Glycan binding profile of a fucolectin-related protein (FRP) encoded by the SP2159 gene of Streptococcus pneumoniae

• Published in: Biochimie open 2018-06, Vol.6, p.17-23
• Main Authors: Wu, Albert M., Singh, Tanuja, Chen, Yung Liang, Anderson, Kimberly M., Li, Su Chen, Li, Yu Teh
• Format: Article
• Language: English
• Subjects: Fucolectin-related protein; Glycan recognition epitopes; Glycotopes; Polyvalency; Research paper
• ISSN: 2214-0085; 2214-0085
• DOI: 10.1016/j.biopen.2017.12.002

The recombinant fucolectin-related protein (FRP) of unknown function, encoded by the SP2159 gene of Streptococcus pneumoniae, was expressed in E. coli. In this study, its glycan-recognition epitopes and their binding potencies were examined by enzyme-linked lectinosorbent and inhibition assays. The results indicate that FRP reacted strongly with human blood group ABH and l-Fucα1→2-active glycotopes and in their polyvalent (super) forms. When expressed by mass relative potency, the binding affinities of FRP to poly-l-Fucα1→glycotopes were about 5.0 × 105 folds higher than that of the mono-l-Fucα1→glycotope form. This unique binding property of FRP can be used as a special tool to differentiate complex forms of l-Fucα1→2 and other forms of glycotopes. •FRP encoded by the SP2159 gene of Streptococcus pneumoniae shows an unusual blood group A, B, and H binding specificity.•Ley, Leb and H determinants, containing the monomeric forms of Fucα1-2Gal-glycotope were weak ligands for FRP.•Ley, Leb and H determinants, corresponding polyvalent forms exhibit unusual strong interactions with FRP.•Lex [Galβ1-4(LFucα1-3)GlcNAc], Lea [Galβ1-3(LFucα1-4) GlcNAc], A (GalNAcα1-3Gal) and B (Galα1-3Gal) are poor inhibitors.•Lex, Lea, A and B same determinants above enhance the FRP-polyvalent LFucα1-2Gal glycotope interactions.•FRP recognizes only LFucα1→ related ligands, but do not with others, such as Man related glycans.