Harari Y, Castro G A
Mol Biochem Parasitol. 1983 Sep;9(1):73-81. doi: 10.1016/0166-6851(83)90058-0.
Maximal binding (Bmax) of the lectin, wheat germ agglutinin, by small intestinal brush border membrane is significantly reduced in rats infected with Trichinella spiralis. Wheat germ agglutinin specificity is for N-acetylglucosamine and sialic acid. Whereas total hexosamine and N-acetylglucosaminidase-labile N-acetylglucosamine were comparable in membranes from uninfected as compared with infected rats, the total sialic acid content and neuraminidase-released sialic acid were significantly higher in BBM from uninfected hosts. N-Acetylglucosaminidase treatment of membranes reduced Bmax for wheat germ agglutinin in both hosts. Neuraminidase treatment reduced Bmax in uninfected hosts, but tended to increase it in infected rats. Membranes from uninfected rats incorporated more N-acetylglucosamine from UDP-N-[14C]acetylglucosamine into oligosaccharide-lipid than did membranes from infected hosts. However, lipid and protein fractions were labeled at the same rate in both sets of membranes. Sialic acid was incorporated into protein at a slightly faster rate in brush border membrane from uninfected rats, indicative of a higher level of sialotransferase activity. These results suggest that the reduction in Bmax for wheat germ agglutinin in gut epithelial cell membranes from infected rats is related to a reduced level of sialic acid available for lectin binding as well as specific interactions between N-acetylglucosamine and sialic acid.
感染旋毛虫的大鼠小肠刷状缘膜对凝集素麦胚凝集素的最大结合量（Bmax）显著降低。麦胚凝集素的特异性针对N-乙酰葡糖胺和唾液酸。与未感染大鼠的膜相比，未感染和感染大鼠的膜中总己糖胺和N-乙酰葡糖胺酶不稳定的N-乙酰葡糖胺含量相当，但未感染宿主的刷状缘膜中总唾液酸含量和神经氨酸酶释放的唾液酸显著更高。用N-乙酰葡糖胺酶处理膜会降低两种宿主中麦胚凝集素的Bmax。用神经氨酸酶处理会降低未感染宿主的Bmax，但在感染大鼠中则倾向于增加。与感染宿主的膜相比，未感染大鼠的膜从UDP-N-[14C]乙酰葡糖胺中摄取更多的N-乙酰葡糖胺并将其掺入寡糖脂中。然而，两组膜中脂质和蛋白质部分的标记速率相同。未感染大鼠的刷状缘膜中唾液酸掺入蛋白质的速率略快，这表明唾液酸转移酶活性水平较高。这些结果表明，感染大鼠肠道上皮细胞膜中麦胚凝集素Bmax的降低与可用于凝集素结合的唾液酸水平降低以及N-乙酰葡糖胺和唾液酸之间的特定相互作用有关。
