Howard R J, Smith P M, Mitchell G F
Parasitology. 1980 Oct;81(2):273-98. doi: 10.1017/s0031182000056031.
The surface proteins and glycoproteins of red cells from Plasmodium berghei-infected blood have been radio-isotope labelled and compared with those of normal mouse erythrocytes using the following protein labelling probes: lactoperoxidase-catalysed radio-iodination of tyrosyl residues, periodate oxidation and NaB3H4 reduction of sialic acid and oxidation of galactosyl/N-acetylgalactosaminyl residues by galactose oxidase with subsequent NaB3H4 reduction. During P. berghei infection, new tyrosyl-labelled proteins with apparent molecular weights (Mr) of 60 000, 54 000, 40 000 and 27 500 appeared on the surface of most, if not all, red cells in the blood. Purified multinucleate cells (mostly reticulocytes) differed only in that they also had a surface protein with Mr of 83 000. However, this molecule is thought to be specific to mouse reticulocytes rather than derived from parasites. In contrast to the relatively minor changes detected with radio-iodination, striking changes in glycoprotein radio-isotope labelling resulted from infection. All of the red cells in infected blood of greater than 20% parasitaemia lost their periodate-sensitive glycoprotein sialic acid. With some samples there was little change in glycoprotein labelling by the galactose oxidase method, provided neuraminidase was also added. Modification of the exocyclic hydroxyls of sialic acid is postulated to account for this. Other blood samples exhibited a dramatic loss of galactose oxidase-dependent labelling. It is suggested that these observations may relate to the excessive red cell destruction of uninfected as well as infminidase was also added. Modification of the exocyclic hydroxyls of sialic acid is postulated to account for this. Other blood samples exhibited a dramatic loss of galactose oxidase-dependent labelling. It is suggested that these observations may relate to the excessive red cell destruction of uninfected as well as infminidase was also added. Modification of the exocyclic hydroxyls of sialic acid is postulated to account for this. Other blood samples exhibited a dramatic loss of galactose oxidase-dependent labelling. It is suggested that these observations may relate to the excessive red cell destruction of uninfected as well as infected cells which has been inferred in many haemosporidial infections, including malaria.
来自感染伯氏疟原虫血液中的红细胞表面蛋白和糖蛋白已用放射性同位素标记，并使用以下蛋白质标记探针与正常小鼠红细胞的表面蛋白和糖蛋白进行比较：乳过氧化物酶催化的酪氨酸残基放射性碘化、高碘酸盐氧化和用硼氢化钠还原唾液酸，以及用半乳糖氧化酶氧化半乳糖基/N-乙酰半乳糖胺基残基，随后用硼氢化钠还原。在伯氏疟原虫感染期间，大多数（如果不是全部）血液中的红细胞表面出现了表观分子量（Mr）为60000、54000、40000和27500的新的酪氨酸标记蛋白。纯化的多核细胞（主要是网织红细胞）的不同之处仅在于它们还具有一个Mr为83000的表面蛋白。然而，这种分子被认为是小鼠网织红细胞特有的，而非源自寄生虫。与放射性碘化检测到的相对较小的变化相反，感染导致糖蛋白放射性同位素标记发生显著变化。寄生虫血症大于20%的感染血液中的所有红细胞都失去了对高碘酸盐敏感的糖蛋白唾液酸。对于一些样本，如果同时添加神经氨酸酶，半乳糖氧化酶法的糖蛋白标记变化不大。推测唾液酸环外羟基的修饰可以解释这一点。其他血液样本显示半乳糖氧化酶依赖性标记显著减少。有人认为，这些观察结果可能与许多血孢子虫感染（包括疟疾）中推断出的未感染和已感染细胞的过度红细胞破坏有关。
