Piller V, Piller F, Cartron J P
Institut National de la Santé et de la Recherche Médicale Unité 76, Institut National de Transfusion Sanguine, Paris, France.
Eur J Biochem. 1990 Jul 31;191(2):461-6. doi: 10.1111/j.1432-1033.1990.tb19144.x.
Seven plant lectins, Dolichos biflorus agglutinin (DBA), Griffonia simplicifolia agglutinin (GSA, isolectin A4), Helix pomatia agglutinin (HPA), soybean (Glycine max) agglutinin (SBA), Salvia sclarea agglutinin (SSA), Vicia villosa agglutinin (VVA, isolectin B4) and Wistaria floribunda agglutinin (WFA), known to be specific for N-acetyl-D-galactosamine-(GalNAc) bearing glycoconjugates, have been compared by the binding of their radiolabelled derivatives, to eight well-characterized synthetic oligosaccharides immobilized via a spacer on an inert silica matrix (Synsorb). The eight oligosaccharides included the Forssman, the blood group A and the T antigens, as well as alpha GalNAc coupled directly to the support (Tn antigen) and also structures with GalNAc linked alpha or beta to positions 3 or 4 of an unsubstituted Gal. The binding studies clearly distinguished the lectins into alpha GalNAc-specific agglutinins like DBA, GSA and SSA, and lectins which recognize alpha- as well as beta-linked GalNAc residues like HPA, VVA, WFA and SBA. HPA was the only lectin which bound to the beta Gal1----3 alpha GalNAc-Synsorb adsorbent (T antigen) indicating that it also recognizes internal GalNAc residues. Among the alpha GalNAc-specific lectins, DBA strongly recognized blood group A structures while GSA displayed weaker recognition, and SSA bound only slightly to this affinity matrix. In addition, DBA and SSA were able to distinguish between GalNAc linked alpha 1----3 and GalNAc linked alpha 1----4, to the support, the latter being a much weaker ligand. These results were corroborated by the binding of the lectins to biological substrates as determined by their hemagglutination titers with native and enzyme-treated red blood cells carrying known GalNAc determinants, e.g. blood group A, and the Cad and Tn antigens. For SSA, the binding to the alpha GalNAc matrix was inhibited by a number of glycopeptides and glycoproteins confirming the strong preference of this lectin for alpha GalNAc-Ser/Thr-bearing glycoproteins.
七种植物凝集素，即双花扁豆凝集素（DBA）、非洲豆蔻凝集素（GSA，异凝集素A4）、蜗牛凝集素（HPA）、大豆（大豆属）凝集素（SBA）、鼠尾草凝集素（SSA）、绒毛野豌豆凝集素（VVA，异凝集素B4）和紫藤凝集素（WFA），已知对带有N-乙酰-D-半乳糖胺-（GalNAc）的糖缀合物具有特异性，通过它们的放射性标记衍生物与八种通过间隔臂固定在惰性硅胶基质（Synsorb）上的充分表征的合成寡糖的结合来进行比较。这八种寡糖包括福斯曼抗原、血型A抗原和T抗原，以及直接偶联到载体上的α-GalNAc（Tn抗原），还有GalNAc以α或β键连接到未取代Gal的3或4位的结构。结合研究清楚地将凝集素分为像DBA、GSA和SSA这样的α-GalNAc特异性凝集素，以及像HPA、VVA、WFA和SBA这样识别α-以及β-连接的GalNAc残基的凝集素。HPA是唯一与β-Gal1----3α-GalNAc-Synsorb吸附剂（T抗原）结合的凝集素，表明它也识别内部GalNAc残基。在α-GalNAc特异性凝集素中，DBA强烈识别血型A结构，而GSA的识别较弱，SSA仅与这种亲和基质有轻微结合。此外，DBA和SSA能够区分连接到载体上的α1----3连接的GalNAc和α1----4连接的GalNAc，后者是一种弱得多的配体。这些结果通过凝集素与生物底物的结合得到证实，这是通过它们与携带已知GalNAc决定簇（如血型A、Cad和Tn抗原）的天然和酶处理红细胞的血凝滴度来确定的。对于SSA，其与α-GalNAc基质的结合被多种糖肽和糖蛋白抑制，证实了这种凝集素对带有α-GalNAc-Ser/Thr的糖蛋白有强烈偏好。
