The amino acids involved in the distinct carbohydrate specificities between macrophage galactose-type C-type lectins 1 and 2 (CD301a and b) of mice

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• 作者：Sarawut Oo-puthinan ; Keisuke Maenuma ; Masayoshi Sakakura ; Kaori Denda-Nagai ; Makoto Tsuiji ; Ichio Shimada ; Sachiko Nakamura-Tsuruta ; Jun Hirabayashi ; Nicolai V. Bovin ; Tatsuro Irimura
• 关键词：C-type lectin ; Macrophage ; Dendritic cells ; Galactose ; Carbohydrate recognition
• 刊名：Biochimica et Biophysica Acta (BBA)/General Subjects
• 出版年：2008
• 出版时间：February 2008
• 年：2008
• 卷：1780
• 期：2
• 页码：89-100
• 全文大小：768 K

文摘

Binding specificities of mouse macrophage galactose-type C-type lectin 1 (MGL1/CD301a) and 2 (MGL2/CD301b) toward various oligosaccharides were compared by frontal affinity chromatography. MGL1 preferentially bound oligosaccharides containing Lewis^X (Le^X) trisaccharides among 111 oligosaccharides tested, whereas MGL2 preferentially bound globoside Gb4. The important amino acids for the preferential bindings were investigated by pair-wise site-directed mutagenesis at positions 61, 89, 97, 100, 110–113, 115, 124, and 125 in the soluble recombinant carbohydrate recognition domains (CRD) prepared in Escherichia coli and purified with galactose-Sepharose. Mutations of Val, Ala, Thr, and Phe at positions 61, 89, 111 and 125 on MGL1 CRD caused reductions in Le^X binding. Mutations of MGL2 CRD at Leu, Arg, Arg, and Tyr at positions 61, 89, 115 and 125 were implicated in the preference for β-GalNAc. Le^X binding was observed with MGL2 mutants of Arg89Ala and Arg89Ala/Ser111Thr. MGL1 mutants of Ala89Arg and Ala89Arg/Pro115Arg showed β-GalNAc bindings. Molecular modeling illustrated potential direct molecular interactions of Leu61, Arg89, and His109 in MGL2 CRD with GalNAc.