Iron(II)-Assisted Assembly of Trivalent GalNAc Clusters and Their Interactions with GalNAc-Specific Lectins
作者:Shin Sakai、Yoshihiro Shigemasa、Tomikazu Sasaki
DOI:10.1246/bcsj.72.1313
日期:1999.6
A novel metal-assisted assembly of mulitivalent carbohydrate ligands is described. A bipyridine-modified N-acetylgalactosamine (bipy-GalNAc) undergoes Fe(II)-induced self-association to form a trimeric GalNAc ligand (FeII(bipy-GalNAc)3). The synthetic GalNAc cluster strongly binds to Vicia villosa B4 lectin and Glycin Max lectin, which recognizes multiple GalNAc residues. The trimeric GalNAc ligand is formed as a mixture of four diastereomeric isomers: Δ-fac, Λ-fac, Δ-mer, and Λ-mer. These stereoisomers are in a dynamic equilibrium at room temperature. The equilibrium allows the spatial arrangement of the three GalNAc residues to change in order to fit into a multivalent carbohydrate binding site of the lectins. Detailed analysis of the kinetic and thermodynamic data for the isomerization can provide structural information of the carbohydrate binding site of the lectins.
本文描述了一种新型金属辅助组装多价碳水化合物配体的方法。双吡啶修饰的 N-乙酰半乳糖胺(bipy-GalNAc)在铁(II)的诱导下发生自结合,形成三聚 GalNAc 配体(FeII(bipy-GalNAc)3)。合成的 GalNAc 簇能与 Vicia villosa B4 凝集素和 Glycin Max 凝集素紧密结合,后者能识别多个 GalNAc 残基。三聚 GalNAc 配体是由Δ-fac、Λ-fac、Δ-mer 和Λ-mer 四种非对映异构体混合形成的。这些立体异构体在室温下处于动态平衡状态。这种平衡使三个 GalNAc 残基的空间排列发生变化,以适应凝集素的多价碳水化合物结合位点。对异构化的动力学和热力学数据进行详细分析,可以提供凝集素碳水化合物结合位点的结构信息。