3LLZ

Crystal Structure Analysis of Maclura pomifera agglutinin complex with Gal-beta-1,3-GalNAc

Summary for 3LLZ

• Entry DOI: 10.2210/pdb3llz/pdb
• Related: 3LLY 3LM1
• Descriptor: Agglutinin alpha chain, Agglutinin beta-2 chain, beta-D-galactopyranose-(1-3)-2-acetamido-2-deoxy-beta-D-galactopyranose, ... (4 entities in total)
• Functional Keywords: maclura pomifera agglutinin, mpa, mpa complex, gal-beta-1, 3-galnac;, lectin, sugar binding protein
• Biological source: Maclura pomifera (Osage orange); More
• Total number of polymer chains: 2
• Total formula weight: 16610.54

Authors

Huang, J.,Xu, Z.,Wang, D.,Ogato, C.,Hirama, T.,Palczewski, K.,Hazen, S.L.,Lee, X.,Young, N.M. (deposition date: 2010-01-29, release date: 2010-09-22, Last modification date: 2023-09-06)

Primary citation

Huang, J.,Xu, Z.,Wang, D.,Ogata, C.M.,Palczewski, K.,Lee, X.,Young, N.M.
Characterization of the secondary binding sites of Maclura pomifera agglutinin by glycan array and crystallographic analyses.
Glycobiology, 20:1643-1653, 2010

PubMed Abstract: The Maclura pomifera agglutinin (MPA) recognizes the T-antigen disaccharide Galβ1,3GalNAc mainly through interaction of the α-GalNAc moiety with its primary site, but the interactions of the two flanking subsites A and B with aglycones and substituents other than Gal, respectively, are not well understood. We therefore characterized the specificity of MPA in more detail by glycan microarray analysis and determined the crystal structures of MPA without ligand and in complexes with Galβ1,3GalNAc and p-nitrophenyl α-GalNAc. In both sugar complexes, pairs of ligands created inter-tetramer hydrogen-bond bridging networks. While subsite A showed increased affinity for hydrophobic aglycones, it also accommodated several sugar substituents. Notably, a GalNAc-O-tripeptide, a Tn-antigen mimic, showed lower affinity than these compounds in surface plasmon resonance (SPR) experiments. The glycan array data that showed subsite B accepted compounds in which the O3 position of the GalNAc was substituted with various sugars other than Gal, but substitutions at O6 led to inactivity. Additions to the Gal moiety of the disaccharide also had only small effects on reactivity. These results are all compatible with the features seen in the crystal structures.

PubMed: 20826825
DOI: 10.1093/glycob/cwq118

Experimental method

X-RAY DIFFRACTION (1.55 Å)