Peumans W J, Kellens J T, Allen A K, Van Damme E J
Katholieke Universiteit Leuven, Fakulteit der Landbouwwetenschappen, Laboratorium voor Fytopathologie en Plantenbescherming, Belgium.
Carbohydr Res. 1991 Jun 25;213:7-17. doi: 10.1016/s0008-6215(00)90593-7.
A third elderberry (Sambucus nigra L.) lectin (SNA-III) has been isolated from dry seeds by affinity chromatography on immobilized 2-acetamido-2-deoxy-D-galactose. This lectin is a blood-group, nonspecific glycoprotein containing 21% of carbohydrate, and is rich in asparagine (or aspartic acid), serine, glutamine (or glutamic acid), and glycine. Gel filtration on Superose 12 yielded a single symmetrical peak corresponding to mol. wt. 50,000, SDS-poly(acrylamide) gel (SDS-PAGE) electrophoresis showed a single polypeptide band of 33 kDa, indicating that the native protein is a dimer of identical subunits. Hapten-inhibition assays of the agglutination of red blood cells showed that 2-acetamido-2-deoxy-D-galactose is the best inhibitor, being twice as potent as D-galactose, melibiose, and 2-amino-2-deoxy-D-galactose. A comparison of SNA-III to the previously described elderberry-bark lectins, SNA-I and SNA-II, indicated that the seed lectin is well distinct from them.
通过固定化2-乙酰氨基-2-脱氧-D-半乳糖的亲和色谱法，从干燥种子中分离出了第三种接骨木（黑接骨木）凝集素（SNA-III）。这种凝集素是一种血型非特异性糖蛋白，含21%的碳水化合物，富含天冬酰胺（或天冬氨酸）、丝氨酸、谷氨酰胺（或谷氨酸）和甘氨酸。在Superose 12上进行凝胶过滤得到一个对应于分子量50,000的单一对称峰，SDS-聚丙烯酰胺凝胶（SDS-PAGE）电泳显示一条33 kDa的单一多肽带，表明天然蛋白是由相同亚基组成的二聚体。红细胞凝集的半抗原抑制试验表明，2-乙酰氨基-2-脱氧-D-半乳糖是最佳抑制剂，其效力是D-半乳糖、蜜二糖和2-氨基-2-脱氧-D-半乳糖的两倍。将SNA-III与先前描述的接骨木树皮凝集素SNA-I和SNA-II进行比较，表明种子凝集素与它们明显不同。
