5j4t
From Proteopedia
Structure of tetrameric jacalin complexed with GlcNAc beta-(1,3) Gal-beta-OMe
Structural highlights
FunctionLECA_ARTIN D-galactose-specific lectin, binds the T-antigen structure Gal-beta1,3-GalNAc (Thomsen-Friedenreich-antigen-specific lectin). Potent and selective stimulant of distinct T- and B-cell functions. Shows a unique ability to specifically recognize IgA-1 from human serum. Publication Abstract from PubMedCrystal structures of jacalin in complex with GlcNAc beta-(1,3) Gal-beta-OMe and Gal beta-(1,3) Gal-beta-OMe have been determined. The binding of the ligands to jacalin is similar to that of analogous alpha-substituted disaccharides. However, the beta-substituted beta-(1,3) linked disaccharides get distorted at the anomeric center and the glycosidic linkage. The distortion results in higher internal energies of the ligands leading to lower affinity to the lectin. This confirms the possibility of using ligand distortion as a strategy for modulating binding affinity. Unlike in the case of beta-substituted monosaccharides bound to jacalin, where a larger distortion at the anomeric center was observed, smaller distortions are distributed among two centers in the structures of the two beta-substituted beta-(1,3) linked disaccharides presented here. These disaccharides, like the unsubstituted and alpha-substituted counterparts, bind jacalin with the reducing Gal at the primary binding site, indicating that the lower binding affinity of beta-substituted disaccharides is not enough to overcome the intrinsic propensity of Gal beta-(1,3) Gal-based disaccharides to bind jacalin with the reducing sugar at the primary site. (c) 2017 IUBMB Life, 69(2):72-78, 2017. Distortion of the ligand molecule as a strategy for modulating binding affinity: Further studies involving complexes of jacalin with beta-substituted disaccharides.,Abhinav KV, Sharma K, Surolia A, Vijayan M IUBMB Life. 2017 Feb;69(2):72-78. doi: 10.1002/iub.1593. Epub 2017 Jan 23. PMID:28111895[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
|