Schoenberger O L
Department of Molecular Biology, Bernhard-Nocht-Institute for Tropical Medicine, Hamburg, Germany.
FEBS Lett. 1992 Dec 21;314(3):430-4. doi: 10.1016/0014-5793(92)81520-v.
Carbohydrate chains of C1-inhibitor were identified with a binding assay using different lectins. Lectins from Sambucus nigra (SNA) and Maackia amurensis (MAA) that are specific for sialic acids bound to C1-inhibitor. Lectin from Datura stramonium (DSA) reacted also with the inhibitor indicating complex and hybrid sugar structures. C1-inhibitor was enzymatically desialylated and reexamined for lectin binding. SNA and MAA did not react anymore, but in addition to DSA, peanut agglutinin, which can bind to carbohydrate chains after sialic acids are removed, bound to desialylated C1-inhibitor. C1-inhibitor contains about 30 sialic acid residues per molecule. SDS-polyacrylamide gel electrophoresis showed that desialylated C1-inhibitor had a faster mobility than native C1-inhibitor. The N-terminal sequence of desialylated C1-inhibitor was the same as of native C1-inhibitor and no change in the inhibition of human plasma kallikrein was observed.
使用不同的凝集素通过结合试验鉴定了C1抑制剂的碳水化合物链。来自接骨木（SNA）和黑果茶藨子（MAA）的对与C1抑制剂结合的唾液酸具有特异性的凝集素与C1抑制剂结合。来自曼陀罗（DSA）的凝集素也与该抑制剂反应，表明存在复杂和杂合的糖结构。对C1抑制剂进行酶促去唾液酸化，并重新检测其与凝集素的结合情况。SNA和MAA不再发生反应，但除了DSA之外，在去除唾液酸后能够与碳水化合物链结合的花生凝集素也与去唾液酸化的C1抑制剂结合。每个C1抑制剂分子含有约30个唾液酸残基。SDS-聚丙烯酰胺凝胶电泳显示，去唾液酸化的C1抑制剂的迁移率比天然C1抑制剂更快。去唾液酸化的C1抑制剂的N端序列与天然C1抑制剂相同，并且未观察到对人血浆激肽释放酶抑制作用的变化。
