimide, under these conditions, reacts with three SH groups per molecule of spectrin, 0.7 SH groups per major intrinsic 100 000 dalton protein (band 3) and 1.1 SH groups per molecule of an extrinsic protein of 72 000 daltons (band 4.2). Blocking studies with iodoacetamide demonstrate that the SH groups of the 100 000-dalton protein are not involved in the effects of the SH-oxidizing agents. It is suggested that a release of constraints imposed by spectrin enables phosphatidylserine and phosphatidylethanolamine to move from the inner to the outer lipid layer of the erythrocyte membrane and that spectrin, in the native erythrocyte, stabilizes the orientation of these phospholipids to the inner surface of the membrane.
用 SH 氧化剂（如连四硫酸盐和二酰胺）处理完整的人红细胞后，磷脂酶 A2 可裂解约 30%的磷脂酰丝氨酸和 50%的磷脂酰乙醇胺，且不会引起溶血（海斯特，C.W.M. 和多特克，B（1976 年）《生物化学与生物物理学报》436 卷，353 - 365 页）。这些磷脂在新鲜红细胞中几乎不被水解，被认为位于膜的内脂质层（韦克莱伊，A.J.，兹瓦尔，R.F.A.，罗洛夫森，B.，康弗里乌斯，P.，卡斯特利恩，D. 和范德嫩恩，L.L.M.（1973 年）《生物化学与生物物理学报》323 卷，178 - 193 页）。现已表明，磷脂裂解的增强伴随着膜 SH 基团减少 50%以及位于膜内表面的血影蛋白交联成小于 10⁶ 道尔顿的寡聚体。用 N - 乙基马来酰亚胺封闭约 10%的膜 SH 基团可抑制血影蛋白的聚合以及磷脂裂解的增强。在这些条件下，N - 乙基马来酰亚胺与每分子血影蛋白的三个 SH 基团、每 100000 道尔顿主要内在蛋白（带 3）的 0.7 个 SH 基团以及每分子 72000 道尔顿外在蛋白（带 4.2）的 1.1 个 SH 基团发生反应。用碘乙酰胺进行的封闭研究表明，100000 道尔顿蛋白的 SH 基团不参与 SH 氧化剂的作用。有人提出，血影蛋白所施加的限制的解除使磷脂酰丝氨酸和磷脂酰乙醇胺能够从红细胞膜的内脂质层移动到外脂质层，并且在天然红细胞中，血影蛋白稳定了这些磷脂朝向膜内表面的取向。
