Ericson T, Rundegren J
Eur J Biochem. 1983 Jun 15;133(2):255-61. doi: 10.1111/j.1432-1033.1983.tb07456.x.
A protein, which can agglutinate a Streptococcus mutans serotype c strain, was isolated from parotid saliva by affinity adsorption of the salivary agglutinin to the microorganism followed by a desorption with a 10 mM phosphate buffer. The agglutinin was subjected to preparative ultracentrifugation, gel filtration, and ultrafiltration. The native purified agglutinin is active only in the presence of Ca. Polyacrylamide gel electrophoresis, analytical centrifugation, and analyses of amino acids and carbohydrates showed that the native agglutinin was a fucose-rich glycoprotein with a carbohydrate content of 45% and with a molecular weight of at least 5 X 10(6). After sodium dodecyl sulphate treatment the molecular weight was 4.4 X 10(5). There was a low content of proline and a high content of aspartic acid, serine and threonine. The concentration of agglutinin in parotid saliva is less than 0.5% of total protein. It has high biological activity: 0.1 microgram agglutinin causes a rapid aggregation of approximately 10(8) bacteria.
一种能凝集变形链球菌血清型c菌株的蛋白质，通过唾液凝集素与该微生物的亲和吸附，随后用10 mM磷酸盐缓冲液解吸，从腮腺唾液中分离得到。将该凝集素进行制备性超速离心、凝胶过滤和超滤。天然纯化的凝集素仅在有钙存在时才具有活性。聚丙烯酰胺凝胶电泳、分析性离心以及氨基酸和碳水化合物分析表明，天然凝集素是一种富含岩藻糖的糖蛋白，碳水化合物含量为45%，分子量至少为5×10⁶ 。经十二烷基硫酸钠处理后，分子量为4.4×10⁵ 。脯氨酸含量低，天冬氨酸、丝氨酸和苏氨酸含量高。腮腺唾液中凝集素的浓度低于总蛋白的0.5%。它具有很高的生物活性：0.1微克凝集素能使约10⁸ 个细菌迅速聚集。
