Studies on the binding site of the galactose-specific agglutinin PA-IL from Pseudomonas aeruginosa
Studies on the binding site of the galactose-specific agglutinin PA-IL from Pseudomonas aeruginosa
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DOI：
10.1093/glycob/8.1.7
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发表时间：
1998-01-01
期刊：
影响因子：
4.3
通讯作者：
Wu, AM
中科院分区：
文献类型：
--
作者：
Chen, CP;Song, SC;Wu, AM
用生物素/亲和素介导的微孔板凝集素结合试验和抑制凝集素-葡聚糖与糖配体相互作用的方法研究了铜绿假单胞菌凝集素-I(PA-IL)与糖蛋白(GPS)和多糖的结合特性。在36种被测的糖蛋白中，PA-IL与两种含有Galα1-Gal决定簇的糖蛋白和一个人ABO血型前体相当于GP的糖蛋白反应最好，但这种凝集素与A和H活性GPS或唾液酸化GPS反应弱或根本不反应。4Gal是最好的，其活性是美立比糖(GalAlpha1-Gt；6Glc)的7.4倍。PA-IL对α-异构体的偏好顺序为：Galα-->；6>；Galalalpha1-->；4>；Galalalpha1-->；3.在所研究的单糖中，Gal的苯基-β-衍生物比甲基-β-衍生物具有更好的抑制作用，而甲基-β-苯基和对-NO2-苯基衍生物的Galα-异构体之间的差异不显著，由此可以得出结论：凝集素的结合大小与非还原端Gal的α-异构体的二糖一样大，与Galα1-GT；6Glc的互补最大。至于PA-IL与β-异构体的结合部位，假设其大小小于Gal；吡喃糖形式的碳-6是必需的，疏水相互作用对结合是重要的。
The binding properties of Pseudomonas aeruginosa agglutinin-I (PA-IL) with glycoproteins (gps) and polysaccharides were studied by both the biotin/avidin-mediated microtiter plate lectin-binding assay and the inhibition of agglutinin-glycan interaction with sugar ligands, Among 36 glycans tested for binding, PA-IL reacted best with two glycoproteins containing Gal alpha 1-->4Gal determinants and a human blood group ABO precursor equivalent gp, but this lectin reacted weakly or not at all with A and H active gps or sialylated gps, Among the mammalian disaccharides tested by the inhibition assay, the human blood group P-k active Gal alpha 1-->4Gal, was the best, It was 7.4-fold less active than melibiose (Gal alpha 1-->6Glc). PA-IL has a preference for the a-anomer in decreasing order as follows: Gal alpha-->6 > Gal alpha 1-->4 > Gal alpha 1-->3. Of the monosaccharides studied, the phenyl beta derivatives of Gal were much better inhibitors than the methyl beta derivative, while only an insignificant difference was found between the Gal alpha anomer of methyl-and p-NO2-phenyl derivatives, From these results, it can be concluded that the combining size of the agglutinin is as large as a disaccharide of the alpha-anomer of Gal at nonreducing end and most complementary to Gal alpha 1-->6Glc. As for the combining site of PA-IL toward the beta-anomer, the size is assumed to be less than that of Gal; carbon-6 in the pyranose form is essential, and hydrophobic interaction is important for binding.