Evaluation of β-1,3-glucan recognition protein binding to β-1,3-glucan and β-1,3-glucan/DNA complexes

Although the interaction between β-1,3-glucans (BG) and β-1,3-glucan recognition protein (BGRP) derived from insects is well established, the binding interaction and recognition mechanism of BG when complexed with deoxyadenosine (dA) or CpG oligodeoxynucleotides (CpG) remain poorly understood. In this study, we investigated the binding properties of Schizophyllan and Curdlan to BGRP both in their native forms and in BG/DNA complexes. Our findings revealed that BG/dA complexes bind to BGRP via a canonical BG-BGRP binding mechanism, whereas BG/CpG complexes exhibited a recognition mechanism distinct from the BG-BGRP interaction. Structural alterations in BG upon complexation with CpGs appear to induce a unique mode of BGRP recognition. This study reveals a novel mode of BGRP recognition in CpG-containing complexes, offering insights into improved immune detection strategies.